├── .github
    └── workflows
    │   └── build.yml
├── README.md
├── api.http
├── bbb.png
├── demo
    └── index.html
├── devbox.d
    └── redis
    │   └── redis.conf
├── devbox.json
├── devbox.lock
├── go.mod
├── go.sum
├── main.go
└── position
    ├── handler.go
    ├── handler_test.go
    ├── position.go
    └── position_test.go


/.github/workflows/build.yml:
--------------------------------------------------------------------------------
 1 | # This workflow will build a golang project
 2 | # For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go
 3 | 
 4 | name: build
 5 | 
 6 | on:
 7 |   push:
 8 |     branches: [ "main" ]
 9 |   pull_request:
10 |     branches: [ "main" ]
11 | 
12 | jobs:
13 |   build:
14 |     runs-on: ubuntu-latest
15 |     steps:
16 |     - uses: actions/checkout@v3
17 | 
18 |     - name: Set up Go
19 |       uses: actions/setup-go@v3
20 |       with:
21 |         go-version: '1.20.5'
22 | 
23 |     - name: Build
24 |       run: go build -v ./...
25 | 
26 |     - name: Test
27 |       run: go test -v ./...
28 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # Continue Watching API
 2 | 
 3 | Please use the issues section to discuss and share your solutions. Remember to tag the issue with the "challenge" label to make it easier to filter and locate solutions in the future.
 4 | 
 5 | <p align="center" width="100%">
 6 |     <img src="bbb.png" alt="big buck bunny" />
 7 | </p>
 8 | 
 9 | ---
10 | 
11 | [![build](https://github.com/learn-video/continue-watching-api/actions/workflows/build.yml/badge.svg)](https://github.com/learn-video/continue-watching-api/actions/workflows/build.yml)
12 | 
13 | Do you enjoy watching videos online? If so, you may have noticed a convenient feature called "Continue Watching." This feature saves you from the hassle of remembering where you left off in a video.
14 | 
15 | In this project, we aim to develop a video player application that incorporates the "Continue Watching" functionality. The video player will interact with an API to store and retrieve the current position being watched in a video.
16 | 
17 | Once you start watching a video, the video player will periodically make requests to the API to record the current position. This ensures that even if you leave the video and come back later, the player will resume playback from the exact moment you last watched.
18 | 
19 | The API will be responsible for handling the requests from the video player and storing the positions in a reliable data store, such as Redis. When requested, the API will retrieve the last known position for a specific video and provide it to the video player, enabling seamless playback from where you left off.
20 | 
21 | Here is a sequence diagram to help you visualize how the information flows:
22 | 
23 | ```mermaid
24 | sequenceDiagram
25 |     participant VideoPlayer
26 |     participant API
27 |     participant Redis
28 | 
29 |     VideoPlayer->>+API: Fetch(videoId)
30 |     API->>+Redis: Fetch(videoId)
31 |     Redis-->>-API: PositionResponse(position)
32 |     alt Position exists
33 |         API->>-VideoPlayer: PositionResponse(position)
34 |         VideoPlayer-->>API: HTTP 200 OK
35 |     else Position does not exist
36 |         VideoPlayer-->>API: HTTP 404 Not Found
37 |     end
38 |     opt Redis query failed
39 |         VideoPlayer-->>API: HTTP 500 Internal Server Error
40 |     end
41 | 
42 |     loop Record position every X seconds
43 |         VideoPlayer->>+API: Record(videoId, position)
44 |         API->>+Redis: Record(videoId, position)
45 |         Redis-->>-API: PositionResponse(success)
46 |         alt Position recorded successfully
47 |             API-->>VideoPlayer: HTTP 200 OK
48 |         else Failed to record position
49 |             API-->>VideoPlayer: HTTP 500 Internal Server Error
50 |         end
51 |     end
52 | ```
53 | 
54 | ## Demo
55 | 
56 | To experience the "Continue Watching" feature in action, we provide a demo page that allows you to experiment with the functionality firsthand.
57 | 
58 | Before running the project, make sure you have the following tools installed:
59 | 
60 | * Go
61 | * Redis
62 | 
63 | This project utilizes a development environment tool called _devbox_, which simplifies the setup process. It provides a pre-configured environment, including Redis, to ensure a smooth experience.
64 | 
65 | To start the project, follow these steps:
66 | 
67 | 1. Launch the `devbox shell` by running the appropriate command.
68 | 2. Within the _devbox shell_, execute `go run main.go` to start the server. This will also expose the index page containing the video player.
69 | 
70 | Once the server is running, you can begin testing the "Continue Watching" feature:
71 | 
72 | 1. Start playing the video and watch it for at least 30 seconds. Close this tab.
73 | 2. Open a private browser tab or window.
74 | 3. Navigate to the index page again in the private tab or window.
75 | 4. The video will resume playback from a position as close as possible to where you left off, allowing you to seamlessly continue watching.
76 | 
77 | By following these steps, you can observe how the project effectively stores and retrieves the last watched position, providing a convenient viewing experience for users. Feel free to explore different scenarios, pause the video, seek to the future to fully grasp the capabilities of the "Continue Watching" feature.
78 | 
79 | ## Challenges to the reader
80 | 
81 | The most basic scenarios are described. How would you evolve the "Continue Watching API" with the following challenges in mind?
82 | 
83 | * **Concurrent requests for the same video's position?** Imagine multiple instances of the video player making simultaneous requests to update the position for a specific video. How would you ensure data consistency and prevent conflicts when multiple requests are received concurrently?
84 | 
85 | * **Scaling the system to handle a large number of users and videos?** As the number of users and videos increases, the system's scalability becomes crucial. How would you design and implement a scalable architecture that can handle a high volume of requests, store and retrieve positions efficiently, and ensure optimal performance across a growing user base?
86 | 
87 | * **Handling API Downtime** Imagine a scenario where the API goes offline for an extended period. How would you ensure that no position events are lost during this downtime?
88 | 
89 | * **Dealing with Bad API Responses** What steps would you take if the API starts responding with error status codes like HTTP 5xx? How would you handle these situations to maintain data integrity and ensure the reliability of the "Continue Watching" feature?
90 | 
91 | * **Optimal Expiring Time in Redis** Determine an appropriate expiration time for the position data stored in Redis. Consider factors such as the frequency of user activity, the maximum duration between user visits, and the balance between storage efficiency and ensuring the freshness of the position data. Find a suitable expiration time that minimizes storage overhead while still providing an accurate representation of the user's most recent position.
92 | 
93 | * **Preserving Values in Expired Redis Keys** As Redis is a volatile storage caching mechanism, keys can expire based on the configured expiration time. How would you handle situations where Redis keys containing position data have expired?
94 | 


--------------------------------------------------------------------------------
/api.http:
--------------------------------------------------------------------------------
 1 | @hostname = 127.0.0.1
 2 | @port = 8000
 3 | 
 4 | ###
 5 | 
 6 | POST http://{{hostname}}:{{port}}/watching HTTP/1.1
 7 | Content-Type: application/json
 8 | Cookie: user_id=bda031c0-4e7d-493a-92ba-6fc1eb3e6216
 9 | 
10 | {
11 |     "video_id": "123",
12 |     "position": 1
13 | }
14 | 
15 | ###
16 | 
17 | GET http://{{hostname}}:{{port}}/watching?video_id=123 HTTP/1.1
18 | Content-Type: application/json
19 | Cookie: user_id=bda031c0-4e7d-493a-92ba-6fc1eb3e6216
20 | 


--------------------------------------------------------------------------------
/bbb.png:
--------------------------------------------------------------------------------
https://raw.githubusercontent.com/learn-video/continue-watching-api/6a8ba295a45803eb48509e0e6f48b660992bc6b7/bbb.png


--------------------------------------------------------------------------------
/demo/index.html:
--------------------------------------------------------------------------------
 1 | <!DOCTYPE html>
 2 | <html>
 3 | 
 4 | <head>
 5 |     <meta charset="utf-8" />
 6 |     <title>Continue Watching API demo</title>
 7 |     <script src="https://hlsjs.video-dev.org/dist/hls.js"></script>
 8 | </head>
 9 | 
10 | <body>
11 |     <video height="600" width="600" id="video" controls></video>
12 | 
13 |     <script>
14 |         document.cookie = "user_id=bda031c0-4e7d-493a-92ba-6fc1eb3e6216";
15 | 
16 |         async function recordPosition(data = {}) {
17 |             const response = await fetch("http://localhost:8000/watching", {
18 |                 method: "POST",
19 |                 mode: "same-origin",
20 |                 cache: "no-cache",
21 |                 credentials: "include",
22 |                 headers: {
23 |                     "Content-Type": "application/json",
24 |                 },
25 |                 body: JSON.stringify(data)
26 |             });
27 |             return response.json();
28 |         }
29 | 
30 |         async function fetchPosition(videoID) {
31 |             const url = `http://localhost:8000/watching?video_id=${videoID}`;
32 | 
33 |             try {
34 |                 const response = await fetch(url);
35 |                 const data = await response.json();
36 | 
37 |                 if (response.ok) {
38 |                     const position = data.position;
39 |                     return position;
40 |                 } else {
41 |                     throw new Error(`Request failed with status ${response.status}`);
42 |                 }
43 |             } catch (error) {
44 |                 console.error('Error:', error.message);
45 |             }
46 |         }
47 | 
48 |         var video = document.getElementById('video');
49 | 
50 |         fetchPosition("123")
51 |             .then(position => {
52 |                 playVideo(video, position);
53 |             })
54 |             .catch(error => {
55 |                 playVideo(video, 0);
56 |             });
57 | 
58 |         function playVideo(video, startPosition) {
59 |             if (Hls.isSupported()) {
60 |                 var hls = new Hls({
61 |                     debug: false,
62 |                     startPosition: startPosition,
63 |                 });
64 |                 hls.loadSource('https://test-streams.mux.dev/x36xhzz/x36xhzz.m3u8');
65 |                 hls.attachMedia(video);
66 |                 hls.on(Hls.Events.MEDIA_ATTACHED, function () {
67 |                     video.muted = true;
68 |                     video.play();
69 |                 });
70 |             }
71 |         }
72 | 
73 |         setInterval(function () {
74 |             recordPosition({ video_id: "123", position: video.currentTime }).then((data) => {
75 |                 console.log(data);
76 |             });
77 |         }, 5000);
78 |     </script>
79 | </body>
80 | 
81 | </html>
82 | 


--------------------------------------------------------------------------------
/devbox.d/redis/redis.conf:
--------------------------------------------------------------------------------
   1 | # Redis configuration file example.
   2 | #
   3 | # Note that in order to read the configuration file, Redis must be
   4 | # started with the file path as first argument:
   5 | #
   6 | # ./redis-server /path/to/redis.conf
   7 | 
   8 | # Note on units: when memory size is needed, it is possible to specify
   9 | # it in the usual form of 1k 5GB 4M and so forth:
  10 | #
  11 | # 1k => 1000 bytes
  12 | # 1kb => 1024 bytes
  13 | # 1m => 1000000 bytes
  14 | # 1mb => 1024*1024 bytes
  15 | # 1g => 1000000000 bytes
  16 | # 1gb => 1024*1024*1024 bytes
  17 | #
  18 | # units are case insensitive so 1GB 1Gb 1gB are all the same.
  19 | 
  20 | ################################## INCLUDES ###################################
  21 | 
  22 | # Include one or more other config files here.  This is useful if you
  23 | # have a standard template that goes to all Redis servers but also need
  24 | # to customize a few per-server settings.  Include files can include
  25 | # other files, so use this wisely.
  26 | #
  27 | # Notice option "include" won't be rewritten by command "CONFIG REWRITE"
  28 | # from admin or Redis Sentinel. Since Redis always uses the last processed
  29 | # line as value of a configuration directive, you'd better put includes
  30 | # at the beginning of this file to avoid overwriting config change at runtime.
  31 | #
  32 | # If instead you are interested in using includes to override configuration
  33 | # options, it is better to use include as the last line.
  34 | #
  35 | # include /path/to/local.conf
  36 | # include /path/to/other.conf
  37 | 
  38 | ################################## MODULES #####################################
  39 | 
  40 | # Load modules at startup. If the server is not able to load modules
  41 | # it will abort. It is possible to use multiple loadmodule directives.
  42 | #
  43 | # loadmodule /path/to/my_module.so
  44 | # loadmodule /path/to/other_module.so
  45 | 
  46 | ################################## NETWORK #####################################
  47 | 
  48 | # By default, if no "bind" configuration directive is specified, Redis listens
  49 | # for connections from all the network interfaces available on the server.
  50 | # It is possible to listen to just one or multiple selected interfaces using
  51 | # the "bind" configuration directive, followed by one or more IP addresses.
  52 | #
  53 | # Examples:
  54 | #
  55 | # bind 192.168.1.100 10.0.0.1
  56 | # bind 127.0.0.1 ::1
  57 | #
  58 | # ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
  59 | # internet, binding to all the interfaces is dangerous and will expose the
  60 | # instance to everybody on the internet. So by default we uncomment the
  61 | # following bind directive, that will force Redis to listen only into
  62 | # the IPv4 lookback interface address (this means Redis will be able to
  63 | # accept connections only from clients running into the same computer it
  64 | # is running).
  65 | #
  66 | # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
  67 | # JUST COMMENT THE FOLLOWING LINE.
  68 | # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  69 | bind 127.0.0.1
  70 | 
  71 | # Protected mode is a layer of security protection, in order to avoid that
  72 | # Redis instances left open on the internet are accessed and exploited.
  73 | #
  74 | # When protected mode is on and if:
  75 | #
  76 | # 1) The server is not binding explicitly to a set of addresses using the
  77 | #    "bind" directive.
  78 | # 2) No password is configured.
  79 | #
  80 | # The server only accepts connections from clients connecting from the
  81 | # IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain
  82 | # sockets.
  83 | #
  84 | # By default protected mode is enabled. You should disable it only if
  85 | # you are sure you want clients from other hosts to connect to Redis
  86 | # even if no authentication is configured, nor a specific set of interfaces
  87 | # are explicitly listed using the "bind" directive.
  88 | protected-mode yes
  89 | 
  90 | # Accept connections on the specified port, default is 6379 (IANA #815344).
  91 | # If port 0 is specified Redis will not listen on a TCP socket.
  92 | port 6379
  93 | 
  94 | # TCP listen() backlog.
  95 | #
  96 | # In high requests-per-second environments you need an high backlog in order
  97 | # to avoid slow clients connections issues. Note that the Linux kernel
  98 | # will silently truncate it to the value of /proc/sys/net/core/somaxconn so
  99 | # make sure to raise both the value of somaxconn and tcp_max_syn_backlog
 100 | # in order to get the desired effect.
 101 | tcp-backlog 511
 102 | 
 103 | # Unix socket.
 104 | #
 105 | # Specify the path for the Unix socket that will be used to listen for
 106 | # incoming connections. There is no default, so Redis will not listen
 107 | # on a unix socket when not specified.
 108 | #
 109 | # unixsocket /tmp/redis.sock
 110 | # unixsocketperm 700
 111 | 
 112 | # Close the connection after a client is idle for N seconds (0 to disable)
 113 | timeout 0
 114 | 
 115 | # TCP keepalive.
 116 | #
 117 | # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
 118 | # of communication. This is useful for two reasons:
 119 | #
 120 | # 1) Detect dead peers.
 121 | # 2) Take the connection alive from the point of view of network
 122 | #    equipment in the middle.
 123 | #
 124 | # On Linux, the specified value (in seconds) is the period used to send ACKs.
 125 | # Note that to close the connection the double of the time is needed.
 126 | # On other kernels the period depends on the kernel configuration.
 127 | #
 128 | # A reasonable value for this option is 300 seconds, which is the new
 129 | # Redis default starting with Redis 3.2.1.
 130 | tcp-keepalive 300
 131 | 
 132 | ################################# GENERAL #####################################
 133 | 
 134 | # By default Redis does not run as a daemon. Use 'yes' if you need it.
 135 | # Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
 136 | daemonize no
 137 | 
 138 | # If you run Redis from upstart or systemd, Redis can interact with your
 139 | # supervision tree. Options:
 140 | #   supervised no      - no supervision interaction
 141 | #   supervised upstart - signal upstart by putting Redis into SIGSTOP mode
 142 | #   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
 143 | #   supervised auto    - detect upstart or systemd method based on
 144 | #                        UPSTART_JOB or NOTIFY_SOCKET environment variables
 145 | # Note: these supervision methods only signal "process is ready."
 146 | #       They do not enable continuous liveness pings back to your supervisor.
 147 | supervised no
 148 | 
 149 | # If a pid file is specified, Redis writes it where specified at startup
 150 | # and removes it at exit.
 151 | #
 152 | # When the server runs non daemonized, no pid file is created if none is
 153 | # specified in the configuration. When the server is daemonized, the pid file
 154 | # is used even if not specified, defaulting to "/var/run/redis.pid".
 155 | #
 156 | # Creating a pid file is best effort: if Redis is not able to create it
 157 | # nothing bad happens, the server will start and run normally.
 158 | pidfile redis.pid
 159 | 
 160 | # Specify the server verbosity level.
 161 | # This can be one of:
 162 | # debug (a lot of information, useful for development/testing)
 163 | # verbose (many rarely useful info, but not a mess like the debug level)
 164 | # notice (moderately verbose, what you want in production probably)
 165 | # warning (only very important / critical messages are logged)
 166 | loglevel notice
 167 | 
 168 | # Specify the log file name. Also the empty string can be used to force
 169 | # Redis to log on the standard output. Note that if you use standard
 170 | # output for logging but daemonize, logs will be sent to /dev/null
 171 | logfile redis.log
 172 | 
 173 | # To enable logging to the system logger, just set 'syslog-enabled' to yes,
 174 | # and optionally update the other syslog parameters to suit your needs.
 175 | # syslog-enabled no
 176 | 
 177 | # Specify the syslog identity.
 178 | # syslog-ident redis
 179 | 
 180 | # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
 181 | # syslog-facility local0
 182 | 
 183 | # Set the number of databases. The default database is DB 0, you can select
 184 | # a different one on a per-connection basis using SELECT <dbid> where
 185 | # dbid is a number between 0 and 'databases'-1
 186 | databases 16
 187 | 
 188 | # By default Redis shows an ASCII art logo only when started to log to the
 189 | # standard output and if the standard output is a TTY. Basically this means
 190 | # that normally a logo is displayed only in interactive sessions.
 191 | #
 192 | # However it is possible to force the pre-4.0 behavior and always show a
 193 | # ASCII art logo in startup logs by setting the following option to yes.
 194 | always-show-logo yes
 195 | 
 196 | ################################ SNAPSHOTTING  ################################
 197 | #
 198 | # Save the DB on disk:
 199 | #
 200 | #   save <seconds> <changes>
 201 | #
 202 | #   Will save the DB if both the given number of seconds and the given
 203 | #   number of write operations against the DB occurred.
 204 | #
 205 | #   In the example below the behaviour will be to save:
 206 | #   after 900 sec (15 min) if at least 1 key changed
 207 | #   after 300 sec (5 min) if at least 10 keys changed
 208 | #   after 60 sec if at least 10000 keys changed
 209 | #
 210 | #   Note: you can disable saving completely by commenting out all "save" lines.
 211 | #
 212 | #   It is also possible to remove all the previously configured save
 213 | #   points by adding a save directive with a single empty string argument
 214 | #   like in the following example:
 215 | #
 216 | #   save ""
 217 | 
 218 | save 900 1
 219 | save 300 10
 220 | save 60 10000
 221 | 
 222 | # By default Redis will stop accepting writes if RDB snapshots are enabled
 223 | # (at least one save point) and the latest background save failed.
 224 | # This will make the user aware (in a hard way) that data is not persisting
 225 | # on disk properly, otherwise chances are that no one will notice and some
 226 | # disaster will happen.
 227 | #
 228 | # If the background saving process will start working again Redis will
 229 | # automatically allow writes again.
 230 | #
 231 | # However if you have setup your proper monitoring of the Redis server
 232 | # and persistence, you may want to disable this feature so that Redis will
 233 | # continue to work as usual even if there are problems with disk,
 234 | # permissions, and so forth.
 235 | stop-writes-on-bgsave-error yes
 236 | 
 237 | # Compress string objects using LZF when dump .rdb databases?
 238 | # For default that's set to 'yes' as it's almost always a win.
 239 | # If you want to save some CPU in the saving child set it to 'no' but
 240 | # the dataset will likely be bigger if you have compressible values or keys.
 241 | rdbcompression yes
 242 | 
 243 | # Since version 5 of RDB a CRC64 checksum is placed at the end of the file.
 244 | # This makes the format more resistant to corruption but there is a performance
 245 | # hit to pay (around 10%) when saving and loading RDB files, so you can disable it
 246 | # for maximum performances.
 247 | #
 248 | # RDB files created with checksum disabled have a checksum of zero that will
 249 | # tell the loading code to skip the check.
 250 | rdbchecksum yes
 251 | 
 252 | # The filename where to dump the DB
 253 | dbfilename dump.rdb
 254 | 
 255 | # The working directory.
 256 | #
 257 | # The DB will be written inside this directory, with the filename specified
 258 | # above using the 'dbfilename' configuration directive.
 259 | #
 260 | # The Append Only File will also be created inside this directory.
 261 | #
 262 | # Note that you must specify a directory here, not a file name.
 263 | dir .devbox/virtenv/redis/
 264 | 
 265 | ################################# REPLICATION #################################
 266 | 
 267 | # Master-Slave replication. Use slaveof to make a Redis instance a copy of
 268 | # another Redis server. A few things to understand ASAP about Redis replication.
 269 | #
 270 | # 1) Redis replication is asynchronous, but you can configure a master to
 271 | #    stop accepting writes if it appears to be not connected with at least
 272 | #    a given number of slaves.
 273 | # 2) Redis slaves are able to perform a partial resynchronization with the
 274 | #    master if the replication link is lost for a relatively small amount of
 275 | #    time. You may want to configure the replication backlog size (see the next
 276 | #    sections of this file) with a sensible value depending on your needs.
 277 | # 3) Replication is automatic and does not need user intervention. After a
 278 | #    network partition slaves automatically try to reconnect to masters
 279 | #    and resynchronize with them.
 280 | #
 281 | # slaveof <masterip> <masterport>
 282 | 
 283 | # If the master is password protected (using the "requirepass" configuration
 284 | # directive below) it is possible to tell the slave to authenticate before
 285 | # starting the replication synchronization process, otherwise the master will
 286 | # refuse the slave request.
 287 | #
 288 | # masterauth <master-password>
 289 | 
 290 | # When a slave loses its connection with the master, or when the replication
 291 | # is still in progress, the slave can act in two different ways:
 292 | #
 293 | # 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
 294 | #    still reply to client requests, possibly with out of date data, or the
 295 | #    data set may just be empty if this is the first synchronization.
 296 | #
 297 | # 2) if slave-serve-stale-data is set to 'no' the slave will reply with
 298 | #    an error "SYNC with master in progress" to all the kind of commands
 299 | #    but to INFO and SLAVEOF.
 300 | #
 301 | slave-serve-stale-data yes
 302 | 
 303 | # You can configure a slave instance to accept writes or not. Writing against
 304 | # a slave instance may be useful to store some ephemeral data (because data
 305 | # written on a slave will be easily deleted after resync with the master) but
 306 | # may also cause problems if clients are writing to it because of a
 307 | # misconfiguration.
 308 | #
 309 | # Since Redis 2.6 by default slaves are read-only.
 310 | #
 311 | # Note: read only slaves are not designed to be exposed to untrusted clients
 312 | # on the internet. It's just a protection layer against misuse of the instance.
 313 | # Still a read only slave exports by default all the administrative commands
 314 | # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
 315 | # security of read only slaves using 'rename-command' to shadow all the
 316 | # administrative / dangerous commands.
 317 | slave-read-only yes
 318 | 
 319 | # Replication SYNC strategy: disk or socket.
 320 | #
 321 | # -------------------------------------------------------
 322 | # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY
 323 | # -------------------------------------------------------
 324 | #
 325 | # New slaves and reconnecting slaves that are not able to continue the replication
 326 | # process just receiving differences, need to do what is called a "full
 327 | # synchronization". An RDB file is transmitted from the master to the slaves.
 328 | # The transmission can happen in two different ways:
 329 | #
 330 | # 1) Disk-backed: The Redis master creates a new process that writes the RDB
 331 | #                 file on disk. Later the file is transferred by the parent
 332 | #                 process to the slaves incrementally.
 333 | # 2) Diskless: The Redis master creates a new process that directly writes the
 334 | #              RDB file to slave sockets, without touching the disk at all.
 335 | #
 336 | # With disk-backed replication, while the RDB file is generated, more slaves
 337 | # can be queued and served with the RDB file as soon as the current child producing
 338 | # the RDB file finishes its work. With diskless replication instead once
 339 | # the transfer starts, new slaves arriving will be queued and a new transfer
 340 | # will start when the current one terminates.
 341 | #
 342 | # When diskless replication is used, the master waits a configurable amount of
 343 | # time (in seconds) before starting the transfer in the hope that multiple slaves
 344 | # will arrive and the transfer can be parallelized.
 345 | #
 346 | # With slow disks and fast (large bandwidth) networks, diskless replication
 347 | # works better.
 348 | repl-diskless-sync no
 349 | 
 350 | # When diskless replication is enabled, it is possible to configure the delay
 351 | # the server waits in order to spawn the child that transfers the RDB via socket
 352 | # to the slaves.
 353 | #
 354 | # This is important since once the transfer starts, it is not possible to serve
 355 | # new slaves arriving, that will be queued for the next RDB transfer, so the server
 356 | # waits a delay in order to let more slaves arrive.
 357 | #
 358 | # The delay is specified in seconds, and by default is 5 seconds. To disable
 359 | # it entirely just set it to 0 seconds and the transfer will start ASAP.
 360 | repl-diskless-sync-delay 5
 361 | 
 362 | # Slaves send PINGs to server in a predefined interval. It's possible to change
 363 | # this interval with the repl_ping_slave_period option. The default value is 10
 364 | # seconds.
 365 | #
 366 | # repl-ping-slave-period 10
 367 | 
 368 | # The following option sets the replication timeout for:
 369 | #
 370 | # 1) Bulk transfer I/O during SYNC, from the point of view of slave.
 371 | # 2) Master timeout from the point of view of slaves (data, pings).
 372 | # 3) Slave timeout from the point of view of masters (REPLCONF ACK pings).
 373 | #
 374 | # It is important to make sure that this value is greater than the value
 375 | # specified for repl-ping-slave-period otherwise a timeout will be detected
 376 | # every time there is low traffic between the master and the slave.
 377 | #
 378 | # repl-timeout 60
 379 | 
 380 | # Disable TCP_NODELAY on the slave socket after SYNC?
 381 | #
 382 | # If you select "yes" Redis will use a smaller number of TCP packets and
 383 | # less bandwidth to send data to slaves. But this can add a delay for
 384 | # the data to appear on the slave side, up to 40 milliseconds with
 385 | # Linux kernels using a default configuration.
 386 | #
 387 | # If you select "no" the delay for data to appear on the slave side will
 388 | # be reduced but more bandwidth will be used for replication.
 389 | #
 390 | # By default we optimize for low latency, but in very high traffic conditions
 391 | # or when the master and slaves are many hops away, turning this to "yes" may
 392 | # be a good idea.
 393 | repl-disable-tcp-nodelay no
 394 | 
 395 | # Set the replication backlog size. The backlog is a buffer that accumulates
 396 | # slave data when slaves are disconnected for some time, so that when a slave
 397 | # wants to reconnect again, often a full resync is not needed, but a partial
 398 | # resync is enough, just passing the portion of data the slave missed while
 399 | # disconnected.
 400 | #
 401 | # The bigger the replication backlog, the longer the time the slave can be
 402 | # disconnected and later be able to perform a partial resynchronization.
 403 | #
 404 | # The backlog is only allocated once there is at least a slave connected.
 405 | #
 406 | # repl-backlog-size 1mb
 407 | 
 408 | # After a master has no longer connected slaves for some time, the backlog
 409 | # will be freed. The following option configures the amount of seconds that
 410 | # need to elapse, starting from the time the last slave disconnected, for
 411 | # the backlog buffer to be freed.
 412 | #
 413 | # Note that slaves never free the backlog for timeout, since they may be
 414 | # promoted to masters later, and should be able to correctly "partially
 415 | # resynchronize" with the slaves: hence they should always accumulate backlog.
 416 | #
 417 | # A value of 0 means to never release the backlog.
 418 | #
 419 | # repl-backlog-ttl 3600
 420 | 
 421 | # The slave priority is an integer number published by Redis in the INFO output.
 422 | # It is used by Redis Sentinel in order to select a slave to promote into a
 423 | # master if the master is no longer working correctly.
 424 | #
 425 | # A slave with a low priority number is considered better for promotion, so
 426 | # for instance if there are three slaves with priority 10, 100, 25 Sentinel will
 427 | # pick the one with priority 10, that is the lowest.
 428 | #
 429 | # However a special priority of 0 marks the slave as not able to perform the
 430 | # role of master, so a slave with priority of 0 will never be selected by
 431 | # Redis Sentinel for promotion.
 432 | #
 433 | # By default the priority is 100.
 434 | slave-priority 100
 435 | 
 436 | # It is possible for a master to stop accepting writes if there are less than
 437 | # N slaves connected, having a lag less or equal than M seconds.
 438 | #
 439 | # The N slaves need to be in "online" state.
 440 | #
 441 | # The lag in seconds, that must be <= the specified value, is calculated from
 442 | # the last ping received from the slave, that is usually sent every second.
 443 | #
 444 | # This option does not GUARANTEE that N replicas will accept the write, but
 445 | # will limit the window of exposure for lost writes in case not enough slaves
 446 | # are available, to the specified number of seconds.
 447 | #
 448 | # For example to require at least 3 slaves with a lag <= 10 seconds use:
 449 | #
 450 | # min-slaves-to-write 3
 451 | # min-slaves-max-lag 10
 452 | #
 453 | # Setting one or the other to 0 disables the feature.
 454 | #
 455 | # By default min-slaves-to-write is set to 0 (feature disabled) and
 456 | # min-slaves-max-lag is set to 10.
 457 | 
 458 | # A Redis master is able to list the address and port of the attached
 459 | # slaves in different ways. For example the "INFO replication" section
 460 | # offers this information, which is used, among other tools, by
 461 | # Redis Sentinel in order to discover slave instances.
 462 | # Another place where this info is available is in the output of the
 463 | # "ROLE" command of a master.
 464 | #
 465 | # The listed IP and address normally reported by a slave is obtained
 466 | # in the following way:
 467 | #
 468 | #   IP: The address is auto detected by checking the peer address
 469 | #   of the socket used by the slave to connect with the master.
 470 | #
 471 | #   Port: The port is communicated by the slave during the replication
 472 | #   handshake, and is normally the port that the slave is using to
 473 | #   list for connections.
 474 | #
 475 | # However when port forwarding or Network Address Translation (NAT) is
 476 | # used, the slave may be actually reachable via different IP and port
 477 | # pairs. The following two options can be used by a slave in order to
 478 | # report to its master a specific set of IP and port, so that both INFO
 479 | # and ROLE will report those values.
 480 | #
 481 | # There is no need to use both the options if you need to override just
 482 | # the port or the IP address.
 483 | #
 484 | # slave-announce-ip 5.5.5.5
 485 | # slave-announce-port 1234
 486 | 
 487 | ################################## SECURITY ###################################
 488 | 
 489 | # Require clients to issue AUTH <PASSWORD> before processing any other
 490 | # commands.  This might be useful in environments in which you do not trust
 491 | # others with access to the host running redis-server.
 492 | #
 493 | # This should stay commented out for backward compatibility and because most
 494 | # people do not need auth (e.g. they run their own servers).
 495 | #
 496 | # Warning: since Redis is pretty fast an outside user can try up to
 497 | # 150k passwords per second against a good box. This means that you should
 498 | # use a very strong password otherwise it will be very easy to break.
 499 | #
 500 | # requirepass foobared
 501 | 
 502 | # Command renaming.
 503 | #
 504 | # It is possible to change the name of dangerous commands in a shared
 505 | # environment. For instance the CONFIG command may be renamed into something
 506 | # hard to guess so that it will still be available for internal-use tools
 507 | # but not available for general clients.
 508 | #
 509 | # Example:
 510 | #
 511 | # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
 512 | #
 513 | # It is also possible to completely kill a command by renaming it into
 514 | # an empty string:
 515 | #
 516 | # rename-command CONFIG ""
 517 | #
 518 | # Please note that changing the name of commands that are logged into the
 519 | # AOF file or transmitted to slaves may cause problems.
 520 | 
 521 | ################################### CLIENTS ####################################
 522 | 
 523 | # Set the max number of connected clients at the same time. By default
 524 | # this limit is set to 10000 clients, however if the Redis server is not
 525 | # able to configure the process file limit to allow for the specified limit
 526 | # the max number of allowed clients is set to the current file limit
 527 | # minus 32 (as Redis reserves a few file descriptors for internal uses).
 528 | #
 529 | # Once the limit is reached Redis will close all the new connections sending
 530 | # an error 'max number of clients reached'.
 531 | #
 532 | # maxclients 10000
 533 | 
 534 | ############################## MEMORY MANAGEMENT ################################
 535 | 
 536 | # Set a memory usage limit to the specified amount of bytes.
 537 | # When the memory limit is reached Redis will try to remove keys
 538 | # according to the eviction policy selected (see maxmemory-policy).
 539 | #
 540 | # If Redis can't remove keys according to the policy, or if the policy is
 541 | # set to 'noeviction', Redis will start to reply with errors to commands
 542 | # that would use more memory, like SET, LPUSH, and so on, and will continue
 543 | # to reply to read-only commands like GET.
 544 | #
 545 | # This option is usually useful when using Redis as an LRU or LFU cache, or to
 546 | # set a hard memory limit for an instance (using the 'noeviction' policy).
 547 | #
 548 | # WARNING: If you have slaves attached to an instance with maxmemory on,
 549 | # the size of the output buffers needed to feed the slaves are subtracted
 550 | # from the used memory count, so that network problems / resyncs will
 551 | # not trigger a loop where keys are evicted, and in turn the output
 552 | # buffer of slaves is full with DELs of keys evicted triggering the deletion
 553 | # of more keys, and so forth until the database is completely emptied.
 554 | #
 555 | # In short... if you have slaves attached it is suggested that you set a lower
 556 | # limit for maxmemory so that there is some free RAM on the system for slave
 557 | # output buffers (but this is not needed if the policy is 'noeviction').
 558 | #
 559 | # maxmemory <bytes>
 560 | 
 561 | # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
 562 | # is reached. You can select among five behaviors:
 563 | #
 564 | # volatile-lru -> Evict using approximated LRU among the keys with an expire set.
 565 | # allkeys-lru -> Evict any key using approximated LRU.
 566 | # volatile-lfu -> Evict using approximated LFU among the keys with an expire set.
 567 | # allkeys-lfu -> Evict any key using approximated LFU.
 568 | # volatile-random -> Remove a random key among the ones with an expire set.
 569 | # allkeys-random -> Remove a random key, any key.
 570 | # volatile-ttl -> Remove the key with the nearest expire time (minor TTL)
 571 | # noeviction -> Don't evict anything, just return an error on write operations.
 572 | #
 573 | # LRU means Least Recently Used
 574 | # LFU means Least Frequently Used
 575 | #
 576 | # Both LRU, LFU and volatile-ttl are implemented using approximated
 577 | # randomized algorithms.
 578 | #
 579 | # Note: with any of the above policies, Redis will return an error on write
 580 | #       operations, when there are no suitable keys for eviction.
 581 | #
 582 | #       At the date of writing these commands are: set setnx setex append
 583 | #       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
 584 | #       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
 585 | #       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
 586 | #       getset mset msetnx exec sort
 587 | #
 588 | # The default is:
 589 | #
 590 | # maxmemory-policy noeviction
 591 | 
 592 | # LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated
 593 | # algorithms (in order to save memory), so you can tune it for speed or
 594 | # accuracy. For default Redis will check five keys and pick the one that was
 595 | # used less recently, you can change the sample size using the following
 596 | # configuration directive.
 597 | #
 598 | # The default of 5 produces good enough results. 10 Approximates very closely
 599 | # true LRU but costs more CPU. 3 is faster but not very accurate.
 600 | #
 601 | # maxmemory-samples 5
 602 | 
 603 | ############################# LAZY FREEING ####################################
 604 | 
 605 | # Redis has two primitives to delete keys. One is called DEL and is a blocking
 606 | # deletion of the object. It means that the server stops processing new commands
 607 | # in order to reclaim all the memory associated with an object in a synchronous
 608 | # way. If the key deleted is associated with a small object, the time needed
 609 | # in order to execute the DEL command is very small and comparable to most other
 610 | # O(1) or O(log_N) commands in Redis. However if the key is associated with an
 611 | # aggregated value containing millions of elements, the server can block for
 612 | # a long time (even seconds) in order to complete the operation.
 613 | #
 614 | # For the above reasons Redis also offers non blocking deletion primitives
 615 | # such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and
 616 | # FLUSHDB commands, in order to reclaim memory in background. Those commands
 617 | # are executed in constant time. Another thread will incrementally free the
 618 | # object in the background as fast as possible.
 619 | #
 620 | # DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.
 621 | # It's up to the design of the application to understand when it is a good
 622 | # idea to use one or the other. However the Redis server sometimes has to
 623 | # delete keys or flush the whole database as a side effect of other operations.
 624 | # Specifically Redis deletes objects independently of a user call in the
 625 | # following scenarios:
 626 | #
 627 | # 1) On eviction, because of the maxmemory and maxmemory policy configurations,
 628 | #    in order to make room for new data, without going over the specified
 629 | #    memory limit.
 630 | # 2) Because of expire: when a key with an associated time to live (see the
 631 | #    EXPIRE command) must be deleted from memory.
 632 | # 3) Because of a side effect of a command that stores data on a key that may
 633 | #    already exist. For example the RENAME command may delete the old key
 634 | #    content when it is replaced with another one. Similarly SUNIONSTORE
 635 | #    or SORT with STORE option may delete existing keys. The SET command
 636 | #    itself removes any old content of the specified key in order to replace
 637 | #    it with the specified string.
 638 | # 4) During replication, when a slave performs a full resynchronization with
 639 | #    its master, the content of the whole database is removed in order to
 640 | #    load the RDB file just transferred.
 641 | #
 642 | # In all the above cases the default is to delete objects in a blocking way,
 643 | # like if DEL was called. However you can configure each case specifically
 644 | # in order to instead release memory in a non-blocking way like if UNLINK
 645 | # was called, using the following configuration directives:
 646 | 
 647 | lazyfree-lazy-eviction no
 648 | lazyfree-lazy-expire no
 649 | lazyfree-lazy-server-del no
 650 | slave-lazy-flush no
 651 | 
 652 | ############################## APPEND ONLY MODE ###############################
 653 | 
 654 | # By default Redis asynchronously dumps the dataset on disk. This mode is
 655 | # good enough in many applications, but an issue with the Redis process or
 656 | # a power outage may result into a few minutes of writes lost (depending on
 657 | # the configured save points).
 658 | #
 659 | # The Append Only File is an alternative persistence mode that provides
 660 | # much better durability. For instance using the default data fsync policy
 661 | # (see later in the config file) Redis can lose just one second of writes in a
 662 | # dramatic event like a server power outage, or a single write if something
 663 | # wrong with the Redis process itself happens, but the operating system is
 664 | # still running correctly.
 665 | #
 666 | # AOF and RDB persistence can be enabled at the same time without problems.
 667 | # If the AOF is enabled on startup Redis will load the AOF, that is the file
 668 | # with the better durability guarantees.
 669 | #
 670 | # Please check http://redis.io/topics/persistence for more information.
 671 | 
 672 | appendonly no
 673 | 
 674 | # The name of the append only file (default: "appendonly.aof")
 675 | 
 676 | appendfilename "appendonly.aof"
 677 | 
 678 | # The fsync() call tells the Operating System to actually write data on disk
 679 | # instead of waiting for more data in the output buffer. Some OS will really flush
 680 | # data on disk, some other OS will just try to do it ASAP.
 681 | #
 682 | # Redis supports three different modes:
 683 | #
 684 | # no: don't fsync, just let the OS flush the data when it wants. Faster.
 685 | # always: fsync after every write to the append only log. Slow, Safest.
 686 | # everysec: fsync only one time every second. Compromise.
 687 | #
 688 | # The default is "everysec", as that's usually the right compromise between
 689 | # speed and data safety. It's up to you to understand if you can relax this to
 690 | # "no" that will let the operating system flush the output buffer when
 691 | # it wants, for better performances (but if you can live with the idea of
 692 | # some data loss consider the default persistence mode that's snapshotting),
 693 | # or on the contrary, use "always" that's very slow but a bit safer than
 694 | # everysec.
 695 | #
 696 | # More details please check the following article:
 697 | # http://antirez.com/post/redis-persistence-demystified.html
 698 | #
 699 | # If unsure, use "everysec".
 700 | 
 701 | # appendfsync always
 702 | appendfsync everysec
 703 | # appendfsync no
 704 | 
 705 | # When the AOF fsync policy is set to always or everysec, and a background
 706 | # saving process (a background save or AOF log background rewriting) is
 707 | # performing a lot of I/O against the disk, in some Linux configurations
 708 | # Redis may block too long on the fsync() call. Note that there is no fix for
 709 | # this currently, as even performing fsync in a different thread will block
 710 | # our synchronous write(2) call.
 711 | #
 712 | # In order to mitigate this problem it's possible to use the following option
 713 | # that will prevent fsync() from being called in the main process while a
 714 | # BGSAVE or BGREWRITEAOF is in progress.
 715 | #
 716 | # This means that while another child is saving, the durability of Redis is
 717 | # the same as "appendfsync none". In practical terms, this means that it is
 718 | # possible to lose up to 30 seconds of log in the worst scenario (with the
 719 | # default Linux settings).
 720 | #
 721 | # If you have latency problems turn this to "yes". Otherwise leave it as
 722 | # "no" that is the safest pick from the point of view of durability.
 723 | 
 724 | no-appendfsync-on-rewrite no
 725 | 
 726 | # Automatic rewrite of the append only file.
 727 | # Redis is able to automatically rewrite the log file implicitly calling
 728 | # BGREWRITEAOF when the AOF log size grows by the specified percentage.
 729 | #
 730 | # This is how it works: Redis remembers the size of the AOF file after the
 731 | # latest rewrite (if no rewrite has happened since the restart, the size of
 732 | # the AOF at startup is used).
 733 | #
 734 | # This base size is compared to the current size. If the current size is
 735 | # bigger than the specified percentage, the rewrite is triggered. Also
 736 | # you need to specify a minimal size for the AOF file to be rewritten, this
 737 | # is useful to avoid rewriting the AOF file even if the percentage increase
 738 | # is reached but it is still pretty small.
 739 | #
 740 | # Specify a percentage of zero in order to disable the automatic AOF
 741 | # rewrite feature.
 742 | 
 743 | auto-aof-rewrite-percentage 100
 744 | auto-aof-rewrite-min-size 64mb
 745 | 
 746 | # An AOF file may be found to be truncated at the end during the Redis
 747 | # startup process, when the AOF data gets loaded back into memory.
 748 | # This may happen when the system where Redis is running
 749 | # crashes, especially when an ext4 filesystem is mounted without the
 750 | # data=ordered option (however this can't happen when Redis itself
 751 | # crashes or aborts but the operating system still works correctly).
 752 | #
 753 | # Redis can either exit with an error when this happens, or load as much
 754 | # data as possible (the default now) and start if the AOF file is found
 755 | # to be truncated at the end. The following option controls this behavior.
 756 | #
 757 | # If aof-load-truncated is set to yes, a truncated AOF file is loaded and
 758 | # the Redis server starts emitting a log to inform the user of the event.
 759 | # Otherwise if the option is set to no, the server aborts with an error
 760 | # and refuses to start. When the option is set to no, the user requires
 761 | # to fix the AOF file using the "redis-check-aof" utility before to restart
 762 | # the server.
 763 | #
 764 | # Note that if the AOF file will be found to be corrupted in the middle
 765 | # the server will still exit with an error. This option only applies when
 766 | # Redis will try to read more data from the AOF file but not enough bytes
 767 | # will be found.
 768 | aof-load-truncated yes
 769 | 
 770 | # When rewriting the AOF file, Redis is able to use an RDB preamble in the
 771 | # AOF file for faster rewrites and recoveries. When this option is turned
 772 | # on the rewritten AOF file is composed of two different stanzas:
 773 | #
 774 | #   [RDB file][AOF tail]
 775 | #
 776 | # When loading Redis recognizes that the AOF file starts with the "REDIS"
 777 | # string and loads the prefixed RDB file, and continues loading the AOF
 778 | # tail.
 779 | #
 780 | # This is currently turned off by default in order to avoid the surprise
 781 | # of a format change, but will at some point be used as the default.
 782 | aof-use-rdb-preamble no
 783 | 
 784 | ################################ LUA SCRIPTING  ###############################
 785 | 
 786 | # Max execution time of a Lua script in milliseconds.
 787 | #
 788 | # If the maximum execution time is reached Redis will log that a script is
 789 | # still in execution after the maximum allowed time and will start to
 790 | # reply to queries with an error.
 791 | #
 792 | # When a long running script exceeds the maximum execution time only the
 793 | # SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
 794 | # used to stop a script that did not yet called write commands. The second
 795 | # is the only way to shut down the server in the case a write command was
 796 | # already issued by the script but the user doesn't want to wait for the natural
 797 | # termination of the script.
 798 | #
 799 | # Set it to 0 or a negative value for unlimited execution without warnings.
 800 | lua-time-limit 5000
 801 | 
 802 | ################################ REDIS CLUSTER  ###############################
 803 | #
 804 | # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 805 | # WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however
 806 | # in order to mark it as "mature" we need to wait for a non trivial percentage
 807 | # of users to deploy it in production.
 808 | # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 809 | #
 810 | # Normal Redis instances can't be part of a Redis Cluster; only nodes that are
 811 | # started as cluster nodes can. In order to start a Redis instance as a
 812 | # cluster node enable the cluster support uncommenting the following:
 813 | #
 814 | # cluster-enabled yes
 815 | 
 816 | # Every cluster node has a cluster configuration file. This file is not
 817 | # intended to be edited by hand. It is created and updated by Redis nodes.
 818 | # Every Redis Cluster node requires a different cluster configuration file.
 819 | # Make sure that instances running in the same system do not have
 820 | # overlapping cluster configuration file names.
 821 | #
 822 | # cluster-config-file nodes-6379.conf
 823 | 
 824 | # Cluster node timeout is the amount of milliseconds a node must be unreachable
 825 | # for it to be considered in failure state.
 826 | # Most other internal time limits are multiple of the node timeout.
 827 | #
 828 | # cluster-node-timeout 15000
 829 | 
 830 | # A slave of a failing master will avoid to start a failover if its data
 831 | # looks too old.
 832 | #
 833 | # There is no simple way for a slave to actually have an exact measure of
 834 | # its "data age", so the following two checks are performed:
 835 | #
 836 | # 1) If there are multiple slaves able to failover, they exchange messages
 837 | #    in order to try to give an advantage to the slave with the best
 838 | #    replication offset (more data from the master processed).
 839 | #    Slaves will try to get their rank by offset, and apply to the start
 840 | #    of the failover a delay proportional to their rank.
 841 | #
 842 | # 2) Every single slave computes the time of the last interaction with
 843 | #    its master. This can be the last ping or command received (if the master
 844 | #    is still in the "connected" state), or the time that elapsed since the
 845 | #    disconnection with the master (if the replication link is currently down).
 846 | #    If the last interaction is too old, the slave will not try to failover
 847 | #    at all.
 848 | #
 849 | # The point "2" can be tuned by user. Specifically a slave will not perform
 850 | # the failover if, since the last interaction with the master, the time
 851 | # elapsed is greater than:
 852 | #
 853 | #   (node-timeout * slave-validity-factor) + repl-ping-slave-period
 854 | #
 855 | # So for example if node-timeout is 30 seconds, and the slave-validity-factor
 856 | # is 10, and assuming a default repl-ping-slave-period of 10 seconds, the
 857 | # slave will not try to failover if it was not able to talk with the master
 858 | # for longer than 310 seconds.
 859 | #
 860 | # A large slave-validity-factor may allow slaves with too old data to failover
 861 | # a master, while a too small value may prevent the cluster from being able to
 862 | # elect a slave at all.
 863 | #
 864 | # For maximum availability, it is possible to set the slave-validity-factor
 865 | # to a value of 0, which means, that slaves will always try to failover the
 866 | # master regardless of the last time they interacted with the master.
 867 | # (However they'll always try to apply a delay proportional to their
 868 | # offset rank).
 869 | #
 870 | # Zero is the only value able to guarantee that when all the partitions heal
 871 | # the cluster will always be able to continue.
 872 | #
 873 | # cluster-slave-validity-factor 10
 874 | 
 875 | # Cluster slaves are able to migrate to orphaned masters, that are masters
 876 | # that are left without working slaves. This improves the cluster ability
 877 | # to resist to failures as otherwise an orphaned master can't be failed over
 878 | # in case of failure if it has no working slaves.
 879 | #
 880 | # Slaves migrate to orphaned masters only if there are still at least a
 881 | # given number of other working slaves for their old master. This number
 882 | # is the "migration barrier". A migration barrier of 1 means that a slave
 883 | # will migrate only if there is at least 1 other working slave for its master
 884 | # and so forth. It usually reflects the number of slaves you want for every
 885 | # master in your cluster.
 886 | #
 887 | # Default is 1 (slaves migrate only if their masters remain with at least
 888 | # one slave). To disable migration just set it to a very large value.
 889 | # A value of 0 can be set but is useful only for debugging and dangerous
 890 | # in production.
 891 | #
 892 | # cluster-migration-barrier 1
 893 | 
 894 | # By default Redis Cluster nodes stop accepting queries if they detect there
 895 | # is at least an hash slot uncovered (no available node is serving it).
 896 | # This way if the cluster is partially down (for example a range of hash slots
 897 | # are no longer covered) all the cluster becomes, eventually, unavailable.
 898 | # It automatically returns available as soon as all the slots are covered again.
 899 | #
 900 | # However sometimes you want the subset of the cluster which is working,
 901 | # to continue to accept queries for the part of the key space that is still
 902 | # covered. In order to do so, just set the cluster-require-full-coverage
 903 | # option to no.
 904 | #
 905 | # cluster-require-full-coverage yes
 906 | 
 907 | # This option, when set to yes, prevents slaves from trying to failover its
 908 | # master during master failures. However the master can still perform a
 909 | # manual failover, if forced to do so.
 910 | #
 911 | # This is useful in different scenarios, especially in the case of multiple
 912 | # data center operations, where we want one side to never be promoted if not
 913 | # in the case of a total DC failure.
 914 | #
 915 | # cluster-slave-no-failover no
 916 | 
 917 | # In order to setup your cluster make sure to read the documentation
 918 | # available at http://redis.io web site.
 919 | 
 920 | ########################## CLUSTER DOCKER/NAT support  ########################
 921 | 
 922 | # In certain deployments, Redis Cluster nodes address discovery fails, because
 923 | # addresses are NAT-ted or because ports are forwarded (the typical case is
 924 | # Docker and other containers).
 925 | #
 926 | # In order to make Redis Cluster working in such environments, a static
 927 | # configuration where each node knows its public address is needed. The
 928 | # following two options are used for this scope, and are:
 929 | #
 930 | # * cluster-announce-ip
 931 | # * cluster-announce-port
 932 | # * cluster-announce-bus-port
 933 | #
 934 | # Each instruct the node about its address, client port, and cluster message
 935 | # bus port. The information is then published in the header of the bus packets
 936 | # so that other nodes will be able to correctly map the address of the node
 937 | # publishing the information.
 938 | #
 939 | # If the above options are not used, the normal Redis Cluster auto-detection
 940 | # will be used instead.
 941 | #
 942 | # Note that when remapped, the bus port may not be at the fixed offset of
 943 | # clients port + 10000, so you can specify any port and bus-port depending
 944 | # on how they get remapped. If the bus-port is not set, a fixed offset of
 945 | # 10000 will be used as usually.
 946 | #
 947 | # Example:
 948 | #
 949 | # cluster-announce-ip 10.1.1.5
 950 | # cluster-announce-port 6379
 951 | # cluster-announce-bus-port 6380
 952 | 
 953 | ################################## SLOW LOG ###################################
 954 | 
 955 | # The Redis Slow Log is a system to log queries that exceeded a specified
 956 | # execution time. The execution time does not include the I/O operations
 957 | # like talking with the client, sending the reply and so forth,
 958 | # but just the time needed to actually execute the command (this is the only
 959 | # stage of command execution where the thread is blocked and can not serve
 960 | # other requests in the meantime).
 961 | #
 962 | # You can configure the slow log with two parameters: one tells Redis
 963 | # what is the execution time, in microseconds, to exceed in order for the
 964 | # command to get logged, and the other parameter is the length of the
 965 | # slow log. When a new command is logged the oldest one is removed from the
 966 | # queue of logged commands.
 967 | 
 968 | # The following time is expressed in microseconds, so 1000000 is equivalent
 969 | # to one second. Note that a negative number disables the slow log, while
 970 | # a value of zero forces the logging of every command.
 971 | slowlog-log-slower-than 10000
 972 | 
 973 | # There is no limit to this length. Just be aware that it will consume memory.
 974 | # You can reclaim memory used by the slow log with SLOWLOG RESET.
 975 | slowlog-max-len 128
 976 | 
 977 | ################################ LATENCY MONITOR ##############################
 978 | 
 979 | # The Redis latency monitoring subsystem samples different operations
 980 | # at runtime in order to collect data related to possible sources of
 981 | # latency of a Redis instance.
 982 | #
 983 | # Via the LATENCY command this information is available to the user that can
 984 | # print graphs and obtain reports.
 985 | #
 986 | # The system only logs operations that were performed in a time equal or
 987 | # greater than the amount of milliseconds specified via the
 988 | # latency-monitor-threshold configuration directive. When its value is set
 989 | # to zero, the latency monitor is turned off.
 990 | #
 991 | # By default latency monitoring is disabled since it is mostly not needed
 992 | # if you don't have latency issues, and collecting data has a performance
 993 | # impact, that while very small, can be measured under big load. Latency
 994 | # monitoring can easily be enabled at runtime using the command
 995 | # "CONFIG SET latency-monitor-threshold <milliseconds>" if needed.
 996 | latency-monitor-threshold 0
 997 | 
 998 | ############################# EVENT NOTIFICATION ##############################
 999 | 
1000 | # Redis can notify Pub/Sub clients about events happening in the key space.
1001 | # This feature is documented at http://redis.io/topics/notifications
1002 | #
1003 | # For instance if keyspace events notification is enabled, and a client
1004 | # performs a DEL operation on key "foo" stored in the Database 0, two
1005 | # messages will be published via Pub/Sub:
1006 | #
1007 | # PUBLISH __keyspace@0__:foo del
1008 | # PUBLISH __keyevent@0__:del foo
1009 | #
1010 | # It is possible to select the events that Redis will notify among a set
1011 | # of classes. Every class is identified by a single character:
1012 | #
1013 | #  K     Keyspace events, published with __keyspace@<db>__ prefix.
1014 | #  E     Keyevent events, published with __keyevent@<db>__ prefix.
1015 | #  g     Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...
1016 | #  $     String commands
1017 | #  l     List commands
1018 | #  s     Set commands
1019 | #  h     Hash commands
1020 | #  z     Sorted set commands
1021 | #  x     Expired events (events generated every time a key expires)
1022 | #  e     Evicted events (events generated when a key is evicted for maxmemory)
1023 | #  A     Alias for g$lshzxe, so that the "AKE" string means all the events.
1024 | #
1025 | #  The "notify-keyspace-events" takes as argument a string that is composed
1026 | #  of zero or multiple characters. The empty string means that notifications
1027 | #  are disabled.
1028 | #
1029 | #  Example: to enable list and generic events, from the point of view of the
1030 | #           event name, use:
1031 | #
1032 | #  notify-keyspace-events Elg
1033 | #
1034 | #  Example 2: to get the stream of the expired keys subscribing to channel
1035 | #             name __keyevent@0__:expired use:
1036 | #
1037 | #  notify-keyspace-events Ex
1038 | #
1039 | #  By default all notifications are disabled because most users don't need
1040 | #  this feature and the feature has some overhead. Note that if you don't
1041 | #  specify at least one of K or E, no events will be delivered.
1042 | notify-keyspace-events ""
1043 | 
1044 | ############################### ADVANCED CONFIG ###############################
1045 | 
1046 | # Hashes are encoded using a memory efficient data structure when they have a
1047 | # small number of entries, and the biggest entry does not exceed a given
1048 | # threshold. These thresholds can be configured using the following directives.
1049 | hash-max-ziplist-entries 512
1050 | hash-max-ziplist-value 64
1051 | 
1052 | # Lists are also encoded in a special way to save a lot of space.
1053 | # The number of entries allowed per internal list node can be specified
1054 | # as a fixed maximum size or a maximum number of elements.
1055 | # For a fixed maximum size, use -5 through -1, meaning:
1056 | # -5: max size: 64 Kb  <-- not recommended for normal workloads
1057 | # -4: max size: 32 Kb  <-- not recommended
1058 | # -3: max size: 16 Kb  <-- probably not recommended
1059 | # -2: max size: 8 Kb   <-- good
1060 | # -1: max size: 4 Kb   <-- good
1061 | # Positive numbers mean store up to _exactly_ that number of elements
1062 | # per list node.
1063 | # The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),
1064 | # but if your use case is unique, adjust the settings as necessary.
1065 | list-max-ziplist-size -2
1066 | 
1067 | # Lists may also be compressed.
1068 | # Compress depth is the number of quicklist ziplist nodes from *each* side of
1069 | # the list to *exclude* from compression.  The head and tail of the list
1070 | # are always uncompressed for fast push/pop operations.  Settings are:
1071 | # 0: disable all list compression
1072 | # 1: depth 1 means "don't start compressing until after 1 node into the list,
1073 | #    going from either the head or tail"
1074 | #    So: [head]->node->node->...->node->[tail]
1075 | #    [head], [tail] will always be uncompressed; inner nodes will compress.
1076 | # 2: [head]->[next]->node->node->...->node->[prev]->[tail]
1077 | #    2 here means: don't compress head or head->next or tail->prev or tail,
1078 | #    but compress all nodes between them.
1079 | # 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]
1080 | # etc.
1081 | list-compress-depth 0
1082 | 
1083 | # Sets have a special encoding in just one case: when a set is composed
1084 | # of just strings that happen to be integers in radix 10 in the range
1085 | # of 64 bit signed integers.
1086 | # The following configuration setting sets the limit in the size of the
1087 | # set in order to use this special memory saving encoding.
1088 | set-max-intset-entries 512
1089 | 
1090 | # Similarly to hashes and lists, sorted sets are also specially encoded in
1091 | # order to save a lot of space. This encoding is only used when the length and
1092 | # elements of a sorted set are below the following limits:
1093 | zset-max-ziplist-entries 128
1094 | zset-max-ziplist-value 64
1095 | 
1096 | # HyperLogLog sparse representation bytes limit. The limit includes the
1097 | # 16 bytes header. When an HyperLogLog using the sparse representation crosses
1098 | # this limit, it is converted into the dense representation.
1099 | #
1100 | # A value greater than 16000 is totally useless, since at that point the
1101 | # dense representation is more memory efficient.
1102 | #
1103 | # The suggested value is ~ 3000 in order to have the benefits of
1104 | # the space efficient encoding without slowing down too much PFADD,
1105 | # which is O(N) with the sparse encoding. The value can be raised to
1106 | # ~ 10000 when CPU is not a concern, but space is, and the data set is
1107 | # composed of many HyperLogLogs with cardinality in the 0 - 15000 range.
1108 | hll-sparse-max-bytes 3000
1109 | 
1110 | # Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in
1111 | # order to help rehashing the main Redis hash table (the one mapping top-level
1112 | # keys to values). The hash table implementation Redis uses (see dict.c)
1113 | # performs a lazy rehashing: the more operation you run into a hash table
1114 | # that is rehashing, the more rehashing "steps" are performed, so if the
1115 | # server is idle the rehashing is never complete and some more memory is used
1116 | # by the hash table.
1117 | #
1118 | # The default is to use this millisecond 10 times every second in order to
1119 | # actively rehash the main dictionaries, freeing memory when possible.
1120 | #
1121 | # If unsure:
1122 | # use "activerehashing no" if you have hard latency requirements and it is
1123 | # not a good thing in your environment that Redis can reply from time to time
1124 | # to queries with 2 milliseconds delay.
1125 | #
1126 | # use "activerehashing yes" if you don't have such hard requirements but
1127 | # want to free memory asap when possible.
1128 | activerehashing yes
1129 | 
1130 | # The client output buffer limits can be used to force disconnection of clients
1131 | # that are not reading data from the server fast enough for some reason (a
1132 | # common reason is that a Pub/Sub client can't consume messages as fast as the
1133 | # publisher can produce them).
1134 | #
1135 | # The limit can be set differently for the three different classes of clients:
1136 | #
1137 | # normal -> normal clients including MONITOR clients
1138 | # slave  -> slave clients
1139 | # pubsub -> clients subscribed to at least one pubsub channel or pattern
1140 | #
1141 | # The syntax of every client-output-buffer-limit directive is the following:
1142 | #
1143 | # client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
1144 | #
1145 | # A client is immediately disconnected once the hard limit is reached, or if
1146 | # the soft limit is reached and remains reached for the specified number of
1147 | # seconds (continuously).
1148 | # So for instance if the hard limit is 32 megabytes and the soft limit is
1149 | # 16 megabytes / 10 seconds, the client will get disconnected immediately
1150 | # if the size of the output buffers reach 32 megabytes, but will also get
1151 | # disconnected if the client reaches 16 megabytes and continuously overcomes
1152 | # the limit for 10 seconds.
1153 | #
1154 | # By default normal clients are not limited because they don't receive data
1155 | # without asking (in a push way), but just after a request, so only
1156 | # asynchronous clients may create a scenario where data is requested faster
1157 | # than it can read.
1158 | #
1159 | # Instead there is a default limit for pubsub and slave clients, since
1160 | # subscribers and slaves receive data in a push fashion.
1161 | #
1162 | # Both the hard or the soft limit can be disabled by setting them to zero.
1163 | client-output-buffer-limit normal 0 0 0
1164 | client-output-buffer-limit slave 256mb 64mb 60
1165 | client-output-buffer-limit pubsub 32mb 8mb 60
1166 | 
1167 | # Client query buffers accumulate new commands. They are limited to a fixed
1168 | # amount by default in order to avoid that a protocol desynchronization (for
1169 | # instance due to a bug in the client) will lead to unbound memory usage in
1170 | # the query buffer. However you can configure it here if you have very special
1171 | # needs, such us huge multi/exec requests or alike.
1172 | #
1173 | # client-query-buffer-limit 1gb
1174 | 
1175 | # In the Redis protocol, bulk requests, that are, elements representing single
1176 | # strings, are normally limited to 512 mb. However you can change this limit
1177 | # here.
1178 | #
1179 | # proto-max-bulk-len 512mb
1180 | 
1181 | # Redis calls an internal function to perform many background tasks, like
1182 | # closing connections of clients in timeout, purging expired keys that are
1183 | # never requested, and so forth.
1184 | #
1185 | # Not all tasks are performed with the same frequency, but Redis checks for
1186 | # tasks to perform according to the specified "hz" value.
1187 | #
1188 | # By default "hz" is set to 10. Raising the value will use more CPU when
1189 | # Redis is idle, but at the same time will make Redis more responsive when
1190 | # there are many keys expiring at the same time, and timeouts may be
1191 | # handled with more precision.
1192 | #
1193 | # The range is between 1 and 500, however a value over 100 is usually not
1194 | # a good idea. Most users should use the default of 10 and raise this up to
1195 | # 100 only in environments where very low latency is required.
1196 | hz 10
1197 | 
1198 | # When a child rewrites the AOF file, if the following option is enabled
1199 | # the file will be fsync-ed every 32 MB of data generated. This is useful
1200 | # in order to commit the file to the disk more incrementally and avoid
1201 | # big latency spikes.
1202 | aof-rewrite-incremental-fsync yes
1203 | 
1204 | # Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good
1205 | # idea to start with the default settings and only change them after investigating
1206 | # how to improve the performances and how the keys LFU change over time, which
1207 | # is possible to inspect via the OBJECT FREQ command.
1208 | #
1209 | # There are two tunable parameters in the Redis LFU implementation: the
1210 | # counter logarithm factor and the counter decay time. It is important to
1211 | # understand what the two parameters mean before changing them.
1212 | #
1213 | # The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis
1214 | # uses a probabilistic increment with logarithmic behavior. Given the value
1215 | # of the old counter, when a key is accessed, the counter is incremented in
1216 | # this way:
1217 | #
1218 | # 1. A random number R between 0 and 1 is extracted.
1219 | # 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1).
1220 | # 3. The counter is incremented only if R < P.
1221 | #
1222 | # The default lfu-log-factor is 10. This is a table of how the frequency
1223 | # counter changes with a different number of accesses with different
1224 | # logarithmic factors:
1225 | #
1226 | # +--------+------------+------------+------------+------------+------------+
1227 | # | factor | 100 hits   | 1000 hits  | 100K hits  | 1M hits    | 10M hits   |
1228 | # +--------+------------+------------+------------+------------+------------+
1229 | # | 0      | 104        | 255        | 255        | 255        | 255        |
1230 | # +--------+------------+------------+------------+------------+------------+
1231 | # | 1      | 18         | 49         | 255        | 255        | 255        |
1232 | # +--------+------------+------------+------------+------------+------------+
1233 | # | 10     | 10         | 18         | 142        | 255        | 255        |
1234 | # +--------+------------+------------+------------+------------+------------+
1235 | # | 100    | 8          | 11         | 49         | 143        | 255        |
1236 | # +--------+------------+------------+------------+------------+------------+
1237 | #
1238 | # NOTE: The above table was obtained by running the following commands:
1239 | #
1240 | #   redis-benchmark -n 1000000 incr foo
1241 | #   redis-cli object freq foo
1242 | #
1243 | # NOTE 2: The counter initial value is 5 in order to give new objects a chance
1244 | # to accumulate hits.
1245 | #
1246 | # The counter decay time is the time, in minutes, that must elapse in order
1247 | # for the key counter to be divided by two (or decremented if it has a value
1248 | # less <= 10).
1249 | #
1250 | # The default value for the lfu-decay-time is 1. A Special value of 0 means to
1251 | # decay the counter every time it happens to be scanned.
1252 | #
1253 | # lfu-log-factor 10
1254 | # lfu-decay-time 1
1255 | 
1256 | ########################### ACTIVE DEFRAGMENTATION #######################
1257 | #
1258 | # WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested
1259 | # even in production and manually tested by multiple engineers for some
1260 | # time.
1261 | #
1262 | # What is active defragmentation?
1263 | # -------------------------------
1264 | #
1265 | # Active (online) defragmentation allows a Redis server to compact the
1266 | # spaces left between small allocations and deallocations of data in memory,
1267 | # thus allowing to reclaim back memory.
1268 | #
1269 | # Fragmentation is a natural process that happens with every allocator (but
1270 | # less so with Jemalloc, fortunately) and certain workloads. Normally a server
1271 | # restart is needed in order to lower the fragmentation, or at least to flush
1272 | # away all the data and create it again. However thanks to this feature
1273 | # implemented by Oran Agra for Redis 4.0 this process can happen at runtime
1274 | # in an "hot" way, while the server is running.
1275 | #
1276 | # Basically when the fragmentation is over a certain level (see the
1277 | # configuration options below) Redis will start to create new copies of the
1278 | # values in contiguous memory regions by exploiting certain specific Jemalloc
1279 | # features (in order to understand if an allocation is causing fragmentation
1280 | # and to allocate it in a better place), and at the same time, will release the
1281 | # old copies of the data. This process, repeated incrementally for all the keys
1282 | # will cause the fragmentation to drop back to normal values.
1283 | #
1284 | # Important things to understand:
1285 | #
1286 | # 1. This feature is disabled by default, and only works if you compiled Redis
1287 | #    to use the copy of Jemalloc we ship with the source code of Redis.
1288 | #    This is the default with Linux builds.
1289 | #
1290 | # 2. You never need to enable this feature if you don't have fragmentation
1291 | #    issues.
1292 | #
1293 | # 3. Once you experience fragmentation, you can enable this feature when
1294 | #    needed with the command "CONFIG SET activedefrag yes".
1295 | #
1296 | # The configuration parameters are able to fine tune the behavior of the
1297 | # defragmentation process. If you are not sure about what they mean it is
1298 | # a good idea to leave the defaults untouched.
1299 | 
1300 | # Enabled active defragmentation
1301 | # activedefrag yes
1302 | 
1303 | # Minimum amount of fragmentation waste to start active defrag
1304 | # active-defrag-ignore-bytes 100mb
1305 | 
1306 | # Minimum percentage of fragmentation to start active defrag
1307 | # active-defrag-threshold-lower 10
1308 | 
1309 | # Maximum percentage of fragmentation at which we use maximum effort
1310 | # active-defrag-threshold-upper 100
1311 | 
1312 | # Minimal effort for defrag in CPU percentage
1313 | # active-defrag-cycle-min 25
1314 | 
1315 | # Maximal effort for defrag in CPU percentage
1316 | # active-defrag-cycle-max 75
1317 | 


--------------------------------------------------------------------------------
/devbox.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "packages": [
 3 |     "go@1.20.3",
 4 |     "redis@latest"
 5 |   ],
 6 |   "env": {
 7 |     "REDIS_HOST": "localhost",
 8 |     "REDIS_PORT": "6379",
 9 |     "REDIS_CONF": "./devbox.d/redis/redis.conf"
10 |   },
11 |   "shell": {
12 |     "init_hook": [
13 |       "echo 'Welcome to devbox!' > /dev/null"
14 |     ],
15 |     "scripts": {
16 |       "test": [
17 |         "echo \"Error: no test specified\" && exit 1"
18 |       ]
19 |     }
20 |   }
21 | }
22 | 


--------------------------------------------------------------------------------
/devbox.lock:
--------------------------------------------------------------------------------
 1 | {
 2 |   "lockfile_version": "1",
 3 |   "packages": {
 4 |     "go@1.20.3": {
 5 |       "last_modified": "2023-05-01T16:53:22Z",
 6 |       "resolved": "github:NixOS/nixpkgs/8670e496ffd093b60e74e7fa53526aa5920d09eb#go",
 7 |       "version": "1.20.3"
 8 |     },
 9 |     "redis@latest": {
10 |       "last_modified": "2023-05-01T16:53:22Z",
11 |       "plugin_version": "0.0.2",
12 |       "resolved": "github:NixOS/nixpkgs/8670e496ffd093b60e74e7fa53526aa5920d09eb#redis",
13 |       "version": "7.0.11"
14 |     }
15 |   }
16 | }


--------------------------------------------------------------------------------
/go.mod:
--------------------------------------------------------------------------------
 1 | module github.com/learn-video/continue-watching-api
 2 | 
 3 | go 1.20
 4 | 
 5 | require (
 6 | 	github.com/caarlos0/env/v9 v9.0.0
 7 | 	github.com/go-playground/validator/v10 v10.14.1
 8 | 	github.com/go-redis/redismock/v9 v9.0.3
 9 | 	github.com/labstack/echo/v4 v4.10.2
10 | 	github.com/redis/go-redis/v9 v9.0.5
11 | 	github.com/stretchr/testify v1.8.4
12 | )
13 | 
14 | require (
15 | 	github.com/cespare/xxhash/v2 v2.2.0 // indirect
16 | 	github.com/davecgh/go-spew v1.1.1 // indirect
17 | 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
18 | 	github.com/gabriel-vasile/mimetype v1.4.2 // indirect
19 | 	github.com/go-playground/locales v0.14.1 // indirect
20 | 	github.com/go-playground/universal-translator v0.18.1 // indirect
21 | 	github.com/golang-jwt/jwt v3.2.2+incompatible // indirect
22 | 	github.com/labstack/gommon v0.4.0 // indirect
23 | 	github.com/leodido/go-urn v1.2.4 // indirect
24 | 	github.com/mattn/go-colorable v0.1.13 // indirect
25 | 	github.com/mattn/go-isatty v0.0.19 // indirect
26 | 	github.com/pmezard/go-difflib v1.0.0 // indirect
27 | 	github.com/valyala/bytebufferpool v1.0.0 // indirect
28 | 	github.com/valyala/fasttemplate v1.2.2 // indirect
29 | 	golang.org/x/crypto v0.10.0 // indirect
30 | 	golang.org/x/net v0.11.0 // indirect
31 | 	golang.org/x/sys v0.9.0 // indirect
32 | 	golang.org/x/text v0.10.0 // indirect
33 | 	golang.org/x/time v0.3.0 // indirect
34 | 	gopkg.in/yaml.v3 v3.0.1 // indirect
35 | )
36 | 


--------------------------------------------------------------------------------
/go.sum:
--------------------------------------------------------------------------------
 1 | github.com/bsm/ginkgo/v2 v2.7.0 h1:ItPMPH90RbmZJt5GtkcNvIRuGEdwlBItdNVoyzaNQao=
 2 | github.com/bsm/gomega v1.26.0 h1:LhQm+AFcgV2M0WyKroMASzAzCAJVpAxQXv4SaI9a69Y=
 3 | github.com/caarlos0/env/v9 v9.0.0 h1:SI6JNsOA+y5gj9njpgybykATIylrRMklbs5ch6wO6pc=
 4 | github.com/caarlos0/env/v9 v9.0.0/go.mod h1:ye5mlCVMYh6tZ+vCgrs/B95sj88cg5Tlnc0XIzgZ020=
 5 | github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj44=
 6 | github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 7 | github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 8 | github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 9 | github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
10 | github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f h1:lO4WD4F/rVNCu3HqELle0jiPLLBs70cWOduZpkS1E78=
11 | github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f/go.mod h1:cuUVRXasLTGF7a8hSLbxyZXjz+1KgoB3wDUb6vlszIc=
12 | github.com/fsnotify/fsnotify v1.4.9 h1:hsms1Qyu0jgnwNXIxa+/V/PDsU6CfLf6CNO8H7IWoS4=
13 | github.com/gabriel-vasile/mimetype v1.4.2 h1:w5qFW6JKBz9Y393Y4q372O9A7cUSequkh1Q7OhCmWKU=
14 | github.com/gabriel-vasile/mimetype v1.4.2/go.mod h1:zApsH/mKG4w07erKIaJPFiX0Tsq9BFQgN3qGY5GnNgA=
15 | github.com/go-playground/assert/v2 v2.2.0 h1:JvknZsQTYeFEAhQwI4qEt9cyV5ONwRHC+lYKSsYSR8s=
16 | github.com/go-playground/locales v0.14.1 h1:EWaQ/wswjilfKLTECiXz7Rh+3BjFhfDFKv/oXslEjJA=
17 | github.com/go-playground/locales v0.14.1/go.mod h1:hxrqLVvrK65+Rwrd5Fc6F2O76J/NuW9t0sjnWqG1slY=
18 | github.com/go-playground/universal-translator v0.18.1 h1:Bcnm0ZwsGyWbCzImXv+pAJnYK9S473LQFuzCbDbfSFY=
19 | github.com/go-playground/universal-translator v0.18.1/go.mod h1:xekY+UJKNuX9WP91TpwSH2VMlDf28Uj24BCp08ZFTUY=
20 | github.com/go-playground/validator/v10 v10.14.1 h1:9c50NUPC30zyuKprjL3vNZ0m5oG+jU0zvx4AqHGnv4k=
21 | github.com/go-playground/validator/v10 v10.14.1/go.mod h1:9iXMNT7sEkjXb0I+enO7QXmzG6QCsPWY4zveKFVRSyU=
22 | github.com/go-redis/redismock/v9 v9.0.3 h1:mtHQi2l51lCmXIbTRTqb1EiHYe9tL5Yk5oorlSJJqR0=
23 | github.com/go-redis/redismock/v9 v9.0.3/go.mod h1:F6tJRfnU8R/NZ0E+Gjvoluk14MqMC5ueSZX6vVQypc0=
24 | github.com/golang-jwt/jwt v3.2.2+incompatible h1:IfV12K8xAKAnZqdXVzCZ+TOjboZ2keLg81eXfW3O+oY=
25 | github.com/golang-jwt/jwt v3.2.2+incompatible/go.mod h1:8pz2t5EyA70fFQQSrl6XZXzqecmYZeUEB8OUGHkxJ+I=
26 | github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
27 | github.com/labstack/echo/v4 v4.10.2 h1:n1jAhnq/elIFTHr1EYpiYtyKgx4RW9ccVgkqByZaN2M=
28 | github.com/labstack/echo/v4 v4.10.2/go.mod h1:OEyqf2//K1DFdE57vw2DRgWY0M7s65IVQO2FzvI4J5k=
29 | github.com/labstack/gommon v0.4.0 h1:y7cvthEAEbU0yHOf4axH8ZG2NH8knB9iNSoTO8dyIk8=
30 | github.com/labstack/gommon v0.4.0/go.mod h1:uW6kP17uPlLJsD3ijUYn3/M5bAxtlZhMI6m3MFxTMTM=
31 | github.com/leodido/go-urn v1.2.4 h1:XlAE/cm/ms7TE/VMVoduSpNBoyc2dOxHs5MZSwAN63Q=
32 | github.com/leodido/go-urn v1.2.4/go.mod h1:7ZrI8mTSeBSHl/UaRyKQW1qZeMgak41ANeCNaVckg+4=
33 | github.com/mattn/go-colorable v0.1.11/go.mod h1:u5H1YNBxpqRaxsYJYSkiCWKzEfiAb1Gb520KVy5xxl4=
34 | github.com/mattn/go-colorable v0.1.13 h1:fFA4WZxdEF4tXPZVKMLwD8oUnCTTo08duU7wxecdEvA=
35 | github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
36 | github.com/mattn/go-isatty v0.0.14/go.mod h1:7GGIvUiUoEMVVmxf/4nioHXj79iQHKdU27kJ6hsGG94=
37 | github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
38 | github.com/mattn/go-isatty v0.0.19 h1:JITubQf0MOLdlGRuRq+jtsDlekdYPia9ZFsB8h/APPA=
39 | github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
40 | github.com/nxadm/tail v1.4.8 h1:nPr65rt6Y5JFSKQO7qToXr7pePgD6Gwiw05lkbyAQTE=
41 | github.com/onsi/ginkgo v1.16.5 h1:8xi0RTUf59SOSfEtZMvwTvXYMzG4gV23XVHOZiXNtnE=
42 | github.com/onsi/gomega v1.25.0 h1:Vw7br2PCDYijJHSfBOWhov+8cAnUf8MfMaIOV323l6Y=
43 | github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
44 | github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
45 | github.com/redis/go-redis/v9 v9.0.5 h1:CuQcn5HIEeK7BgElubPP8CGtE0KakrnbBSTLjathl5o=
46 | github.com/redis/go-redis/v9 v9.0.5/go.mod h1:WqMKv5vnQbRuZstUwxQI195wHy+t4PuXDOjzMvcuQHk=
47 | github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
48 | github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
49 | github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
50 | github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
51 | github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
52 | github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
53 | github.com/stretchr/testify v1.8.2/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
54 | github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
55 | github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
56 | github.com/valyala/bytebufferpool v1.0.0 h1:GqA5TC/0021Y/b9FG4Oi9Mr3q7XYx6KllzawFIhcdPw=
57 | github.com/valyala/bytebufferpool v1.0.0/go.mod h1:6bBcMArwyJ5K/AmCkWv1jt77kVWyCJ6HpOuEn7z0Csc=
58 | github.com/valyala/fasttemplate v1.2.1/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
59 | github.com/valyala/fasttemplate v1.2.2 h1:lxLXG0uE3Qnshl9QyaK6XJxMXlQZELvChBOCmQD0Loo=
60 | github.com/valyala/fasttemplate v1.2.2/go.mod h1:KHLXt3tVN2HBp8eijSv/kGJopbvo7S+qRAEEKiv+SiQ=
61 | golang.org/x/crypto v0.10.0 h1:LKqV2xt9+kDzSTfOhx4FrkEBcMrAgHSYgzywV9zcGmM=
62 | golang.org/x/crypto v0.10.0/go.mod h1:o4eNf7Ede1fv+hwOwZsTHl9EsPFO6q6ZvYR8vYfY45I=
63 | golang.org/x/net v0.11.0 h1:Gi2tvZIJyBtO9SDr1q9h5hEQCp/4L2RQ+ar0qjx2oNU=
64 | golang.org/x/net v0.11.0/go.mod h1:2L/ixqYpgIVXmeoSA/4Lu7BzTG4KIyPIryS4IsOd1oQ=
65 | golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
66 | golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
67 | golang.org/x/sys v0.0.0-20211103235746-7861aae1554b/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
68 | golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
69 | golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
70 | golang.org/x/sys v0.9.0 h1:KS/R3tvhPqvJvwcKfnBHJwwthS11LRhmM5D59eEXa0s=
71 | golang.org/x/sys v0.9.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
72 | golang.org/x/text v0.10.0 h1:UpjohKhiEgNc0CSauXmwYftY1+LlaC75SJwh0SgCX58=
73 | golang.org/x/text v0.10.0/go.mod h1:TvPlkZtksWOMsz7fbANvkp4WM8x/WCo/om8BMLbz+aE=
74 | golang.org/x/time v0.3.0 h1:rg5rLMjNzMS1RkNLzCG38eapWhnYLFYXDXj2gOlr8j4=
75 | golang.org/x/time v0.3.0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
76 | gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
77 | gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
78 | gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
79 | gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
80 | gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
81 | gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
82 | gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
83 | 


--------------------------------------------------------------------------------
/main.go:
--------------------------------------------------------------------------------
 1 | package main
 2 | 
 3 | import (
 4 | 	"fmt"
 5 | 	"log"
 6 | 
 7 | 	"github.com/caarlos0/env/v9"
 8 | 	"github.com/labstack/echo/v4"
 9 | 	"github.com/labstack/echo/v4/middleware"
10 | 	"github.com/learn-video/continue-watching-api/position"
11 | 	"github.com/redis/go-redis/v9"
12 | )
13 | 
14 | type config struct {
15 | 	RedisHost string `env:"REDIS_HOST"`
16 | 	RedisPort int    `env:"REDIS_PORT"`
17 | }
18 | 
19 | func main() {
20 | 	cfg := config{}
21 | 	if err := env.Parse(&cfg); err != nil {
22 | 		log.Fatalf("error loading config: %s", err)
23 | 	}
24 | 
25 | 	rdb := redis.NewClient(&redis.Options{
26 | 		Addr:     fmt.Sprintf("%s:%d", cfg.RedisHost, cfg.RedisPort),
27 | 		Password: "",
28 | 		DB:       0,
29 | 	})
30 | 
31 | 	handler := position.NewHandler(rdb)
32 | 
33 | 	e := echo.New()
34 | 	e.Use(middleware.Logger())
35 | 	e.POST("/watching", handler.Record)
36 | 	e.GET("/watching", handler.Fetch)
37 | 	e.File("/", "demo/index.html")
38 | 	e.Logger.Fatal(e.Start(":8000"))
39 | }
40 | 


--------------------------------------------------------------------------------
/position/handler.go:
--------------------------------------------------------------------------------
 1 | package position
 2 | 
 3 | import (
 4 | 	"net/http"
 5 | 
 6 | 	"github.com/go-playground/validator/v10"
 7 | 	"github.com/labstack/echo/v4"
 8 | 	"github.com/redis/go-redis/v9"
 9 | )
10 | 
11 | type Position struct {
12 | 	VideoID  string  `json:"video_id" validate:"required"`
13 | 	Position float64 `json:"position" validate:"required"`
14 | }
15 | 
16 | type PositionDetail struct {
17 | 	Position float64 `json:"position"`
18 | }
19 | 
20 | type (
21 | 	Handler struct {
22 | 		r *redis.Client
23 | 	}
24 | )
25 | 
26 | func NewHandler(r *redis.Client) *Handler {
27 | 	return &Handler{r: r}
28 | }
29 | 
30 | func (h *Handler) Record(c echo.Context) error {
31 | 	userID, err := c.Cookie("user_id")
32 | 	if err != nil {
33 | 		return c.NoContent(http.StatusBadRequest)
34 | 	}
35 | 	validate := validator.New()
36 | 	pos := new(Position)
37 | 	if err := c.Bind(pos); err != nil {
38 | 		return c.NoContent(http.StatusBadRequest)
39 | 	}
40 | 	if err := validate.Struct(pos); err != nil {
41 | 		return c.JSON(http.StatusBadRequest, err)
42 | 	}
43 | 
44 | 	if err := Record(h.r, userID.Value, pos.VideoID, pos.Position); err != nil {
45 | 		return c.NoContent(http.StatusInternalServerError)
46 | 	}
47 | 
48 | 	return c.NoContent(http.StatusCreated)
49 | }
50 | 
51 | func (h *Handler) Fetch(c echo.Context) error {
52 | 	userID, err := c.Cookie("user_id")
53 | 	if err != nil {
54 | 		return c.NoContent(http.StatusBadRequest)
55 | 	}
56 | 	videoID := c.QueryParam("video_id")
57 | 	pos, err := Fetch(h.r, userID.Value, videoID)
58 | 	if err == ErrNotFound {
59 | 		return c.NoContent(http.StatusNotFound)
60 | 	}
61 | 	if err != nil {
62 | 		return c.NoContent(http.StatusInternalServerError)
63 | 	}
64 | 	return c.JSON(http.StatusOK, &PositionDetail{Position: pos})
65 | }
66 | 


--------------------------------------------------------------------------------
/position/handler_test.go:
--------------------------------------------------------------------------------
  1 | package position_test
  2 | 
  3 | import (
  4 | 	"errors"
  5 | 	"net/http"
  6 | 	"net/http/httptest"
  7 | 	"strings"
  8 | 	"testing"
  9 | 	"time"
 10 | 
 11 | 	"github.com/go-redis/redismock/v9"
 12 | 	"github.com/labstack/echo/v4"
 13 | 	"github.com/learn-video/continue-watching-api/position"
 14 | 	"github.com/redis/go-redis/v9"
 15 | 	"github.com/stretchr/testify/assert"
 16 | )
 17 | 
 18 | type contextSetup struct {
 19 | 	Method  string
 20 | 	Path    string
 21 | 	Body    string
 22 | 	Cookies []*http.Cookie
 23 | }
 24 | 
 25 | func setupContext(setup contextSetup) (echo.Context, *httptest.ResponseRecorder) {
 26 | 	e := echo.New()
 27 | 	req := httptest.NewRequest(setup.Method, setup.Path, strings.NewReader(setup.Body))
 28 | 	req.Header.Set(echo.HeaderContentType, echo.MIMEApplicationJSON)
 29 | 	for _, cookie := range setup.Cookies {
 30 | 		req.AddCookie(cookie)
 31 | 	}
 32 | 	rec := httptest.NewRecorder()
 33 | 	c := e.NewContext(req, rec)
 34 | 	return c, rec
 35 | }
 36 | 
 37 | func TestRecordPositionOK(t *testing.T) {
 38 | 	setup := contextSetup{
 39 | 		Method: http.MethodPost,
 40 | 		Path:   "/",
 41 | 		Body:   `{"video_id": "123", "position": 1.0}`,
 42 | 		Cookies: []*http.Cookie{
 43 | 			{Name: "user_id", Value: "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"},
 44 | 		},
 45 | 	}
 46 | 	c, rec := setupContext(setup)
 47 | 	db, mock := redismock.NewClientMock()
 48 | 	mock.Regexp().ExpectSet("bda031c0-4e7d-493a-92ba-6fc1eb3e6216_123", 1.0, 1*time.Minute).
 49 | 		SetVal("OK")
 50 | 	h := position.NewHandler(db)
 51 | 
 52 | 	if assert.NoError(t, h.Record(c)) {
 53 | 		assert.Equal(t, http.StatusCreated, rec.Code)
 54 | 	}
 55 | }
 56 | 
 57 | func TestRecordPositionMissingUserID(t *testing.T) {
 58 | 	setup := contextSetup{
 59 | 		Method: http.MethodPost,
 60 | 		Path:   "/",
 61 | 		Body:   `{"video_id": "123", "position": 1}`,
 62 | 	}
 63 | 	c, rec := setupContext(setup)
 64 | 	db, _ := redismock.NewClientMock()
 65 | 	h := position.NewHandler(db)
 66 | 	h.Record(c)
 67 | 
 68 | 	assert.Equal(t, http.StatusBadRequest, rec.Code)
 69 | }
 70 | 
 71 | func TestRecordPositionMissingPayload(t *testing.T) {
 72 | 	setup := contextSetup{
 73 | 		Method: http.MethodPost,
 74 | 		Path:   "/",
 75 | 	}
 76 | 	c, rec := setupContext(setup)
 77 | 	req := c.Request()
 78 | 	req.AddCookie(&http.Cookie{Name: "user_id", Value: "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"})
 79 | 	db, _ := redismock.NewClientMock()
 80 | 	h := position.NewHandler(db)
 81 | 	h.Record(c)
 82 | 
 83 | 	assert.Equal(t, http.StatusBadRequest, rec.Code)
 84 | }
 85 | 
 86 | func TestRecordPositionRedisError(t *testing.T) {
 87 | 	setup := contextSetup{
 88 | 		Method: http.MethodPost,
 89 | 		Path:   "/",
 90 | 		Body:   `{"video_id": "123", "position": 1}`,
 91 | 		Cookies: []*http.Cookie{
 92 | 			{Name: "user_id", Value: "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"},
 93 | 		},
 94 | 	}
 95 | 	c, rec := setupContext(setup)
 96 | 	db, mock := redismock.NewClientMock()
 97 | 	mock.Regexp().ExpectSet("bda031c0-4e7d-493a-92ba-6fc1eb3e6216_123", 1, 1*time.Minute).
 98 | 		SetErr(errors.New("failed to set key"))
 99 | 	h := position.NewHandler(db)
100 | 	h.Record(c)
101 | 
102 | 	assert.Equal(t, http.StatusInternalServerError, rec.Code)
103 | }
104 | 
105 | func TestHandlerFetchOK(t *testing.T) {
106 | 	setup := contextSetup{
107 | 		Method: http.MethodGet,
108 | 		Path:   "/?video_id=123",
109 | 		Cookies: []*http.Cookie{
110 | 			{Name: "user_id", Value: "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"},
111 | 		},
112 | 	}
113 | 	c, rec := setupContext(setup)
114 | 	db, mock := redismock.NewClientMock()
115 | 	mock.ExpectGet("bda031c0-4e7d-493a-92ba-6fc1eb3e6216_123").SetVal("1")
116 | 	h := position.NewHandler(db)
117 | 
118 | 	expectedJSON := `{"position": 1}`
119 | 	if assert.NoError(t, h.Fetch(c)) {
120 | 		assert.Equal(t, http.StatusOK, rec.Code)
121 | 		assert.JSONEq(t, expectedJSON, rec.Body.String())
122 | 	}
123 | }
124 | 
125 | func TestHandlerMissingUserID(t *testing.T) {
126 | 	setup := contextSetup{
127 | 		Method: http.MethodGet,
128 | 		Path:   "/?video_id=123",
129 | 	}
130 | 	c, rec := setupContext(setup)
131 | 	db, _ := redismock.NewClientMock()
132 | 	h := position.NewHandler(db)
133 | 
134 | 	h.Fetch(c)
135 | 
136 | 	assert.Equal(t, http.StatusBadRequest, rec.Code)
137 | }
138 | 
139 | func TestHandlerFetchPositionNotFound(t *testing.T) {
140 | 	setup := contextSetup{
141 | 		Method: http.MethodGet,
142 | 		Path:   "/?video_id=123",
143 | 		Cookies: []*http.Cookie{
144 | 			{Name: "user_id", Value: "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"},
145 | 		},
146 | 	}
147 | 	c, rec := setupContext(setup)
148 | 	db, mock := redismock.NewClientMock()
149 | 	mock.ExpectGet("bda031c0-4e7d-493a-92ba-6fc1eb3e6216_123").SetErr(redis.Nil)
150 | 	h := position.NewHandler(db)
151 | 
152 | 	h.Fetch(c)
153 | 
154 | 	assert.Equal(t, http.StatusNotFound, rec.Code)
155 | }
156 | 
157 | func TestHandlerFetchPositionRedisError(t *testing.T) {
158 | 	setup := contextSetup{
159 | 		Method: http.MethodGet,
160 | 		Path:   "/?video_id=123",
161 | 		Cookies: []*http.Cookie{
162 | 			{Name: "user_id", Value: "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"},
163 | 		},
164 | 	}
165 | 	c, rec := setupContext(setup)
166 | 	db, mock := redismock.NewClientMock()
167 | 	mock.ExpectGet("bda031c0-4e7d-493a-92ba-6fc1eb3e6216_123").SetErr(errors.New("failed to get"))
168 | 	h := position.NewHandler(db)
169 | 
170 | 	h.Fetch(c)
171 | 
172 | 	assert.Equal(t, http.StatusInternalServerError, rec.Code)
173 | }
174 | 


--------------------------------------------------------------------------------
/position/position.go:
--------------------------------------------------------------------------------
 1 | package position
 2 | 
 3 | import (
 4 | 	"context"
 5 | 	"errors"
 6 | 	"fmt"
 7 | 	"strconv"
 8 | 	"time"
 9 | 
10 | 	"github.com/redis/go-redis/v9"
11 | )
12 | 
13 | var (
14 | 	ErrNotFound = errors.New("no position tracked")
15 | )
16 | 
17 | func Record(r *redis.Client, userID, videoID string, position float64) error {
18 | 	key := fmt.Sprintf("%s_%s", userID, videoID)
19 | 	return r.Set(context.TODO(), key, position, 1*time.Minute).Err()
20 | }
21 | 
22 | func Fetch(r *redis.Client, userID, videoID string) (float64, error) {
23 | 	key := fmt.Sprintf("%s_%s", userID, videoID)
24 | 	val, err := r.Get(context.TODO(), key).Result()
25 | 	if err == redis.Nil {
26 | 		return 0, ErrNotFound
27 | 	} else if err != nil {
28 | 		return 0, err
29 | 	}
30 | 
31 | 	pos, err := strconv.ParseFloat(val, 64)
32 | 	if err != nil {
33 | 		return 0, err
34 | 	}
35 | 
36 | 	return pos, nil
37 | }
38 | 


--------------------------------------------------------------------------------
/position/position_test.go:
--------------------------------------------------------------------------------
 1 | package position_test
 2 | 
 3 | import (
 4 | 	"errors"
 5 | 	"fmt"
 6 | 	"testing"
 7 | 	"time"
 8 | 
 9 | 	"github.com/go-redis/redismock/v9"
10 | 	"github.com/learn-video/continue-watching-api/position"
11 | 	"github.com/redis/go-redis/v9"
12 | 	"github.com/stretchr/testify/assert"
13 | )
14 | 
15 | func TestRecordOK(t *testing.T) {
16 | 	db, mock := redismock.NewClientMock()
17 | 	userID := "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"
18 | 	videoID := "a1fbd2af-ab5e-44ac-9e5d-1a24051f89cf"
19 | 	key := fmt.Sprintf("%s_%s", userID, videoID)
20 | 
21 | 	mock.ExpectSet(key, 1.0, 1*time.Minute).SetVal("OK")
22 | 
23 | 	err := position.Record(db, userID, videoID, 1.0)
24 | 	assert.Nil(t, err)
25 | 	assert.Nil(t, mock.ExpectationsWereMet())
26 | }
27 | 
28 | func TestRecordRedisError(t *testing.T) {
29 | 	db, mock := redismock.NewClientMock()
30 | 	userID := "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"
31 | 	videoID := "a1fbd2af-ab5e-44ac-9e5d-1a24051f89cf"
32 | 	key := fmt.Sprintf("%s_%s", userID, videoID)
33 | 	mock.ExpectSet(key, 1.0, 1*time.Minute).SetErr(errors.New("failed to set key"))
34 | 
35 | 	err := position.Record(db, userID, videoID, 1.0)
36 | 
37 | 	assert.NotNil(t, err)
38 | 	assert.Nil(t, mock.ExpectationsWereMet())
39 | }
40 | 
41 | func TestFetchOK(t *testing.T) {
42 | 	db, mock := redismock.NewClientMock()
43 | 	userID := "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"
44 | 	videoID := "a1fbd2af-ab5e-44ac-9e5d-1a24051f89cf"
45 | 	key := fmt.Sprintf("%s_%s", userID, videoID)
46 | 	mock.ExpectGet(key).SetVal("1")
47 | 
48 | 	pos, err := position.Fetch(db, userID, videoID)
49 | 
50 | 	assert.Nil(t, err)
51 | 	assert.Equal(t, pos, 1.0)
52 | 	assert.Nil(t, mock.ExpectationsWereMet())
53 | }
54 | 
55 | func TestFetchPositionNotFound(t *testing.T) {
56 | 	db, mock := redismock.NewClientMock()
57 | 	userID := "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"
58 | 	videoID := "a1fbd2af-ab5e-44ac-9e5d-1a24051f89cf"
59 | 	key := fmt.Sprintf("%s_%s", userID, videoID)
60 | 	mock.ExpectGet(key).SetErr(redis.Nil)
61 | 
62 | 	pos, err := position.Fetch(db, userID, videoID)
63 | 
64 | 	assert.Equal(t, err, position.ErrNotFound)
65 | 	assert.Equal(t, pos, 0.0)
66 | 	assert.Nil(t, mock.ExpectationsWereMet())
67 | }
68 | 
69 | func TestFetchRedisError(t *testing.T) {
70 | 	db, mock := redismock.NewClientMock()
71 | 	userID := "bda031c0-4e7d-493a-92ba-6fc1eb3e6216"
72 | 	videoID := "a1fbd2af-ab5e-44ac-9e5d-1a24051f89cf"
73 | 	key := fmt.Sprintf("%s_%s", userID, videoID)
74 | 	mock.ExpectGet(key).SetErr(errors.New("failed to get key"))
75 | 
76 | 	pos, err := position.Fetch(db, userID, videoID)
77 | 
78 | 	assert.Equal(t, err, errors.New("failed to get key"))
79 | 	assert.Equal(t, pos, 0.0)
80 | 	assert.Nil(t, mock.ExpectationsWereMet())
81 | }
82 | 


--------------------------------------------------------------------------------