When we don't own a buffer (asize=0) we currently allow the usage of
grow to copy the memory into a buffer we do own. This muddles the
meaning of grow, and lets us be a bit cavalier with ownership semantics.
Don't allow this any more. Usage of grow should be restricted to buffers
which we know own their own memory. If unsure, we must not attempt to
modify it.
Provide a convenience function that creates a buffer that can be provided
to callers but will not be freed via `git_buf_free`, so the buffer
creator maintains the allocation lifecycle of the buffer's contents.
Make our overflow checking look more like gcc and clang's, so that
we can substitute it out with the compiler instrinsics on platforms
that support it. This means dropping the ability to pass `NULL` as
an out parameter.
As a result, the macros also get updated to reflect this as well.
This adds in missing calls to `git_buf_sanitize` and fixes a
number of places where `git_buf` APIs could inadvertently write
NUL terminator bytes into invalid buffers. This also changes the
behavior of `git_buf_sanitize` to NUL terminate a buffer if it can
and of `git_buf_shorten` to do nothing if it can.
Adds tests of filtering code with zeroed (i.e. unsanitized) buffer
which was previously triggering a segfault.
There are a few places where we need to join three strings to
assemble a path. This adds a simple join3 function to avoid the
comparatively expensive join_n (which calls strlen on each string
twice).
This replaces some git_buf_printf calls with simple calls to
git_buf_put instead. Also, it fixes a missing va_end inside
the git_buf_vprintf implementation.
This makes the git_buf struct that was used internally into an
externally available structure and eliminates the git_buffer.
As part of that, some of the special cases that arose with the
externally used git_buffer were blended into the git_buf, such as
being careful about git_buf objects that may have a NULL ptr and
allowing for bufs with a valid ptr and size but zero asize as a
way of referring to externally owned data.
Extend the git2/sys/filter API with functions to look up a filter
and add it manually to a filter list. This requires some trickery
because the regular attribute lookups and checks are bypassed when
this happens, but in the right hands, it will allow a user to have
granular control over applying filters.
This moves the git_filter_list into the public API so that users
can create, apply, and dispose of filter lists. This allows more
granular application of filters to user data outside of libgit2
internals.
This also converts all the internal usage of filters to the public
APIs along with a few small tweaks to make it easier to use the
public git_buffer stuff alongside the internal git_buf.
This begins the process of exposing git_filter objects to the
public API. This includes:
* new public type and API for `git_buffer` through which an
allocated buffer can be passed to the user
* new API `git_blob_filtered_content`
* make the git_filter type and GIT_FILTER_TO_... constants public
There are many scattered functions that look into the contents of
buffers to do various text manipulations (such as escaping or
unescaping data, calculating text stats, guessing if content is
binary, etc). This groups all those functions together into a
new file and converts the code to use that.
This has two enhancements to existing functionality. The old
text stats function is significantly rewritten and the BOM
detection code was extended (although largely we can't deal with
anything other than a UTF8 BOM).
This fixes up a number of problems flagged by valgrind and also
cleans up the internal `git_submodule` allocation handling
overall with a simpler model.
* `git_buf_rfind` (with tests and tests for `git_buf_rfind_next`)
* `git_buf_puts_escaped` and `git_buf_puts_escaped_regex` (with tests)
to copy strings into a buffer while injecting an escape sequence
(e.g. '\') in front of particular characters.
GProf shows `git_text_gather_stats` as the most expensive call
in large diffs. The function calculates a lot of information
that is not actually used and does not do so in a optimal
order. This introduces a tuned `git_buf_is_binary` function
that executes the same algorithm in a fraction of the time.
The goal of this work is to rewrite git_status_file to use the
same underlying code as git_status_foreach.
This is done in 3 phases:
1. Extend iterators to allow ranged iteration with start and
end prefixes for the range of file names to be covered.
2. Improve diff so that when there is a pathspec and there is
a common non-wildcard prefix of the pathspec, it will use
ranged iterators to minimize excess iteration.
3. Rewrite git_status_file to call git_status_foreach_ext
with a pathspec that covers just the one file being checked.
Since ranged iterators underlie the status & diff implementation,
this is actually fairly efficient. The workdir iterator does
end up loading the contents of all the directories down to the
single file, which should ideally be avoided, but it is pretty
good.
This adds a `git_pool` object that can do simple paged memory
allocation with free for the entire pool at once. Using this,
you can replace many small allocations with large blocks that
can then cheaply be doled out in small pieces. This is best
used when you plan to free the small blocks all at once - for
example, if they represent the parsed state from a file or data
stream that are either all kept or all discarded.
There are two real patterns of usage for `git_pools`: either
for "string" allocation, where the item size is a single byte
and you end up just packing the allocations in together, or for
"fixed size" allocation where you are allocating a large object
(e.g. a `git_oid`) and you generally just allocation single
objects that can be tightly packed. Of course, you can use it
for other things, but those two cases are the easiest.
There was a bug in git_buf_join_n when the contents of the
original buffer were joined into itself and the realloc
moved the pointer to the original buffer.
This converts blob.c, fileops.c, and all of the win32 files.
Also, various minor cleanups throughout the code. Plus, in
testing the win32 build, I cleaned up a bunch (although not
all) of the warnings with the 64-bit build.
This also includes droping `git_buf_lasterror` because it makes no sense
in the new system. Note that in most of the places were it has been
dropped, the code needs cleanup. I.e. GIT_ENOMEM is going away, so
instead it should return a generic `-1` and obviously not throw
anything.
