mirrors/git
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

commit-slab: introduce slabname##_peek() function

Browse Source 
There is no API to ask "Does this commit have associated data in
slab?".  If an application wants to (1) parse just a few commits at
the beginning of a process, (2) store data for only these commits,
and then (3) start processing many commits, taking into account the
data stored (for a few of them) in the slab, the application would
use slabname##_at() to allocate a space to store data in (2), but
there is no API other than slabname##_at() to use in step (3).  This
allocates and wastes new space for these commits the caller is only
interested in checking if they have data stored in step (2).

Introduce slabname##_peek(), which is similar to slabname##_at() but
returns NULL when there is no data already associated to it in such
a use case.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Junio C Hamano
2015-05-14 15:25:52 -07:00
parent 282616c72d
commit 862e730ec1
2 changed files with 49 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
commit.c
View File

@ -244,7 +244,12 @@ void set_commit_buffer(struct commit *commit, void *buffer, unsigned long size)
const void *get_cached_commit_buffer(const struct commit *commit, unsigned long *sizep)
{
struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
if (!v) {
if (sizep)
*sizep = 0;
return NULL;
}
if (sizep)
*sizep = v->size;
return v->buffer;
@ -271,24 +276,31 @@ const void *get_commit_buffer(const struct commit *commit, unsigned long *sizep)
void unuse_commit_buffer(const struct commit *commit, const void *buffer)
{
struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
if (v->buffer != buffer)
struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
if (!(v && v->buffer == buffer))
free((void *)buffer);
}
void free_commit_buffer(struct commit *commit)
{
struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
free(v->buffer);
v->buffer = NULL;
v->size = 0;
struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
if (v) {
free(v->buffer);
v->buffer = NULL;
v->size = 0;
}
}
const void *detach_commit_buffer(struct commit *commit, unsigned long *sizep)
{
struct commit_buffer *v = buffer_slab_at(&buffer_slab, commit);
struct commit_buffer *v = buffer_slab_peek(&buffer_slab, commit);
void *ret;
if (!v) {
if (sizep)
*sizep = 0;
return NULL;
}
ret = v->buffer;
if (sizep)
*sizep = v->size;