I frequently want to the the first N digits of an OID formatted
as a string and I'd like it to be efficient. This function makes
that easy and I could rewrite the OID formatters in terms of it.
Add a new git_oid_strcmp that compares a string OID with a hex
oid for sort order, and then reimplement git_oid_streq using it.
This actually should speed up git_oid_streq because it only reads
as far into the string as it needs to, whereas previously it would
convert the whole string into an OID and then use git_oid_cmp.
git_oid_ncmp was making some assumptions about the length of
the data - this shifts the check to the top of the loop so it
will work more robustly, limits the max, and adds some tests
to verify the functionality.
Previously a NULL oid was handled like an empty buffer and
returned a status empty string. This makes git_oid_tostr()
set the output buffer to the empty string instead.
git.git uses an inlined hashcmp function instead of memcmp, since it
performes much better when comparing hashes (most hashes compared
diverge within the first byte).
Measurements and rationale for the curious reader:
http://thread.gmane.org/gmane.comp.version-control.git/172286
This includes a few cleanups that came up while converting
these files.
This commit introduces a could new git error classes, including
the catchall class: GITERR_INVALID which I'm using as the class
for invalid and out of range values which are detected at too low
a level of library to use a higher level classification. For
example, an overflow error in parsing an integer or a bad letter
in parsing an OID string would generate an error in this class.
This is a major reorganization of the diff code. This changes
the diff functions to use the iterators for traversing the
content. This allowed a lot of code to be simplified. Also,
this moved the functions relating to outputting a diff into a
new file (diff_output.c).
This includes a number of other changes - adding utility
functions, extending iterators, etc. plus more tests for the
diff code. This also takes the example diff.c program much
further in terms of emulating git-diff command line options.
There were quite a few places were spaces were being used instead of
tabs. Try to catch them all. This should hopefully not break anything.
Except for `git blame`. Oh well.
1. The license header is technically not valid if it doesn't have a
copyright signature.
2. The COPYING file has been updated with the different licenses used in
the project.
3. The full GPLv2 header in each file annoys me.
The direct-writes commit left some (slow) internals methods that
were no longer needed. These have been removed.
Also, the Reflog code was using the old `git_signature__write`, so
it has been rewritten to use a normal buffer and the new `writebuf`
signature writer. It's now slightly simpler and faster.
DIRECT WRITES ARE BACK AND FASTER THAN EVER. The streaming writer to the
ODB was an overkill for the smaller objects like Commit and Tags; most
of the streaming logic was taking too long.
This commit makes Commits, Tags and Trees to be built-up in memory, and
then written to disk in 2 pushes (header + data), instead of streaming
everything.
This is *always* faster, even for big files (since the git_filebuf class
still does streaming writes when the memory cache overflows). This is
also a gazillion lines of code smaller, because we don't have to
precompute the final size of the object before starting the stream (this
was kind of defeating the point of streaming, anyway).
Blobs are still written with full streaming instead of loading them in
memory, since this is still the fastest way.
A new `git_buf` class has been added. It's missing some features, but
it'll get there.
A bunch of redundant methods have been removed from the external API.
- All the reference/tag creation methods with `_f` are gone. The force
flag is now passed as an argument to the normal create methods.
- All the different commit creation methods are gone; commit creation
now always requires a `git_commit` pointer for parents and a `git_tree`
pointer for tree, to ensure that corrupted commits cannot be generated.
- All the different tag creation methods are gone; tag creation now
always requires a `git_object` pointer to ensure that tags are not
created to inexisting objects.
As suggested by carlosmn, git_oid_ncmp would probably
be a better name than git_oid_match, for it does the same
as git_oid_cmp but only up to a certain amount of hex digits.
