/*
   * Copyright (c) 2013
   * Phillip Lougher <phillip@squashfs.org.uk>
   *
   * This work is licensed under the terms of the GNU GPL, version 2. See
   * the COPYING file in the top-level directory.
   */
  
  #include <linux/types.h>
  #include <linux/mutex.h>
  #include <linux/slab.h>
  #include <linux/buffer_head.h>
  
  #include "squashfs_fs.h"
  #include "squashfs_fs_sb.h"
  #include "decompressor.h"
  #include "squashfs.h"
  
  /*
   * This file implements single-threaded decompression in the
   * decompressor framework
   */
  
  struct squashfs_stream {
  	void		*stream;
  	struct mutex	mutex;
  };
  
  void *squashfs_decompressor_create(struct squashfs_sb_info *msblk,
  						void *comp_opts)
  {
  	struct squashfs_stream *stream;
  	int err = -ENOMEM;
  
  	stream = kmalloc(sizeof(*stream), GFP_KERNEL);
  	if (stream == NULL)
  		goto out;
  
  	stream->stream = msblk->decompressor->init(msblk, comp_opts);
  	if (IS_ERR(stream->stream)) {
  		err = PTR_ERR(stream->stream);
  		goto out;
  	}
  
  	kfree(comp_opts);
  	mutex_init(&stream->mutex);
  	return stream;
  
  out:
  	kfree(stream);
  	return ERR_PTR(err);
  }
  
  void squashfs_decompressor_destroy(struct squashfs_sb_info *msblk)
  {
  	struct squashfs_stream *stream = msblk->stream;
  
  	if (stream) {
  		msblk->decompressor->free(stream->stream);
  		kfree(stream);
  	}
  }

  int squashfs_decompress(struct squashfs_sb_info *msblk, struct buffer_head **bh,
  	int b, int offset, int length, struct squashfs_page_actor *output)

  {
  	int res;
  	struct squashfs_stream *stream = msblk->stream;
  
  	mutex_lock(&stream->mutex);

  	res = msblk->decompressor->decompress(msblk, stream->stream, bh, b,
  		offset, length, output);

  	mutex_unlock(&stream->mutex);
  
  	if (res < 0)
  		ERROR("%s decompression failed, data probably corrupt
  ",
  			msblk->decompressor->name);
  
  	return res;
  }
  
  int squashfs_max_decompressors(void)
  {
  	return 1;
  }