// Copyright (C) 2004-2021 Artifex Software, Inc.

//

// This file is part of MuPDF.

//

// MuPDF is free software: you can redistribute it and/or modify it under the

// terms of the GNU Affero General Public License as published by the Free

// Software Foundation, either version 3 of the License, or (at your option)

// any later version.

//

// MuPDF 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 Affero General Public License for more

// details.

//

// You should have received a copy of the GNU Affero General Public License

// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>

//

// Alternative licensing terms are available from the licensor.

// For commercial licensing, see <https://www.artifex.com/> or contact

// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,

// CA 94129, USA, for further information.

#include "mupdf/fitz.h"

#include "z-imp.h"

#include <limits.h>

void fz_deflate(fz_context *ctx, unsigned char *dest, size_t *destLen, const unsigned char *source, size_t sourceLen, fz_deflate_level level)

{

  z_stream stream;

  int err;

  size_t left;

  left = *destLen;

  *destLen = 0;

  stream.zalloc = fz_zlib_alloc;

  stream.zfree = fz_zlib_free;

  stream.opaque = ctx;

  err = deflateInit(&stream, (int)level);

  if (err != Z_OK)

    fz_throw(ctx, FZ_ERROR_LIBRARY, "deflateInit failed: %d", err);

  stream.next_out = dest;

  stream.avail_out = 0;

  stream.next_in = (z_const Bytef *)source;

  stream.avail_in = 0;

  do {

    if (stream.avail_out == 0) {

      stream.avail_out = left > UINT_MAX ? UINT_MAX : (uInt)left;

      left -= stream.avail_out;

    }

    if (stream.avail_in == 0) {

      stream.avail_in = sourceLen > UINT_MAX ? UINT_MAX : (uInt)sourceLen;

      sourceLen -= stream.avail_in;

    }

    err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);

  } while (err == Z_OK);

  /* We might have problems if the compressed length > uLong sized. Tough, for now. */

  *destLen = stream.total_out;

  deflateEnd(&stream);

  if (err != Z_STREAM_END)

    fz_throw(ctx, FZ_ERROR_LIBRARY, "deflate error: %d", err);

}

unsigned char *fz_new_deflated_data(fz_context *ctx, size_t *compressed_length, const unsigned char *source, size_t source_length, fz_deflate_level level)

{

  size_t bound = fz_deflate_bound(ctx, source_length);

  unsigned char *cdata = Memento_label(fz_malloc(ctx, bound), "deflated_data");

  *compressed_length = 0;

  fz_try(ctx)

    fz_deflate(ctx, cdata, &bound, source, source_length, level);

  fz_catch(ctx)

  {

    fz_free(ctx, cdata);

    fz_rethrow(ctx);

  }

  *compressed_length = bound;

  return cdata;

}

unsigned char *fz_new_deflated_data_from_buffer(fz_context *ctx, size_t *compressed_length, fz_buffer *buffer, fz_deflate_level level)

{

  unsigned char *data;

  size_t size = fz_buffer_storage(ctx, buffer, &data);

  if (size == 0 || data == NULL)

  {

    *compressed_length = 0;

    return NULL;

  }

  return fz_new_deflated_data(ctx, compressed_length, data, size, level);

}

size_t fz_deflate_bound(fz_context *ctx, size_t size)

{

  /* Copied from zlib to account for size_t vs uLong */

  return size + (size >> 12) + (size >> 14) + (size >> 25) + 13;

}