Index optimization

`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.

reference_rename: git compliant reference renaming v2

 - msvc compilation warnings
 - not released file handle that prevents file removal

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>

Signed-off-by: schu <schu-github@schulog.org>

git_futils_rmdir_recurs() shall remove the given directory and all
subdirectories. This happens only if the directories are empty.

Signed-off-by: schu <schu-github@schulog.org>

Signed-off-by: schu <schu-github@schulog.org>

the old name succeeds, e.g. refs/heads/foo -> refs/heads/foo/bar

Reported-by: nulltoken <emeric.fermas@gmail.com>
Signed-off-by: schu <schu-github@schulog.org>

Run `make -f Makefile.embed` to get a `libgit2.a` with no dependencies
and no configuration on any Unix-like system.

The generated library can be linked with any piece of software without
licensing issues.

Have fun.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

repository: fix typo'ed assert

Restore config10 test file

Removing a section variable doesn't remove its section
header. Overwrite the config10 file so there are no changes after the
test is run.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

It removes all entries with equal path except last added.

On large indexes git_index_append() + git_index_uniq() before writing is
*much* faster, than git_index_add().

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

The routine remove duplictes from the vector. Only the last added element
of elements with equal keys remains in the vector.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

Index operation use git_vector_sort() to sort index entries. Since index
support adding duplicates (two or more entries with the same path), it's
important to preserve order of elements. Preserving order of elements
allows to make decisions based on order. For example it's possible to
implement function witch removes all duplicates except last added.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

In some cases it's important to preserve order of elements with equal
keys (stable sort). qsort(3) doesn't define order of elements with
equal keys.

git__msort() implements merge sort which is stable sort.

Implementation taken from git. Function renamed git_qsort() -> git__msort().

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

git_index_find() in index_insert() is useless if replace is not
requested (append). Do not call it in this case.
It speedup git_index_append() *dramatically* on large indexes.

$ cat index_test.c

int main(int argc, char **argv)
{
        git_index *index;
        git_repository *repo;
        git_odb *odb;
        struct git_index_entry entry;
        git_oid tree_oid;
        char tree_hex[41];
        int i;

        git_repository_init(&repo, "/tmp/myrepo", 0);
        odb = git_repository_database(repo);
        git_repository_index(&index, repo);

        memset(&entry, 0, sizeof(entry));
        git_odb_write(&entry.oid, odb, "", 0, GIT_OBJ_BLOB);
        entry.path = "test.file";

        for (i = 0; i < 50000; i++)
                git_index_append2(index, &entry);

        git_tree_create_fromindex(&tree_oid, index);
        git_oid_fmt(tree_hex, &tree_oid);
        tree_hex[40] = '\0';
        printf("tree: %s\n", tree_hex);

        git_index_free(index);
        git_repository_free(repo);

        return 0;
}

Before:
$ time ./index_test
tree: 43f73659c43b651588cc81459d9e25b08721b95d
./index_test  151.19s user 0.05s system 99% cpu 2:31.78 total

After:
$ time ./index_test
tree: 43f73659c43b651588cc81459d9e25b08721b95d
./index_test  0.05s user 0.00s system 94% cpu 0.059 total

About 2573 times speedup on this test :)

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

Small fixes in pack_window_open

Fix warning in examples/general.c

Fix MSVC compilation issue

Check if the window structure has actually been allocated before
trying to access it, and don't leak said structure if the map fails.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

Include common.h in hashtable.h

Without this, hashtable.h doesn't know what uint32_t is and the
compiler thinks that it's a function type.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

A bit of networking

examples/general.c:393:25: warning: unused variable ‘reftarget’ [-Wunused-variable]
examples/general.c:357:19: warning: unused variable ‘e’ [-Wunused-variable]
examples/general.c:444:1: warning: control reaches end of non-void function [-Wreturn-type]

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

examples/general.c:402:5: warning: enumeration value ‘GIT_REF_INVALID’ not handled in switch [-Wswitch]
examples/general.c:402:5: warning: enumeration value ‘GIT_REF_PACKED’ not handled in switch [-Wswitch]
examples/general.c:402:5: warning: enumeration value ‘GIT_REF_HAS_PEEL’ not handled in switch [-Wswitch]
examples/general.c:402:5: warning: enumeration value ‘GIT_REF_LISTALL’ not handled in switch [-Wswitch]

Signe-off-by: Kirill A. Shutemov <kirill@shutemov.name>

general.c:208: warning: passing argument 7 of 'git_commit_create_v' from incompatible pointer type

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

If the section header is the last line in the file,
parse_section_header would incorrectly decide that the input had been
truncated.

Fix this by checking whether the actual input line is correctly
formatted.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>

Otherwise, the information about why there was an error gets lost.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>