The performance improvements I introduced for rename detection
were not able to run successfully for tree-to-tree diffs because
the blob size was not known early enough and so the file signature
always had to be calculated nonetheless.
This change separates loading blobs into memory from calculating
the signature. I can't avoid having to load the large blobs into
memory, but by moving it forward, I'm able to avoid the signature
calculation if the blob won't come into play for renames.
This allows libgit2 to be cross-compiled (e.g. when building native rugged binaries for windows from Linux or OS X).
```
CROSS_COMPILE=i686-w64-mingw32 make -f Makefile.embed
```
Before the optimization commits, this test used to take about 20
seconds to run on my machine. Afterwards, there is still a couple
seconds of data setup, but the actual diff and rename detection
runs in a fraction of a second.
This restores the usage of GIT_DIFF_LINE_BINARY for the diff
output line that reads "Binary files x and y differ" so that it
can be optionally colorized independently of the file header.
This allows git_diff_patch_size to account for hunk headers and
file headers in the returned size. This required some refactoring
of the code that is used to print file headers so that it could be
invoked by the git_diff_patch_size API.
Also this increases the test coverage and fixes an off-by-one bug
in the size calculation when newline changes happen at the end of
the file.
The description of what the function does hasn't been true for quite a
while. Change it to reflect the way it currently works.
While here, remove an even older comment about missing features that
have been implemented.
Instead of using lots of strdup calls, this adds a memory pool to
the loose refs iteration code and uses it for keeping track of the
loose refs array. Memory usage could probably be reduced even
further by eliminating the vector and just scanning by adding the
strlen of each ref, but that would be a more intrusive changes.
This also updates the error handling to be more thorough about
checking for failed allocations, etc.
The git_reference_next API silently skips invalid references when
scanning the loose refs. The git_reference_next_name API should
skip the same ones even though it isn't creating the reference
object.
This adds a test with a an invalid loose reference and makes sure
that both APIs skip the same entries and generate the same results.
