Drop the GLibc implementation of Merge Sort and replace it with Timsort.
The algorithm has been tuned to work on arrays of pointers (void **),
so there's no longer a need to abstract the byte-width of each element
in the array.
All the comparison callbacks now take pointers-to-elements, not
pointers-to-pointers, so there's now one less level of dereferencing.
E.g.
int index_cmp(const void *a, const void *b)
{
- const git_index_entry *entry_a = *(const git_index_entry **)(a);
+ const git_index_entry *entry_a = (const git_index_entry *)(a);
The result is up to a 40% speed-up when sorting vectors. Memory usage
remains lineal.
A new `bsearch` implementation has been added, whose callback also
supplies pointer-to-elements, to uniform the Vector API again.
`git_futils_rmdir_r`: rename, clean up.
`git_reference_rename`: cleanup. Do not use 3x4096 buffers on the stack
or things will get ugly very fast. We can reuse the same buffer.
So far libgit2 didn't handle the following scenarios:
* Rename of reference m -> m/m
* Rename of reference n/n -> n
Fixed.
Since we don't write reflogs, we have to delete any old reflog for the
renamed reference. Otherwise git.git will possibly fail when it finds
invalid logs.
Reported-by: nulltoken <emeric.fermas@gmail.com>
Signed-off-by: schu <schu-github@schulog.org>
Cleaned up the structure of the whole OS-abstraction layer.
fileops.c now contains a set of utility methods for file management used
by the library. These are abstractions on top of the original POSIX
calls.
There's a new file called `posix.c` that contains
emulations/reimplementations of all the POSIX calls the library uses.
These are prefixed with `p_`. There's a specific posix file for each
platform (win32 and unix).
All the path-related methods have been moved from `utils.c` to `path.c`
and have their own prefix.
The assertion in line 360 was there to check that only loose refs were
being written as loose, but there are times when we need to re-write a
packed reference as loose.
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.
There is no need to store the format outselves, as the library
provides git_filebuf_printf which takes care of the formatting itself.
Also get rid of an use of strcat + strcpy which is always a nice
thing.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Ok, this is the real deal. Hopefully. Here's how it's going to work:
- One main method, called `git__throw`, that sets the error
code and error message when an error happens.
This method must be called in every single place where an error
code was being returned previously, setting an error message
instead.
Example, instead of:
return GIT_EOBJCORRUPTED;
Use:
return git__throw(GIT_EOBJCORRUPTED,
"The object is missing a finalizing line feed");
And instead of:
[...] {
error = GIT_EOBJCORRUPTED;
goto cleanup;
}
Use:
[...] {
error = git__throw(GIT_EOBJCORRUPTED, "What an error!");
goto cleanup;
}
The **only** exception to this are the allocation methods, which
return NULL on failure but already set the message manually.
/* only place where an error code can be returned directly,
because the error message has already been set by the wrapper */
if (foo == NULL)
return GIT_ENOMEM;
- One secondary method, called `git__rethrow`, which can be used to
fine-grain an error message and build an error stack.
Example, instead of:
if ((error = foobar(baz)) < GIT_SUCCESS)
return error;
You can now do:
if ((error = foobar(baz)) < GIT_SUCCESS)
return git__rethrow(error, "Failed to do a major operation");
The return of the `git_lasterror` method will be a string in the
shape of:
"Failed to do a major operation. (Failed to do an internal
operation)"
E.g.
"Failed to open the index. (Not enough permissions to access
'/path/to/index')."
NOTE: do not abuse this method. Try to write all `git__throw`
messages in a descriptive manner, to avoid having to rethrow them to
clarify their meaning.
This method should only be used in the places where the original
error message set by a subroutine is not specific enough.
It is encouraged to continue using this style as much possible to
enforce error propagation:
if ((error = foobar(baz)) < GIT_SUCCESS)
return error; /* `foobar` has set an error message, and
we are just propagating it */
The error handling revamp will take place in two phases:
- Phase 1: Replace all pieces of code that return direct error codes
with calls to `git__throw`. This can be done semi-automatically
using `ack` to locate all the error codes that must be replaced.
- Phase 2: Add some `git__rethrow` calls in those cases where the
original error messages are not specific enough.
Phase 1 is the main goal. A minor libgit2 release will be shipped once
Phase 1 is ready, and the work will start on gradually improving the
error handling mechanism by refining specific error messages.
OTHER NOTES:
- When writing error messages, please refrain from using weasel
words. They add verbosity to the message without giving any real
information. (<3 Emeric)
E.g.
"The reference file appears to be missing a carriage return"
Nope.
"The reference file is missing a carriage return"
Yes.
- When calling `git__throw`, please try to use more generic error
codes so we can eventually reduce the list of error codes to
something more reasonable. Feel free to add new, more generic error
codes if these are going to replace several of the old ones.
E.g.
return GIT_EREFCORRUPTED;
Can be turned into:
return git__throw(GIT_EOBJCORRUPTED,
"The reference is corrupted");
Typical use is git_reference_resolve(&ref, ref). Currently, if there is
an error, ref will point to NULL, causing the user to lose that
reference.
Always update resolved_ref instead of just on finding an OID ref,
storing the last valid reference in it.
This change helps simplify the code for allowing root commits.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Allow any well-formed reference name to live under refs/ removing the
condition that they be under refs/{heads,tags,remotes}/ as was the
design of git.
An exception is made for HEAD which is allowed to contain an OID
reference in detached HEAD state.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Add internal reference create and rename functions which take a force
parameter, telling them to overwrite an existing reference if it
exists.
These functions try to update the reference if it's of the same type
as the one it's going to be replaced by. Otherwise the old reference
becomes invalid.
Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
List all the references in the repository, calling a custom
callback for each one.
The listed references may be filtered by type, or using
a bitwise OR of several types. Use the magic value
`GIT_REF_LISTALL` to obtain all references, including
packed ones.
The `callback` function will be called for each of the references
in the repository, and will receive the name of the reference and
the `payload` value passed to this method.
It's no longer retarded. All object interdependencies are stored as OIDs
instead of actual objects. This should be hundreds of times faster,
specially on big repositories. Heck, who knows, maye it doesn't even
segfault -- wouldn't that be awesome?
What has changed on the API?
`git_commit_parent`, `git_commit_tree`, `git_tag_target` now return
their values through a pointer-to-pointer, and have an error code.
`git_commit_set_tree` and `git_tag_set_target` now return an error
code and may fail.
`git_repository_free__no_gc` has been deprecated because it's
stupid. Since there are no longer any interdependencies between
objects, we don't need internal reference counting, and GC
never fails or double-free's pointers.
`git_object_close` now does a very sane thing: marks an object
as unused. Closed objects will be eventually free'd from the
object cache based on LRU. Please use `git_object_close` from
the garbage collector `destroy` method on your bindings. It's
100% safe.
`git_repository_gc` is a new method that forces a garbage collector
pass through the repo, to free as many LRU objects as possible.
This is useful if we are running out of memory.
We now store only one sorting callback that does entry comparison. This
is used when sorting the entries using a quicksort, and when looking for
a specific entry with the new search methods.
The following search methods now exist:
git_vector_search(vector, entry)
git_vector_search2(vector, custom_search_callback, key)
git_vector_bsearch(vector, entry)
git_vector_bsearch2(vector, custom_search_callback, key)
The sorting state of the vector is now stored internally.
Signed-off-by: Vicent Marti <tanoku@gmail.com>
The methods previously known as
git_repository_lookup
git_repository_newobject
git_repository_lookup_ref
are now part of their respective namespaces:
git_object_lookup
git_object_new
git_reference_lookup
This makes the API more consistent with the new references API.
Signed-off-by: Vicent Marti <tanoku@gmail.com>
