Changeset 38322 for branches/eam_branches/ohana.20150429/src/libfits/extern/gzip.c

Timestamp:

May 25, 2015, 8:08:57 PM (11 years ago)

Author:

eugene

Message:

adding compression of images in prep for compression / uncompression of tables

File:

• branches/eam_branches/ohana.20150429/src/libfits/extern/gzip.c (modified) (1 diff)

branches/eam_branches/ohana.20150429/src/libfits/extern/gzip.c

@@ -151 +151 @@
     return err;
 }
+
+int gfits_compress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
+{
+  z_stream stream;
+  int err;
+
+  stream.next_in = (Bytef*)source;
+  stream.avail_in = (uInt)sourceLen;
+
+  /* Check for source > 64K on 16-bit machine: */
+  if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
+
+  stream.next_out = dest;
+  stream.avail_out = (uInt)*destLen; // allocated space
+  if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
+
+  stream.zalloc = (alloc_func)0;
+  stream.zfree = (free_func)0;
+
+  err = deflateInit(&stream);
+  if (err != Z_OK) return err;
+
+  // XXX this is written to do the compression in a single pass.  it could be re-done to have 
+  // the compression occur in a series of steps
+  err = deflate(&stream, Z_FINISH);
+  if (err != Z_STREAM_END) {
+    deflateEnd(&stream);
+    return err;
+  }
+  assert (stream.total_out <= *destLen);
+  *destLen = stream.total_out;
+  
+  err = deflateEnd(&stream);
+  return err;
+}