src/hashsig.c


Log

Author Commit Date CI Message
Vicent Marti 737b5051 2014-10-01T12:03:24 hashsig: Export as a `sys` header
Russell Belfer d730d3f4 2013-07-31T16:40:42 Major rename detection changes After doing further profiling, I found that a lot of time was being spent attempting to insert hashes into the file hash signature when using the rolling hash because the rolling hash approach generates a hash per byte of the file instead of one per run/line of data. To optimize this, I decided to convert back to a run-based file signature algorithm which would be more like core Git. After changing this, a number of the existing tests started to fail. In some cases, this appears to have been because the test was coded to be too specific to the particular results of the file similarity metric and in some cases there appear to have been bugs in the core rename detection code where only by the coincidence of the file similarity scoring were the expected results being generated. This renames all the variables in the core rename detection code to be more consistent and hopefully easier to follow which made it a bit easier to reason about the behavior of that code and fix the problems that I was seeing. I think it's in better shape now. There are a couple of tests now that attempt to stress test the rename detection code and they are quite slow. Most of the time is spent setting up the test data on disk and in the index. When we roll out performance improvements for index insertion, it should also speed up these tests I hope.
Russell Belfer 427cc255 2013-07-24T13:11:11 Use local variables in hash calc to avoid aliasing
nulltoken 1fed6b07 2013-05-13T21:57:37 Fix trailing whitespaces
Russell Belfer e40f1c2d 2013-03-08T16:39:57 Make tree iterator handle icase equivalence There is a serious bug in the previous tree iterator implementation. If case insensitivity resulted in member elements being equivalent to one another, and those member elements were trees, then the children of the colliding elements would be processed in sequence instead of in a single flattened list. This meant that the tree iterator was not truly acting like a case-insensitive list. This completely reworks the tree iterator to manage lists with case insensitive equivalence classes and advance through the items in a unified manner in a single sorted frame. It is possible that at a future date we might want to update this to separate the case insensitive and case sensitive tree iterators so that the case sensitive one could be a minimal amount of code and the insensitive one would always know what it needed to do without checking flags. But there would be so much shared code between the two, that I'm not sure it that's a win. For now, this gets what we need. More tests are needed, though.
Russell Belfer 97b71374 2013-02-28T14:14:45 Add GIT_STDLIB_CALL This removes the one-off GIT_CDECL and adds a new standard way of doing this named GIT_STDLIB_CALL with a src/win32 specific def when on the Windows platform.
Russell Belfer f708c89f 2013-02-27T15:15:39 fixing some warnings on Windows
Russell Belfer 11b5beb7 2013-02-27T15:07:28 use cdecl for hashsig sorting functions on Windows
Russell Belfer 9bc8be3d 2013-02-19T10:25:41 Refine pluggable similarity API This plugs in the three basic similarity strategies for handling whitespace via internal use of the pluggable API. In so doing, I realized that the use of git_buf in the hashsig API was not needed and actually just made it harder to use, so I tweaked that API as well. Note that the similarity metric is still not hooked up in the find_similarity code - this is just setting out the function that will be used.
Russell Belfer 5e5848eb 2013-02-14T17:25:10 Change similarity metric to sampled hashes This moves the similarity metric code out of buf_text and into a new file. Also, this implements a different approach to similarity measurement based on a Rabin-Karp rolling hash where we only keep the top 100 and bottom 100 hashes. In theory, that should be sufficient samples to given a fairly accurate measurement while limiting the amount of data we keep for file signatures no matter how large the file is.