b3f307434e
rustdoc-search: tighter encoding for f index
Depends on https://github.com/rust-lang/rust/pull/119457
Two optimizations for the function signature search:
* Instead of using JSON arrays, like `[1,20]`, it uses VLQ
hex with no commas, like `[aAd]`.
* This also adds backrefs: if you have more than one function
with exactly the same signature, it'll not only store it once,
it'll *decode* it once, and store in the typeIdMap only once.
Based partially on discussions on zulip:
https://rust-lang.zulipchat.com/#narrow/stream/266220-t-rustdoc/topic/search.20index.20size
Performance
-----------
https://notriddle.com/rustdoc-html-demo-8/compression-perf-v2/index.html
### memory/time profiler output (for more details, consult the above link)
<table>
<thead><tr><th>benchmark<th>before<th>after</tr></thead>
<tbody>
<tr><th>arti<td>
```
user: 002.789 s
sys: 000.390 s
wall: 002.096 s
child_RSS_high: 440796 KiB
group_mem_high: 414924 KiB
```
</td><td>
```
user: 002.295 s
sys: 000.278 s
wall: 001.738 s
child_RSS_high: 314588 KiB
group_mem_high: 285220 KiB
```
</td></tr><tr><th>cortex-m<td>
```
user: 000.127 s
sys: 000.030 s
wall: 000.134 s
child_RSS_high: 60264 KiB
group_mem_high: 23824 KiB
```
</td><td>
```
user: 000.136 s
sys: 000.038 s
wall: 000.137 s
child_RSS_high: 59204 KiB
group_mem_high: 22712 KiB
```
</td></tr><tr><th>sqlx<td>
```
user: 000.887 s
sys: 000.118 s
wall: 000.592 s
child_RSS_high: 190408 KiB
group_mem_high: 157804 KiB
```
</td><td>
```
user: 000.798 s
sys: 000.101 s
wall: 000.525 s
child_RSS_high: 159292 KiB
group_mem_high: 126292 KiB
```
</td></tr><tr><th>stm32f4<td>
```
user: 013.884 s
sys: 005.399 s
wall: 013.149 s
child_RSS_high: 1942244 KiB
group_mem_high: 1954916 KiB
```
</td><td>
```
user: 006.128 s
sys: 003.297 s
wall: 007.994 s
child_RSS_high: 1038108 KiB
group_mem_high: 1023900 KiB
```
</td></tr><tr><th>ripgrep<td>
```
user: 000.441 s
sys: 000.063 s
wall: 000.264 s
child_RSS_high: 109180 KiB
group_mem_high: 74272 KiB
```
</td><td>
```
user: 000.408 s
sys: 000.044 s
wall: 000.238 s
child_RSS_high: 101488 KiB
group_mem_high: 66000 KiB
```
</td></tr></tbody></table>
Size change
-----------
standard library without gzip:
```console
$ du -bs search-index-old.js search-index-new.js
4976370 search-index-old.js
4404391 search-index-new.js
```
((4976370-4404391)/4404391)*100% = 12.9%
with gzip:
```console
$ du -hs search-index-old.js.gz search-index-new.js.gz
520K search-index-old.js.gz
504K search-index-new.js.gz
$ du -bs search-index-old.js.gz search-index-new.js.gz
522092 search-index-old.js.gz
507654 search-index-new.js.gz
```
((522092-507654)/507654)*100% = 2.8%
Benchmarks are similarly shrunk.
Without gzip:
```console
$ du -hs tmp/{arti,cortex-m,sqlx,stm32f4,ripgrep}/toolchain_{old,new}/doc/search-index.js
10555067 tmp/arti/toolchain_old/doc/search-index.js
8921236 tmp/arti/toolchain_new/doc/search-index.js
77018 tmp/cortex-m/toolchain_old/doc/search-index.js
66676 tmp/cortex-m/toolchain_new/doc/search-index.js
|
||
|---|---|---|
| .. | ||
| clean | ||
| doctest | ||
| formats | ||
| html | ||
| json | ||
| passes | ||
| theme | ||
| askama.toml | ||
| Cargo.toml | ||
| config.rs | ||
| core.rs | ||
| docfs.rs | ||
| doctest.rs | ||
| error.rs | ||
| externalfiles.rs | ||
| fold.rs | ||
| lib.rs | ||
| lint.rs | ||
| markdown.rs | ||
| README.md | ||
| scrape_examples.rs | ||
| theme.rs | ||
| visit.rs | ||
| visit_ast.rs | ||
| visit_lib.rs | ||
For more information about how librustdoc works, see the rustc dev guide.