├── .editorconfig ├── .gitignore ├── CONTRIBUTING.md ├── LICENSE ├── README.md ├── bench.sh ├── build.js ├── package.json ├── realm-js.js └── realm-json.js /.editorconfig: -------------------------------------------------------------------------------- 1 | root = true 2 | 3 | [*] 4 | charset = utf-8 5 | indent_style = space 6 | indent_size = 2 7 | end_of_line = lf 8 | insert_final_newline = true 9 | trim_trailing_whitespace = true 10 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | node_modules 2 | data.js 3 | out 4 | -------------------------------------------------------------------------------- /CONTRIBUTING.md: -------------------------------------------------------------------------------- 1 | # How to contribute 2 | 3 | We’d love to accept your patches and contributions to this project. There are just a few small guidelines you need to follow. 4 | 5 | ## Contributor License Agreement 6 | 7 | Contributions to this project must be accompanied by a Contributor License Agreement. You (or your employer) retain the copyright to your contribution; this simply gives us permission to use and redistribute your contributions as part of the project. Head over to to see your current agreements on file or to sign a new one. 8 | 9 | You generally only need to submit a CLA once, so if you’ve already submitted one (even if it was for a different project), you probably don’t need to do it again. 10 | 11 | ## Code reviews 12 | 13 | All submissions, including submissions by project members, require review. We use GitHub pull requests for this purpose. 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However, in accepting such obligations, You may act only 170 | on Your own behalf and on Your sole responsibility, not on behalf 171 | of any other Contributor, and only if You agree to indemnify, 172 | defend, and hold each Contributor harmless for any liability 173 | incurred by, or claims asserted against, such Contributor by reason 174 | of your accepting any such warranty or additional liability. 175 | 176 | END OF TERMS AND CONDITIONS 177 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # `JSON.parse` benchmark 2 | 3 | See [the cost of parsing JSON](https://v8.dev/blog/cost-of-javascript-2019#json). 4 | 5 | ## Instructions 6 | 7 | Clone this repository, and then run these commands: 8 | 9 | ```bash 10 | npm install 11 | export PATH="${HOME}/.jsvu/bin:${PATH}" 12 | npm run bench 13 | ``` 14 | 15 | ## Analysis 16 | 17 | [`JetStream2/SeaMonster/inspector-json-payload.js`](https://raw.githubusercontent.com/WebKit/webkit/ffdd2799d3237993354978b9d0cdd1d248fe3787/PerformanceTests/JetStream2/SeaMonster/inspector-json-payload.js) contains a 7.33-MB JavaScript array literal containing 846 object literals. This entire array literal can be [serialized to JSON](https://github.com/GoogleChromeLabs/json-parse-benchmark/blob/c0dec965dfbb6e30f077974ce172296f1f90d5da/build.js#L18) and [turned into a 8.2-MB JavaScript string literal](https://github.com/GoogleChromeLabs/json-parse-benchmark/blob/c0dec965dfbb6e30f077974ce172296f1f90d5da/build.js#L19), which can be [passed to `JSON.parse()`](https://github.com/GoogleChromeLabs/json-parse-benchmark/blob/c0dec965dfbb6e30f077974ce172296f1f90d5da/build.js#L22) to produce an equivalent array. 18 | 19 | This repository tests each approach in 100 different contexts in the dumbest possible way, i.e. by simply invoking `d8` a 100 times per script. That is, we perform 100 cold loads, and measure everything (parsing, compilation, and execution) until the program halts. 20 | 21 | On my workstation (HP Z840 with 2 × 14-core Intel Xeon E5-2690 v4 processors @ 2.6GHz, 35MB Cache + 128GB DDR4 2400MHz RAM), I got the following results: 22 | 23 | | | JS literal | `JSON.parse` | Speed-up | 24 | | ---------------------- | ---------: | -----------: | -------: | 25 | | V8 v7.5 | 23.765 s | 15.766 s | 1.5× | 26 | | V8 v7.6 | 23.639 s | 14.102 s | 1.7× | 27 | | V8 v7.7 | 23.489 s | 13.886 s | 1.7× | 28 | | Chakra v1.11.10.0 | 24.999 s | 16.547 s | 1.5× | 29 | | JavaScriptCore v246878 | 28.503 s | 14.315 s | 2.0× | 30 | | SpiderMonkey v68.0b13 | 25.554 s | 21.174 s | 1.2× | 31 | 32 | For V8 specifically, you can get detailed metrics for a single run by using `--runtime-call-stats`: 33 | 34 | ``` 35 | $ v8 --runtime-call-stats out/js.js | grep Parse 36 | ParseProgram 124.33ms 47.00% 1 0.00% 37 | 38 | $ v8 --runtime-call-stats out/json.js | grep Parse 39 | JsonParse 47.67ms 28.29% 1 0.07% 40 | ParseProgram 43.17ms 25.62% 1 0.07% 41 | ``` 42 | 43 | ## Licensing 44 | 45 | The source files in this repository are released under the Apache 2.0 license, as detailed in the LICENSE file. 46 | 47 | The scripts in this repository dynamically download [`JetStream2/SeaMonster/inspector-json-payload.js`](https://raw.githubusercontent.com/WebKit/WebKit/ab7171c1d63acb8c77216b5a11f98323b56b998b/PerformanceTests/JetStream2/SeaMonster/inspector-json-payload.js), which has its own license: 48 | 49 | ``` 50 | /* 51 | * Copyright (C) 2018 Apple Inc. All rights reserved. 52 | * 53 | * Redistribution and use in source and binary forms, with or without 54 | * modification, are permitted provided that the following conditions 55 | * are met: 56 | * 1. Redistributions of source code must retain the above copyright 57 | * notice, this list of conditions and the following disclaimer. 58 | * 2. Redistributions in binary form must reproduce the above copyright 59 | * notice, this list of conditions and the following disclaimer in the 60 | * documentation and/or other materials provided with the distribution. 61 | * 62 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 63 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 64 | * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 65 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 66 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 67 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 68 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 69 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 70 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 71 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 72 | * THE POSSIBILITY OF SUCH DAMAGE. 73 | */ 74 | ``` 75 | 76 | This license also applies to the generated `*.js` files produced by the scripts in this repository. 77 | -------------------------------------------------------------------------------- /bench.sh: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env bash 2 | 3 | # Copyright 2019 Google Inc. 4 | # 5 | # Licensed under the Apache License, Version 2.0 (the “License”); 6 | # you may not use this file except in compliance with the License. 7 | # You may obtain a copy of the License at 8 | # . 9 | # 10 | # Unless required by applicable law or agreed to in writing, software 11 | # distributed under the License is distributed on an “AS IS” BASIS, 12 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 13 | # implied. See the License for the specific language governing 14 | # permissions and limitations under the License. 15 | 16 | binaries=" 17 | v8-7.5.288 18 | v8-7.6.303 19 | v8-7.7.299 20 | v8-7.8.279 21 | v8 22 | chakra 23 | javascriptcore 24 | spidermonkey 25 | "; 26 | TIMEFORMAT=%lR; 27 | for bin in $binaries; do 28 | printf "Benchmarking JS literal on ${bin}… "; 29 | time (for i in {1..100}; do $bin out/js.js; done); 30 | printf "Benchmarking JSON.parse on ${bin}… "; 31 | time (for i in {1..100}; do $bin out/json.js; done); 32 | if [[ $bin == v8* ]]; then 33 | printf "Benchmarking JS literal with cold loads on ${bin}…\n"; 34 | time $bin realm-js.js --nocompilation-cache; 35 | printf "Benchmarking JSON.parse with cold loads on ${bin}…\n"; 36 | time $bin realm-json.js --nocompilation-cache; 37 | printf "Benchmarking JS literal with warm loads on ${bin}…\n"; 38 | time $bin realm-js.js; 39 | printf "Benchmarking JSON.parse with warm loads on ${bin}…\n"; 40 | time $bin realm-json.js; 41 | fi; 42 | done; 43 | -------------------------------------------------------------------------------- /build.js: -------------------------------------------------------------------------------- 1 | // Copyright 2019 Google Inc. 2 | // 3 | // Licensed under the Apache License, Version 2.0 (the “License”); 4 | // you may not use this file except in compliance with the License. 5 | // You may obtain a copy of the License at 6 | // . 7 | // 8 | // Unless required by applicable law or agreed to in writing, software 9 | // distributed under the License is distributed on an “AS IS” BASIS, 10 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 11 | // implied. See the License for the specific language governing 12 | // permissions and limitations under the License. 13 | 14 | const fs = require('fs'); 15 | 16 | const data = require('./data.js'); 17 | 18 | const json = JSON.stringify(data); 19 | const jsStringLiteral = JSON.stringify(json); 20 | 21 | fs.writeFileSync('./out/json.js', 22 | `const data = JSON.parse(${ jsStringLiteral });\n`); 23 | 24 | // JSON is a syntactic subset of ECMAScript as of 25 | // https://github.com/tc39/proposal-json-superset, so we can 26 | // safely inject the JSON-stringified data as an array literal. 27 | // (We'd need additional escaping if the target was a