void mem_free(void *ptr) {
#ifndef USE_DMT
--g_mem_mem_allocs_count;
free(ptr);
#else
dmt_free(ptr);
#endif
}
static void* tar_read(mount_t *mnt, const char *filename, int *size) {
mtar_t *tar = mnt->udata;
int err;
mtar_header_t h;
/* Find and load header for file */
err = tar_find(mnt, filename, &h);
if (err) {
return 0;
}
/* Allocate and read data, set size and return */
char *p = dmt_malloc(h.size);
err = mtar_read_data(tar, p, h.size);
if (err) {
dmt_free(p);
return NULL;
}
*size = h.size;
return p;
}
static int tar_mount(mount_t *mnt, const char *path) {
tar_mount_t *tm = NULL;
FILE *fp = NULL;
/* Try to open file */
fp = fopen(path, "rb");
if (!fp) {
goto fail;
}
/* Init tar_mount_t */
tm = dmt_calloc(1, sizeof(*tm));
tm->fp = fp;
/* Init tar */
mtar_t *tar = &tm->tar;
tar->read = tar_stream_read;
tar->seek = tar_stream_seek;
tar->close = tar_stream_close;
tar->stream = tm;
/* Check start of file for valid tar header */
mtar_header_t h;
int err = mtar_read_header(tar, &h);
/* If checking the start of the file failed then check the end of file for a
* "TAR\0" tag and offset, this would have been added when packaging (see
* `package.c`) to indicate the offset of the tar archive's beginning from the
* file's end */
if (err) {
int offset;
char buf[4] = "";
fseek(fp, -8, SEEK_END);
fread(buf, 1, 4, fp);
fread(&offset, 1, 4, fp);
if ( !memcmp(buf, "TAR\0", 4) ) {
fseek(fp, -offset, SEEK_END);
tm->offset = ftell(fp);
}
mtar_rewind(tar);
err = mtar_read_header(tar, &h);
if (err) {
goto fail;
}
}
/* Iterate all files and store [namehash:position] pairs; this is used by
* tar_find() */
mtar_rewind(tar);
int n = 0;
int cap = 0;
while ( (mtar_read_header(tar, &h)) == MTAR_ESUCCESS ) {
/* Realloc if map capacity was reached */
if (n >= cap) {
cap = cap ? (cap << 1) : 16;
tm->map = dmt_realloc(tm->map, cap * sizeof(*tm->map));
}
/* Store entry */
strip_trailing_slash(h.name);
tm->map[n].hash = hash_string_ignore_case(h.name);
tm->map[n].pos = tar->pos;
/* Next */
mtar_next(tar);
n++;
}
tm->nfiles = n;
/* Init mount */
mnt->udata = tar;
mnt->unmount = tar_unmount;
mnt->exists = tar_exists;
mnt->isFile = tar_isFile;
mnt->isDirectory = tar_isDirectory;
mnt->read = tar_read;
/* Return ok */
return FILESYSTEM_ESUCCESS;
fail:
if (fp) fclose(fp);
if (tm) {
dmt_free(tm->map);
dmt_free(tm);
}
return FILESYSTEM_EFAILURE;
}
static void tar_unmount(mount_t *mnt) {
tar_mount_t *tm = mnt->udata;
mtar_close(&tm->tar);
dmt_free(tm->map);
dmt_free(tm);
}
