Cache chunks result between multiple entry point html page

[jinker]

In some time the method compilation.getStats().toJson() take long.
At my project, it takes about 1 to 3s, and I have 155 pages, it will take 155 to 460s total, too slow.
Cache the chunks result between entry points, it will reduce a lot of time.

compiler.plugin('emit', function (compilation, callback) {
    //...
    // Get all chunks
    var allChunks = compilation.getStats().toJson().chunks;
    //....
}

/**
 * Cache chunks result between multiple entry point html page
 */
var hashToChunksMap = {};
//...
compiler.plugin('emit', function (compilation, callback) {
    //...
    // Get all chunks
    var allChunks = self.getAllChunks(compilation);
    //....
}
//....
/**
 * Get all chunks from compilation
 * @param compilation
 * @return {Array}
 */
HtmlWebpackPlugin.prototype.getAllChunks = function (compilation) {
  var allChunks = hashToChunksMap[compilation.hash];
  if (!allChunks) {
    allChunks = compilation.getStats().toJson().chunks;
    hashToChunksMap[compilation.hash] = allChunks;
  }
  return allChunks;
};

[mastilver]

Thank you for the PR :)
looks good so far, just a few changes

[mastilver]

Can you revert the changes on this file please

[jinker]

Has been reverted

[mastilver]

I don't think it should returns only the chunks, it should return the whole JSON so we can use it for

html-webpack-plugin/index.js

Line 255 in aedc623

webpack: compilation.getStats().toJson(),

[jinker]

Push new opt commit, these two places are handled uniformly

[mastilver]

lgtm thank you

[sdoomz]

@mastilver what is missing to merge this PR?

[githoniel]

well I really need this PR, My project have 50 entries now..

[gregjacobs]

Hey guys, what's the status on this? Failing test?

I'm also wondering (and I mentioned this on another issue before): How come we need to use getStats().toJson() at all? How come the regular object returned by getStats() can't be used?

[gerges-zz]

This toJson call can be passed a number of false options for specific keys to save more time, and limit generation to only the chunk information (which is all that's used by this plugin). You can see an example of that here in another perf PR: https://github.com/jantimon/html-webpack-plugin/pull/825/files#diff-168726dbe96b3ce427e7fedce31bb0bcL67

[gerges-zz]

getStats().toJSON() is also explicitly called again in the template renderer, so that it could be provided to the template if needed. This causes another pretty large performance hit. There's another PR that allows a plugin parameter which prevents that call: #825

[jinker]

i don't know why the test failed, what can i do for this pr to merge.@mastilver

[yingye]

My project have 100+ entries, it's very slow. I really need this PR, to improve pref.

[p11o]

Please merge.

[lock]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.