Code addresses are now written as an offset from the previous address for ticks, code move and delete events. Employed backreference and RLE compression for code move and delete events. This gives additional 30% log size reduction for benchmarks run w/o snapshot.
Overall compression results (compared with the revision of V8 having no compression):
- V8: 70% size reduction for benchmarks run w/o snapshot (for reference, gzip gives 87%)
- Chromium: 65% size reduction for public html version of benchmarks (v4) (for reference, gzip gives 90%)
The one obvious opportunity for improving compression results in Chromium is to compress URLs of scripts.
Review URL: http://codereview.chromium.org/125114
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2162 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Two techniques are involved:
- compress repeated line ends (common stack beginnings) by using back references;
- do RLE compression of repeated tick events.
This gives only 5% size reduction on benchmarks run, but this is because tick events are only comprise 10% of file size. Under Chromium winnings are bigger because long repeated samples of idleness are now compressed into a single line.
Tickprocessor will be updated in the next patch.
Review URL: http://codereview.chromium.org/123012
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2147 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
When profiler's memory buffer is filled up, profiling is stopped and it is ensured that the last record in the buffer is "profiler,\"pause\"" thus making the end of profiling session explicit. Otherwise DevTools Profiler would need to guess whether the current profiling session has been stopped.
Tested with Chromium.
Review URL: http://codereview.chromium.org/115859
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2072 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The goal of this change is to allow longer profiling sessions and preserve memory when profiler isn't started. The buffer starts with 64K and grows until it reaches the upper limit, which is currently set to 50MB --- according to my evaluations, this is enough for at least 20 minutes of GMail profiling. As we're planning to introduce compression for the profiler log, this time boundary will be significantly increased soon.
To make possible unit testing of the new component, I've factored out Logger's utility classes into a separate source file: log-utils.h/cc. Log and LogMessageBuilder are moved there from log.cc without any semantical changes.
Review URL: http://codereview.chromium.org/115814
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2067 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
