├── .gitmodules
├── .travis.yml
├── README.md
├── bin
└── wasm-meter
├── defaultCostTable.json
├── demo
├── index.js
├── package-lock.json
└── package.json
├── example
├── fac.wasm
├── fac.wast
└── index.js
├── index.js
├── package-lock.json
├── package.json
└── test
├── buildTests.js
├── defaultCostTable.json
├── expected-out
├── initCosts.json
├── json
│ ├── basic+import.wast.json
│ ├── basic.wast.json
│ ├── element.wast.json
│ ├── fac.wast.json
│ ├── memory0.wast.json
│ ├── memory1.wast.json
│ ├── memory2.wast.json
│ ├── mixedImports.wast.json
│ ├── start.wast.json
│ ├── stuff.wast.json
│ └── zeroCostOps.wast.json
└── wast
│ ├── basic+import.wast
│ ├── basic.wast
│ ├── element.wast
│ ├── fac.wast
│ ├── memory0.wast
│ ├── memory1.wast
│ ├── memory2.wast
│ ├── mixedImports.wast
│ ├── start.wast
│ ├── stuff.wast
│ └── zeroCostOps.wast
├── in
├── costTables
│ ├── memory0.wast.json.js
│ ├── memory1.wast.json.js
│ ├── memory2.wast.json.js
│ └── zeroCostOps.wast.json.js
├── json
│ ├── basic+import.wast.json
│ ├── basic.wast.json
│ ├── element.wast.json
│ ├── fac.wast.json
│ ├── memory0.wast.json
│ ├── memory1.wast.json
│ ├── memory2.wast.json
│ ├── mixedImports.wast.json
│ ├── start.wast.json
│ ├── stuff.wast.json
│ └── zeroCostOps.wast.json
└── wast
│ ├── basic+import.wast
│ ├── basic.wast
│ ├── element.wast
│ ├── fac.wast
│ ├── memory0.wast
│ ├── memory1.wast
│ ├── memory2.wast
│ ├── mixedImports.wast
│ ├── start.wast
│ ├── stuff.wast
│ └── zeroCostOps.wast
└── index.js
/.gitmodules:
--------------------------------------------------------------------------------
1 | [submodule "test/wabt"]
2 | path = test/wabt
3 | url = https://github.com/WebAssembly/wabt.git
4 |
--------------------------------------------------------------------------------
/.travis.yml:
--------------------------------------------------------------------------------
1 | language: node_js
2 | node_js:
3 | - "9"
4 | env:
5 | matrix:
6 | - TEST_SUITE=test
7 | matrix:
8 | fast_finish: true
9 | include:
10 | - os: linux
11 | node_js: "9"
12 | env: TEST_SUITE=coveralls
13 | - os: linux
14 | node_js: "9"
15 | env: TEST_SUITE=lint
16 | script: npm run $TEST_SUITE
17 |
--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
1 | # SYNOPSIS
2 |
3 | [](https://www.npmjs.org/package/wasm-metering)
4 | [](https://travis-ci.org/ewasm/wasm-metering)
5 | [](https://coveralls.io/r/ewasm/wasm-metering)
6 |
7 | [](https://github.com/feross/standard)
8 |
9 | Injects metering into webassembly binaries. The metering counts computation
10 | time for a given program in units of `gas`. The metered wasm binary expects an
11 | import that functions as the gas counter. This works for binary version 0x1.
12 | For a more detailed description of how this works see [metering.md](https://github.com/ewasm/design/blob/master/metering.md)
13 |
14 | # INSTALL
15 | `npm install wasm-metering`
16 |
17 | # USAGE
18 | ```javascript
19 | const fs = require('fs')
20 | const metering = require('wasm-metering')
21 |
22 | const wasm = fs.readFileSync('fac.wasm')
23 | const meteredWasm = metering.meterWASM(wasm, {
24 | meterType: 'i32'
25 | })
26 |
27 | const limit = 90000000
28 | let gasUsed = 0
29 |
30 | const mod = WebAssembly.Module(meteredWasm.module)
31 | const instance = WebAssembly.Instance(mod, {
32 | 'metering': {
33 | 'usegas': (gas) => {
34 | gasUsed += gas
35 | if (gasUsed > limit) {
36 | throw new Error('out of gas!')
37 | }
38 | }
39 | }
40 | })
41 |
42 | const result = instance.exports.fac(6)
43 | console.log(`result:${result}, gas used ${gasUsed * 1e-4}`) // result:720, gas used 0.4177
44 | ```
45 | [Source](./example/index.js)
46 |
47 | # API
48 | ## meterJSON
49 |
50 | [./index.js:104-224](https://github.com/ewasm/wasm-metering/blob/5ab76de89bc07d0abfaa6d0c776c204a752a0d9d/./index.js#L104-L224 "Source code on GitHub")
51 |
52 | Injects metering into a JSON output of [wasm2json](https://github.com/ewasm/wasm-json-toolkit#wasm2json)
53 |
54 | **Parameters**
55 |
56 | - `json` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** the json tobe metered
57 | - `opts` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)**
58 | - `opts.costTable` **\[[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)]** the cost table to meter with. See these notes about the default. (optional, default `defaultTable`)
59 | - `opts.moduleStr` **\[[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** the import string for the metering function (optional, default `'metering'`)
60 | - `opts.fieldStr` **\[[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** the field string for the metering function (optional, default `'usegas'`)
61 | - `opts.meterType` **\[[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** the register type that is used to meter. Can be `i64`, `i32`, `f64`, `f32` (optional, default `'i64'`)
62 |
63 | Returns **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** the metered json
64 |
65 | ## meterWASM
66 |
67 | [./index.js:236-240](https://github.com/ewasm/wasm-metering/blob/5ab76de89bc07d0abfaa6d0c776c204a752a0d9d/./index.js#L236-L240 "Source code on GitHub")
68 |
69 | Injects metering into a webassembly binary
70 |
71 | **Parameters**
72 |
73 | - `json` **[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)** the json tobe metered
74 | - `opts` **\[[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)](default {})**
75 | - `opts.costTable` **\[[Object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)]** the cost table to meter with. See these notes about the default. (optional, default `defaultTable`)
76 | - `opts.moduleStr` **\[[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** the import string for the metering function (optional, default `'metering'`)
77 | - `opts.fieldStr` **\[[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** the field string for the metering function (optional, default `'usegas'`)
78 | - `opts.meterType` **\[[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)]** the register type that is used to meter. Can be `i64`, `i32`, `f64`, `f32` (optional, default `'i64'`)
79 | - `wasm`
80 |
81 | Returns **[Buffer](https://nodejs.org/api/buffer.html)**
82 |
83 | ## costTable
84 |
85 | The costTable option defines the cost of each of the operations.
86 | Cost Tables consist of an object whose keys are sections in a wasm binary.
87 | For example
88 | ```
89 | module.exports = {
90 | 'start': 1,
91 | 'type': {
92 | 'params': {
93 | 'DEFAULT': 1
94 | },
95 | 'return_type': {
96 | 'DEFAULT': 1
97 | }
98 | },
99 | 'import': 1,
100 | 'code': {
101 | 'locals': {
102 | 'DEFAULT': 1
103 | },
104 | 'code': {
105 | 'DEFAULT': 1
106 | }
107 | },
108 | 'memory': (entry) => {
109 | return entry.maximum * 10
110 | },
111 | 'data': 5
112 | }
113 |
114 | ```
115 |
116 | Keys can either map to a function which will be given that section's entries or
117 | an integer which will be used as the cost for each entry or an object whose
118 | keys are matched against the [JSON representation](https://github.com/ewasm/wasm-json-toolkit) of the code.
119 | The default cost table used is from [here](https://github.com/ewasm/design/blob/master/determining_wasm_gas_costs.md)
120 |
121 | The cost table can use a special key 'DEFAULT' that will be used as the cost value for any fields in a section that are not defined.
122 |
123 | ## Initial Cost
124 | The Initial cost for instantation for the module is calculated from all the
125 | sections other than the code section (which is metered at runtime). This information is
126 | stored as a [custom section](https://github.com/WebAssembly/design/blob/master/BinaryEncoding.md#name-section)
127 | that is inserted directly after the preamble. It uses the the name `initCost` and
128 | its payload contains the initial cost encoded as an unsigned leb128 interger.
129 |
130 | # LICENSE
131 | [MPL-2.0](https://tldrlegal.com/license/mozilla-public-license-2.0-(mpl-2))
132 |
--------------------------------------------------------------------------------
/bin/wasm-meter:
--------------------------------------------------------------------------------
1 | #!/usr/bin/env node
2 | const fs = require('fs')
3 | const meter = require('../')
4 |
5 | const file = process.argv[2]
6 | const out = process.argv[3]
7 |
8 | if (file) {
9 | const wasm = fs.readFileSync(file)
10 | const meteredWasm = meter.meterWASM(wasm)
11 |
12 | fs.writeFileSync(out, meteredWasm)
13 | } else {
14 | const helpMessage = 'Usage: meter-meter [FILE]'
15 | process.stdout.write(helpMessage)
16 | }
17 |
--------------------------------------------------------------------------------
/defaultCostTable.json:
--------------------------------------------------------------------------------
1 | {
2 | "start": 0,
3 | "type": {
4 | "params": {
5 | "DEFAULT": 0
6 | },
7 | "return_type": {
8 | "DEFAULT": 0
9 | }
10 | },
11 | "import": 0,
12 | "code": {
13 | "locals": {
14 | "DEFAULT": 1
15 | },
16 | "code": {
17 | "get_local": 120,
18 | "set_local": 120,
19 | "tee_local": 120,
20 | "get_global": 120,
21 | "set_global": 120,
22 |
23 | "load8_s": 120,
24 | "load8_u": 120,
25 | "load16_s": 120,
26 | "load16_u": 120,
27 | "load32_s": 120,
28 | "load32_u": 120,
29 | "load": 120,
30 |
31 | "store8": 120,
32 | "store16": 120,
33 | "store32": 120,
34 | "store": 120,
35 |
36 | "grow_memory": 10000,
37 | "current_memory": 100,
38 |
39 | "nop": 1,
40 | "block": 1,
41 | "loop": 1,
42 | "if": 1,
43 | "then": 90,
44 | "else": 90,
45 | "br": 90,
46 | "br_if": 90,
47 | "br_table": 120,
48 | "return": 90,
49 |
50 | "call": 90,
51 | "call_indirect": 10000,
52 |
53 | "const": 1,
54 |
55 | "add": 45,
56 | "sub": 45,
57 | "mul": 45,
58 | "div_s": 36000,
59 | "div_u": 36000,
60 | "rem_s": 36000,
61 | "rem_u": 36000,
62 | "and": 45,
63 | "or": 45,
64 | "xor": 45,
65 | "shl": 67,
66 | "shr_u": 67,
67 | "shr_s": 67,
68 | "rotl": 90,
69 | "rotr": 90,
70 | "eq": 45,
71 | "eqz": 45,
72 | "ne": 45,
73 | "lt_s": 45,
74 | "lt_u": 45,
75 | "le_s": 45,
76 | "le_u": 45,
77 | "gt_s": 45,
78 | "gt_u": 45,
79 | "ge_s": 45,
80 | "ge_u": 45,
81 | "clz": 45,
82 | "ctz": 45,
83 | "popcnt": 45,
84 |
85 | "drop": 120,
86 | "select": 120,
87 |
88 | "unreachable": 1
89 | }
90 | },
91 | "data": 0
92 | }
93 |
--------------------------------------------------------------------------------
/demo/index.js:
--------------------------------------------------------------------------------
1 | const html = require('nanohtml')
2 | const wabt = require('wabt')
3 | const metering = require('../')
4 |
5 | function inject (wat) {
6 | const mod = wabt.parseWat('module.wast', wat)
7 | const binary = mod.toBinary({log: true})
8 | console.log('here', binary)
9 | const meteredCode = metering.meterWASM(Buffer.from(binary.buffer))
10 | const textMod = wabt.readWasm(meteredCode, { readDebugNames: true })
11 | textMod.generateNames()
12 | textMod.applyNames()
13 | const text = textMod.toText({ foldExprs: true, inlineExport: false })
14 | document.getElementById('result').innerHTML = text
15 | }
16 |
17 | const textarea = html`
18 |
19 |
23 |
24 |
25 |