├── Elsafile.el ├── .gitignore ├── tests ├── helpers.el ├── test-lgr-appender.el ├── test-lgr-logger.el └── test-lgr-layout.el ├── Eask ├── .github └── workflows │ └── test.yml ├── README.md ├── lgr.el └── LICENSE /Elsafile.el: -------------------------------------------------------------------------------- 1 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | /.eask 2 | /.elsa 3 | lgr-autoloads.el 4 | lgr-pkg.el 5 | -------------------------------------------------------------------------------- /tests/helpers.el: -------------------------------------------------------------------------------- 1 | (require 'eieio) 2 | 3 | (defclass lgr-test-appender (lgr-appender) 4 | ((events :initform nil))) 5 | 6 | (cl-defmethod lgr-append ((appender lgr-test-appender) event) 7 | (push event (oref appender events))) 8 | -------------------------------------------------------------------------------- /Eask: -------------------------------------------------------------------------------- 1 | (package "lgr" 2 | "0.1.0" 3 | "A fully featured logging framework") 4 | 5 | (website-url "https://github.com/Fuco1/emacs-lgr") 6 | (keywords "tools") 7 | 8 | (package-file "lgr.el") 9 | 10 | (files "lgr.el") 11 | 12 | (script "test" "echo \"Error: no test specified\" && exit 1") 13 | 14 | (source "gnu") 15 | (source "melpa") 16 | 17 | (depends-on "emacs" "26.1") 18 | 19 | (development 20 | (depends-on "buttercup") 21 | (when (version<= "26.3" emacs-version) 22 | (depends-on "elsa"))) 23 | -------------------------------------------------------------------------------- /.github/workflows/test.yml: -------------------------------------------------------------------------------- 1 | name: CI 2 | 3 | on: 4 | push: 5 | branches: 6 | - master 7 | pull_request: 8 | workflow_dispatch: 9 | 10 | concurrency: 11 | group: ${{ github.workflow }}-${{ github.ref }} 12 | cancel-in-progress: true 13 | 14 | jobs: 15 | test: 16 | runs-on: ${{ matrix.os }} 17 | strategy: 18 | fail-fast: false 19 | matrix: 20 | os: [ubuntu-latest, macos-latest, windows-latest] 21 | emacs-version: 22 | - 26.1 23 | - 26.2 24 | - 26.3 25 | - 27.1 26 | - 27.2 27 | - 28.1 28 | - 28.2 29 | - snapshot 30 | 31 | steps: 32 | - uses: actions/checkout@v3 33 | 34 | - uses: jcs090218/setup-emacs@master 35 | with: 36 | version: ${{ matrix.emacs-version }} 37 | 38 | - uses: emacs-eask/setup-eask@master 39 | with: 40 | version: 'snapshot' 41 | 42 | - name: Workaround for Emacs 27.2's Windows build from GNU FTP 43 | if: ${{ runner.os == 'Windows' && contains(fromJson('["26.1", "26.2", "26.3", "27.1", "27.2"]'), matrix.emacs-version) }} 44 | run: | 45 | gci cert:\LocalMachine\Root\DAC9024F54D8F6DF94935FB1732638CA6AD77C13 46 | gci cert:\LocalMachine\Root\DAC9024F54D8F6DF94935FB1732638CA6AD77C13 | Remove-Item 47 | 48 | - name: Install dependencies 49 | run: | 50 | eask install-deps --dev 51 | 52 | - name: Run buttercup 53 | run: | 54 | eask test buttercup 55 | 56 | - name: Run tests 57 | run: | 58 | eask clean all 59 | eask package 60 | eask install 61 | eask compile 62 | -------------------------------------------------------------------------------- /tests/test-lgr-appender.el: -------------------------------------------------------------------------------- 1 | (require 'buttercup) 2 | (require 'lgr) 3 | 4 | (describe "Appender test" 5 | 6 | (describe "lgr-appender" 7 | 8 | (it "should set threshold" 9 | (let ((appender (lgr-appender))) 10 | (expect (lgr-get-threshold (lgr-set-threshold appender lgr-level-debug)) 11 | :to-equal lgr-level-debug))) 12 | 13 | (it "should set layout" 14 | (let ((appender (lgr-appender))) 15 | (expect (lgr-to-string 16 | (lgr-get-layout (lgr-set-layout appender (lgr-layout-json)))) 17 | :to-equal "json layout"))) 18 | 19 | (it "should return itself from lgr-append" 20 | (let ((appender (lgr-appender))) 21 | (expect (lgr-append appender (lgr-event :msg "" 22 | :logger-name "" 23 | :timestamp (current-time) 24 | :level 400)) 25 | :to-equal appender)))) 26 | 27 | (describe "lgr-appender-buffer" 28 | 29 | (it "should log to a buffer if given a string buffer name" 30 | (let ((appender (lgr-appender-buffer :buffer "test-buffer"))) 31 | (lgr-append appender (lgr-event :msg "test message" 32 | :logger-name "" 33 | :timestamp (current-time) 34 | :level 400)) 35 | (expect (with-current-buffer (get-buffer "test-buffer") 36 | (buffer-string)) 37 | :to-match "test message"))) 38 | 39 | (it "should log to a buffer if given a buffer object" 40 | (let ((appender (lgr-appender-buffer :buffer (get-buffer-create "test-buffer")))) 41 | (lgr-append appender (lgr-event :msg "test message" 42 | :logger-name "" 43 | :timestamp (current-time) 44 | :level 400)) 45 | (expect (with-current-buffer (get-buffer "test-buffer") 46 | (buffer-string)) 47 | :to-match "test message"))))) 48 | -------------------------------------------------------------------------------- /tests/test-lgr-logger.el: -------------------------------------------------------------------------------- 1 | (require 'buttercup) 2 | (require 'lgr) 3 | 4 | (load "tests/helpers.el") 5 | 6 | (describe "Lgr logger" 7 | 8 | (before-each 9 | (setq lgr--loggers 10 | (let ((ht (make-hash-table :test #'equal))) 11 | (puthash "lgr--root" (lgr-logger :name "lgr--root" :threshold 400) ht) 12 | ht))) 13 | 14 | (describe "Propagation of events" 15 | 16 | (it "should propagate event to parent loggers" 17 | (let* ((appender (lgr-test-appender)) 18 | (logger (lgr-add-appender (lgr-get-logger "test") appender)) 19 | (sublogger (lgr-add-appender (lgr-get-logger "test.sub") appender))) 20 | (lgr-log sublogger 100 "test") 21 | (expect (length (oref appender events)) :to-equal 2))) 22 | 23 | (it "should not propagate to parents if propagate is set to nil" 24 | (let* ((appender (lgr-test-appender)) 25 | (logger (lgr-add-appender (lgr-get-logger "test") appender)) 26 | (sublogger (lgr-set-propagate 27 | (lgr-add-appender (lgr-get-logger "test.sub") appender) 28 | nil))) 29 | (lgr-log sublogger 100 "test") 30 | (expect (length (oref appender events)) :to-equal 1)))) 31 | 32 | (describe "Checking event level against threshold" 33 | 34 | (it "should not create an event if level of parent is less than threshold" 35 | (let ((logger (lgr-add-appender (lgr-get-logger "test") (lgr-test-appender)))) 36 | (lgr-log logger 500 "This should not be logged") 37 | (expect (oref (car (oref logger appenders)) events) :to-be nil))) 38 | 39 | (it "should create an event if level of parent is greater than threshold" 40 | (let ((logger (lgr-add-appender (lgr-get-logger "test") (lgr-test-appender)))) 41 | (lgr-log logger 100 "This should be logged") 42 | (expect (oref (car (oref logger appenders)) events) :not :to-be nil))) 43 | 44 | (it "should not create an event if level on this logger is less than threshold" 45 | (let ((logger (lgr-set-threshold 46 | (lgr-add-appender 47 | (lgr-get-logger "test") 48 | (lgr-test-appender)) 49 | 300))) 50 | (lgr-log logger 500 "This should not be logged") 51 | (expect (oref (car (oref logger appenders)) events) :to-be nil))) 52 | 53 | (it "should create an event if level on this logger is greater than threshold" 54 | (let ((logger (lgr-set-threshold 55 | (lgr-add-appender 56 | (lgr-get-logger "test") 57 | (lgr-test-appender)) 58 | 300))) 59 | (lgr-log logger 100 "This should be logged") 60 | (expect (oref (car (oref logger appenders)) events) :not :to-be nil)))) 61 | 62 | (describe "Checking appender level before appending" 63 | 64 | (it "should not append if level of event is more than appender threshold" 65 | (let ((logger (lgr-add-appender 66 | (lgr-get-logger "test") 67 | (lgr-test-appender :threshold 300)))) 68 | (lgr-log logger 500 "This should not be logged") 69 | (expect (oref (car (oref logger appenders)) events) :to-be nil))) 70 | 71 | (it "should append if level of event is less than appender threshold" 72 | (let ((logger (lgr-add-appender 73 | (lgr-get-logger "test") 74 | (lgr-test-appender :threshold 300)))) 75 | (lgr-log logger 100 "This should be logged") 76 | (expect (oref (car (oref logger appenders)) events) :not :to-be nil)))) 77 | 78 | (describe "Test generated logging macros" 79 | 80 | (it "lgr-fatal should emit a fatal level event" 81 | (let ((logger (lgr-add-appender 82 | (lgr-get-logger "test") 83 | (lgr-test-appender :threshold lgr-level-trace)))) 84 | (lgr-fatal logger "This should be logged") 85 | (expect (oref (car (oref (car (oref logger appenders)) events)) level) :to-be 100))) 86 | 87 | (it "lgr-error should emit a error level event" 88 | (let ((logger (lgr-add-appender 89 | (lgr-get-logger "test") 90 | (lgr-test-appender :threshold lgr-level-trace)))) 91 | (lgr-error logger "This should be logged") 92 | (expect (oref (car (oref (car (oref logger appenders)) events)) level) :to-be 200))) 93 | 94 | (it "lgr-warn should emit a warn level event" 95 | (let ((logger (lgr-add-appender 96 | (lgr-get-logger "test") 97 | (lgr-test-appender :threshold lgr-level-trace)))) 98 | (lgr-warn logger "This should be logged") 99 | (expect (oref (car (oref (car (oref logger appenders)) events)) level) :to-be 300))) 100 | 101 | (it "lgr-info should emit a info level event" 102 | (let ((logger (lgr-add-appender 103 | (lgr-get-logger "test") 104 | (lgr-test-appender :threshold lgr-level-trace)))) 105 | (lgr-info logger "This should be logged") 106 | (expect (oref (car (oref (car (oref logger appenders)) events)) level) :to-be 400))) 107 | 108 | (it "lgr-debug should emit a debug level event" 109 | (let ((logger (lgr-set-threshold 110 | (lgr-add-appender 111 | (lgr-get-logger "test") 112 | (lgr-test-appender :threshold lgr-level-trace)) 113 | lgr-level-trace))) 114 | (lgr-debug logger "This should be logged") 115 | (expect (oref (car (oref (car (oref logger appenders)) events)) level) :to-be 500))) 116 | 117 | (it "lgr-trace should emit a trace level event" 118 | (let ((logger (lgr-set-threshold 119 | (lgr-add-appender 120 | (lgr-get-logger "test") 121 | (lgr-test-appender :threshold lgr-level-trace)) 122 | lgr-level-trace))) 123 | (lgr-trace logger "This should be logged") 124 | (expect (oref (car (oref (car (oref logger appenders)) events)) level) :to-be 600))))) 125 | -------------------------------------------------------------------------------- /tests/test-lgr-layout.el: -------------------------------------------------------------------------------- 1 | (require 'buttercup) 2 | (require 'lgr) 3 | 4 | (describe "Logger layouts" 5 | 6 | (describe "lgr-layout" 7 | 8 | (it "should format an event using the event's lgr-to-string" 9 | (let ((event (lgr-event :msg "hello" 10 | :level 400 11 | :timestamp (list 25611 55393 715589 340000) 12 | :logger-name "main" 13 | :meta (list :key "value")))) 14 | (expect (lgr-format-event (lgr-layout) event) 15 | :to-equal "[2023-03-11T01:24:49+0000] (400) main - hello (:key value)")))) 16 | 17 | (describe "lgr-layout-json" 18 | 19 | (it "should format an event as a JSON string" 20 | (let ((event (lgr-event :msg "hello" 21 | :level 400 22 | :timestamp (list 25611 55393 715589 340000) 23 | :logger-name "main" 24 | :meta (list :key "value")))) 25 | (expect (lgr-format-event (lgr-layout-json) event) 26 | :to-equal "{\"timestamp\":\"2023-03-11T01:24:49+0000\",\"level\":400,\"logger-name\":\"main\",\"msg\":\"hello\",\"meta\":{\"key\":\"value\"}}")))) 27 | 28 | 29 | (describe "lgr-layout-format" 30 | 31 | (it "should format an event using a format string" 32 | (let ((event (lgr-event :msg "hello" 33 | :level 400 34 | :timestamp (list 25611 55393 715589 340000) 35 | :logger-name "main" 36 | :meta (list :key "value")))) 37 | (expect (lgr-format-event (lgr-layout-format :format "%t %n %g - %m %f") event) 38 | :to-equal "2023-03-11T01:24:49+0000 400 main - hello (:key value)"))) 39 | 40 | (it "should have customizable timestamp-format" 41 | (let ((event (lgr-event :msg "hello" 42 | :level 400 43 | :timestamp (list 25611 55393 715589 340000) 44 | :logger-name "main" 45 | :meta (list :key "value")))) 46 | (expect (lgr-format-event (lgr-layout-format :format "%t %n %g - %m %f" 47 | :timestamp-format "%Y-%m-%d") 48 | event) 49 | :to-equal "2023-03-11 400 main - hello (:key value)"))) 50 | 51 | (describe "format spec tests" 52 | 53 | (it "should format %t as timestamp" 54 | (let ((event (lgr-event :msg "hello" 55 | :level 400 56 | :timestamp (list 25611 55393 715589 340000) 57 | :logger-name "main" 58 | :meta (list :key "value")))) 59 | (expect (lgr-format-event (lgr-layout-format :format "%t") event) 60 | :to-equal "2023-03-11T01:24:49+0000"))) 61 | 62 | (it "should format %l as lowercase level name" 63 | (let ((event (lgr-event :msg "hello" 64 | :level 400 65 | :timestamp (list 25611 55393 715589 340000) 66 | :logger-name "main" 67 | :meta (list :key "value")))) 68 | (expect (lgr-format-event (lgr-layout-format :format "%l") event) 69 | :to-equal "info"))) 70 | 71 | (it "should format %L as uppercase level name" 72 | (let ((event (lgr-event :msg "hello" 73 | :level 400 74 | :timestamp (list 25611 55393 715589 340000) 75 | :logger-name "main" 76 | :meta (list :key "value")))) 77 | (expect (lgr-format-event (lgr-layout-format :format "%L") event) 78 | :to-equal "INFO"))) 79 | 80 | (it "should format %k as lowercase one letter level name" 81 | (let ((event (lgr-event :msg "hello" 82 | :level 400 83 | :timestamp (list 25611 55393 715589 340000) 84 | :logger-name "main" 85 | :meta (list :key "value")))) 86 | (expect (lgr-format-event (lgr-layout-format :format "%k") event) 87 | :to-equal "i"))) 88 | 89 | (it "should format %K as uppercase one letter level name" 90 | (let ((event (lgr-event :msg "hello" 91 | :level 400 92 | :timestamp (list 25611 55393 715589 340000) 93 | :logger-name "main" 94 | :meta (list :key "value")))) 95 | (expect (lgr-format-event (lgr-layout-format :format "%K") event) 96 | :to-equal "I"))) 97 | 98 | (it "should format %n as numeric level" 99 | (let ((event (lgr-event :msg "hello" 100 | :level 400 101 | :timestamp (list 25611 55393 715589 340000) 102 | :logger-name "main" 103 | :meta (list :key "value")))) 104 | (expect (lgr-format-event (lgr-layout-format :format "%n") event) 105 | :to-equal "400"))) 106 | 107 | (it "should format %g as logger name" 108 | (let ((event (lgr-event :msg "hello" 109 | :level 400 110 | :timestamp (list 25611 55393 715589 340000) 111 | :logger-name "main" 112 | :meta (list :key "value")))) 113 | (expect (lgr-format-event (lgr-layout-format :format "%g") event) 114 | :to-equal "main"))) 115 | 116 | (it "should format %m as message" 117 | (let ((event (lgr-event :msg "hello" 118 | :level 400 119 | :timestamp (list 25611 55393 715589 340000) 120 | :logger-name "main" 121 | :meta (list :key "value")))) 122 | (expect (lgr-format-event (lgr-layout-format :format "%m") event) 123 | :to-equal "hello"))) 124 | 125 | (it "should format %f as plist representation of meta" 126 | (let ((event (lgr-event :msg "hello" 127 | :level 400 128 | :timestamp (list 25611 55393 715589 340000) 129 | :logger-name "main" 130 | :meta (list :key "value")))) 131 | (expect (lgr-format-event (lgr-layout-format :format "%f") event) 132 | :to-equal "(:key value)"))) 133 | 134 | (it "should format %j as JSON representation of meta" 135 | (let ((event (lgr-event :msg "hello" 136 | :level 400 137 | :timestamp (list 25611 55393 715589 340000) 138 | :logger-name "main" 139 | :meta (list :key "value")))) 140 | (expect (lgr-format-event (lgr-layout-format :format "%j") event) 141 | :to-equal "{\"key\":\"value\"}")))))) 142 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # lgr 2 | 3 | lgr is a logging package for Emacs built on the back of 4 | [EIEIO](https://www.gnu.org/software/emacs/manual/html_node/eieio/) 5 | classes. It is designed to be flexible, performant, and 6 | extensible. 7 | 8 | # Features 9 | 10 | - *Hierarchical loggers* like in log4j and python logging. This is 11 | useful if you want to be able to configure logging on a per-package 12 | basis. 13 | - An *arbitrary number of appenders* for each logger. A single logger 14 | can write to the console, a logfile, a database, etc… . 15 | - Support for structured logging. As opposed to many other logging 16 | packages for Emacs a log event is not just a message with a 17 | timestamp, but an object that can contain arbitrary data 18 | fields. This is useful for producing machine readable logs. 19 | - *Lazy evaluated* arguments for log messages. If the log event level 20 | is above the threshold, arguments won't be evaluated to save time. 21 | - Appenders that write logs to a wide range of destinations: 22 | - minibuffer via `message`, 23 | - standard output with `princ`, 24 | - plaintext files (with a powerful formatting syntax), 25 | - JSON files with arbitrary data fields, 26 | - ... or your own custom appender. 27 | 28 | # Usage 29 | 30 | ## How do I log! 31 | 32 | To log an *event* with lgr, we call `(lgr-LEVEL lgr )`. Rest 33 | of the arguments to the logging function are interpreted by `format` 34 | until all the format control sequences are replaced, then the rest is 35 | stored as arbitrary event metadata. 36 | 37 | To get a `lgr` logger object, call `(lgr-get-logger "logger-name")`. 38 | Logger name is an arbitrary string, but should somehow correspond to 39 | your package's name. 40 | 41 | ```emacs-lisp 42 | (lgr-fatal lgr "A critical error") 43 | ;=> [2023-03-11T01:24:49+0000] (fatal) A critical error 44 | (lgr-error lgr "A less severe error") 45 | ;=> [2023-03-11T01:24:49+0000] (error) A less severe error 46 | (lgr-warn lgr "A potentially bad situation") 47 | ;=> [2023-03-11T01:24:49+0000] (warn) A potentially bad situation 48 | (lgr-info lgr "iris has %s rows" (nrow iris)) 49 | ;=> [2023-03-11T01:24:49+0000] (info) iris has 150 rows 50 | 51 | ; the following log levels are hidden by default 52 | (lgr-debug lgr "A debug message") 53 | (lgr-trace lgr "A finer grained debug message") 54 | ``` 55 | 56 | Loggers **should never** be created manually but only be retrieved 57 | using `lgr-get-logger`. If a logger with the same name already 58 | exists, it will be returned from a cache. The common idiom is to 59 | let-bind a logger at the beginning of a function and then use it 60 | throughout the function. 61 | 62 | ``` emacs-lisp 63 | (defun start-worker (worker-id) 64 | (let ((lgr (lgr-get-logger "package.worker"))) 65 | (lgr-info lgr "Starting worker %d" worker-id) 66 | ...)) 67 | 68 | (defun main () 69 | (let ((lgr (lgr-get-logger "package"))) 70 | (lgr-info lgr "Starting the package main event loop") 71 | (start-worker 1) 72 | (start-worker 2))) 73 | ``` 74 | 75 | You can of course use multiple loggers in a single function by 76 | let-binding multiple calls to `lgr-get-logger` (or even use them 77 | inline). 78 | 79 | ## Give me 3 minute rundown of configuration 80 | 81 | Logging an event by itself wont store it anywhere, for that, the 82 | logger must be configured with an appended. A Logger can have several 83 | appenders to write to multiple destinations. 84 | 85 | For example, we can add a file appender to format events as JSONs and 86 | save them to file. To do this, we need to configure two settings: 87 | 88 | - add the JSON layout to the appender so it knows how to format the 89 | events before writing them to the file. 90 | - attach this appender to the logger object `lgr` 91 | 92 | Configuration is very convenient with the usage of the `->` macro from 93 | the 94 | [dash.el](https://github.com/magnars/dash.el#--x-optional-form-rest-more) 95 | package, but can be equally done without. 96 | 97 | ``` emacs-lisp 98 | (-> lgr 99 | (lgr-add-appender 100 | (-> (lgr-appender-file :file "json-logs.log") 101 | (lgr-set-layout (lgr-layout-json))))) 102 | 103 | ;; same code macro-expanded 104 | (lgr-add-appender 105 | lgr 106 | (lgr-set-layout 107 | (lgr-appender-file :file "json-logs.log") 108 | (lgr-layout-json))) 109 | ``` 110 | 111 | The `->` style resembles the method "dot chaining" from traditional 112 | OOP languages like Java or C++. To make this possible, we make sure 113 | that all the configuration methods always take the instance as the 114 | first argument and return itself so they can be chained: 115 | 116 | ``` emacs-lisp 117 | (-> lgr 118 | (lgr-add-appender (lgr-appender-princ)) 119 | (lgr-set-threshold lgr-level-trace) 120 | (lgr-set-propagate nil)) 121 | ``` 122 | 123 | ## Logger hierarchies 124 | 125 | Loggers are organized in hierarchies. The loggers are automatically 126 | nested by separating the segments of the name with a dot: 127 | 128 | ``` emacs-lisp 129 | (lgr-get-logger "lgr") 130 | (lgr-get-logger "lgr.appender") 131 | (lgr-get-logger "lgr.layout") 132 | 133 | ;; lgr 134 | ;; ├─ appender 135 | ;; └─ layout 136 | ``` 137 | 138 | Loggers *propagate* events up the hierarchy unless configured not to 139 | with `lgr-set-propagate`. 140 | 141 | The most common situation is to configure appenders only on top-level 142 | logger and let events bubble up and be processed there. But if an 143 | appender is added to some logger lower in the hierarchy, an event can 144 | be dispatched twice or more times. 145 | 146 | Use `M-x lgr-loggers-format-to-tree` to visualize the logger 147 | hierarchy. The results are displayed in a `*lgr loggers*` buffer: 148 | 149 | ``` 150 | lgr logger hierarchy 151 | ==================== 152 | 153 | 🔇 Loggers without appenders 154 | 155 | 🔇 lgr--root [info] 156 | ├─ elsa [info] > Princ 157 | │ └─ lsp 158 | ├─ 🔇 lgr 159 | │ ├─ 🔇 appender 160 | │ └─ 🔇 layout 161 | ├─ local > Warnings 162 | │ ├─ error [error] 163 | │ └─ test 164 | │ ├─ one 165 | │ └─ two 166 | └─ 🔇 test [error] 167 | ``` 168 | 169 | ## Configuring thresholds 170 | 171 | Loggers and appenders can both be configured independently with 172 | thresholds. 173 | 174 | Currently, six levels are built-in in `lgr`: 175 | 176 | - `fatal` => 100 or constant `lgr-level-fatal` 177 | - `error` => 200 or constant `lgr-level-error` 178 | - `warn` => 300 or constant `lgr-level-warn` 179 | - `info` => 400 or constant `lgr-level-info` **[default]** 180 | - `debug` => 500 or constant `lgr-level-debug` 181 | - `trace` => 600 or constant `lgr-level-trace` 182 | 183 | A logger won't emit an event whose level is higher than the logger 184 | threshold. 185 | 186 | An appender won't append an event whose level is higher than the 187 | appender threshold. 188 | 189 | This way, we can create interesting setups such as: 190 | 191 | Configure one logger with two appenders, one for file logging and one 192 | sending emails. We configure the file appender to debug threshold and 193 | the email appender to error threshold. 194 | 195 | If the logger itself has an info threshold, only events info and above 196 | will be emited. All those will be saved in the file, because the file 197 | appender has debug threshold. But only fatal and error events will be 198 | sent as emails to an SRE operator. 199 | 200 | If a logger has no configured threshold, it will look up the logger 201 | hierarchy to inherit the threshold of first configured logger. This 202 | way, you can selectively increase or decrease the log granularity of 203 | parts of the logger hierarchy when debugging specific parts of code. 204 | 205 | Thresholds are configured with `lgr-set-threshold` method: 206 | 207 | ``` emacs-lisp 208 | (-> (lgr-get-logger "lgr") 209 | (lgr-set-threshold lgr-level-debug)) 210 | ``` 211 | 212 | ## Event metadata 213 | 214 | By passing additional key-value pairs in form of a plist, you can add 215 | arbitrary metadata to your events. 216 | 217 | ``` emacs-lisp 218 | (lgr-info lgr "This is a message number %d" 5 :worker-id "west-eu-7" :datacenter "dc1") 219 | ``` 220 | 221 | Various layouts handle the formatting of metadata differently, you can 222 | read in their documentation. For example, JSON layout will serialize 223 | it as JSON subobject under a `meta` key. 224 | 225 | # Available Loggers, Appenders and Layouts 226 | 227 | lgr comes with many appenders and layouts out of the box. You can 228 | read the built-in documentation with `C-h f `. 229 | 230 | Currently implemented loggers: 231 | 232 | - `lgr-logger` - log message as-is 233 | - `lgr-logger-format` - interpret message as format string for 234 | `format`, using remaining arguments as replacement. 235 | 236 | The `lgr-logger-format` is the default format returned by 237 | `lgr-get-logger`. 238 | 239 | Currently implemented appenders: 240 | 241 | - `lgr-appender` - print events using `message` 242 | - `lgr-appender-princ` - print events using `princ` (standard output in `-batch`) 243 | - `lgr-appender-file` - write events to a file 244 | - `lgr-appender-buffer` - write events to a buffer 245 | - `lgr-appender-warnings` - use `display-warning` to log events 246 | - `lgr-appender-journald` - write logs to systemd journal 247 | 248 | Available layouts: 249 | 250 | - `lgr-layout-format` - use custom format string template to format events 251 | - `lgr-layout-json` - format as JSON string 252 | 253 | # But isn't it going to slow down my code? 254 | 255 | No. `lgr` uses macros to implement lazy evaluation of the arguments. 256 | If the logger threshold doesn't exceed the event level, no arguments 257 | to the `lgr-LEVEL` call are actually evaluated (except the logger 258 | itself which needs to be checked). 259 | 260 | This is why it is not advisable to use `lgr-log` directly but instead 261 | always use the `lgr-LEVEL` macros. 262 | 263 | # Extending lgr 264 | 265 | The main idea of `lgr` is to make it easily extensible by adding your 266 | own layouts and appenders. 267 | 268 | Here is an example appender used in `lgr`'s own test suite. It simply 269 | pushes the events to an internal list. 270 | 271 | ``` emacs-lisp 272 | (defclass lgr-test-appender 273 | ;; extend `lgr-appender' class 274 | (lgr-appender) 275 | ;; add a new slot to store the events 276 | ((events :type list :initform nil))) 277 | 278 | ;; implement the `log-append' method 279 | (cl-defmethod lgr-append ((appender lgr-test-appender) (event lgr-event)) 280 | (push event (oref appender events))) 281 | ``` 282 | 283 | 284 | Here is a more interesting example of an appender using 285 | [emacs-async](https://github.com/jwiegley/emacs-async/pull/167) to 286 | send messages from worker processes to the main process: 287 | 288 | ``` emacs-lisp 289 | (defclass elsa-worker-appender (lgr-appender) () 290 | "Appender sending messages back to parent process.") 291 | 292 | (cl-defmethod lgr-append ((this elsa-worker-appender) event) 293 | (when async-in-child-emacs 294 | (async-send 295 | :op "echo" 296 | :message (lgr-format-event (oref this layout) event))) 297 | this) 298 | 299 | ;; configure the logging in a worker process 300 | (-> (lgr-get-logger "elsa") 301 | (lgr-reset-appenders) 302 | (lgr-add-appender 303 | (-> (elsa-worker-appender) 304 | (lgr-set-layout (elsa-plain-layout)))) 305 | (lgr-set-threshold lgr-level-info)) 306 | ``` 307 | 308 | (as seen in [Elsa](https://github.com/emacs-elsa/Elsa)) 309 | 310 | This example shows the power of `lgr`. We can keep the same 311 | `lgr-info` and `lgr-debug` calls everywhere and based on the 312 | configuration in either the main process or the worker process 313 | different appender will be used to dispatch the messages where they 314 | need to go. Therefore, the logging logic, destinations and formatting 315 | are separate from the logging *calls*. 316 | 317 | # Using lgr in my own package. 318 | 319 | Because all the packages loaded in Emacs share the common namespace, 320 | there are some basic guidelines for using lgr in your own private or 321 | published packages: 322 | 323 | - The main logger name should correspond to your package name. 324 | - All the loggers you use in the package should be nested under your main logger. 325 | - If your package is used inside Emacs, you should provide some 326 | reasonable default configuration, for example in the major-mode 327 | function or as a separate function `PACKAGE-setup-lgr` that users 328 | can call in their init file. 329 | 330 | That's it!. This way, *consumers* of your package can independently 331 | of you as the author increase or decrease or even completely disable 332 | logging in your package. 333 | 334 | # Acknowledgement 335 | 336 | This library's architecture was inspired in great deal by 337 | [s-fleck/lgr](https://github.com/s-fleck/lgr) package for R language, 338 | which in turn is modelled after [python 339 | logging](https://docs.python.org/3/library/logging.html). 340 | -------------------------------------------------------------------------------- /lgr.el: -------------------------------------------------------------------------------- 1 | ;;; lgr.el --- A fully featured logging framework -*- lexical-binding: t -*- 2 | 3 | ;; Copyright (C) 2023 Matúš Goljer 4 | 5 | ;; Author: Matúš Goljer 6 | ;; Maintainer: Matúš Goljer 7 | ;; Version: 0.1.0 8 | ;; Package-Requires: ((emacs "26.1")) 9 | ;; Created: 10th March 2023 10 | ;; Keywords: tools 11 | ;; URL: https://github.com/Fuco1/emacs-lgr 12 | 13 | ;; This program is free software; you can redistribute it and/or 14 | ;; modify it under the terms of the GNU General Public License 15 | ;; as published by the Free Software Foundation; either version 3 16 | ;; of the License, or (at your option) any later version. 17 | 18 | ;; This program is distributed in the hope that it will be useful, 19 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of 20 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21 | ;; GNU General Public License for more details. 22 | 23 | ;; You should have received a copy of the GNU General Public License 24 | ;; along with this program. If not, see . 25 | 26 | ;;; Commentary: 27 | 28 | ;; lgr is a logging package for Emacs built on the back of EIEIO 29 | ;; classes. It is designed to be flexible, performant, and 30 | ;; extensible. 31 | 32 | ;;; Code: 33 | 34 | (require 'seq) 35 | (require 'eieio) 36 | (eval-and-compile (setq eieio-backward-compatibility nil)) 37 | (require 'format-spec) 38 | 39 | ;; (lgr-log :: (function ((class lgr-logger) int string &rest mixed) mixed)) 40 | (cl-defgeneric lgr-log (this level message &rest meta) 41 | "Log a MESSAGE at a specific LEVEL. 42 | 43 | THIS is a logger instance. 44 | 45 | META is the additional custom data stored as metadata on the 46 | event. The exact interpretation of this argument depends on the 47 | logger class. 48 | 49 | Rather than using this function directly it is preferable to use 50 | the logging macros which implement lazy evaluation for the 51 | arguments. In case the logger level is less than the granularity 52 | of the event to be produced, the arguments will not be 53 | evaluated. 54 | 55 | The logging macros are: 56 | 57 | - `lgr-fatal' 58 | - `lgr-error' 59 | - `lgr-warn' 60 | - `lgr-info' 61 | - `lgr-debug' 62 | - `lgr-trace'.") 63 | 64 | (eval-and-compile 65 | (defconst lgr-log-levels '((fatal . 100) 66 | (error . 200) 67 | (warn . 300) 68 | (info . 400) 69 | (debug . 500) 70 | (trace . 600)) 71 | "Log levels used in `lgr-log'.") 72 | 73 | (defmacro lgr--def-level (level) 74 | "Generate the `lgr-level-LEVEL' constant and `lgr-LEVEL' macro for LEVEL." 75 | (let ((lgr-level (intern (concat "lgr-level-" (symbol-name level)))) 76 | (lgr-name (intern (concat "lgr-" (symbol-name level))))) 77 | `(progn 78 | (defconst ,lgr-level 79 | ,(cdr (assq level lgr-log-levels))) 80 | 81 | (defmacro ,lgr-name (this message &rest meta) 82 | ,(format "Log MESSAGE using THIS logger at %s level." level) 83 | (declare (indent 1)) 84 | (macroexp-let2 symbolp logger this 85 | ,(list 86 | 'backquote 87 | `(when (>= (lgr-get-threshold ,',logger) ,lgr-level) 88 | (lgr-log ,',logger ,lgr-level ,',message ,',@meta)))))))) 89 | 90 | (lgr--def-level fatal) 91 | (lgr--def-level error) 92 | (lgr--def-level warn) 93 | (lgr--def-level info) 94 | (lgr--def-level debug) 95 | (lgr--def-level trace)) 96 | 97 | ;; (lgr--json-serialize :: (function (mixed) string)) 98 | (defmacro lgr--json-serialize (data) 99 | "Serialize DATA using either `json-serialize' or `json-encode'." 100 | (if (fboundp 'json-serialize) 101 | `(json-serialize ,data) 102 | `(json-encode ,data))) 103 | 104 | ;; (lgr-level-to-name :: (function (int) symbol)) 105 | (defun lgr-level-to-name (level) 106 | "Convert logging LEVEL to symbol." 107 | (cdr (assq 108 | level 109 | (mapcar 110 | (lambda (x) (cons (cdr x) (car x))) 111 | lgr-log-levels)))) 112 | 113 | ;; (lgr-to-string :: (function (mixed) string)) 114 | (cl-defgeneric lgr-to-string (obj) 115 | "Format OBJ as string." 116 | (format "%s" obj)) 117 | 118 | (defclass lgr-event () 119 | ((msg 120 | :type string 121 | :initarg :msg 122 | :documentation "String message to be appended.") 123 | (level 124 | :type integer 125 | :initarg :level 126 | :documentation "Log level. See `lgr-log-levels'") 127 | (timestamp 128 | :type (list-of integer) 129 | :initarg :timestamp 130 | :documentation "Timestamp created by `current-time'.") 131 | (timezone 132 | :type (or string boolean symbol) 133 | :initarg :timezone 134 | :initform t 135 | :documentation "Timezone of the event.") 136 | (logger-name 137 | :type string 138 | :initarg :logger-name 139 | :documentation "Name of the logger which emited this event.") 140 | (meta 141 | :type list 142 | :initarg :meta 143 | :initform nil 144 | :documentation "Plist of arbitrary additional metadata.")) 145 | "Log event produced by `lgr-logger'. 146 | 147 | To provide different way of formatting, rather than extending the 148 | event and providing different `lgr-to-string', it is advisable to 149 | extend `lgr-layout' and implement new `lgr-format-event' method. 150 | 151 | The event can be extended along with a logger if we want to track 152 | additional properties.") 153 | 154 | (cl-defmethod lgr-to-string ((this lgr-event)) 155 | "Format THIS event as string." 156 | (format "[%s] (%s) %s - %s%s" 157 | (format-time-string "%FT%T%z" (oref this timestamp) (oref this timezone)) 158 | (oref this level) 159 | (oref this logger-name) 160 | (oref this msg) 161 | (if (oref this meta) 162 | (format " %s" (oref this meta)) 163 | ""))) 164 | 165 | (defclass lgr-layout () () 166 | "Layouts format `lgr-event' as strings for appending via `lgr-appender'. 167 | 168 | A layout needs to implement the method `lgr-format-event'.") 169 | 170 | ;; (lgr-format-event :: (function ((class lgr-layout) (class lgr-event)) string)) 171 | (cl-defgeneric lgr-format-event (this event) 172 | "Format `lgr-event' EVENT to string using THIS layout.") 173 | 174 | (cl-defmethod lgr-format-event ((_this lgr-layout) (event lgr-event)) 175 | "Use `lgr-to-string' to format EVENT." 176 | (lgr-to-string event)) 177 | 178 | (defclass lgr-layout-format (lgr-layout) 179 | ((format 180 | :type string 181 | :initarg :format 182 | :documentation "Format spec.") 183 | (timestamp-format 184 | :type string 185 | :initarg :timestamp-format 186 | :initform "%FT%T%z" 187 | :documentation "Time format string used by `format-time-string'.")) 188 | "Format the event using a format spec. 189 | 190 | %t The timestamp of the message, formatted according to 191 | timestamp-format. 192 | %l The log level, lowercase character representation. 193 | %L The log level, uppercase character representation. 194 | %k The log level, first letter of lowercase character 195 | representation. 196 | %K The log level, first letter of uppercase character 197 | representation. 198 | %n The log level, integer representation. 199 | %g The name of the logger. 200 | %m The log message. 201 | %f All custom fields of x as a plist. 202 | %j All custom fields of x in proper JSON.") 203 | 204 | (cl-defmethod lgr-format-event ((this lgr-layout-format) (event lgr-event)) 205 | "Format EVENT using format spec from `lgr-layout-format'. 206 | 207 | THIS is the layout." 208 | (format-spec 209 | (oref this format) 210 | (format-spec-make 211 | ?t (format-time-string 212 | (oref this timestamp-format) 213 | (oref event timestamp) 214 | (oref event timezone)) 215 | ?l (downcase (symbol-name (lgr-level-to-name (oref event level)))) 216 | ?L (upcase (symbol-name (lgr-level-to-name (oref event level)))) 217 | ?k (substring (downcase (symbol-name (lgr-level-to-name (oref event level)))) 0 1) 218 | ?K (substring (upcase (symbol-name (lgr-level-to-name (oref event level)))) 0 1) 219 | ?n (oref event level) 220 | ?g (oref event logger-name) 221 | ?m (oref event msg) 222 | ?f (or (oref event meta) "nil") 223 | ?j (lgr--json-serialize (oref event meta))))) 224 | 225 | (defclass lgr-layout-json (lgr-layout) () 226 | "Format the event as JSON.") 227 | 228 | (cl-defmethod lgr-to-string ((_this lgr-layout-json)) 229 | "Format THIS layout to string." 230 | "json layout") 231 | 232 | (cl-defmethod lgr-format-event ((_this lgr-layout-json) (event lgr-event)) 233 | "Format EVENT as JSON." 234 | (lgr--json-serialize 235 | (list 236 | :timestamp (format-time-string "%FT%T%z" 237 | (oref event timestamp) 238 | (oref event timezone)) 239 | :level (oref event level) 240 | :logger-name (oref event logger-name) 241 | :msg (oref event msg) 242 | :meta (oref event meta)))) 243 | 244 | ;; (lgr-set-threshold :: (function (mixed int) mixed)) 245 | (cl-defgeneric lgr-set-threshold (this level) 246 | "Set threshold for THIS to LEVEL. 247 | 248 | The implementations should always return THIS.") 249 | 250 | ;; (lgr-get-threshold :: (function (mixed) int)) 251 | (cl-defgeneric lgr-get-threshold (this) 252 | "Get threshold for THIS.") 253 | 254 | (defclass lgr-appender () 255 | ((threshold 256 | :type integer 257 | :initarg :threshold 258 | :initform (progn lgr-level-trace) 259 | :accessor lgr-get-threshold) 260 | (layout 261 | :type lgr-layout 262 | :initarg :layout 263 | :initform (progn (lgr-layout-format :format "[%t] (%L) %g - %m %f")) 264 | :accessor lgr-get-layout)) 265 | "Appender manages the output of events to proper destinations. 266 | 267 | Destination can be the terminal, a file, an external service, en 268 | Elisp function or anything else in general. 269 | 270 | Appenders only handle the *destination* where the event is 271 | output. 272 | 273 | Appenders can have thresholds configured independently of 274 | loggers. For example, one logger can have one file appenders 275 | logging everything and one email appender for errors only. This 276 | way, all events can be logged to the file but only error and 277 | above will be emailed to a SRE personnel. 278 | 279 | To change the way events are formatted, change the layout for 280 | this appender with `lgr-set-layout'. See `lgr-layout'.") 281 | 282 | ;; (lgr-set-layout :: (function ((class lgr-appender) (class lgr-layout)) (class lgr-appender))) 283 | (cl-defgeneric lgr-set-layout (this layout) 284 | "Set the LAYOUT for THIS appender.") 285 | 286 | ;; (lgr-append :: (function ((class lgr-appender) (class lgr-event)) (class lgr-appender))) 287 | (cl-defgeneric lgr-append (this event) 288 | "Append EVENT to THIS appender's output.") 289 | 290 | (cl-defmethod lgr-to-string ((_this lgr-appender)) 291 | "Format THIS appender as string." 292 | "Message") 293 | 294 | (cl-defmethod lgr-set-threshold ((this lgr-appender) level) 295 | "Set threshold for THIS appender to LEVEL." 296 | (oset this threshold level) 297 | this) 298 | 299 | (cl-defmethod lgr-set-layout ((this lgr-appender) (layout lgr-layout)) 300 | "Set layout for THIS appender to LAYOUT." 301 | (oset this layout layout) 302 | this) 303 | 304 | (cl-defmethod lgr-append ((this lgr-appender) (event lgr-event)) 305 | "Print the EVENT to minibuffer using `message'. 306 | 307 | THIS is an appender." 308 | (message "%s" (lgr-format-event (oref this layout) event)) 309 | this) 310 | 311 | (defclass lgr-appender-princ (lgr-appender) () 312 | "Print events to standard output using `princ'.") 313 | 314 | (cl-defmethod lgr-to-string ((_this lgr-appender-princ)) 315 | "Format THIS appender as string." 316 | "Princ") 317 | 318 | (cl-defmethod lgr-append ((this lgr-appender-princ) (event lgr-event)) 319 | "Print the EVENT to standard output using `princ'. 320 | 321 | THIS is an appender." 322 | (princ (lgr-format-event (oref this layout) event)) 323 | (princ "\n") 324 | this) 325 | 326 | (defclass lgr-appender-file (lgr-appender) 327 | ((file 328 | :type string 329 | :initarg :file 330 | :documentation "Destination file.")) 331 | "Log events to a file.") 332 | 333 | (cl-defmethod lgr-to-string ((this lgr-appender-file)) 334 | "Format THIS appender as string." 335 | (format "File %s" (oref this file))) 336 | 337 | (cl-defmethod lgr-append ((this lgr-appender-file) (event lgr-event)) 338 | "Print the EVENT to a file. 339 | 340 | THIS is an appender." 341 | (let ((msg (lgr-format-event (oref this layout) event))) 342 | (with-temp-buffer 343 | (insert msg "\n") 344 | (append-to-file (point-min) (point-max) (oref this file)))) 345 | this) 346 | 347 | (defclass lgr-appender-buffer (lgr-appender) 348 | ((buffer 349 | :type (or string buffer) 350 | :initarg :buffer 351 | :documentation "Destination buffer.")) 352 | "Log events to a buffer.") 353 | 354 | (cl-defmethod lgr-to-string ((this lgr-appender-buffer)) 355 | "Format THIS appender as string." 356 | (format "%S" (get-buffer-create (oref this buffer)))) 357 | 358 | (cl-defmethod lgr-append ((this lgr-appender-buffer) (event lgr-event)) 359 | "Print the EVENT to a buffer. 360 | 361 | THIS is an appender." 362 | (let ((msg (lgr-format-event (oref this layout) event))) 363 | (with-current-buffer (get-buffer-create (oref this buffer)) 364 | (read-only-mode -1) 365 | (goto-char (point-max)) 366 | (insert msg "\n") 367 | (read-only-mode 1))) 368 | this) 369 | 370 | (defclass lgr-appender-journald (lgr-appender) 371 | ((proc 372 | :type (or process null) 373 | :initform nil)) 374 | "Log events to systemd journal. 375 | 376 | This appender maps the lgr log levels to journald levels in the 377 | following way: 378 | 379 | - fatal -> 2 - Critical 380 | - error -> 3 - Error 381 | - warn -> 4 - Warning 382 | - info -> 6 - Informational 383 | - debug -> 7 - Debug 384 | - trace -> 7 - Debug") 385 | 386 | (cl-defmethod lgr-to-string ((_this lgr-appender-journald)) 387 | "Format THIS appender as string." 388 | "Journald") 389 | 390 | (cl-defmethod lgr-append ((this lgr-appender-journald) (event lgr-event)) 391 | "Log EVENT to journald. 392 | 393 | If EVENT's meta contains any of the following, they will be added 394 | to the datagram. 395 | 396 | - :SYSLOG_IDENTIFIER (defaults to \"emacs-lgr\") 397 | - :CODE_FILE 398 | - :CODE_LINE 399 | - :CODE_FUNC 400 | 401 | Documentation for user journal fields are available at 402 | https://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html" 403 | (unless (oref this proc) 404 | (let ((name (generate-new-buffer-name "*lgr-appender-journald*"))) 405 | (oset this proc 406 | (make-network-process :name name 407 | :buffer (get-buffer-create name) 408 | :type 'datagram 409 | :family 'local 410 | :remote "/run/systemd/journal/socket")))) 411 | (let* ((level (oref event level)) 412 | (priority (cond 413 | ((<= level lgr-level-fatal) 2) 414 | ((<= level lgr-level-error) 3) 415 | ((<= level lgr-level-warn) 4) 416 | ((<= level lgr-level-info) 6) 417 | (t 7)))) 418 | (process-send-string 419 | (oref this proc) 420 | (format "PRIORITY=%d 421 | SYSLOG_IDENTIFIER=%s%s%s%s 422 | MESSAGE=%s 423 | " 424 | priority 425 | (or (plist-get (oref event meta) :SYSLOG_IDENTIFIER) 426 | "emacs-lgr") 427 | (if-let ((cf (plist-get (oref event meta) :CODE_FILE))) 428 | (format "CODE_FILE=%s\n" cf) 429 | "") 430 | (if-let ((cl (plist-get (oref event meta) :CODE_LINE))) 431 | (format "CODE_LINE=%s\n" cl) 432 | "") 433 | (if-let ((cf (plist-get (oref event meta) :CODE_FUNC))) 434 | (format "CODE_FUNC=%s\n" cf) 435 | "") 436 | (lgr-format-event (oref this layout) event))))) 437 | 438 | (defclass lgr-appender-warnings (lgr-appender) () 439 | "Append messages using `display-warning'. 440 | 441 | This appender maps the lgr log levels to warning log levels in 442 | the following way: 443 | 444 | - fatal -> :emergency 445 | - error -> :error 446 | - warn -> :warning 447 | - info -> :debug 448 | - debug -> :debug 449 | - trace -> :debug") 450 | 451 | (cl-defmethod lgr-to-string ((_this lgr-appender-warnings)) 452 | "Format THIS appender as string." 453 | "Warnings") 454 | 455 | (cl-defmethod lgr-append ((this lgr-appender-warnings) (event lgr-event)) 456 | "Display the EVENT using `display-warning'. 457 | 458 | THIS is an appender." 459 | (display-warning 460 | (mapcar #'intern (split-string (oref event logger-name) "\\.")) 461 | (lgr-format-event (oref this layout) event) 462 | (let ((level (oref event level))) 463 | (cond 464 | ((<= level lgr-level-fatal) :emergency) 465 | ((<= level lgr-level-error) :error) 466 | ((<= level lgr-level-warn) :warning) 467 | (t :debug))))) 468 | 469 | (defclass lgr-logger () 470 | ((name 471 | :type string 472 | :initarg :name 473 | :documentation "Name of the logger.") 474 | (threshold 475 | :type integer 476 | :initarg :threshold 477 | :documentation "Threshold for this logger.") 478 | (propagate 479 | :type boolean 480 | :initarg :propagate 481 | :initform t 482 | :documentation "If non-nil, propagate events to parent loggers.") 483 | (parent 484 | :type (or lgr-logger null) 485 | :initarg :parent 486 | :initform nil 487 | :documentation "Parent logger.") 488 | (appenders 489 | :type (list-of lgr-appender) 490 | :initform nil 491 | :documentation "List of appenders for this logger.")) 492 | "Logger produces `lgr-event' objects and passes them to appenders.") 493 | 494 | (cl-defmethod lgr-set-threshold ((this lgr-logger) level) 495 | "Set threshold for THIS logger to LEVEL." 496 | (oset this threshold level) 497 | this) 498 | 499 | (cl-defmethod lgr-get-threshold ((this lgr-logger)) 500 | "Get the threshold of THIS logger or first configured parent. 501 | 502 | If this logger has no configured threshold, recursively check the 503 | parents and pick the first one with configured level. 504 | 505 | The root logger which is always present has default level info." 506 | (if (slot-boundp this 'threshold) 507 | (oref this threshold) 508 | (when-let ((parent (oref this parent))) 509 | (lgr-get-threshold parent)))) 510 | 511 | ;; (lgr-set-propagate :: (function ((class lgr-logger) bool) (class lgr-logger))) 512 | (cl-defgeneric lgr-set-propagate (this propagate) 513 | "Set PROPAGATE for THIS." 514 | (oset this propagate propagate) 515 | this) 516 | 517 | ;; (lgr-add-appender :: (function ((class lgr-logger) (class lgr-appender)) (class lgr-logger))) 518 | (cl-defgeneric lgr-add-appender (this appender) 519 | "Add APPENDER to THIS logger." 520 | (oset this appenders 521 | (append (oref this appenders) (list appender))) 522 | this) 523 | 524 | ;; (lgr-remove-appender :: (function ((class lgr-logger) int) (class lgr-logger))) 525 | (cl-defgeneric lgr-remove-appender (this pos) 526 | "Remove appender at POS from THIS logger." 527 | (oset this appenders 528 | (append (seq-take (oref this appenders) (1- pos)) 529 | (seq-drop (oref this appenders) pos))) 530 | this) 531 | 532 | ;; (lgr-reset-appenders :: (function ((class lgr-logger)) (class lgr-logger))) 533 | (cl-defgeneric lgr-reset-appenders (this) 534 | "Remove all appenders from THIS logger." 535 | (oset this appenders nil) 536 | this) 537 | 538 | ;; (lgr-get-appenders :: (function ((class lgr-logger)) (list (class lgr-appender)))) 539 | (cl-defgeneric lgr-get-appenders (this) 540 | "Get all appenders for THIS logger and its parents." 541 | (append (oref this appenders) 542 | (when-let ((parent (oref this parent))) 543 | (when (oref this propagate) 544 | (lgr-get-appenders parent))))) 545 | 546 | (cl-defmethod lgr-log ((this lgr-logger) level message &rest meta) 547 | "Log MESSAGE as-is at LEVEL. 548 | 549 | META arguments are stored as event metadata. 550 | 551 | THIS is a logger." 552 | (when (>= (lgr-get-threshold this) level) 553 | (let ((event (lgr-event :msg message 554 | :level level 555 | :timestamp (current-time) 556 | :logger-name (oref this name) 557 | :meta meta))) 558 | (dolist (app (lgr-get-appenders this)) 559 | (when (>= (lgr-get-threshold app) (oref event level)) 560 | (lgr-append app event)))))) 561 | 562 | (defvar lgr--loggers (let ((ht (make-hash-table :test #'equal))) 563 | (puthash "lgr--root" (lgr-logger :name "lgr--root" :threshold 400) ht) 564 | ht) 565 | "Hash table of configured loggers.") 566 | 567 | ;; (lgr-get-all-loggers :: (function () (list (class lgr-logger)))) 568 | (defun lgr-get-all-loggers () 569 | "Return a list of all configured loggers." 570 | (hash-table-values lgr--loggers)) 571 | 572 | (defun lgr--flat-to-tree (lst &optional depth) 573 | "Convert a flat list LST into a tree. 574 | 575 | LST is a list of items (depth logger) which are converted to a 576 | tree structure." 577 | (setq depth (or depth 0)) 578 | (let ((layer nil) 579 | (block nil)) 580 | (while lst 581 | (push (pop lst) block) 582 | (while (and lst (> (caar lst) depth)) 583 | (push (pop lst) block)) 584 | (push (reverse block) layer) 585 | (setq block nil)) 586 | (mapcar (lambda (l) 587 | (append 588 | (car l) 589 | (reverse (lgr--flat-to-tree (cdr l) (1+ depth))))) 590 | layer))) 591 | 592 | (defun lgr--graphify (tree &optional prefix) 593 | "Convert TREE to a graphical tree. 594 | 595 | PREFIX is the current string prefix for the processed row. 596 | 597 | Return a multi-line string with rendered graph." 598 | (setq prefix (or prefix "")) 599 | (cond 600 | ((consp (car tree)) 601 | (mapcar (lambda (item) (cons prefix (lgr--graphify item prefix))) tree)) 602 | ((null tree) 603 | (cdr tree)) 604 | (t (let ((head (seq-take tree 2)) 605 | (children (nthcdr 2 tree)) 606 | (index 0)) 607 | (append 608 | head 609 | (mapcar 610 | (lambda (node) 611 | (prog1 (cond 612 | ((= index (1- (length children))) 613 | (cons (concat prefix "└─ ") 614 | (lgr--graphify node (concat prefix " ")))) 615 | (t (cons (concat prefix "├─ ") 616 | (lgr--graphify node (concat prefix "│ "))))) 617 | (cl-incf index))) 618 | children)))))) 619 | 620 | (defun lgr--flatten-tree (tree) 621 | "Flatten a TREE by appending all leaf nodes to a list." 622 | (if (atom tree) 623 | (list tree) 624 | (apply #'append (mapcar #'lgr--flatten-tree tree)))) 625 | 626 | (defun lgr--level-to-face (level) 627 | (cond 628 | ((<= level lgr-level-error) 'error) 629 | ((<= level lgr-level-warn) 'warning) 630 | (t 'default))) 631 | 632 | (defun lgr-loggers-format-to-tree () 633 | "Format all loggers as a tree." 634 | (interactive) 635 | (let* ((keys (sort (hash-table-keys lgr--loggers) #'string<)) 636 | (loggers (mapcar 637 | (lambda (key) 638 | (list (if (equal key "lgr--root") 0 639 | (length (split-string key "\\."))) 640 | key)) 641 | keys)) 642 | ;; put the root logger to front 643 | (loggers (sort loggers (lambda (a _b) (= (car a) 0))))) 644 | 645 | (with-current-buffer (get-buffer-create "*lgr loggers*") 646 | (read-only-mode -1) 647 | (erase-buffer) 648 | (insert "lgr logger hierarchy\n") 649 | (insert "====================\n\n") 650 | (insert (propertize "🔇 Loggers without appenders" 'face 'shadow)) 651 | (insert "\n\n") 652 | (insert (mapconcat 653 | (lambda (x) 654 | (concat 655 | (car x) 656 | (let* ((logger (gethash (nth 2 x) lgr--loggers)) 657 | (name (car (last (split-string (oref logger name) "\\.")))) 658 | (level (and (slot-boundp logger 'threshold) 659 | (oref logger threshold))) 660 | (appenders (oref logger appenders)) 661 | (has-appender (lgr-get-appenders logger))) 662 | (format "%s%s%s%s" 663 | (if has-appender "" "🔇 ") 664 | (propertize name 665 | 'font-lock-face (if has-appender 'default 'shadow)) 666 | (if level 667 | (propertize (format " [%s]" (lgr-level-to-name level)) 668 | 'font-lock-face (lgr--level-to-face level)) 669 | "") 670 | (if appenders 671 | (format " > %s" (mapconcat #'lgr-to-string appenders ", ")) 672 | "" 673 | ))))) 674 | (seq-partition 675 | (lgr--flatten-tree 676 | (lgr--graphify 677 | (lgr--flat-to-tree loggers))) 678 | 3) 679 | "\n")) 680 | (read-only-mode 1) 681 | (font-lock-mode 1) 682 | (pop-to-buffer (current-buffer))))) 683 | 684 | (defun lgr-get-logger (name &optional logger-class) 685 | "Return a logger with NAME. 686 | 687 | If no logger with NAME exists, create a new one and return it. 688 | 689 | The NAME is dot-separated hierarchy of loggers. For example, the 690 | name \"foo.bar\" will create a logger named \"bar\" with parent 691 | \"foo\". 692 | 693 | Each logger has automatically a root logger as parent. The root 694 | logger is named \"lgr--root\" and has a threshold of 400. This 695 | logger should not be used directly. 696 | 697 | You should always configure at least one top-level logger for 698 | your package named after your package. This way consumers can 699 | selectively enable or disable logging for your package. 700 | 701 | If LOGGER-CLASS is non-nil, use it to create the logger of that 702 | class." 703 | (setq logger-class (or logger-class 'lgr-logger-format)) 704 | (if-let ((logger (gethash name lgr--loggers))) 705 | logger 706 | (let* ((path (split-string name "\\.")) 707 | (parent (if (= (length path) 1) 708 | (gethash "lgr--root" lgr--loggers) 709 | (lgr-get-logger (string-join (seq-take path (1- (length path))) ".") logger-class))) 710 | (logger (funcall logger-class :name name :parent parent))) 711 | (puthash name logger lgr--loggers) 712 | logger))) 713 | 714 | (defclass lgr-logger-format (lgr-logger) () 715 | "Logger which uses `format' to format messages.") 716 | 717 | ;; (lgr--count-format-sequences :: (function (string) int)) 718 | (defun lgr--count-format-sequences (string) 719 | "Count the number of format sequences in STRING." 720 | (with-temp-buffer 721 | (insert string) 722 | (goto-char (point-min)) 723 | (let ((count 0)) 724 | (while (re-search-forward "%" nil t) 725 | (if (looking-at-p "%") 726 | (forward-char 1) 727 | (cl-incf count))) 728 | count))) 729 | 730 | (cl-defmethod lgr-log ((this lgr-logger-format) level fmt &rest meta) 731 | "Format FMT using `format' drawing values from META. 732 | 733 | LEVEL is the log level, see `lgr-log-levels'. 734 | 735 | FMT is a `format' compatible format string. 736 | 737 | The placeholders in FMT are replaced by arguments from META. Any 738 | leftover arguments are stored on the event as metadata. 739 | 740 | THIS is a logger." 741 | (when (>= (lgr-get-threshold this) level) 742 | (let* ((num-of-format-controls (lgr--count-format-sequences fmt)) 743 | (event (lgr-event :msg (apply #'format fmt (seq-take meta num-of-format-controls)) 744 | :level level 745 | :timestamp (current-time) 746 | :logger-name (oref this name) 747 | :meta (seq-drop meta num-of-format-controls)))) 748 | (dolist (app (lgr-get-appenders this)) 749 | (when (>= (lgr-get-threshold app) (oref event level)) 750 | (lgr-append app event)))))) 751 | 752 | (provide 'lgr) 753 | ;;; lgr.el ends here 754 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 3, 29 June 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU General Public License is a free, copyleft license for 11 | software and other kinds of works. 12 | 13 | The licenses for most software and other practical works are designed 14 | to take away your freedom to share and change the works. By contrast, 15 | the GNU General Public License is intended to guarantee your freedom to 16 | share and change all versions of a program--to make sure it remains free 17 | software for all its users. We, the Free Software Foundation, use the 18 | GNU General Public License for most of our software; it applies also to 19 | any other work released this way by its authors. You can apply it to 20 | your programs, too. 21 | 22 | When we speak of free software, we are referring to freedom, not 23 | price. Our General Public Licenses are designed to make sure that you 24 | have the freedom to distribute copies of free software (and charge for 25 | them if you wish), that you receive source code or can get it if you 26 | want it, that you can change the software or use pieces of it in new 27 | free programs, and that you know you can do these things. 28 | 29 | To protect your rights, we need to prevent others from denying you 30 | these rights or asking you to surrender the rights. Therefore, you have 31 | certain responsibilities if you distribute copies of the software, or if 32 | you modify it: responsibilities to respect the freedom of others. 33 | 34 | For example, if you distribute copies of such a program, whether 35 | gratis or for a fee, you must pass on to the recipients the same 36 | freedoms that you received. You must make sure that they, too, receive 37 | or can get the source code. And you must show them these terms so they 38 | know their rights. 39 | 40 | Developers that use the GNU GPL protect your rights with two steps: 41 | (1) assert copyright on the software, and (2) offer you this License 42 | giving you legal permission to copy, distribute and/or modify it. 43 | 44 | For the developers' and authors' protection, the GPL clearly explains 45 | that there is no warranty for this free software. For both users' and 46 | authors' sake, the GPL requires that modified versions be marked as 47 | changed, so that their problems will not be attributed erroneously to 48 | authors of previous versions. 49 | 50 | Some devices are designed to deny users access to install or run 51 | modified versions of the software inside them, although the manufacturer 52 | can do so. This is fundamentally incompatible with the aim of 53 | protecting users' freedom to change the software. The systematic 54 | pattern of such abuse occurs in the area of products for individuals to 55 | use, which is precisely where it is most unacceptable. Therefore, we 56 | have designed this version of the GPL to prohibit the practice for those 57 | products. If such problems arise substantially in other domains, we 58 | stand ready to extend this provision to those domains in future versions 59 | of the GPL, as needed to protect the freedom of users. 60 | 61 | Finally, every program is threatened constantly by software patents. 62 | States should not allow patents to restrict development and use of 63 | software on general-purpose computers, but in those that do, we wish to 64 | avoid the special danger that patents applied to a free program could 65 | make it effectively proprietary. To prevent this, the GPL assures that 66 | patents cannot be used to render the program non-free. 67 | 68 | The precise terms and conditions for copying, distribution and 69 | modification follow. 70 | 71 | TERMS AND CONDITIONS 72 | 73 | 0. Definitions. 74 | 75 | "This License" refers to version 3 of the GNU General Public License. 76 | 77 | "Copyright" also means copyright-like laws that apply to other kinds of 78 | works, such as semiconductor masks. 79 | 80 | "The Program" refers to any copyrightable work licensed under this 81 | License. Each licensee is addressed as "you". "Licensees" and 82 | "recipients" may be individuals or organizations. 83 | 84 | To "modify" a work means to copy from or adapt all or part of the work 85 | in a fashion requiring copyright permission, other than the making of an 86 | exact copy. The resulting work is called a "modified version" of the 87 | earlier work or a work "based on" the earlier work. 88 | 89 | A "covered work" means either the unmodified Program or a work based 90 | on the Program. 91 | 92 | To "propagate" a work means to do anything with it that, without 93 | permission, would make you directly or secondarily liable for 94 | infringement under applicable copyright law, except executing it on a 95 | computer or modifying a private copy. Propagation includes copying, 96 | distribution (with or without modification), making available to the 97 | public, and in some countries other activities as well. 98 | 99 | To "convey" a work means any kind of propagation that enables other 100 | parties to make or receive copies. Mere interaction with a user through 101 | a computer network, with no transfer of a copy, is not conveying. 102 | 103 | An interactive user interface displays "Appropriate Legal Notices" 104 | to the extent that it includes a convenient and prominently visible 105 | feature that (1) displays an appropriate copyright notice, and (2) 106 | tells the user that there is no warranty for the work (except to the 107 | extent that warranties are provided), that licensees may convey the 108 | work under this License, and how to view a copy of this License. If 109 | the interface presents a list of user commands or options, such as a 110 | menu, a prominent item in the list meets this criterion. 111 | 112 | 1. Source Code. 113 | 114 | The "source code" for a work means the preferred form of the work 115 | for making modifications to it. "Object code" means any non-source 116 | form of a work. 117 | 118 | A "Standard Interface" means an interface that either is an official 119 | standard defined by a recognized standards body, or, in the case of 120 | interfaces specified for a particular programming language, one that 121 | is widely used among developers working in that language. 122 | 123 | The "System Libraries" of an executable work include anything, other 124 | than the work as a whole, that (a) is included in the normal form of 125 | packaging a Major Component, but which is not part of that Major 126 | Component, and (b) serves only to enable use of the work with that 127 | Major Component, or to implement a Standard Interface for which an 128 | implementation is available to the public in source code form. A 129 | "Major Component", in this context, means a major essential component 130 | (kernel, window system, and so on) of the specific operating system 131 | (if any) on which the executable work runs, or a compiler used to 132 | produce the work, or an object code interpreter used to run it. 133 | 134 | The "Corresponding Source" for a work in object code form means all 135 | the source code needed to generate, install, and (for an executable 136 | work) run the object code and to modify the work, including scripts to 137 | control those activities. However, it does not include the work's 138 | System Libraries, or general-purpose tools or generally available free 139 | programs which are used unmodified in performing those activities but 140 | which are not part of the work. For example, Corresponding Source 141 | includes interface definition files associated with source files for 142 | the work, and the source code for shared libraries and dynamically 143 | linked subprograms that the work is specifically designed to require, 144 | such as by intimate data communication or control flow between those 145 | subprograms and other parts of the work. 146 | 147 | The Corresponding Source need not include anything that users 148 | can regenerate automatically from other parts of the Corresponding 149 | Source. 150 | 151 | The Corresponding Source for a work in source code form is that 152 | same work. 153 | 154 | 2. Basic Permissions. 155 | 156 | All rights granted under this License are granted for the term of 157 | copyright on the Program, and are irrevocable provided the stated 158 | conditions are met. This License explicitly affirms your unlimited 159 | permission to run the unmodified Program. The output from running a 160 | covered work is covered by this License only if the output, given its 161 | content, constitutes a covered work. This License acknowledges your 162 | rights of fair use or other equivalent, as provided by copyright law. 163 | 164 | You may make, run and propagate covered works that you do not 165 | convey, without conditions so long as your license otherwise remains 166 | in force. You may convey covered works to others for the sole purpose 167 | of having them make modifications exclusively for you, or provide you 168 | with facilities for running those works, provided that you comply with 169 | the terms of this License in conveying all material for which you do 170 | not control copyright. Those thus making or running the covered works 171 | for you must do so exclusively on your behalf, under your direction 172 | and control, on terms that prohibit them from making any copies of 173 | your copyrighted material outside their relationship with you. 174 | 175 | Conveying under any other circumstances is permitted solely under 176 | the conditions stated below. Sublicensing is not allowed; section 10 177 | makes it unnecessary. 178 | 179 | 3. Protecting Users' Legal Rights From Anti-Circumvention Law. 180 | 181 | No covered work shall be deemed part of an effective technological 182 | measure under any applicable law fulfilling obligations under article 183 | 11 of the WIPO copyright treaty adopted on 20 December 1996, or 184 | similar laws prohibiting or restricting circumvention of such 185 | measures. 186 | 187 | When you convey a covered work, you waive any legal power to forbid 188 | circumvention of technological measures to the extent such circumvention 189 | is effected by exercising rights under this License with respect to 190 | the covered work, and you disclaim any intention to limit operation or 191 | modification of the work as a means of enforcing, against the work's 192 | users, your or third parties' legal rights to forbid circumvention of 193 | technological measures. 194 | 195 | 4. Conveying Verbatim Copies. 196 | 197 | You may convey verbatim copies of the Program's source code as you 198 | receive it, in any medium, provided that you conspicuously and 199 | appropriately publish on each copy an appropriate copyright notice; 200 | keep intact all notices stating that this License and any 201 | non-permissive terms added in accord with section 7 apply to the code; 202 | keep intact all notices of the absence of any warranty; and give all 203 | recipients a copy of this License along with the Program. 204 | 205 | You may charge any price or no price for each copy that you convey, 206 | and you may offer support or warranty protection for a fee. 207 | 208 | 5. Conveying Modified Source Versions. 209 | 210 | You may convey a work based on the Program, or the modifications to 211 | produce it from the Program, in the form of source code under the 212 | terms of section 4, provided that you also meet all of these conditions: 213 | 214 | a) The work must carry prominent notices stating that you modified 215 | it, and giving a relevant date. 216 | 217 | b) The work must carry prominent notices stating that it is 218 | released under this License and any conditions added under section 219 | 7. This requirement modifies the requirement in section 4 to 220 | "keep intact all notices". 221 | 222 | c) You must license the entire work, as a whole, under this 223 | License to anyone who comes into possession of a copy. This 224 | License will therefore apply, along with any applicable section 7 225 | additional terms, to the whole of the work, and all its parts, 226 | regardless of how they are packaged. This License gives no 227 | permission to license the work in any other way, but it does not 228 | invalidate such permission if you have separately received it. 229 | 230 | d) If the work has interactive user interfaces, each must display 231 | Appropriate Legal Notices; however, if the Program has interactive 232 | interfaces that do not display Appropriate Legal Notices, your 233 | work need not make them do so. 234 | 235 | A compilation of a covered work with other separate and independent 236 | works, which are not by their nature extensions of the covered work, 237 | and which are not combined with it such as to form a larger program, 238 | in or on a volume of a storage or distribution medium, is called an 239 | "aggregate" if the compilation and its resulting copyright are not 240 | used to limit the access or legal rights of the compilation's users 241 | beyond what the individual works permit. Inclusion of a covered work 242 | in an aggregate does not cause this License to apply to the other 243 | parts of the aggregate. 244 | 245 | 6. Conveying Non-Source Forms. 246 | 247 | You may convey a covered work in object code form under the terms 248 | of sections 4 and 5, provided that you also convey the 249 | machine-readable Corresponding Source under the terms of this License, 250 | in one of these ways: 251 | 252 | a) Convey the object code in, or embodied in, a physical product 253 | (including a physical distribution medium), accompanied by the 254 | Corresponding Source fixed on a durable physical medium 255 | customarily used for software interchange. 256 | 257 | b) Convey the object code in, or embodied in, a physical product 258 | (including a physical distribution medium), accompanied by a 259 | written offer, valid for at least three years and valid for as 260 | long as you offer spare parts or customer support for that product 261 | model, to give anyone who possesses the object code either (1) a 262 | copy of the Corresponding Source for all the software in the 263 | product that is covered by this License, on a durable physical 264 | medium customarily used for software interchange, for a price no 265 | more than your reasonable cost of physically performing this 266 | conveying of source, or (2) access to copy the 267 | Corresponding Source from a network server at no charge. 268 | 269 | c) Convey individual copies of the object code with a copy of the 270 | written offer to provide the Corresponding Source. This 271 | alternative is allowed only occasionally and noncommercially, and 272 | only if you received the object code with such an offer, in accord 273 | with subsection 6b. 274 | 275 | d) Convey the object code by offering access from a designated 276 | place (gratis or for a charge), and offer equivalent access to the 277 | Corresponding Source in the same way through the same place at no 278 | further charge. You need not require recipients to copy the 279 | Corresponding Source along with the object code. If the place to 280 | copy the object code is a network server, the Corresponding Source 281 | may be on a different server (operated by you or a third party) 282 | that supports equivalent copying facilities, provided you maintain 283 | clear directions next to the object code saying where to find the 284 | Corresponding Source. Regardless of what server hosts the 285 | Corresponding Source, you remain obligated to ensure that it is 286 | available for as long as needed to satisfy these requirements. 287 | 288 | e) Convey the object code using peer-to-peer transmission, provided 289 | you inform other peers where the object code and Corresponding 290 | Source of the work are being offered to the general public at no 291 | charge under subsection 6d. 292 | 293 | A separable portion of the object code, whose source code is excluded 294 | from the Corresponding Source as a System Library, need not be 295 | included in conveying the object code work. 296 | 297 | A "User Product" is either (1) a "consumer product", which means any 298 | tangible personal property which is normally used for personal, family, 299 | or household purposes, or (2) anything designed or sold for incorporation 300 | into a dwelling. In determining whether a product is a consumer product, 301 | doubtful cases shall be resolved in favor of coverage. For a particular 302 | product received by a particular user, "normally used" refers to a 303 | typical or common use of that class of product, regardless of the status 304 | of the particular user or of the way in which the particular user 305 | actually uses, or expects or is expected to use, the product. A product 306 | is a consumer product regardless of whether the product has substantial 307 | commercial, industrial or non-consumer uses, unless such uses represent 308 | the only significant mode of use of the product. 309 | 310 | "Installation Information" for a User Product means any methods, 311 | procedures, authorization keys, or other information required to install 312 | and execute modified versions of a covered work in that User Product from 313 | a modified version of its Corresponding Source. The information must 314 | suffice to ensure that the continued functioning of the modified object 315 | code is in no case prevented or interfered with solely because 316 | modification has been made. 317 | 318 | If you convey an object code work under this section in, or with, or 319 | specifically for use in, a User Product, and the conveying occurs as 320 | part of a transaction in which the right of possession and use of the 321 | User Product is transferred to the recipient in perpetuity or for a 322 | fixed term (regardless of how the transaction is characterized), the 323 | Corresponding Source conveyed under this section must be accompanied 324 | by the Installation Information. But this requirement does not apply 325 | if neither you nor any third party retains the ability to install 326 | modified object code on the User Product (for example, the work has 327 | been installed in ROM). 328 | 329 | The requirement to provide Installation Information does not include a 330 | requirement to continue to provide support service, warranty, or updates 331 | for a work that has been modified or installed by the recipient, or for 332 | the User Product in which it has been modified or installed. Access to a 333 | network may be denied when the modification itself materially and 334 | adversely affects the operation of the network or violates the rules and 335 | protocols for communication across the network. 336 | 337 | Corresponding Source conveyed, and Installation Information provided, 338 | in accord with this section must be in a format that is publicly 339 | documented (and with an implementation available to the public in 340 | source code form), and must require no special password or key for 341 | unpacking, reading or copying. 342 | 343 | 7. Additional Terms. 344 | 345 | "Additional permissions" are terms that supplement the terms of this 346 | License by making exceptions from one or more of its conditions. 347 | Additional permissions that are applicable to the entire Program shall 348 | be treated as though they were included in this License, to the extent 349 | that they are valid under applicable law. If additional permissions 350 | apply only to part of the Program, that part may be used separately 351 | under those permissions, but the entire Program remains governed by 352 | this License without regard to the additional permissions. 353 | 354 | When you convey a copy of a covered work, you may at your option 355 | remove any additional permissions from that copy, or from any part of 356 | it. (Additional permissions may be written to require their own 357 | removal in certain cases when you modify the work.) You may place 358 | additional permissions on material, added by you to a covered work, 359 | for which you have or can give appropriate copyright permission. 360 | 361 | Notwithstanding any other provision of this License, for material you 362 | add to a covered work, you may (if authorized by the copyright holders of 363 | that material) supplement the terms of this License with terms: 364 | 365 | a) Disclaiming warranty or limiting liability differently from the 366 | terms of sections 15 and 16 of this License; or 367 | 368 | b) Requiring preservation of specified reasonable legal notices or 369 | author attributions in that material or in the Appropriate Legal 370 | Notices displayed by works containing it; or 371 | 372 | c) Prohibiting misrepresentation of the origin of that material, or 373 | requiring that modified versions of such material be marked in 374 | reasonable ways as different from the original version; or 375 | 376 | d) Limiting the use for publicity purposes of names of licensors or 377 | authors of the material; or 378 | 379 | e) Declining to grant rights under trademark law for use of some 380 | trade names, trademarks, or service marks; or 381 | 382 | f) Requiring indemnification of licensors and authors of that 383 | material by anyone who conveys the material (or modified versions of 384 | it) with contractual assumptions of liability to the recipient, for 385 | any liability that these contractual assumptions directly impose on 386 | those licensors and authors. 387 | 388 | All other non-permissive additional terms are considered "further 389 | restrictions" within the meaning of section 10. If the Program as you 390 | received it, or any part of it, contains a notice stating that it is 391 | governed by this License along with a term that is a further 392 | restriction, you may remove that term. If a license document contains 393 | a further restriction but permits relicensing or conveying under this 394 | License, you may add to a covered work material governed by the terms 395 | of that license document, provided that the further restriction does 396 | not survive such relicensing or conveying. 397 | 398 | If you add terms to a covered work in accord with this section, you 399 | must place, in the relevant source files, a statement of the 400 | additional terms that apply to those files, or a notice indicating 401 | where to find the applicable terms. 402 | 403 | Additional terms, permissive or non-permissive, may be stated in the 404 | form of a separately written license, or stated as exceptions; 405 | the above requirements apply either way. 406 | 407 | 8. Termination. 408 | 409 | You may not propagate or modify a covered work except as expressly 410 | provided under this License. Any attempt otherwise to propagate or 411 | modify it is void, and will automatically terminate your rights under 412 | this License (including any patent licenses granted under the third 413 | paragraph of section 11). 414 | 415 | However, if you cease all violation of this License, then your 416 | license from a particular copyright holder is reinstated (a) 417 | provisionally, unless and until the copyright holder explicitly and 418 | finally terminates your license, and (b) permanently, if the copyright 419 | holder fails to notify you of the violation by some reasonable means 420 | prior to 60 days after the cessation. 421 | 422 | Moreover, your license from a particular copyright holder is 423 | reinstated permanently if the copyright holder notifies you of the 424 | violation by some reasonable means, this is the first time you have 425 | received notice of violation of this License (for any work) from that 426 | copyright holder, and you cure the violation prior to 30 days after 427 | your receipt of the notice. 428 | 429 | Termination of your rights under this section does not terminate the 430 | licenses of parties who have received copies or rights from you under 431 | this License. If your rights have been terminated and not permanently 432 | reinstated, you do not qualify to receive new licenses for the same 433 | material under section 10. 434 | 435 | 9. Acceptance Not Required for Having Copies. 436 | 437 | You are not required to accept this License in order to receive or 438 | run a copy of the Program. Ancillary propagation of a covered work 439 | occurring solely as a consequence of using peer-to-peer transmission 440 | to receive a copy likewise does not require acceptance. However, 441 | nothing other than this License grants you permission to propagate or 442 | modify any covered work. These actions infringe copyright if you do 443 | not accept this License. Therefore, by modifying or propagating a 444 | covered work, you indicate your acceptance of this License to do so. 445 | 446 | 10. Automatic Licensing of Downstream Recipients. 447 | 448 | Each time you convey a covered work, the recipient automatically 449 | receives a license from the original licensors, to run, modify and 450 | propagate that work, subject to this License. You are not responsible 451 | for enforcing compliance by third parties with this License. 452 | 453 | An "entity transaction" is a transaction transferring control of an 454 | organization, or substantially all assets of one, or subdividing an 455 | organization, or merging organizations. If propagation of a covered 456 | work results from an entity transaction, each party to that 457 | transaction who receives a copy of the work also receives whatever 458 | licenses to the work the party's predecessor in interest had or could 459 | give under the previous paragraph, plus a right to possession of the 460 | Corresponding Source of the work from the predecessor in interest, if 461 | the predecessor has it or can get it with reasonable efforts. 462 | 463 | You may not impose any further restrictions on the exercise of the 464 | rights granted or affirmed under this License. For example, you may 465 | not impose a license fee, royalty, or other charge for exercise of 466 | rights granted under this License, and you may not initiate litigation 467 | (including a cross-claim or counterclaim in a lawsuit) alleging that 468 | any patent claim is infringed by making, using, selling, offering for 469 | sale, or importing the Program or any portion of it. 470 | 471 | 11. Patents. 472 | 473 | A "contributor" is a copyright holder who authorizes use under this 474 | License of the Program or a work on which the Program is based. The 475 | work thus licensed is called the contributor's "contributor version". 476 | 477 | A contributor's "essential patent claims" are all patent claims 478 | owned or controlled by the contributor, whether already acquired or 479 | hereafter acquired, that would be infringed by some manner, permitted 480 | by this License, of making, using, or selling its contributor version, 481 | but do not include claims that would be infringed only as a 482 | consequence of further modification of the contributor version. For 483 | purposes of this definition, "control" includes the right to grant 484 | patent sublicenses in a manner consistent with the requirements of 485 | this License. 486 | 487 | Each contributor grants you a non-exclusive, worldwide, royalty-free 488 | patent license under the contributor's essential patent claims, to 489 | make, use, sell, offer for sale, import and otherwise run, modify and 490 | propagate the contents of its contributor version. 491 | 492 | In the following three paragraphs, a "patent license" is any express 493 | agreement or commitment, however denominated, not to enforce a patent 494 | (such as an express permission to practice a patent or covenant not to 495 | sue for patent infringement). To "grant" such a patent license to a 496 | party means to make such an agreement or commitment not to enforce a 497 | patent against the party. 498 | 499 | If you convey a covered work, knowingly relying on a patent license, 500 | and the Corresponding Source of the work is not available for anyone 501 | to copy, free of charge and under the terms of this License, through a 502 | publicly available network server or other readily accessible means, 503 | then you must either (1) cause the Corresponding Source to be so 504 | available, or (2) arrange to deprive yourself of the benefit of the 505 | patent license for this particular work, or (3) arrange, in a manner 506 | consistent with the requirements of this License, to extend the patent 507 | license to downstream recipients. "Knowingly relying" means you have 508 | actual knowledge that, but for the patent license, your conveying the 509 | covered work in a country, or your recipient's use of the covered work 510 | in a country, would infringe one or more identifiable patents in that 511 | country that you have reason to believe are valid. 512 | 513 | If, pursuant to or in connection with a single transaction or 514 | arrangement, you convey, or propagate by procuring conveyance of, a 515 | covered work, and grant a patent license to some of the parties 516 | receiving the covered work authorizing them to use, propagate, modify 517 | or convey a specific copy of the covered work, then the patent license 518 | you grant is automatically extended to all recipients of the covered 519 | work and works based on it. 520 | 521 | A patent license is "discriminatory" if it does not include within 522 | the scope of its coverage, prohibits the exercise of, or is 523 | conditioned on the non-exercise of one or more of the rights that are 524 | specifically granted under this License. You may not convey a covered 525 | work if you are a party to an arrangement with a third party that is 526 | in the business of distributing software, under which you make payment 527 | to the third party based on the extent of your activity of conveying 528 | the work, and under which the third party grants, to any of the 529 | parties who would receive the covered work from you, a discriminatory 530 | patent license (a) in connection with copies of the covered work 531 | conveyed by you (or copies made from those copies), or (b) primarily 532 | for and in connection with specific products or compilations that 533 | contain the covered work, unless you entered into that arrangement, 534 | or that patent license was granted, prior to 28 March 2007. 535 | 536 | Nothing in this License shall be construed as excluding or limiting 537 | any implied license or other defenses to infringement that may 538 | otherwise be available to you under applicable patent law. 539 | 540 | 12. No Surrender of Others' Freedom. 541 | 542 | If conditions are imposed on you (whether by court order, agreement or 543 | otherwise) that contradict the conditions of this License, they do not 544 | excuse you from the conditions of this License. If you cannot convey a 545 | covered work so as to satisfy simultaneously your obligations under this 546 | License and any other pertinent obligations, then as a consequence you may 547 | not convey it at all. For example, if you agree to terms that obligate you 548 | to collect a royalty for further conveying from those to whom you convey 549 | the Program, the only way you could satisfy both those terms and this 550 | License would be to refrain entirely from conveying the Program. 551 | 552 | 13. Use with the GNU Affero General Public License. 553 | 554 | Notwithstanding any other provision of this License, you have 555 | permission to link or combine any covered work with a work licensed 556 | under version 3 of the GNU Affero General Public License into a single 557 | combined work, and to convey the resulting work. The terms of this 558 | License will continue to apply to the part which is the covered work, 559 | but the special requirements of the GNU Affero General Public License, 560 | section 13, concerning interaction through a network will apply to the 561 | combination as such. 562 | 563 | 14. Revised Versions of this License. 564 | 565 | The Free Software Foundation may publish revised and/or new versions of 566 | the GNU General Public License from time to time. Such new versions will 567 | be similar in spirit to the present version, but may differ in detail to 568 | address new problems or concerns. 569 | 570 | Each version is given a distinguishing version number. If the 571 | Program specifies that a certain numbered version of the GNU General 572 | Public License "or any later version" applies to it, you have the 573 | option of following the terms and conditions either of that numbered 574 | version or of any later version published by the Free Software 575 | Foundation. If the Program does not specify a version number of the 576 | GNU General Public License, you may choose any version ever published 577 | by the Free Software Foundation. 578 | 579 | If the Program specifies that a proxy can decide which future 580 | versions of the GNU General Public License can be used, that proxy's 581 | public statement of acceptance of a version permanently authorizes you 582 | to choose that version for the Program. 583 | 584 | Later license versions may give you additional or different 585 | permissions. However, no additional obligations are imposed on any 586 | author or copyright holder as a result of your choosing to follow a 587 | later version. 588 | 589 | 15. Disclaimer of Warranty. 590 | 591 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 592 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 596 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 597 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 599 | 600 | 16. Limitation of Liability. 601 | 602 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 610 | SUCH DAMAGES. 611 | 612 | 17. Interpretation of Sections 15 and 16. 613 | 614 | If the disclaimer of warranty and limitation of liability provided 615 | above cannot be given local legal effect according to their terms, 616 | reviewing courts shall apply local law that most closely approximates 617 | an absolute waiver of all civil liability in connection with the 618 | Program, unless a warranty or assumption of liability accompanies a 619 | copy of the Program in return for a fee. 620 | 621 | END OF TERMS AND CONDITIONS 622 | 623 | How to Apply These Terms to Your New Programs 624 | 625 | If you develop a new program, and you want it to be of the greatest 626 | possible use to the public, the best way to achieve this is to make it 627 | free software which everyone can redistribute and change under these terms. 628 | 629 | To do so, attach the following notices to the program. It is safest 630 | to attach them to the start of each source file to most effectively 631 | state the exclusion of warranty; and each file should have at least 632 | the "copyright" line and a pointer to where the full notice is found. 633 | 634 | 635 | Copyright (C) 636 | 637 | This program is free software: you can redistribute it and/or modify 638 | it under the terms of the GNU General Public License as published by 639 | the Free Software Foundation, either version 3 of the License, or 640 | (at your option) any later version. 641 | 642 | This program is distributed in the hope that it will be useful, 643 | but WITHOUT ANY WARRANTY; without even the implied warranty of 644 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 645 | GNU General Public License for more details. 646 | 647 | You should have received a copy of the GNU General Public License 648 | along with this program. If not, see . 649 | 650 | Also add information on how to contact you by electronic and paper mail. 651 | 652 | If the program does terminal interaction, make it output a short 653 | notice like this when it starts in an interactive mode: 654 | 655 | Copyright (C) 656 | This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 657 | This is free software, and you are welcome to redistribute it 658 | under certain conditions; type `show c' for details. 659 | 660 | The hypothetical commands `show w' and `show c' should show the appropriate 661 | parts of the General Public License. Of course, your program's commands 662 | might be different; for a GUI interface, you would use an "about box". 663 | 664 | You should also get your employer (if you work as a programmer) or school, 665 | if any, to sign a "copyright disclaimer" for the program, if necessary. 666 | For more information on this, and how to apply and follow the GNU GPL, see 667 | . 668 | 669 | The GNU General Public License does not permit incorporating your program 670 | into proprietary programs. If your program is a subroutine library, you 671 | may consider it more useful to permit linking proprietary applications with 672 | the library. If this is what you want to do, use the GNU Lesser General 673 | Public License instead of this License. But first, please read 674 | . 675 | --------------------------------------------------------------------------------