gio/gzlibcompressor.c - third_party/glib - Git at Google

 /* GIO - GLib Input, Output and Streaming Library
  *
  * Copyright (C) 2009 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * 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, see <http://www.gnu.org/licenses/>.
  *
  * Author: Alexander Larsson <alexl@redhat.com>
  */

 #include "config.h"

 #include "gzlibcompressor.h"

 #include <errno.h>
 #include <zlib.h>
 #include <string.h>

 #include "gfileinfo.h"
 #include "gioerror.h"
 #include "gioenums.h"
 #include "gioenumtypes.h"
 #include "glibintl.h"


 enum {
   PROP_0,
   PROP_FORMAT,
   PROP_LEVEL,
   PROP_FILE_INFO
 };

 /**
  * SECTION:gzcompressor
  * @short_description: Zlib compressor
  * @include: gio/gio.h
  *
  * #GZlibCompressor is an implementation of #GConverter that
  * compresses data using zlib.
  */

 static void g_zlib_compressor_iface_init          (GConverterIface *iface);

 /**
  * GZlibCompressor:
  *
  * Zlib decompression
  */
 struct _GZlibCompressor
 {
   GObject parent_instance;

   GZlibCompressorFormat format;
   int level;
   z_stream zstream;
   gz_header gzheader;
   GFileInfo *file_info;
 };

 static void
 g_zlib_compressor_set_gzheader (GZlibCompressor *compressor)
 {
   /* On win32, these functions were not exported before 1.2.4 */
 #if !defined (G_OS_WIN32) || ZLIB_VERNUM >= 0x1240
   const gchar *filename;

   if (compressor->format != G_ZLIB_COMPRESSOR_FORMAT_GZIP ||
       compressor->file_info == NULL)
     return;

   memset (&compressor->gzheader, 0, sizeof (gz_header));
   compressor->gzheader.os = 0x03; /* Unix */

   filename = g_file_info_get_name (compressor->file_info);
   compressor->gzheader.name = (Bytef *) filename;
   compressor->gzheader.name_max = filename ? strlen (filename) + 1 : 0;

   compressor->gzheader.time =
       (uLong) g_file_info_get_attribute_uint64 (compressor->file_info,
                                                 G_FILE_ATTRIBUTE_TIME_MODIFIED);

   if (deflateSetHeader (&compressor->zstream, &compressor->gzheader) != Z_OK)
     g_warning ("unexpected zlib error: %s", compressor->zstream.msg);
 #endif /* !G_OS_WIN32 || ZLIB >= 1.2.4 */
 }

 G_DEFINE_TYPE_WITH_CODE (GZlibCompressor, g_zlib_compressor, G_TYPE_OBJECT,
 			 G_IMPLEMENT_INTERFACE (G_TYPE_CONVERTER,
 						g_zlib_compressor_iface_init))

 static void
 g_zlib_compressor_finalize (GObject *object)
 {
   GZlibCompressor *compressor;

   compressor = G_ZLIB_COMPRESSOR (object);

   deflateEnd (&compressor->zstream);

   if (compressor->file_info)
     g_object_unref (compressor->file_info);

   G_OBJECT_CLASS (g_zlib_compressor_parent_class)->finalize (object);
 }


 static void
 g_zlib_compressor_set_property (GObject      *object,
 				  guint         prop_id,
 				  const GValue *value,
 				  GParamSpec   *pspec)
 {
   GZlibCompressor *compressor;

   compressor = G_ZLIB_COMPRESSOR (object);

   switch (prop_id)
     {
     case PROP_FORMAT:
       compressor->format = g_value_get_enum (value);
       break;

     case PROP_LEVEL:
       compressor->level = g_value_get_int (value);
       break;

     case PROP_FILE_INFO:
       g_zlib_compressor_set_file_info (compressor, g_value_get_object (value));
       break;

     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
     }

 }

 static void
 g_zlib_compressor_get_property (GObject    *object,
 				  guint       prop_id,
 				  GValue     *value,
 				  GParamSpec *pspec)
 {
   GZlibCompressor *compressor;

   compressor = G_ZLIB_COMPRESSOR (object);

   switch (prop_id)
     {
     case PROP_FORMAT:
       g_value_set_enum (value, compressor->format);
       break;

     case PROP_LEVEL:
       g_value_set_int (value, compressor->level);
       break;

     case PROP_FILE_INFO:
       g_value_set_object (value, compressor->file_info);
       break;

     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
     }
 }

 static void
 g_zlib_compressor_init (GZlibCompressor *compressor)
 {
 }

 static void
 g_zlib_compressor_constructed (GObject *object)
 {
   GZlibCompressor *compressor;
   int res;

   compressor = G_ZLIB_COMPRESSOR (object);

   if (compressor->format == G_ZLIB_COMPRESSOR_FORMAT_GZIP)
     {
       /* + 16 for gzip */
       res = deflateInit2 (&compressor->zstream,
 			  compressor->level, Z_DEFLATED,
 			  MAX_WBITS + 16, 8,
 			  Z_DEFAULT_STRATEGY);
     }
   else if (compressor->format == G_ZLIB_COMPRESSOR_FORMAT_RAW)
     {
       /* negative wbits for raw */
       res = deflateInit2 (&compressor->zstream,
 			  compressor->level, Z_DEFLATED,
 			  -MAX_WBITS, 8,
 			  Z_DEFAULT_STRATEGY);
     }
   else /* ZLIB */
     res = deflateInit (&compressor->zstream, compressor->level);

   if (res == Z_MEM_ERROR )
     g_error ("GZlibCompressor: Not enough memory for zlib use");

   if (res != Z_OK)
     g_warning ("unexpected zlib error: %s", compressor->zstream.msg);

   g_zlib_compressor_set_gzheader (compressor);
 }

 static void
 g_zlib_compressor_class_init (GZlibCompressorClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

   gobject_class->finalize = g_zlib_compressor_finalize;
   gobject_class->constructed = g_zlib_compressor_constructed;
   gobject_class->get_property = g_zlib_compressor_get_property;
   gobject_class->set_property = g_zlib_compressor_set_property;

   g_object_class_install_property (gobject_class,
 				   PROP_FORMAT,
 				   g_param_spec_enum ("format",
 						      P_("compression format"),
 						      P_("The format of the compressed data"),
 						      G_TYPE_ZLIB_COMPRESSOR_FORMAT,
 						      G_ZLIB_COMPRESSOR_FORMAT_ZLIB,
 						      G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
 						      G_PARAM_STATIC_STRINGS));
   g_object_class_install_property (gobject_class,
 				   PROP_LEVEL,
 				   g_param_spec_int ("level",
 						     P_("compression level"),
 						     P_("The level of compression from 0 (no compression) to 9 (most compression), -1 for the default level"),
 						     -1, 9,
 						     -1,
 						     G_PARAM_READWRITE |
 						     G_PARAM_CONSTRUCT_ONLY |
 						     G_PARAM_STATIC_STRINGS));

   /**
    * GZlibCompressor:file-info:
    *
    * If set to a non-%NULL #GFileInfo object, and #GZlibCompressor:format is
    * %G_ZLIB_COMPRESSOR_FORMAT_GZIP, the compressor will write the file name
    * and modification time from the file info to the GZIP header.
    *
    * Since: 2.26
    */
   g_object_class_install_property (gobject_class,
                                    PROP_FILE_INFO,
                                    g_param_spec_object ("file-info",
                                                        P_("file info"),
                                                        P_("File info"),
                                                        G_TYPE_FILE_INFO,
                                                        G_PARAM_READWRITE |
                                                        G_PARAM_STATIC_STRINGS));
 }

 /**
  * g_zlib_compressor_new:
  * @format: The format to use for the compressed data
  * @level: compression level (0-9), -1 for default
  *
  * Creates a new #GZlibCompressor.
  *
  * Returns: a new #GZlibCompressor
  *
  * Since: 2.24
  **/
 GZlibCompressor *
 g_zlib_compressor_new (GZlibCompressorFormat format,
 		       int level)
 {
   GZlibCompressor *compressor;

   compressor = g_object_new (G_TYPE_ZLIB_COMPRESSOR,
 			     "format", format,
 			     "level", level,
 			     NULL);

   return compressor;
 }

 /**
  * g_zlib_compressor_get_file_info:
  * @compressor: a #GZlibCompressor
  *
  * Returns the #GZlibCompressor:file-info property.
  *
  * Returns: (transfer none): a #GFileInfo, or %NULL
  *
  * Since: 2.26
  */
 GFileInfo *
 g_zlib_compressor_get_file_info (GZlibCompressor *compressor)
 {
   g_return_val_if_fail (G_IS_ZLIB_COMPRESSOR (compressor), NULL);

   return compressor->file_info;
 }

 /**
  * g_zlib_compressor_set_file_info:
  * @compressor: a #GZlibCompressor
  * @file_info: (nullable): a #GFileInfo
  *
  * Sets @file_info in @compressor. If non-%NULL, and @compressor's
  * #GZlibCompressor:format property is %G_ZLIB_COMPRESSOR_FORMAT_GZIP,
  * it will be used to set the file name and modification time in
  * the GZIP header of the compressed data.
  *
  * Note: it is an error to call this function while a compression is in
  * progress; it may only be called immediately after creation of @compressor,
  * or after resetting it with g_converter_reset().
  *
  * Since: 2.26
  */
 void
 g_zlib_compressor_set_file_info (GZlibCompressor *compressor,
                                  GFileInfo       *file_info)
 {
   g_return_if_fail (G_IS_ZLIB_COMPRESSOR (compressor));

   if (file_info == compressor->file_info)
     return;

   if (compressor->file_info)
     g_object_unref (compressor->file_info);
   if (file_info)
     g_object_ref (file_info);
   compressor->file_info = file_info;
   g_object_notify (G_OBJECT (compressor), "file-info");

   g_zlib_compressor_set_gzheader (compressor);
 }

 static void
 g_zlib_compressor_reset (GConverter *converter)
 {
   GZlibCompressor *compressor = G_ZLIB_COMPRESSOR (converter);
   int res;

   res = deflateReset (&compressor->zstream);
   if (res != Z_OK)
     g_warning ("unexpected zlib error: %s", compressor->zstream.msg);

   /* deflateReset reset the header too, so re-set it */
   g_zlib_compressor_set_gzheader (compressor);
 }

 static GConverterResult
 g_zlib_compressor_convert (GConverter *converter,
 			   const void *inbuf,
 			   gsize       inbuf_size,
 			   void       *outbuf,
 			   gsize       outbuf_size,
 			   GConverterFlags flags,
 			   gsize      *bytes_read,
 			   gsize      *bytes_written,
 			   GError    **error)
 {
   GZlibCompressor *compressor;
   int res;
   int flush;

   compressor = G_ZLIB_COMPRESSOR (converter);

   compressor->zstream.next_in = (void *)inbuf;
   compressor->zstream.avail_in = inbuf_size;

   compressor->zstream.next_out = outbuf;
   compressor->zstream.avail_out = outbuf_size;

   flush = Z_NO_FLUSH;
   if (flags & G_CONVERTER_INPUT_AT_END)
     flush = Z_FINISH;
   else if (flags & G_CONVERTER_FLUSH)
     flush = Z_SYNC_FLUSH;

   res = deflate (&compressor->zstream, flush);

   if (res == Z_MEM_ERROR)
     {
       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
 			   _("Not enough memory"));
       return G_CONVERTER_ERROR;
     }

     if (res == Z_STREAM_ERROR)
     {
       g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
 		   _("Internal error: %s"), compressor->zstream.msg);
       return G_CONVERTER_ERROR;
     }

     if (res == Z_BUF_ERROR)
       {
 	if (flags & G_CONVERTER_FLUSH)
 	  return G_CONVERTER_FLUSHED;

 	/* We do have output space, so this should only happen if we
 	   have no input but need some */

 	g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PARTIAL_INPUT,
 			     _("Need more input"));
 	return G_CONVERTER_ERROR;
       }

   if (res == Z_OK || res == Z_STREAM_END)
     {
       *bytes_read = inbuf_size - compressor->zstream.avail_in;
       *bytes_written = outbuf_size - compressor->zstream.avail_out;

       if (res == Z_STREAM_END)
 	return G_CONVERTER_FINISHED;
       return G_CONVERTER_CONVERTED;
     }

   g_assert_not_reached ();
 }

 static void
 g_zlib_compressor_iface_init (GConverterIface *iface)
 {
   iface->convert = g_zlib_compressor_convert;
   iface->reset = g_zlib_compressor_reset;
 }
	/* GIO - GLib Input, Output and Streaming Library
	*
	* Copyright (C) 2009 Red Hat, Inc.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* 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, see <http://www.gnu.org/licenses/>.
	*
	* Author: Alexander Larsson <alexl@redhat.com>
	*/

	#include "config.h"

	#include "gzlibcompressor.h"

	#include <errno.h>
	#include <zlib.h>
	#include <string.h>

	#include "gfileinfo.h"
	#include "gioerror.h"
	#include "gioenums.h"
	#include "gioenumtypes.h"
	#include "glibintl.h"


	enum {
	PROP_0,
	PROP_FORMAT,
	PROP_LEVEL,
	PROP_FILE_INFO
	};

	/**
	* SECTION:gzcompressor
	* @short_description: Zlib compressor
	* @include: gio/gio.h
	*
	* #GZlibCompressor is an implementation of #GConverter that
	* compresses data using zlib.
	*/

	static void g_zlib_compressor_iface_init (GConverterIface *iface);

	/**
	* GZlibCompressor:
	*
	* Zlib decompression
	*/
	struct _GZlibCompressor
	{
	GObject parent_instance;

	GZlibCompressorFormat format;
	int level;
	z_stream zstream;
	gz_header gzheader;
	GFileInfo *file_info;
	};

	static void
	g_zlib_compressor_set_gzheader (GZlibCompressor *compressor)
	{
	/* On win32, these functions were not exported before 1.2.4 */
	#if !defined (G_OS_WIN32) \|\| ZLIB_VERNUM >= 0x1240
	const gchar *filename;

	if (compressor->format != G_ZLIB_COMPRESSOR_FORMAT_GZIP \|\|
	compressor->file_info == NULL)
	return;

	memset (&compressor->gzheader, 0, sizeof (gz_header));
	compressor->gzheader.os = 0x03; /* Unix */

	filename = g_file_info_get_name (compressor->file_info);
	compressor->gzheader.name = (Bytef *) filename;
	compressor->gzheader.name_max = filename ? strlen (filename) + 1 : 0;

	compressor->gzheader.time =
	(uLong) g_file_info_get_attribute_uint64 (compressor->file_info,
	G_FILE_ATTRIBUTE_TIME_MODIFIED);

	if (deflateSetHeader (&compressor->zstream, &compressor->gzheader) != Z_OK)
	g_warning ("unexpected zlib error: %s", compressor->zstream.msg);
	#endif /* !G_OS_WIN32 \|\| ZLIB >= 1.2.4 */
	}

	G_DEFINE_TYPE_WITH_CODE (GZlibCompressor, g_zlib_compressor, G_TYPE_OBJECT,
	G_IMPLEMENT_INTERFACE (G_TYPE_CONVERTER,
	g_zlib_compressor_iface_init))

	static void
	g_zlib_compressor_finalize (GObject *object)
	{
	GZlibCompressor *compressor;

	compressor = G_ZLIB_COMPRESSOR (object);

	deflateEnd (&compressor->zstream);

	if (compressor->file_info)
	g_object_unref (compressor->file_info);

	G_OBJECT_CLASS (g_zlib_compressor_parent_class)->finalize (object);
	}


	static void
	g_zlib_compressor_set_property (GObject *object,
	guint prop_id,
	const GValue *value,
	GParamSpec *pspec)
	{
	GZlibCompressor *compressor;

	compressor = G_ZLIB_COMPRESSOR (object);

	switch (prop_id)
	{
	case PROP_FORMAT:
	compressor->format = g_value_get_enum (value);
	break;

	case PROP_LEVEL:
	compressor->level = g_value_get_int (value);
	break;

	case PROP_FILE_INFO:
	g_zlib_compressor_set_file_info (compressor, g_value_get_object (value));
	break;

	default:
	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
	break;
	}

	}

	static void
	g_zlib_compressor_get_property (GObject *object,
	guint prop_id,
	GValue *value,
	GParamSpec *pspec)
	{
	GZlibCompressor *compressor;

	compressor = G_ZLIB_COMPRESSOR (object);

	switch (prop_id)
	{
	case PROP_FORMAT:
	g_value_set_enum (value, compressor->format);
	break;

	case PROP_LEVEL:
	g_value_set_int (value, compressor->level);
	break;

	case PROP_FILE_INFO:
	g_value_set_object (value, compressor->file_info);
	break;

	default:
	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
	break;
	}
	}

	static void
	g_zlib_compressor_init (GZlibCompressor *compressor)
	{
	}

	static void
	g_zlib_compressor_constructed (GObject *object)
	{
	GZlibCompressor *compressor;
	int res;

	compressor = G_ZLIB_COMPRESSOR (object);

	if (compressor->format == G_ZLIB_COMPRESSOR_FORMAT_GZIP)
	{
	/* + 16 for gzip */
	res = deflateInit2 (&compressor->zstream,
	compressor->level, Z_DEFLATED,
	MAX_WBITS + 16, 8,
	Z_DEFAULT_STRATEGY);
	}
	else if (compressor->format == G_ZLIB_COMPRESSOR_FORMAT_RAW)
	{
	/* negative wbits for raw */
	res = deflateInit2 (&compressor->zstream,
	compressor->level, Z_DEFLATED,
	-MAX_WBITS, 8,
	Z_DEFAULT_STRATEGY);
	}
	else /* ZLIB */
	res = deflateInit (&compressor->zstream, compressor->level);

	if (res == Z_MEM_ERROR )
	g_error ("GZlibCompressor: Not enough memory for zlib use");

	if (res != Z_OK)
	g_warning ("unexpected zlib error: %s", compressor->zstream.msg);

	g_zlib_compressor_set_gzheader (compressor);
	}

	static void
	g_zlib_compressor_class_init (GZlibCompressorClass *klass)
	{
	GObjectClass *gobject_class = G_OBJECT_CLASS (klass);

	gobject_class->finalize = g_zlib_compressor_finalize;
	gobject_class->constructed = g_zlib_compressor_constructed;
	gobject_class->get_property = g_zlib_compressor_get_property;
	gobject_class->set_property = g_zlib_compressor_set_property;

	g_object_class_install_property (gobject_class,
	PROP_FORMAT,
	g_param_spec_enum ("format",
	P_("compression format"),
	P_("The format of the compressed data"),
	G_TYPE_ZLIB_COMPRESSOR_FORMAT,
	G_ZLIB_COMPRESSOR_FORMAT_ZLIB,
	G_PARAM_READWRITE \| G_PARAM_CONSTRUCT_ONLY \|
	G_PARAM_STATIC_STRINGS));
	g_object_class_install_property (gobject_class,
	PROP_LEVEL,
	g_param_spec_int ("level",
	P_("compression level"),
	P_("The level of compression from 0 (no compression) to 9 (most compression), -1 for the default level"),
	-1, 9,
	-1,
	G_PARAM_READWRITE \|
	G_PARAM_CONSTRUCT_ONLY \|
	G_PARAM_STATIC_STRINGS));

	/**
	* GZlibCompressor:file-info:
	*
	* If set to a non-%NULL #GFileInfo object, and #GZlibCompressor:format is
	* %G_ZLIB_COMPRESSOR_FORMAT_GZIP, the compressor will write the file name
	* and modification time from the file info to the GZIP header.
	*
	* Since: 2.26
	*/
	g_object_class_install_property (gobject_class,
	PROP_FILE_INFO,
	g_param_spec_object ("file-info",
	P_("file info"),
	P_("File info"),
	G_TYPE_FILE_INFO,
	G_PARAM_READWRITE \|
	G_PARAM_STATIC_STRINGS));
	}

	/**
	* g_zlib_compressor_new:
	* @format: The format to use for the compressed data
	* @level: compression level (0-9), -1 for default
	*
	* Creates a new #GZlibCompressor.
	*
	* Returns: a new #GZlibCompressor
	*
	* Since: 2.24
	**/
	GZlibCompressor *
	g_zlib_compressor_new (GZlibCompressorFormat format,
	int level)
	{
	GZlibCompressor *compressor;

	compressor = g_object_new (G_TYPE_ZLIB_COMPRESSOR,
	"format", format,
	"level", level,
	NULL);

	return compressor;
	}

	/**
	* g_zlib_compressor_get_file_info:
	* @compressor: a #GZlibCompressor
	*
	* Returns the #GZlibCompressor:file-info property.
	*
	* Returns: (transfer none): a #GFileInfo, or %NULL
	*
	* Since: 2.26
	*/
	GFileInfo *
	g_zlib_compressor_get_file_info (GZlibCompressor *compressor)
	{
	g_return_val_if_fail (G_IS_ZLIB_COMPRESSOR (compressor), NULL);

	return compressor->file_info;
	}

	/**
	* g_zlib_compressor_set_file_info:
	* @compressor: a #GZlibCompressor
	* @file_info: (nullable): a #GFileInfo
	*
	* Sets @file_info in @compressor. If non-%NULL, and @compressor's
	* #GZlibCompressor:format property is %G_ZLIB_COMPRESSOR_FORMAT_GZIP,
	* it will be used to set the file name and modification time in
	* the GZIP header of the compressed data.
	*
	* Note: it is an error to call this function while a compression is in
	* progress; it may only be called immediately after creation of @compressor,
	* or after resetting it with g_converter_reset().
	*
	* Since: 2.26
	*/
	void
	g_zlib_compressor_set_file_info (GZlibCompressor *compressor,
	GFileInfo *file_info)
	{
	g_return_if_fail (G_IS_ZLIB_COMPRESSOR (compressor));

	if (file_info == compressor->file_info)
	return;

	if (compressor->file_info)
	g_object_unref (compressor->file_info);
	if (file_info)
	g_object_ref (file_info);
	compressor->file_info = file_info;
	g_object_notify (G_OBJECT (compressor), "file-info");

	g_zlib_compressor_set_gzheader (compressor);
	}

	static void
	g_zlib_compressor_reset (GConverter *converter)
	{
	GZlibCompressor *compressor = G_ZLIB_COMPRESSOR (converter);
	int res;

	res = deflateReset (&compressor->zstream);
	if (res != Z_OK)
	g_warning ("unexpected zlib error: %s", compressor->zstream.msg);

	/* deflateReset reset the header too, so re-set it */
	g_zlib_compressor_set_gzheader (compressor);
	}

	static GConverterResult
	g_zlib_compressor_convert (GConverter *converter,
	const void *inbuf,
	gsize inbuf_size,
	void *outbuf,
	gsize outbuf_size,
	GConverterFlags flags,
	gsize *bytes_read,
	gsize *bytes_written,
	GError **error)
	{
	GZlibCompressor *compressor;
	int res;
	int flush;

	compressor = G_ZLIB_COMPRESSOR (converter);

	compressor->zstream.next_in = (void *)inbuf;
	compressor->zstream.avail_in = inbuf_size;

	compressor->zstream.next_out = outbuf;
	compressor->zstream.avail_out = outbuf_size;

	flush = Z_NO_FLUSH;
	if (flags & G_CONVERTER_INPUT_AT_END)
	flush = Z_FINISH;
	else if (flags & G_CONVERTER_FLUSH)
	flush = Z_SYNC_FLUSH;

	res = deflate (&compressor->zstream, flush);

	if (res == Z_MEM_ERROR)
	{
	g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED,
	_("Not enough memory"));
	return G_CONVERTER_ERROR;
	}

	if (res == Z_STREAM_ERROR)
	{
	g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
	_("Internal error: %s"), compressor->zstream.msg);
	return G_CONVERTER_ERROR;
	}

	if (res == Z_BUF_ERROR)
	{
	if (flags & G_CONVERTER_FLUSH)
	return G_CONVERTER_FLUSHED;

	/* We do have output space, so this should only happen if we
	have no input but need some */

	g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PARTIAL_INPUT,
	_("Need more input"));
	return G_CONVERTER_ERROR;
	}

	if (res == Z_OK \|\| res == Z_STREAM_END)
	{
	*bytes_read = inbuf_size - compressor->zstream.avail_in;
	*bytes_written = outbuf_size - compressor->zstream.avail_out;

	if (res == Z_STREAM_END)
	return G_CONVERTER_FINISHED;
	return G_CONVERTER_CONVERTED;
	}

	g_assert_not_reached ();
	}

	static void
	g_zlib_compressor_iface_init (GConverterIface *iface)
	{
	iface->convert = g_zlib_compressor_convert;
	iface->reset = g_zlib_compressor_reset;
	}