/* GIO - GLib Input, Output and Streaming Library

 *

 * Copyright (C) 2009 Red Hat, Inc.

 *

 * SPDX-License-Identifier: LGPL-2.1-or-later

 *

 * 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

};

/**

 * GZlibCompressor:

 *

 * `GZlibCompressor` is an implementation of [iface@Gio.Converter] that

 * compresses data using zlib.

 */

static void g_zlib_compressor_iface_init          (GConverterIface *iface);

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;

  /**

   * GZlibCompressor:format:

   *

   * The format of the compressed data.

   *

   * Since: 2.24

   */

  g_object_class_install_property (gobject_class,

           PROP_FORMAT,

           g_param_spec_enum ("format", NULL, NULL,

                  G_TYPE_ZLIB_COMPRESSOR_FORMAT,

                  G_ZLIB_COMPRESSOR_FORMAT_ZLIB,

                  G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |

                  G_PARAM_STATIC_STRINGS));

  /**

   * GZlibCompressor:level:

   *

   * The level of compression from `0` (no compression) to `9` (most

   * compression). `-1` for the default level.

   *

   * Since: 2.24

   */

  g_object_class_install_property (gobject_class,

           PROP_LEVEL,

           g_param_spec_int ("level", NULL, NULL,

                 -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", NULL, NULL,

                                                       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: (nullable) (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;

}