// natInflater.cc - Implementation of Inflater native methods.

/* Copyright (C) 1999  Free Software Foundation

   This file is part of libgcj.

This software is copyrighted work licensed under the terms of the
Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
details.  */

// Written by Tom Tromey <tromey@cygnus.com>

#include <config.h>

#include <zlib.h>
#include <stdlib.h>

#include <gcj/cni.h>
#include <jvm.h>

#include <java/util/zip/Inflater.h>
#include <java/util/zip/DataFormatException.h>

#include <java/lang/InternalError.h>
#include <java/lang/NullPointerException.h>
#include <java/lang/ArrayIndexOutOfBoundsException.h>
#include <java/lang/OutOfMemoryError.h>



// A couple of helper functions used to interface with zlib's
// allocation.

void *
_Jv_ZMalloc (void *, uInt nitems, uInt size)
{
  return _Jv_Malloc (nitems * size);
}

void
_Jv_ZFree (void *, void *addr)
{
  _Jv_Free (addr);
}



void
java::util::zip::Inflater::end ()
{
  JvSynchronize sync (this);
  // Just ignore errors.
  inflateEnd ((z_streamp) zstream);
  _Jv_Free (zstream);
  zstream = NULL;
}

jint
java::util::zip::Inflater::getAdler ()
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;
  return s->adler;
}

jint
java::util::zip::Inflater::getRemaining ()
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;
  return s->avail_in;
}

jint
java::util::zip::Inflater::getTotalIn ()
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;
  return s->total_in;
}

jint
java::util::zip::Inflater::getTotalOut ()
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;
  return s->total_out;
}

jint
java::util::zip::Inflater::inflate (jbyteArray buf, jint off, jint len)
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;

  if (! buf)
    throw new java::lang::NullPointerException;
  if (off < 0 || len < 0 || off + len > buf->length)
    throw new java::lang::ArrayIndexOutOfBoundsException;

  if (len == 0)
    return 0;

  s->next_out = (Bytef *) (elements (buf) + off);
  s->avail_out = len;

  switch (::inflate (s, Z_SYNC_FLUSH))
    {
    case Z_BUF_ERROR:
      /* Using the no_header option, zlib requires an extra padding byte at the
      end of the stream in order to successfully complete decompression (see
      zlib/contrib/minizip/unzip.c). We don't do this, so can end up with a 
      Z_BUF_ERROR at the end of a stream when zlib has completed inflation
      and there's no more input. Thats not a problem. */
      if (s->avail_in != 0)
        throw new java::lang::InternalError;
      // Fall through.
      
    case Z_STREAM_END:
      is_finished = true;
      if (s->avail_out == (unsigned int) len)
	return -1;
      break;

    case Z_NEED_DICT:
      dict_needed = true;
      break;

    case Z_DATA_ERROR:
      throw new java::util::zip::DataFormatException 
	(s->msg == NULL ? NULL : JvNewStringLatin1 (s->msg));
      break;

    case Z_MEM_ERROR:
      throw new java::lang::OutOfMemoryError;
      break;

    case Z_OK:
      break;
    }

  return len - s->avail_out;
}

void
java::util::zip::Inflater::reset ()
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;
  // Just ignore errors.
  inflateReset (s);
}

void
java::util::zip::Inflater::setDictionary (jbyteArray buf, jint off, jint len)
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;

  if (! buf)
    throw new java::lang::NullPointerException;
  if (off < 0 || len < 0 || off + len > buf->length)
    throw new java::lang::ArrayIndexOutOfBoundsException;

  // Ignore errors.
  inflateSetDictionary (s, (Bytef *) (elements (buf) + off), len);
  dict_needed = false;
}

void
java::util::zip::Inflater::setInput (jbyteArray buf, jint off, jint len)
{
  JvSynchronize sync (this);
  z_streamp s = (z_streamp) zstream;

  if (! buf)
    throw new java::lang::NullPointerException;
  if (off < 0 || len < 0 || off + len > buf->length)
    throw new java::lang::ArrayIndexOutOfBoundsException;

  s->next_in = (Bytef *) (elements (buf) + off);
  s->avail_in = len;
}

void
java::util::zip::Inflater::init (jboolean no_header)
{
  z_stream_s *stream = (z_stream_s *) _Jv_Malloc (sizeof (z_stream_s));
  stream->next_in = Z_NULL;
  stream->avail_in = 0;
  stream->zalloc = _Jv_ZMalloc;
  stream->zfree = _Jv_ZFree;
  stream->opaque = NULL;

  // Handle NO_HEADER using undocumented zlib feature.
  int wbits = MAX_WBITS;
  if (no_header)
    wbits = - wbits;

  if (inflateInit2 (stream, wbits) != Z_OK)
    {
      jstring msg = NULL;
      if (stream->msg != NULL)
	msg = JvNewStringLatin1 (stream->msg);
      throw new java::lang::InternalError (msg);
    }

  zstream = reinterpret_cast<gnu::gcj::RawData *> (stream);
  is_finished = false;
  dict_needed = false;
}