All the ODB backends have a specific refresh interface. When reading an
object, first we attempt every single backend: if the read fails, then
we refresh all the backends and retry the read one more time to see if
the object has appeared.
The new API allows us to read the object bit by bit from the packfile,
instead of needing it all at once in the packfile. This also allows us
to hash the object as it comes in from the network instead of having
to try to read it all and failing repeatedly for larger objects.
This is only the first step, but it already shows huge improvements
when dealing with objects over a few megabytes in size. It reduces the
memory needs in some cases, but delta objects still need to be
completely in memory and the old inefficent method is still used for
that.
Fixed some minor `git_repository_hashfile` issues:
- Fixed incorrect doc (saying that repo could be NULL)
- Added checking of object type value to acceptable ones
- Added more tests for various parameter permutations
Often `git_odb_read_header` will "fail" and have to read the
entire object into memory instead of just the header. When this
happens, the object is loaded and then disposed of immediately,
which makes it difficult to efficiently use the header information
to decide if the object should be loaded (since attempting to do
so will often result in loading the object twice).
This commit takes the existing code and reorganizes it to have
two new functions:
- `git_odb__read_header_or_object` which acts just like the old
read header function except that it returns the object, too, if
it was forced to load the whole thing. It then becomes the
callers responsibility to free the `git_odb_object`.
- `git_object__from_odb_object` which was extracted from the old
`git_object_lookup` and creates a subclass of `git_object` from
an existing `git_odb_object` (separating the ODB lookup from the
`git_object` creation). This allows you to use the first header
reading function efficiently without instantiating the
`git_odb_object` twice.
There is no net change to the behavior of any of the existing
functions, but this allows internal code to tap into the ODB
lookup and object creation to be more efficient.
This adds support to diff and status for running filters (a la crlf)
on blobs in the workdir before computing SHAs and before generating
text diffs. This ended up being a bit more code change than I had
thought since I had to reorganize some of the diff logic to minimize
peak memory use when filtering blobs in a diff.
This also adds a cap on the maximum size of data that will be loaded
to diff. I set it at 512Mb which should match core git. Right now
it is a #define in src/diff.h but it could be moved into the public
API if desired.
This updates all the `foreach()` type functions across the library
that take callbacks from the user to have a consistent behavior.
The rules are:
* A callback terminates the loop by returning any non-zero value
* Once the callback returns non-zero, it will not be called again
(i.e. the loop stops all iteration regardless of state)
* If the callback returns non-zero, the parent fn returns GIT_EUSER
* Although the parent returns GIT_EUSER, no error will be set in
the library and `giterr_last()` will return NULL if called.
This commit makes those changes across the library and adds tests
for most of the iteration APIs to make sure that they follow the
above rules.
If we find several objects with the same prefix, we need to free the
memory where we stored the earlier object. Keep track of the raw.data
pointer across read_prefix calls and free it if we find another
object.
There are three changes here:
- correctly propogate error code from failed object lookups
- make zlib inflate use our allocators
- add OID to notfound error in ODB lookups
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.
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 migrates odb.c, odb_loose.c, odb_pack.c and pack.c to
the new style of error handling. Also got the unix and win32
versions of map.c. There are some minor changes to other
files but no others were completely converted.
This also contains an update to filebuf so that a zeroed out
filebuf will not think that the fd (== 0) is actually open
(and inadvertently call close() on fd 0 if cleaned up).
Lastly, this was built and tested on win32 and contains a
bunch of fixes for the win32 build which was pretty broken.
This makes so much sense that I can't believe it hasn't been done
before. Kill the old `git_fbuffer` and read files straight into
`git_buf` objects.
Also: In order to fully support 4GB files in 32-bit systems, the
`git_buf` implementation has been changed from using `ssize_t` for
storage and storing negative values on allocation failure, to using
`size_t` and changing the buffer pointer to a magical pointer on
allocation failure.
Hopefully this won't break anything.
This is legacy compat stuff for when `deflateBound` is not defined, but
we're not embedding zlib and that function is always available. Kill
that with fire.
This takes all of the functions that look up simple data about
paths (such as `git_futils_isdir`) and moves them over to path.h
(becoming `git_path_isdir`). This leaves fileops.h just with
functions that actually manipulate the filesystem or look at
the file contents in some way.
As part of this, the dir.h header which is really just for win32
support was moved into win32 (with some minor changes).
