/*

# Copyright 2018 Google Inc.

#

# Licensed under the Apache License, Version 2.0 (the "License");

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#      http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an "AS IS" BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

#

###############################################################################

*/

#include "bzlib.h"

#include <stdint.h>

#include <stdlib.h>

#include <assert.h>

#include <string.h>

extern int BZ2_bzBuffToBuffCompress(char* dest,

                           unsigned int* destLen,

                           char*         source,

                           unsigned int  sourceLen,

                           int           blockSize100k,

                           int           verbosity,

                           int           workFactor);

extern int BZ2_bzBuffToBuffDecompress(char* dest,

                                      unsigned int* destLen,

                                      char*         source,

                                      unsigned int  sourceLen,

                                      int           small,

                                      int           verbosity);

int

LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)

{

    int r, blockSize100k, workFactor, small;

    unsigned int nZ, nOut;

    /* Copying @julian-seward1's comment from

     * https://github.com/google/oss-fuzz/pull/1887#discussion_r226852388

     *

     * They just reflect the fact that the worst case output size is 101%

     * of the input size + 600 bytes (I assume -- this is now nearly 20

     * years old). Since the buffer is in mallocville, presumably asan

     * will complain if it gets overrun. I doubt that will happen though.

     */

    nZ = size + 600 + (size / 100);

    char *zbuf = malloc(nZ);

    blockSize100k = (size % 11) + 1;

    if (blockSize100k > 9) {

        blockSize100k = 9;

    }

    workFactor = size % 251;

    // Choose highest compression (blockSize100k=9)

    r = BZ2_bzBuffToBuffCompress(zbuf, &nZ, (char *)data, size,

            blockSize100k, /*verbosity=*/0, workFactor);

    if (r != BZ_OK) {

#ifdef __DEBUG__

        fprintf(stdout, "Compression error: %d\n", r);

#endif

        free(zbuf);

        return 0;

    }

    nOut = size*2;

    char *outbuf = malloc(nOut);

    small = size % 2;

    r = BZ2_bzBuffToBuffDecompress(outbuf, &nOut, zbuf, nZ, small,

            /*verbosity=*/0);

    if (r != BZ_OK) {

#ifdef __DEBUG__

        fprintf(stdout, "Decompression error: %d\n", r);

#endif

        free(zbuf);

        free(outbuf);

        return 0;

    }

    assert(nOut == size);

    assert(memcmp(data, outbuf, size) == 0);

    free(zbuf);

    free(outbuf);

    return 0;

}