ssize_t udfread_file_read(UDFFILE *p, void *buf, size_t bytes)
{
uint8_t *bufpt = (uint8_t *)buf;
/* sanity checks */
if (!p || !buf || p->pos < 0) {
return -1;
}
if ((ssize_t)bytes < 0 || (int64_t)bytes < 0) {
return -1;
}
/* limit range to file size */
if ((uint64_t)p->pos + bytes > (uint64_t)udfread_file_size(p)) {
bytes = udfread_file_size(p) - p->pos;
}
/* small files may be stored inline in file entry */
if (p->fe->content_inline) {
memcpy(buf, &p->fe->data.content + p->pos, bytes);
p->pos += bytes;
return bytes;
}
/* allocate temp storage for input block */
if (!p->block) {
p->block_mem = malloc(2 * UDF_BLOCK_SIZE);
p->block = ALIGN(p->block_mem, UDF_BLOCK_SIZE);
}
/* read chunks */
while (bytes > 0) {
int64_t r = _read(p, bufpt, bytes);
if (r < 0) {
if (bufpt != buf) {
/* got some bytes */
break;
}
/* got nothing */
return -1;
}
bufpt += r;
bytes -= r;
}
return (intptr_t)bufpt - (intptr_t)buf;
}
int64_t udfread_file_seek(UDFFILE *p, int64_t pos, int whence)
{
if (p) {
switch (whence) {
case UDF_SEEK_CUR:
pos += p->pos;
break;
case UDF_SEEK_END:
pos = udfread_file_size(p) - pos;
break;
case UDF_SEEK_SET:
default:
break;
}
if (pos >= 0 && pos <= udfread_file_size(p)) {
p->pos = pos;
p->block_valid = 0;
return p->pos;
}
}
return -1;
}
static void _cat(UDFFILE *fp)
{
uint8_t buf[2048];
int64_t got = 0;
ssize_t result;
while ((result = udfread_file_read(fp, buf, sizeof(buf))) > 0) {
fwrite(buf, 1, (size_t)result, stdout);
got += result;
}
if (result < 0) {
fprintf(stderr, "udfread_file_read(offset=%"PRId64") failed\n", udfread_file_tell(fp));
}
fprintf(stderr, "wrote %"PRId64" bytes of %"PRId64"\n", got, udfread_file_size(fp));
}
