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| author | littleblack111 <littleblack11111@gmail.com> | 2026-05-18 23:10:59 +0800 |
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| committer | littleblack111 <littleblack11111@gmail.com> | 2026-05-18 23:41:44 +0800 |
| commit | fc87c009806dcc98867f6b58efe29b042aa01dee (patch) | |
| tree | 8f59b3f4a5b66e9dfef2d40c8d318e258a521228 /node_modules/@jridgewell/gen-mapping/README.md | |
| parent | 3336b2356ee6152d9c6ae59bd9b87ccbc0958407 (diff) | |
node: updatemain
Diffstat (limited to 'node_modules/@jridgewell/gen-mapping/README.md')
| -rw-r--r-- | node_modules/@jridgewell/gen-mapping/README.md | 227 |
1 files changed, 0 insertions, 227 deletions
diff --git a/node_modules/@jridgewell/gen-mapping/README.md b/node_modules/@jridgewell/gen-mapping/README.md deleted file mode 100644 index 4066cdbb..00000000 --- a/node_modules/@jridgewell/gen-mapping/README.md +++ /dev/null @@ -1,227 +0,0 @@ -# @jridgewell/gen-mapping - -> Generate source maps - -`gen-mapping` allows you to generate a source map during transpilation or minification. -With a source map, you're able to trace the original location in the source file, either in Chrome's -DevTools or using a library like [`@jridgewell/trace-mapping`][trace-mapping]. - -You may already be familiar with the [`source-map`][source-map] package's `SourceMapGenerator`. This -provides the same `addMapping` and `setSourceContent` API. - -## Installation - -```sh -npm install @jridgewell/gen-mapping -``` - -## Usage - -```typescript -import { GenMapping, addMapping, setSourceContent, toEncodedMap, toDecodedMap } from '@jridgewell/gen-mapping'; - -const map = new GenMapping({ - file: 'output.js', - sourceRoot: 'https://example.com/', -}); - -setSourceContent(map, 'input.js', `function foo() {}`); - -addMapping(map, { - // Lines start at line 1, columns at column 0. - generated: { line: 1, column: 0 }, - source: 'input.js', - original: { line: 1, column: 0 }, -}); - -addMapping(map, { - generated: { line: 1, column: 9 }, - source: 'input.js', - original: { line: 1, column: 9 }, - name: 'foo', -}); - -assert.deepEqual(toDecodedMap(map), { - version: 3, - file: 'output.js', - names: ['foo'], - sourceRoot: 'https://example.com/', - sources: ['input.js'], - sourcesContent: ['function foo() {}'], - mappings: [ - [ [0, 0, 0, 0], [9, 0, 0, 9, 0] ] - ], -}); - -assert.deepEqual(toEncodedMap(map), { - version: 3, - file: 'output.js', - names: ['foo'], - sourceRoot: 'https://example.com/', - sources: ['input.js'], - sourcesContent: ['function foo() {}'], - mappings: 'AAAA,SAASA', -}); -``` - -### Smaller Sourcemaps - -Not everything needs to be added to a sourcemap, and needless markings can cause signficantly -larger file sizes. `gen-mapping` exposes `maybeAddSegment`/`maybeAddMapping` APIs that will -intelligently determine if this marking adds useful information. If not, the marking will be -skipped. - -```typescript -import { maybeAddMapping } from '@jridgewell/gen-mapping'; - -const map = new GenMapping(); - -// Adding a sourceless marking at the beginning of a line isn't useful. -maybeAddMapping(map, { - generated: { line: 1, column: 0 }, -}); - -// Adding a new source marking is useful. -maybeAddMapping(map, { - generated: { line: 1, column: 0 }, - source: 'input.js', - original: { line: 1, column: 0 }, -}); - -// But adding another marking pointing to the exact same original location isn't, even if the -// generated column changed. -maybeAddMapping(map, { - generated: { line: 1, column: 9 }, - source: 'input.js', - original: { line: 1, column: 0 }, -}); - -assert.deepEqual(toEncodedMap(map), { - version: 3, - names: [], - sources: ['input.js'], - sourcesContent: [null], - mappings: 'AAAA', -}); -``` - -## Benchmarks - -``` -node v18.0.0 - -amp.js.map -Memory Usage: -gen-mapping: addSegment 5852872 bytes -gen-mapping: addMapping 7716042 bytes -source-map-js 6143250 bytes -source-map-0.6.1 6124102 bytes -source-map-0.8.0 6121173 bytes -Smallest memory usage is gen-mapping: addSegment - -Adding speed: -gen-mapping: addSegment x 441 ops/sec ±2.07% (90 runs sampled) -gen-mapping: addMapping x 350 ops/sec ±2.40% (86 runs sampled) -source-map-js: addMapping x 169 ops/sec ±2.42% (80 runs sampled) -source-map-0.6.1: addMapping x 167 ops/sec ±2.56% (80 runs sampled) -source-map-0.8.0: addMapping x 168 ops/sec ±2.52% (80 runs sampled) -Fastest is gen-mapping: addSegment - -Generate speed: -gen-mapping: decoded output x 150,824,370 ops/sec ±0.07% (102 runs sampled) -gen-mapping: encoded output x 663 ops/sec ±0.22% (98 runs sampled) -source-map-js: encoded output x 197 ops/sec ±0.45% (84 runs sampled) -source-map-0.6.1: encoded output x 198 ops/sec ±0.33% (85 runs sampled) -source-map-0.8.0: encoded output x 197 ops/sec ±0.06% (93 runs sampled) -Fastest is gen-mapping: decoded output - - -*** - - -babel.min.js.map -Memory Usage: -gen-mapping: addSegment 37578063 bytes -gen-mapping: addMapping 37212897 bytes -source-map-js 47638527 bytes -source-map-0.6.1 47690503 bytes -source-map-0.8.0 47470188 bytes -Smallest memory usage is gen-mapping: addMapping - -Adding speed: -gen-mapping: addSegment x 31.05 ops/sec ±8.31% (43 runs sampled) -gen-mapping: addMapping x 29.83 ops/sec ±7.36% (51 runs sampled) -source-map-js: addMapping x 20.73 ops/sec ±6.22% (38 runs sampled) -source-map-0.6.1: addMapping x 20.03 ops/sec ±10.51% (38 runs sampled) -source-map-0.8.0: addMapping x 19.30 ops/sec ±8.27% (37 runs sampled) -Fastest is gen-mapping: addSegment - -Generate speed: -gen-mapping: decoded output x 381,379,234 ops/sec ±0.29% (96 runs sampled) -gen-mapping: encoded output x 95.15 ops/sec ±2.98% (72 runs sampled) -source-map-js: encoded output x 15.20 ops/sec ±7.41% (33 runs sampled) -source-map-0.6.1: encoded output x 16.36 ops/sec ±10.46% (31 runs sampled) -source-map-0.8.0: encoded output x 16.06 ops/sec ±6.45% (31 runs sampled) -Fastest is gen-mapping: decoded output - - -*** - - -preact.js.map -Memory Usage: -gen-mapping: addSegment 416247 bytes -gen-mapping: addMapping 419824 bytes -source-map-js 1024619 bytes -source-map-0.6.1 1146004 bytes -source-map-0.8.0 1113250 bytes -Smallest memory usage is gen-mapping: addSegment - -Adding speed: -gen-mapping: addSegment x 13,755 ops/sec ±0.15% (98 runs sampled) -gen-mapping: addMapping x 13,013 ops/sec ±0.11% (101 runs sampled) -source-map-js: addMapping x 4,564 ops/sec ±0.21% (98 runs sampled) -source-map-0.6.1: addMapping x 4,562 ops/sec ±0.11% (99 runs sampled) -source-map-0.8.0: addMapping x 4,593 ops/sec ±0.11% (100 runs sampled) -Fastest is gen-mapping: addSegment - -Generate speed: -gen-mapping: decoded output x 379,864,020 ops/sec ±0.23% (93 runs sampled) -gen-mapping: encoded output x 14,368 ops/sec ±4.07% (82 runs sampled) -source-map-js: encoded output x 5,261 ops/sec ±0.21% (99 runs sampled) -source-map-0.6.1: encoded output x 5,124 ops/sec ±0.58% (99 runs sampled) -source-map-0.8.0: encoded output x 5,434 ops/sec ±0.33% (96 runs sampled) -Fastest is gen-mapping: decoded output - - -*** - - -react.js.map -Memory Usage: -gen-mapping: addSegment 975096 bytes -gen-mapping: addMapping 1102981 bytes -source-map-js 2918836 bytes -source-map-0.6.1 2885435 bytes -source-map-0.8.0 2874336 bytes -Smallest memory usage is gen-mapping: addSegment - -Adding speed: -gen-mapping: addSegment x 4,772 ops/sec ±0.15% (100 runs sampled) -gen-mapping: addMapping x 4,456 ops/sec ±0.13% (97 runs sampled) -source-map-js: addMapping x 1,618 ops/sec ±0.24% (97 runs sampled) -source-map-0.6.1: addMapping x 1,622 ops/sec ±0.12% (99 runs sampled) -source-map-0.8.0: addMapping x 1,631 ops/sec ±0.12% (100 runs sampled) -Fastest is gen-mapping: addSegment - -Generate speed: -gen-mapping: decoded output x 379,107,695 ops/sec ±0.07% (99 runs sampled) -gen-mapping: encoded output x 5,421 ops/sec ±1.60% (89 runs sampled) -source-map-js: encoded output x 2,113 ops/sec ±1.81% (98 runs sampled) -source-map-0.6.1: encoded output x 2,126 ops/sec ±0.10% (100 runs sampled) -source-map-0.8.0: encoded output x 2,176 ops/sec ±0.39% (98 runs sampled) -Fastest is gen-mapping: decoded output -``` - -[source-map]: https://www.npmjs.com/package/source-map -[trace-mapping]: https://github.com/jridgewell/trace-mapping |
