/*

 * Copyright (c) 2023, Tim Schumacher <timschumi@gmx.de>.

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#include <AK/MemoryStream.h>

#include <LibCompress/Lzma.h>

extern "C" int LLVMFuzzerTestOneInput(uint8_t const* data, size_t size)

{

    AK::set_debug_enabled(false);

    // LibFuzzer has a default memory limit of 2048 MB, so limit the dictionary size to a

    // reasonable number to make sure that we don't actually run into it by allocating a

    // huge dictionary. The chosen value is double of what the largest dictionary in the

    // specifications test files is, so it should be more than enough for fuzzing everything

    // that we would want to fuzz.

    constexpr size_t largest_reasonable_dictionary_size = 16 * MiB;

    if (size >= sizeof(Compress::LzmaHeader)) {

        auto const* header = reinterpret_cast<Compress::LzmaHeader const*>(data);

        if (header->dictionary_size() > largest_reasonable_dictionary_size)

            return -1;

    }

    auto stream = make<FixedMemoryStream>(ReadonlyBytes { data, size });

    auto decompressor_or_error = Compress::LzmaDecompressor::create_from_container(move(stream));

    if (decompressor_or_error.is_error())

        return 0;

    auto decompressor = decompressor_or_error.release_value();

    while (!decompressor->is_eof()) {

        auto maybe_error = decompressor->discard(4096);

        if (maybe_error.is_error())

            break;

    }

    return 0;

}