Changeset ea459d4 in mainline for uspace/lib/riff/src/chunk.c

Timestamp:

2020-09-24T14:25:21Z (5 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

120031a5

Parents:

aaf962e6

git-author:

Jiri Svoboda <jiri@…> (2020-09-22 17:25:10)

git-committer:

Jiri Svoboda <jiri@…> (2020-09-24 14:25:21)

Message:

Reading typeface from TPF file

File:

• uspace/lib/riff/src/chunk.c (modified) (3 diffs)

uspace/lib/riff/src/chunk.c

@@ -393 +393 @@
 }
 
+/** Seek to position in chunk.
+ *
+ * @param rchunk RIFF chunk
+ * @param offset Offset
+ * @param whence SEEK_SET, SEEK_CUR or SEEK_END
+ * @return EOK on success or an error code
+ */
+errno_t riff_rchunk_seek(riff_rchunk_t *rchunk, long offset, int whence)
+{
+        long pos;
+        long dest;
+        int rv;
+
+        switch (whence) {
+        case SEEK_SET:
+                dest = rchunk->ckstart + offset;
+                break;
+        case SEEK_END:
+                dest = rchunk->ckstart + rchunk->cksize + offset;
+                break;
+        case SEEK_CUR:
+                pos = ftell(rchunk->riffr->f);
+                if (pos < 0)
+                        return EIO;
+                dest = pos + offset;
+                break;
+        default:
+                return EINVAL;
+        }
+
+        if (dest < rchunk->ckstart || dest > rchunk->ckstart + rchunk->cksize)
+                return ELIMIT;
+
+        rv = fseek(rchunk->riffr->f, dest, SEEK_SET);
+        if (rv < 0)
+                return EIO;
+
+        return EOK;
+}
+
 /** Return chunk data size.
  *
@@ -431 +471 @@
 /** Finish reading RIFF chunk.
  *
- * Seek to the first byte after end of chunk.
+ * Seek to the first byte after end of chunk. It is allowed, though,
+ * to return to the chunk later, e.g. using riff_rchunk_seek(@a rchunk, ..).
  *
  * @param rchunk Chunk structure
@@ -444 +485 @@
                 return EIO;
 
-        rchunk->riffr = NULL;
         return EOK;
 }