You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
55 lines
2.1 KiB
55 lines
2.1 KiB
# v8-compile-cache |
|
|
|
[](https://travis-ci.org/zertosh/v8-compile-cache) |
|
|
|
`v8-compile-cache` attaches a `require` hook to use [V8's code cache](https://v8project.blogspot.com/2015/07/code-caching.html) to speed up instantiation time. The "code cache" is the work of parsing and compiling done by V8. |
|
|
|
The ability to tap into V8 to produce/consume this cache was introduced in [Node v5.7.0](https://nodejs.org/en/blog/release/v5.7.0/). |
|
|
|
## Usage |
|
|
|
1. Add the dependency: |
|
|
|
```sh |
|
$ npm install --save v8-compile-cache |
|
``` |
|
|
|
2. Then, in your entry module add: |
|
|
|
```js |
|
require('v8-compile-cache'); |
|
``` |
|
|
|
**Requiring `v8-compile-cache` in Node <5.7.0 is a noop – but you need at least Node 4.0.0 to support the ES2015 syntax used by `v8-compile-cache`.** |
|
|
|
## Options |
|
|
|
Set the environment variable `DISABLE_V8_COMPILE_CACHE=1` to disable the cache. |
|
|
|
Cache directory is defined by environment variable `V8_COMPILE_CACHE_CACHE_DIR` or defaults to `<os.tmpdir()>/v8-compile-cache-<V8_VERSION>`. |
|
|
|
## Internals |
|
|
|
Cache files are suffixed `.BLOB` and `.MAP` corresponding to the entry module that required `v8-compile-cache`. The cache is _entry module specific_ because it is faster to load the entire code cache into memory at once, than it is to read it from disk on a file-by-file basis. |
|
|
|
## Benchmarks |
|
|
|
See https://github.com/zertosh/v8-compile-cache/tree/master/bench. |
|
|
|
**Load Times:** |
|
|
|
| Module | Without Cache | With Cache | |
|
| ---------------- | -------------:| ----------:| |
|
| `babel-core` | `218ms` | `185ms` | |
|
| `yarn` | `153ms` | `113ms` | |
|
| `yarn` (bundled) | `228ms` | `105ms` | |
|
|
|
_^ Includes the overhead of loading the cache itself._ |
|
|
|
## Acknowledgements |
|
|
|
* `FileSystemBlobStore` and `NativeCompileCache` are based on Atom's implementation of their v8 compile cache: |
|
- https://github.com/atom/atom/blob/b0d7a8a/src/file-system-blob-store.js |
|
- https://github.com/atom/atom/blob/b0d7a8a/src/native-compile-cache.js |
|
* `mkdirpSync` is based on: |
|
- https://github.com/substack/node-mkdirp/blob/f2003bb/index.js#L55-L98
|
|
|