Bug 143857 – Use less memory when compiling content extensions

• Component: WebCore Misc.
• Status: RESOLVED FIXED

[Alex Christensen]

We keep a lot of things alive when compiling.  Using less memory would start with keeping fewer things alive.

[Alex Christensen]

Created attachment 250983 [details]
Patch

[Benjamin Poulain]

Comment on attachment 250983 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=250983&action=review

Simon would like more info in the changelog.

I don't like the "// Free memory.", they are not adding any information.

> Source/WebCore/contentextensions/ContentExtensionCompiler.cpp:165
> +    parsedRuleList = Vector<ContentExtensionRule>(); // Free memory.
> +    actionLocations = Vector<unsigned>(); // Free memory.

Vector has clear().

A single comment on top of the two lines would be better.

> Source/WebCore/contentextensions/ContentExtensionCompiler.cpp:179
>      Vector<NFA> nfas = combinedURLFilters.createNFAs();
>      if (!nfas.size() && universalActionLocations.size())
>          nfas.append(NFA());
> +    combinedURLFilters.clear(); // Free memory.

I am unconvinced this is the right balance.

We should look into generating the NFAs one by one out of the combinedURLFilters, generate its DFA, clear the NFA, generate the bytecode, clear the DFA.

> Source/WebCore/contentextensions/ContentExtensionCompiler.cpp:240
> +    nfas = Vector<NFA>(); // Free memory.

nfas.clear()?

[Alex Christensen]

Created attachment 250984 [details]
Patch

[Alex Christensen]

Created attachment 250986 [details]
Patch

[Alex Christensen]

http://trac.webkit.org/changeset/182935