/** Open an archive for reading and perform the necessary boilerplate.
* This takes care of creating the libarchive 'archive' struct, setting up
* compression and format options, opening a file descriptor, setting up the
* buffer size, and performing a stat on the path once opened.
* On error, no file descriptor is opened, and the archive pointer returned
* will be set to NULL.
* @param handle the context handle
* @param path the path of the archive to open
* @param buf space for a stat buffer for the given path
* @param archive pointer to place the created archive object
* @param error error code to set on failure to open archive
* @return -1 on failure, >=0 file descriptor on success
*/
int _alpm_open_archive(alpm_handle_t *handle, const char *path,
struct stat *buf, struct archive **archive, alpm_errno_t error)
{
int fd;
size_t bufsize = ALPM_BUFFER_SIZE;
errno = 0;
if((*archive = archive_read_new()) == NULL) {
RET_ERR(handle, ALPM_ERR_LIBARCHIVE, -1);
}
_alpm_archive_read_support_filter_all(*archive);
archive_read_support_format_all(*archive);
_alpm_log(handle, ALPM_LOG_DEBUG, "opening archive %s\n", path);
OPEN(fd, path, O_RDONLY | O_CLOEXEC);
if(fd < 0) {
_alpm_log(handle, ALPM_LOG_ERROR,
_("could not open file %s: %s\n"), path, strerror(errno));
goto error;
}
if(fstat(fd, buf) != 0) {
_alpm_log(handle, ALPM_LOG_ERROR,
_("could not stat file %s: %s\n"), path, strerror(errno));
goto error;
}
#ifdef HAVE_STRUCT_STAT_ST_BLKSIZE
if(buf->st_blksize > ALPM_BUFFER_SIZE) {
bufsize = buf->st_blksize;
}
#endif
if(archive_read_open_fd(*archive, fd, bufsize) != ARCHIVE_OK) {
_alpm_log(handle, ALPM_LOG_ERROR, _("could not open file %s: %s\n"),
path, archive_error_string(*archive));
goto error;
}
return fd;
error:
_alpm_archive_read_free(*archive);
*archive = NULL;
if(fd >= 0) {
close(fd);
}
RET_ERR(handle, error, -1);
}
/**
* Open a package mtree file for reading.
* @param pkg the local package to read the changelog of
* @return a archive structure for the package mtree file
*/
static struct archive *_cache_mtree_open(alpm_pkg_t *pkg)
{
int r;
struct archive *mtree;
alpm_db_t *db = alpm_pkg_get_db(pkg);
char *mtfile = _alpm_local_db_pkgpath(db, pkg, "mtree");
if(access(mtfile, F_OK) != 0) {
/* there is no mtree file for this package */
goto error;
}
if((mtree = archive_read_new()) == NULL) {
pkg->handle->pm_errno = ALPM_ERR_LIBARCHIVE;
goto error;
}
_alpm_archive_read_support_filter_all(mtree);
archive_read_support_format_mtree(mtree);
if((r = _alpm_archive_read_open_file(mtree, mtfile, ALPM_BUFFER_SIZE))) {
_alpm_log(pkg->handle, ALPM_LOG_ERROR, _("error while reading file %s: %s\n"),
mtfile, archive_error_string(mtree));
pkg->handle->pm_errno = ALPM_ERR_LIBARCHIVE;
_alpm_archive_read_free(mtree);
goto error;
}
free(mtfile);
return mtree;
error:
free(mtfile);
return NULL;
}
