Changeset 38340 for branches/eam_branches/ohana.20150429/src/libfits/extern/gzip.c

Timestamp:

May 30, 2015, 7:59:48 PM (11 years ago)

Author:

eugene

Message:

more work on compression : cfitsio assumes gzip, not zlib (I have made uncompress general )

File:

• branches/eam_branches/ohana.20150429/src/libfits/extern/gzip.c (modified) (8 diffs)

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

@@ -2 +2 @@
 # include <gfitsio.h>
 # include <zlib.h>
+# define EXTRA_VERBOSE 1
 
 /** the two functions in this file re-implement the uncompress function of zlib.  
@@ -10 +11 @@
 
 /* zlib.h -- interface of the 'zlib' general purpose compression library
-  version 1.2.3, July 18th, 2005
-
-  Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
-
-  This software is provided 'as-is', without any express or implied
-  warranty.  In no event will the authors be held liable for any damages
-  arising from the use of this software.
-
-  Permission is granted to anyone to use this software for any purpose,
-  including commercial applications, and to alter it and redistribute it
-  freely, subject to the following restrictions:
-
-  1. The origin of this software must not be misrepresented; you must not
-     claim that you wrote the original software. If you use this software
-     in a product, an acknowledgment in the product documentation would be
-     appreciated but is not required.
-  2. Altered source versions must be plainly marked as such, and must not be
-     misrepresented as being the original software.
-  3. This notice may not be removed or altered from any source distribution.
-
-  Jean-loup Gailly        Mark Adler
-  jloup@gzip.org          madler@alumni.caltech.edu
-
-
-  The data format used by the zlib library is described by RFCs (Request for
-  Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
-  (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
+   version 1.2.3, July 18th, 2005
+
+   Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
+
+   This software is provided 'as-is', without any express or implied
+   warranty.  In no event will the authors be held liable for any damages
+   arising from the use of this software.
+
+   Permission is granted to anyone to use this software for any purpose,
+   including commercial applications, and to alter it and redistribute it
+   freely, subject to the following restrictions:
+
+   1. The origin of this software must not be misrepresented; you must not
+   claim that you wrote the original software. If you use this software
+   in a product, an acknowledgment in the product documentation would be
+   appreciated but is not required.
+   2. Altered source versions must be plainly marked as such, and must not be
+   misrepresented as being the original software.
+   3. This notice may not be removed or altered from any source distribution.
+
+   Jean-loup Gailly        Mark Adler
+   jloup@gzip.org          madler@alumni.caltech.edu
+
+
+   The data format used by the zlib library is described by RFCs (Request for
+   Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
+   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
 */
 
 /*
-     The 'zlib' compression library provides in-memory compression and
+  The 'zlib' compression library provides in-memory compression and
   decompression functions, including integrity checks of the uncompressed
   data.  This version of the library supports only one compression method
@@ -46 +47 @@
   stream interface.
 
-     Compression can be done in a single step if the buffers are large
+  Compression can be done in a single step if the buffers are large
   enough (for example if an input file is mmap'ed), or can be done by
   repeated calls of the compression function.  In the latter case, the
@@ -52 +53 @@
   (providing more output space) before each call.
 
-     The compressed data format used by default by the in-memory functions is
+  The compressed data format used by default by the in-memory functions is
   the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
   around a deflate stream, which is itself documented in RFC 1951.
 
-     The library also supports reading and writing files in gzip (.gz) format
+  The library also supports reading and writing files in gzip (.gz) format
   with an interface similar to that of stdio using the functions that start
   with "gz".  The gzip format is different from the zlib format.  gzip is a
   gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
 
-     This library can optionally read and write gzip streams in memory as well.
-
-     The zlib format was designed to be compact and fast for use in memory
+  This library can optionally read and write gzip streams in memory as well.
+
+  The zlib format was designed to be compact and fast for use in memory
   and on communications channels.  The gzip format was designed for single-
   file compression on file systems, has a larger header than zlib to maintain
   directory information, and uses a different, slower check method than zlib.
 
-     The library does not install any signal handler. The decoder checks
+  The library does not install any signal handler. The decoder checks
   the consistency of the compressed data, so the library should never
   crash even in case of corrupted input.
@@ -116 +117 @@
 }
 
-// XXX ??? is cfitsio writing data which is incompatible with zlib ???
+# define ESCAPE(RET) { fprintf (stderr, "gzip error in %s @ %s:%d\n", __func__, __FILE__, __LINE__); return (RET); }
+
+// NOTE: CFITSIO uses gzip format, not just zlib
 int gfits_uncompress (Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)
 {
-    z_stream stream;
-    int i, 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;
-    if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
-
-    stream.zalloc = Z_NULL;
-    stream.zfree  = Z_NULL;
-    stream.opaque = Z_NULL;
-
-    if (0) {
-      fprintf (stderr, "inp unc: ");
-      for (i = 0; i < sourceLen; i++) {
-        fprintf (stderr, "0x%02hhx ", source[i]);
-      }
-      fprintf (stderr, "\n");
-    }
-
-    // err = inflateInit2(&stream, -15);
-    err = inflateInit(&stream);
-    if (0) fprintf (stderr, "inp buffers unc 0: %d => %d => %d\n", stream.avail_in, stream.avail_out, (int) stream.total_out);
-
-    if (err != Z_OK) return err;
-
-    err = inflate(&stream, Z_FINISH);
-    if (0) fprintf (stderr, "out buffers unc 1: %d => %d => %d\n", stream.avail_in, stream.avail_out, (int) stream.total_out);
-    if (err != Z_STREAM_END) {
-        inflateEnd(&stream);
-        if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0)) return Z_DATA_ERROR;
-        return err;
-    }
-    if (0) fprintf (stderr, "out buffers unc 2: %d => %d => %d\n", stream.avail_in, stream.avail_out, (int) stream.total_out);
-
-    if (0) {
-      fprintf (stderr, "out unc: ");
-      for (i = 0; i < stream.total_out; i++) {
-        fprintf (stderr, "0x%02hhx ", dest[i]);
-      }
-      fprintf (stderr, "\n");
-    }
-
-    assert (stream.total_out <= *destLen);
-    *destLen = stream.total_out;
-
-    err = inflateEnd(&stream);
-    return err;
+  z_stream stream;
+  int i, 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) ESCAPE (Z_BUF_ERROR);
+  
+  stream.next_out = dest;
+  stream.avail_out = (uInt)*destLen;
+  if ((uLong)stream.avail_out != *destLen) ESCAPE (Z_BUF_ERROR);
+  
+  stream.zalloc = Z_NULL;
+  stream.zfree  = Z_NULL;
+  stream.opaque = Z_NULL;
+  
+  if (EXTRA_VERBOSE) {
+    fprintf (stderr, "inp unc: ");
+    for (i = 0; i < sourceLen; i++) {
+      fprintf (stderr, "0x%02hhx ", source[i]);
+    }
+    fprintf (stderr, "\n");
+  }
+  
+  // a value of 32 tells inflate to use the window size used in the compression AND to look for both zlib and gzip headers
+  err = inflateInit2(&stream, 32);
+  if (err != Z_OK) ESCAPE (err);
+  
+  err = inflate(&stream, Z_FINISH);
+  if (err != Z_STREAM_END) {
+    inflateEnd(&stream);
+    if (err == Z_NEED_DICT || (err == Z_BUF_ERROR && stream.avail_in == 0)) ESCAPE (Z_DATA_ERROR);
+    ESCAPE(err);
+  }
+  
+  if (EXTRA_VERBOSE) {
+    fprintf (stderr, "out unc: ");
+    for (i = 0; i < stream.total_out; i++) {
+      fprintf (stderr, "0x%02hhx ", dest[i]);
+    }
+    fprintf (stderr, "\n");
+  }
+
+  assert (stream.total_out <= *destLen);
+  *destLen = stream.total_out;
+
+  err = inflateEnd(&stream);
+  return err;
 }
 
@@ -182 +182 @@
 
   /* Check for source > 64K on 16-bit machine: */
-  if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
+  if ((uLong)stream.avail_in != sourceLen) ESCAPE (Z_BUF_ERROR);
 
   stream.next_out = dest;
   stream.avail_out = (uInt)*destLen; // allocated space
-  if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
+  if ((uLong)stream.avail_out != *destLen) ESCAPE (Z_BUF_ERROR);
 
   stream.zalloc = Z_NULL;
@@ -192 +192 @@
   stream.opaque = Z_NULL;
 
-  if (0) {
+  if (EXTRA_VERBOSE) {
     fprintf (stderr, "inp cmp: ");
     for (i = 0; i < sourceLen; i++) {
@@ -202 +202 @@
   // the '1' is the compression level: make this a user argument
   // NOTE: cfitsio uses a fixed value of 1
-  err = deflateInit(&stream, 1);
+  // I am using deflateInit2 because cfitsio expects gzip, not just zlib
+  err = deflateInit2(&stream, 1, Z_DEFLATED, 31, 8, Z_DEFAULT_STRATEGY);
   if (0) fprintf (stderr, "inp buffers cmp 0: %d => %d => %d\n", stream.avail_in, stream.avail_out, (int) stream.total_out);
 
-  if (err != Z_OK) return err;
+  if (err != Z_OK) ESCAPE(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 (0) fprintf (stderr, "out buffers cmp 1: %d => %d => %d\n", stream.avail_in, stream.avail_out, (int) stream.total_out);
-
   if (err != Z_STREAM_END) {
     err = deflateEnd(&stream);
-    return Z_BUF_ERROR;
-  }
-  if (0) fprintf (stderr, "out buffers cmp 2: %d => %d => %d\n", stream.avail_in, stream.avail_out, (int) stream.total_out);
-
-  if (0) {
+    ESCAPE (Z_BUF_ERROR);
+  }
+
+  if (EXTRA_VERBOSE) {
     fprintf (stderr, "out cmp: ");
     for (i = 0; i < stream.total_out; i++) {