libgit2/src/status.c
Jason Penny 205166d27c status: get blob object id of file on disk
Add git_status_hashfile() to get blob's object id for a file without adding
it to the object database or needing a repository at all.
This functionality is similar to `git hash-object` without '-w'.
2011-07-09 13:49:50 +02:00

78 lines
2.3 KiB
C

/*
* This file is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2,
* as published by the Free Software Foundation.
*
* In addition to the permissions in the GNU General Public License,
* the authors give you unlimited permission to link the compiled
* version of this file into combinations with other programs,
* and to distribute those combinations without any restriction
* coming from the use of this file. (The General Public License
* restrictions do apply in other respects; for example, they cover
* modification of the file, and distribution when not linked into
* a combined executable.)
*
* This file is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "common.h"
#include "git2.h"
#include "fileops.h"
#include "hash.h"
int git_status_hashfile(git_oid *out, const char *path)
{
int fd, len;
char hdr[64], buffer[2048];
git_off_t size;
git_hash_ctx *ctx;
if ((fd = p_open(path, O_RDONLY)) < 0)
return git__throw(GIT_ENOTFOUND, "Could not open '%s'", path);
if ((size = git_futils_filesize(fd)) < 0 || !git__is_sizet(size)) {
p_close(fd);
return git__throw(GIT_EOSERR, "'%s' appears to be corrupted", path);
}
ctx = git_hash_new_ctx();
len = snprintf(hdr, sizeof(hdr), "blob %"PRIuZ, (size_t)size);
assert(len > 0);
assert(((size_t) len) < sizeof(hdr));
if (len < 0 || ((size_t) len) >= sizeof(hdr))
return git__throw(GIT_ERROR, "Failed to format blob header. Length is out of bounds");
git_hash_update(ctx, hdr, len+1);
while (size > 0) {
ssize_t read_len;
read_len = read(fd, buffer, sizeof(buffer));
if (read_len < 0) {
p_close(fd);
git_hash_free_ctx(ctx);
return git__throw(GIT_EOSERR, "Can't read full file '%s'", path);
}
git_hash_update(ctx, buffer, read_len);
size -= read_len;
}
p_close(fd);
git_hash_final(out, ctx);
git_hash_free_ctx(ctx);
return GIT_SUCCESS;
}