Bug 144602

Summary: [Content Extensions] Use less memory when writing byte code to file
Product: WebKit Reporter: Alex Christensen <achristensen>
Component: WebCore Misc.Assignee: Alex Christensen <achristensen>
Status: RESOLVED FIXED    
Severity: Normal    
Priority: P2    
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch
none
Patch darin: review+

Alex Christensen
Reported 2015-05-04 15:55:20 PDT
Right now we keep several copies of all the data in memory at the same time. We only need one copy of one DFA's byte code alive at a time.
Attachments
Patch (12.80 KB, patch)
2015-05-04 15:57 PDT, Alex Christensen 		no flags
DetailsFormatted DiffDiff
Patch (19.05 KB, patch)
2015-05-04 16:55 PDT, Alex Christensen 		darin: review+
DetailsFormatted DiffDiff
Show Obsolete (1) View All Add attachment proposed patch, testcase, etc.
Alex Christensen
Comment 1 2015-05-04 15:57:22 PDT
Created attachment 252343 [details] Patch
Darin Adler
Comment 2 2015-05-04 16:04:09 PDT
Comment on attachment 252343 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=252343&action=review > Source/WebKit2/UIProcess/API/APIUserContentExtensionStore.cpp:77 > +const size_t ContentExtensionFileHeaderSize = sizeof(uint32_t) + 2 * sizeof(uint64_t); Why do this instead of sizeof(ContentExtensionMetaData)? Because of alignment, I suspect the expression above will be wrong.
Alex Christensen
Comment 3 2015-05-04 16:06:01 PDT
Comment on attachment 252343 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=252343&action=review >> Source/WebKit2/UIProcess/API/APIUserContentExtensionStore.cpp:77 >> +const size_t ContentExtensionFileHeaderSize = sizeof(uint32_t) + 2 * sizeof(uint64_t); > > Why do this instead of sizeof(ContentExtensionMetaData)? Because of alignment, I suspect the expression above will be wrong. When writing the header, we only want to write 20 bytes. Otherwise we would be writing uninitialized memory to file.
Alex Christensen
Comment 4 2015-05-04 16:55:39 PDT
Created attachment 252355 [details] Patch
Darin Adler
Comment 5 2015-05-05 09:07:52 PDT
Comment on attachment 252355 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=252355&action=review > Source/WebKit2/UIProcess/API/APIUserContentExtensionStore.cpp:84 > static Data encodeContentExtensionMetaData(const ContentExtensionMetaData& metaData) I think you want to add this to the end of this function: ASSERT(encoder.bufferSize() == ContentExtensionFileHeaderSize); > Source/WebKit2/UIProcess/API/APIUserContentExtensionStore.cpp:218 > + memset(invalidHeader, 0xff, sizeof(invalidHeader)); We normally use capitalized hex, 0xFF, in WebKit code.
Alex Christensen
Comment 6 2015-05-05 10:14:43 PDT
http://trac.webkit.org/changeset/183817
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