Separate zlib related code rather than having several #ifdef blocks.

taglib/CMakeLists.txt

@@ -309,6 +309,7 @@ set(toolkit_SRCS
   toolkit/tpropertymap.cpp
   toolkit/trefcounter.cpp
   toolkit/tdebuglistener.cpp
+  toolkit/tzlib.cpp
 )
 
 if(NOT WIN32)

taglib/mpeg/id3v2/id3v2frame.cpp

@@ -23,22 +23,16 @@
  *   http://www.mozilla.org/MPL/                                           *
  ***************************************************************************/
 
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
-#if HAVE_ZLIB
-#include <zlib.h>
-#endif
-
 #include <bitset>
 
 #include <tdebug.h>
 #include <tstringlist.h>
+#include <tzlib.h>
 
 #include "id3v2tag.h"
 #include "id3v2frame.h"
 #include "id3v2synchdata.h"
+
 #include "tpropertymap.h"
 #include "frames/textidentificationframe.h"
 #include "frames/urllinkframe.h"
@@ -251,60 +245,21 @@ ByteVector Frame::fieldData(const ByteVector &frameData) const
     frameDataOffset += 4;
   }
 
-#if HAVE_ZLIB
-  if(d->header->compression() &&
-     !d->header->encryption())
-  {
+  if(zlib::isAvailable() && d->header->compression() && !d->header->encryption()) {
     if(frameData.size() <= frameDataOffset) {
       debug("Compressed frame doesn't have enough data to decode");
       return ByteVector();
     }
 
-    z_stream stream = {};
-
-    if(inflateInit(&stream) != Z_OK)
-      return ByteVector();
-
-    ByteVector inData = frameData;
-
-    stream.avail_in = static_cast<uInt>(inData.size() - frameDataOffset);
-    stream.next_in = reinterpret_cast<Bytef *>(inData.data() + frameDataOffset);
-
-    static const unsigned int chunkSize = 1024;
-
-    ByteVector outData;
-    ByteVector chunk(chunkSize);
-
-    do {
-      stream.avail_out = static_cast<uInt>(chunk.size());
-      stream.next_out = reinterpret_cast<Bytef *>(chunk.data());
-
-      int result = inflate(&stream, Z_NO_FLUSH);
-
-      if(result == Z_STREAM_ERROR ||
-         result == Z_NEED_DICT ||
-         result == Z_DATA_ERROR ||
-         result == Z_MEM_ERROR)
-      {
-        if(result != Z_STREAM_ERROR)
-          inflateEnd(&stream);
-        debug("Error reading compressed stream");
-        return ByteVector();
-      }
-
-      outData.append(stream.avail_out == 0 ? chunk : chunk.mid(0, chunk.size() - stream.avail_out));
-    } while(stream.avail_out == 0);
-
-    inflateEnd(&stream);
-
-    if(frameDataLength != outData.size())
+    const ByteVector outData = zlib::decompress(frameData.mid(frameDataOffset));
+    if(frameDataLength != outData.size()) {
       debug("frameDataLength does not match the data length returned by zlib");
+    }
 
     return outData;
   }
-  else
-#endif
-    return frameData.mid(frameDataOffset, frameDataLength);
+
+  return frameData.mid(frameDataOffset, frameDataLength);
 }
 
 String Frame::readStringField(const ByteVector &data, String::Type encoding, int *position)

taglib/mpeg/id3v2/id3v2framefactory.cpp

@@ -23,11 +23,8 @@
  *   http://www.mozilla.org/MPL/                                           *
  ***************************************************************************/
 
-#ifdef HAVE_CONFIG_H
-#include <config.h>
-#endif
-
 #include <tdebug.h>
+#include <tzlib.h>
 
 #include "id3v2framefactory.h"
 #include "id3v2synchdata.h"
@@ -174,12 +171,11 @@ Frame *FrameFactory::createFrame(const ByteVector &origData, Header *tagHeader)
   // TagLib doesn't mess with encrypted frames, so just treat them
   // as unknown frames.
 
-#if !defined(HAVE_ZLIB) || HAVE_ZLIB == 0
-  if(header->compression()) {
+  if(!zlib::isAvailable() && header->compression()) {
     debug("Compressed frames are currently not supported.");
     return new UnknownFrame(data, header);
   }
-#endif
+
   if(header->encryption()) {
     debug("Encrypted frames are currently not supported.");
     return new UnknownFrame(data, header);

taglib/toolkit/tzlib.cpp

@@ -0,0 +1,107 @@
+/***************************************************************************
+    copyright            : (C) 2016 by Tsuda Kageyu
+    email                : tsuda.kageyu@gmail.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *   This library is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU Lesser General Public License version   *
+ *   2.1 as published by the Free Software Foundation.                     *
+ *                                                                         *
+ *   This library is distributed in the hope that it will be useful, but   *
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
+ *   Lesser General Public License for more details.                       *
+ *                                                                         *
+ *   You should have received a copy of the GNU Lesser General Public      *
+ *   License along with this library; if not, write to the Free Software   *
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA         *
+ *   02110-1301  USA                                                       *
+ *                                                                         *
+ *   Alternatively, this file is available under the Mozilla Public        *
+ *   License Version 1.1.  You may obtain a copy of the License at         *
+ *   http://www.mozilla.org/MPL/                                           *
+ ***************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#ifdef HAVE_ZLIB
+# include <zlib.h>
+#endif
+
+#include <tstring.h>
+#include <tdebug.h>
+
+#include "tzlib.h"
+
+using namespace TagLib;
+
+bool zlib::isAvailable()
+{
+#ifdef HAVE_ZLIB
+
+  return true;
+
+#else
+
+  return false;
+
+#endif
+}
+
+ByteVector zlib::decompress(const ByteVector &data)
+{
+#ifdef HAVE_ZLIB
+
+    z_stream stream = {};
+
+    if(inflateInit(&stream) != Z_OK) {
+      debug("zlib::decompress() - Failed to initizlize zlib.");
+      return ByteVector();
+    }
+
+    ByteVector inData = data;
+
+    stream.avail_in = static_cast<uInt>(inData.size());
+    stream.next_in  = reinterpret_cast<Bytef *>(inData.data());
+
+    const unsigned int chunkSize = 1024;
+
+    ByteVector outData;
+
+    do {
+      const size_t offset = outData.size();
+      outData.resize(outData.size() + chunkSize);
+
+      stream.avail_out = static_cast<uInt>(chunkSize);
+      stream.next_out  = reinterpret_cast<Bytef *>(outData.data() + offset);
+
+      const int result = inflate(&stream, Z_NO_FLUSH);
+
+      if(result == Z_STREAM_ERROR ||
+         result == Z_NEED_DICT ||
+         result == Z_DATA_ERROR ||
+         result == Z_MEM_ERROR)
+      {
+        if(result != Z_STREAM_ERROR)
+          inflateEnd(&stream);
+
+        debug("zlib::decompress() - Error reading compressed stream.");
+        return ByteVector();
+      }
+
+      outData.resize(outData.size() - stream.avail_out);
+    } while(stream.avail_out == 0);
+
+    inflateEnd(&stream);
+
+    return outData;
+
+#else
+
+  return ByteVector();
+
+#endif
+}

taglib/toolkit/tzlib.h

@@ -0,0 +1,54 @@
+/***************************************************************************
+    copyright            : (C) 2016 by Tsuda Kageyu
+    email                : tsuda.kageyu@gmail.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *   This library is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU Lesser General Public License version   *
+ *   2.1 as published by the Free Software Foundation.                     *
+ *                                                                         *
+ *   This library is distributed in the hope that it will be useful, but   *
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
+ *   Lesser General Public License for more details.                       *
+ *                                                                         *
+ *   You should have received a copy of the GNU Lesser General Public      *
+ *   License along with this library; if not, write to the Free Software   *
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA         *
+ *   02110-1301  USA                                                       *
+ *                                                                         *
+ *   Alternatively, this file is available under the Mozilla Public        *
+ *   License Version 1.1.  You may obtain a copy of the License at         *
+ *   http://www.mozilla.org/MPL/                                           *
+ ***************************************************************************/
+
+#ifndef TAGLIB_TZLIB_H
+#define TAGLIB_TZLIB_H
+
+#include <tbytevector.h>
+
+// THIS FILE IS NOT A PART OF THE TAGLIB API
+
+#ifndef DO_NOT_DOCUMENT  // tell Doxygen not to document this header
+
+namespace TagLib {
+
+  namespace zlib {
+
+     /*!
+      * Returns whether or not zlib is installed and ready to use.
+      */
+     bool isAvailable();
+
+     /*!
+      * Decompress \a data by zlib.
+      */
+     ByteVector decompress(const ByteVector &data);
+
+  }
+}
+
+#endif
+
+#endif