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/*
* 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 "filelock.h"
#include "fileops.h"
static const char *GIT_FILELOCK_EXTENSION = ".lock\0";
static const size_t GIT_FILELOCK_EXTLENGTH = 6;
#define BUILD_PATH_LOCK(_lock, _path) { \
memcpy(_path, _lock->path, _lock->path_length); \
memcpy(_path + _lock->path_length, GIT_FILELOCK_EXTENSION,\
GIT_FILELOCK_EXTLENGTH);\
}
int git_filelock_init(git_filelock *lock, const char *path)
{
if (lock == NULL || path == NULL)
return GIT_ERROR;
memset(lock, 0x0, sizeof(git_filelock));
lock->path_length = strlen(path);
if (lock->path_length + GIT_FILELOCK_EXTLENGTH >= GIT_PATH_MAX)
return GIT_ERROR;
memcpy(lock->path, path, lock->path_length);
return GIT_SUCCESS;
}
int git_filelock_lock(git_filelock *lock, int append)
{
char path_lock[GIT_PATH_MAX];
BUILD_PATH_LOCK(lock, path_lock);
/* If file already exists, we cannot create a lock */
if (gitfo_exists(path_lock) == 0)
return GIT_EOSERR;
lock->file_lock = gitfo_creat(path_lock, 0666);
if (lock->file_lock < 0)
return GIT_EOSERR;
lock->is_locked = 1;
/* TODO: do a flock() in the descriptor file_lock */
if (append && gitfo_exists(lock->path) == 0) {
git_file source;
char buffer[2048];
size_t read_bytes;
source = gitfo_open(lock->path, O_RDONLY);
if (source < 0)
return GIT_EOSERR;
while ((read_bytes = gitfo_read(source, buffer, 2048)) > 0)
gitfo_write(lock->file_lock, buffer, read_bytes);
gitfo_close(source);
}
return GIT_SUCCESS;
}
void git_filelock_unlock(git_filelock *lock)
{
char path_lock[GIT_PATH_MAX];
BUILD_PATH_LOCK(lock, path_lock);
if (lock->is_locked) {
/* The flock() in lock->file_lock is removed
* automatically when closing the descriptor */
gitfo_close(lock->file_lock);
gitfo_unlink(path_lock);
lock->is_locked = 0;
}
}
int git_filelock_commit(git_filelock *lock)
{
int error;
char path_lock[GIT_PATH_MAX];
BUILD_PATH_LOCK(lock, path_lock);
if (!lock->is_locked || lock->file_lock < 0)
return GIT_ERROR;
/* FIXME: flush the descriptor? */
gitfo_close(lock->file_lock);
error = gitfo_move_file(path_lock, lock->path);
if (error < GIT_SUCCESS)
gitfo_unlink(path_lock);
lock->is_locked = 0;
return error;
}
int git_filelock_write(git_filelock *lock, const void *buffer, size_t length)
{
if (!lock->is_locked || lock->file_lock < 0)
return GIT_ERROR;
return gitfo_write(lock->file_lock, (void *)buffer, length);
}
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