// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you 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 "exec/decompressor.h"

#include <strings.h>

#include <memory>

#include <ostream>

#include "common/logging.h"

#include "common/status.h"

#include "gutil/endian.h"

#include "gutil/strings/substitute.h"

namespace doris {

Status Decompressor::create_decompressor(CompressType type,

                                         std::unique_ptr<Decompressor>* decompressor) {

    switch (type) {

    case CompressType::UNCOMPRESSED:

        decompressor->reset(nullptr);

        break;

    case CompressType::GZIP:

        decompressor->reset(new GzipDecompressor(false));

        break;

    case CompressType::DEFLATE:

        decompressor->reset(new GzipDecompressor(true));

        break;

    case CompressType::BZIP2:

        decompressor->reset(new Bzip2Decompressor());

        break;

    case CompressType::ZSTD:

        decompressor->reset(new ZstdDecompressor());

        break;

    case CompressType::LZ4FRAME:

        decompressor->reset(new Lz4FrameDecompressor());

        break;

    case CompressType::LZ4BLOCK:

        decompressor->reset(new Lz4BlockDecompressor());

        break;

    case CompressType::SNAPPYBLOCK:

        decompressor->reset(new SnappyBlockDecompressor());

        break;

    case CompressType::LZOP:

        decompressor->reset(new LzopDecompressor());

        break;

    default:

        return Status::InternalError("Unknown compress type: {}", type);

    }

    Status st = Status::OK();

    if (*decompressor != nullptr) {

        st = (*decompressor)->init();

    }

    return st;

}

Status Decompressor::create_decompressor(TFileCompressType::type type,

                                         std::unique_ptr<Decompressor>* decompressor) {

    CompressType compress_type;

    switch (type) {

    case TFileCompressType::PLAIN:

    case TFileCompressType::UNKNOWN:

        compress_type = CompressType::UNCOMPRESSED;

        break;

    case TFileCompressType::GZ:

        compress_type = CompressType::GZIP;

        break;

    case TFileCompressType::LZO:

    case TFileCompressType::LZOP:

        compress_type = CompressType::LZOP;

        break;

    case TFileCompressType::BZ2:

        compress_type = CompressType::BZIP2;

        break;

    case TFileCompressType::ZSTD:

        compress_type = CompressType::ZSTD;

        break;

    case TFileCompressType::LZ4FRAME:

        compress_type = CompressType::LZ4FRAME;

        break;

    case TFileCompressType::LZ4BLOCK:

        compress_type = CompressType::LZ4BLOCK;

        break;

    case TFileCompressType::DEFLATE:

        compress_type = CompressType::DEFLATE;

        break;

    case TFileCompressType::SNAPPYBLOCK:

        compress_type = CompressType::SNAPPYBLOCK;

        break;

    default:

        return Status::InternalError<false>("unknown compress type: {}", type);

    }

    RETURN_IF_ERROR(Decompressor::create_decompressor(compress_type, decompressor));

    return Status::OK();

}

Status Decompressor::create_decompressor(TFileFormatType::type type,

                                         std::unique_ptr<Decompressor>* decompressor) {

    CompressType compress_type;

    switch (type) {

    case TFileFormatType::FORMAT_PROTO:

        [[fallthrough]];

    case TFileFormatType::FORMAT_CSV_PLAIN:

        compress_type = CompressType::UNCOMPRESSED;

        break;

    case TFileFormatType::FORMAT_CSV_GZ:

        compress_type = CompressType::GZIP;

        break;

    case TFileFormatType::FORMAT_CSV_BZ2:

        compress_type = CompressType::BZIP2;

        break;

    case TFileFormatType::FORMAT_CSV_LZ4FRAME:

        compress_type = CompressType::LZ4FRAME;

        break;

    case TFileFormatType::FORMAT_CSV_LZ4BLOCK:

        compress_type = CompressType::LZ4BLOCK;

        break;

    case TFileFormatType::FORMAT_CSV_LZOP:

        compress_type = CompressType::LZOP;

        break;

    case TFileFormatType::FORMAT_CSV_DEFLATE:

        compress_type = CompressType::DEFLATE;

        break;

    case TFileFormatType::FORMAT_CSV_SNAPPYBLOCK:

        compress_type = CompressType::SNAPPYBLOCK;

        break;

    default:

        return Status::InternalError<false>("unknown compress type: {}", type);

    }

    RETURN_IF_ERROR(Decompressor::create_decompressor(compress_type, decompressor));

    return Status::OK();

}

uint32_t Decompressor::_read_int32(uint8_t* buf) {

    return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];

}

std::string Decompressor::debug_info() {

    return "Decompressor";

}

// Gzip

GzipDecompressor::GzipDecompressor(bool is_deflate)

        : Decompressor(is_deflate ? CompressType::DEFLATE : CompressType::GZIP),

          _is_deflate(is_deflate) {}

GzipDecompressor::~GzipDecompressor() {

    (void)inflateEnd(&_z_strm);

}

Status GzipDecompressor::init() {

    _z_strm = {};

    _z_strm.zalloc = Z_NULL;

    _z_strm.zfree = Z_NULL;

    _z_strm.opaque = Z_NULL;

    int window_bits = _is_deflate ? WINDOW_BITS : (WINDOW_BITS | DETECT_CODEC);

    int ret = inflateInit2(&_z_strm, window_bits);

    if (ret < 0) {

        return Status::InternalError("Failed to init inflate. status code: {}", ret);

    }

    return Status::OK();

}

Status GzipDecompressor::decompress(uint8_t* input, size_t input_len, size_t* input_bytes_read,

                                    uint8_t* output, size_t output_max_len,

                                    size_t* decompressed_len, bool* stream_end,

                                    size_t* more_input_bytes, size_t* more_output_bytes) {

    // 1. set input and output

    _z_strm.next_in = input;

    _z_strm.avail_in = input_len;

    _z_strm.next_out = output;

    _z_strm.avail_out = output_max_len;

    while (_z_strm.avail_out > 0 && _z_strm.avail_in > 0) {

        *stream_end = false;

        // inflate() performs one or both of the following actions:

        //   Decompress more input starting at next_in and update next_in and avail_in

        //       accordingly.

        //   Provide more output starting at next_out and update next_out and avail_out

        //       accordingly.

        // inflate() returns Z_OK if some progress has been made (more input processed

        // or more output produced)

        int ret = inflate(&_z_strm, Z_NO_FLUSH);

        *input_bytes_read = input_len - _z_strm.avail_in;

        *decompressed_len = output_max_len - _z_strm.avail_out;

        VLOG_TRACE << "gzip dec ret: " << ret << " input_bytes_read: " << *input_bytes_read

                   << " decompressed_len: " << *decompressed_len;

        if (ret == Z_BUF_ERROR) {

            // Z_BUF_ERROR indicates that inflate() could not consume more input or

            // produce more output. inflate() can be called again with more output space

            // or more available input

            // ATTN: even if ret == Z_OK, decompressed_len may also be zero

            return Status::OK();

        } else if (ret == Z_STREAM_END) {

            *stream_end = true;

            // reset _z_strm to continue decoding a subsequent gzip stream

            ret = inflateReset(&_z_strm);

            if (ret != Z_OK) {

                return Status::InternalError("Failed to inflateReset. return code: {}", ret);

            }

        } else if (ret != Z_OK) {

            return Status::InternalError("Failed to inflate. return code: {}", ret);

        } else {

            // here ret must be Z_OK.

            // we continue if avail_out and avail_in > 0.

            // this means 'inflate' is not done yet.

        }

    }

    return Status::OK();

}

std::string GzipDecompressor::debug_info() {

    std::stringstream ss;

    ss << "GzipDecompressor."

       << " is_deflate: " << _is_deflate;

    return ss.str();

}

// Bzip2

Bzip2Decompressor::~Bzip2Decompressor() {

    BZ2_bzDecompressEnd(&_bz_strm);

}

Status Bzip2Decompressor::init() {

    bzero(&_bz_strm, sizeof(_bz_strm));

    int ret = BZ2_bzDecompressInit(&_bz_strm, 0, 0);

    if (ret != BZ_OK) {

        return Status::InternalError("Failed to init bz2. status code: {}", ret);

    }

    return Status::OK();

}

Status Bzip2Decompressor::decompress(uint8_t* input, size_t input_len, size_t* input_bytes_read,

                                     uint8_t* output, size_t output_max_len,

                                     size_t* decompressed_len, bool* stream_end,

                                     size_t* more_input_bytes, size_t* more_output_bytes) {

    // 1. set input and output

    _bz_strm.next_in = const_cast<char*>(reinterpret_cast<const char*>(input));

    _bz_strm.avail_in = input_len;

    _bz_strm.next_out = reinterpret_cast<char*>(output);

    _bz_strm.avail_out = output_max_len;

    while (_bz_strm.avail_out > 0 && _bz_strm.avail_in > 0) {

        *stream_end = false;

        // decompress

        int ret = BZ2_bzDecompress(&_bz_strm);

        *input_bytes_read = input_len - _bz_strm.avail_in;

        *decompressed_len = output_max_len - _bz_strm.avail_out;

        if (ret == BZ_DATA_ERROR || ret == BZ_DATA_ERROR_MAGIC) {

            LOG(INFO) << "input_bytes_read: " << *input_bytes_read

                      << " decompressed_len: " << *decompressed_len;

            return Status::InternalError("Failed to bz2 decompress. status code: {}", ret);

        } else if (ret == BZ_STREAM_END) {

            *stream_end = true;

            ret = BZ2_bzDecompressEnd(&_bz_strm);

            if (ret != BZ_OK) {

                return Status::InternalError(

                        "Failed to end bz2 after meet BZ_STREAM_END. status code: {}", ret);

            }

            ret = BZ2_bzDecompressInit(&_bz_strm, 0, 0);

            if (ret != BZ_OK) {

                return Status::InternalError(

                        "Failed to init bz2 after meet BZ_STREAM_END. status code: {}", ret);

            }

        } else if (ret != BZ_OK) {

            return Status::InternalError("Failed to bz2 decompress. status code: {}", ret);

        } else {

            // continue

        }

    }

    return Status::OK();

}

std::string Bzip2Decompressor::debug_info() {

    std::stringstream ss;

    ss << "Bzip2Decompressor.";

    return ss.str();

}

ZstdDecompressor::~ZstdDecompressor() {

    ZSTD_freeDStream(_zstd_strm);

}

Status ZstdDecompressor::init() {

    _zstd_strm = ZSTD_createDStream();

    if (!_zstd_strm) {

        std::stringstream ss;

        return Status::InternalError("ZSTD_dctx creation error");

    }

    auto ret = ZSTD_initDStream(_zstd_strm);

    if (ZSTD_isError(ret)) {

        return Status::InternalError("ZSTD_initDStream error: {}", ZSTD_getErrorName(ret));

    }

    return Status::OK();

}

Status ZstdDecompressor::decompress(uint8_t* input, size_t input_len, size_t* input_bytes_read,

                                    uint8_t* output, size_t output_max_len,

                                    size_t* decompressed_len, bool* stream_end,

                                    size_t* more_input_bytes, size_t* more_output_bytes) {

    // 1. set input and output

    ZSTD_inBuffer inputBuffer = {input, input_len, 0};

    ZSTD_outBuffer outputBuffer = {output, output_max_len, 0};

    // decompress

    int ret = ZSTD_decompressStream(_zstd_strm, &outputBuffer, &inputBuffer);

    *input_bytes_read = inputBuffer.pos;

    *decompressed_len = outputBuffer.pos;

    if (ZSTD_isError(ret)) {

        return Status::InternalError("Failed to zstd decompress: {}", ZSTD_getErrorName(ret));

    }

    *stream_end = ret == 0;

    return Status::OK();

}

std::string ZstdDecompressor::debug_info() {

    std::stringstream ss;

    ss << "ZstdDecompressor.";

    return ss.str();

}

// Lz4Frame

// Lz4 version: 1.7.5

// define LZ4F_VERSION = 100

const unsigned Lz4FrameDecompressor::DORIS_LZ4F_VERSION = 100;

Lz4FrameDecompressor::~Lz4FrameDecompressor() {

    LZ4F_freeDecompressionContext(_dctx);

}

Status Lz4FrameDecompressor::init() {

    size_t ret = LZ4F_createDecompressionContext(&_dctx, DORIS_LZ4F_VERSION);

    if (LZ4F_isError(ret)) {

        std::stringstream ss;

        ss << "LZ4F_dctx creation error: " << std::string(LZ4F_getErrorName(ret));

        return Status::InternalError(ss.str());

    }

    // init as -1

    _expect_dec_buf_size = -1;

    return Status::OK();

}

Status Lz4FrameDecompressor::decompress(uint8_t* input, size_t input_len, size_t* input_bytes_read,

                                        uint8_t* output, size_t output_max_len,

                                        size_t* decompressed_len, bool* stream_end,

                                        size_t* more_input_bytes, size_t* more_output_bytes) {

    uint8_t* src = input;

    size_t remaining_input_size = input_len;

    size_t ret = 1;

    *input_bytes_read = 0;

    if (_expect_dec_buf_size == -1) {

        // init expected decompress buf size, and check if output_max_len is large enough

        // ATTN: _expect_dec_buf_size is uninit, which means this is the first time to call

        //       decompress(), so *input* should point to the head of the compressed file,

        //       where lz4 header section is there.

        if (input_len < 15) {

            return Status::InternalError(

                    "Lz4 header size is between 7 and 15 bytes. "

                    "but input size is only: {}",

                    input_len);

        }

        LZ4F_frameInfo_t info;

        ret = LZ4F_getFrameInfo(_dctx, &info, (void*)src, &remaining_input_size);

        if (LZ4F_isError(ret)) {

            return Status::InternalError("LZ4F_getFrameInfo error: {}",

                                         std::string(LZ4F_getErrorName(ret)));

        }

        _expect_dec_buf_size = get_block_size(&info);

        if (_expect_dec_buf_size == -1) {

            return Status::InternalError(

                    "Impossible lz4 block size unless more block sizes are allowed {}",

                    std::string(LZ4F_getErrorName(ret)));

        }

        *input_bytes_read = remaining_input_size;

        src += remaining_input_size;

        remaining_input_size = input_len - remaining_input_size;

        LOG(INFO) << "lz4 block size: " << _expect_dec_buf_size;

    }

    // decompress

    size_t output_len = output_max_len;

    ret = LZ4F_decompress(_dctx, (void*)output, &output_len, (void*)src, &remaining_input_size,

                          /* LZ4F_decompressOptions_t */ nullptr);

    if (LZ4F_isError(ret)) {

        return Status::InternalError("Decompression error: {}",

                                     std::string(LZ4F_getErrorName(ret)));

    }

    // update

    *input_bytes_read += remaining_input_size;

    *decompressed_len = output_len;

    if (ret == 0) {

        *stream_end = true;

    } else {

        *stream_end = false;

    }

    return Status::OK();

}

std::string Lz4FrameDecompressor::debug_info() {

    std::stringstream ss;

    ss << "Lz4FrameDecompressor."

       << " expect dec buf size: " << _expect_dec_buf_size

       << " Lz4 Frame Version: " << DORIS_LZ4F_VERSION;

    return ss.str();

}

size_t Lz4FrameDecompressor::get_block_size(const LZ4F_frameInfo_t* info) {

    switch (info->blockSizeID) {

    case LZ4F_default:

    case LZ4F_max64KB:

        return 1 << 16;

    case LZ4F_max256KB:

        return 1 << 18;

    case LZ4F_max1MB:

        return 1 << 20;

    case LZ4F_max4MB:

        return 1 << 22;

    default:

        // error

        return -1;

    }

}

/// Lz4BlockDecompressor

Status Lz4BlockDecompressor::init() {

    return Status::OK();

}

// Hadoop lz4codec source :

// https://github.com/apache/hadoop/blob/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/native/src/codec/Lz4Codec.cc

// Example:

// OriginData(The original data will be divided into several large data block.) :

//      large data block1 | large data block2 | large data block3 | ....

// The large data block will be divided into several small data block.

// Suppose a large data block is divided into three small blocks:

// large data block1:            | small block1 | small block2 | small block3 |

// CompressData:   <A [B1 compress(small block1) ] [B2 compress(small block1) ] [B3 compress(small block1)]>

//

// A : original length of the current block of large data block.

// sizeof(A) = 4 bytes.

// A = length(small block1) + length(small block2) + length(small block3)

// Bx : length of  small data block bx.

// sizeof(Bx) = 4 bytes.

// Bx = length(compress(small blockx))

Status Lz4BlockDecompressor::decompress(uint8_t* input, size_t input_len, size_t* input_bytes_read,

                                        uint8_t* output, size_t output_max_len,

                                        size_t* decompressed_len, bool* stream_end,

                                        size_t* more_input_bytes, size_t* more_output_bytes) {

    auto* input_ptr = input;

    auto* output_ptr = output;

    while (input_len > 0) {

        //if faild ,  fall back to large block begin

        auto* large_block_input_ptr = input_ptr;

        auto* large_block_output_ptr = output_ptr;

        if (input_len < sizeof(uint32_t)) {

            return Status::InvalidArgument(strings::Substitute(

                    "fail to do hadoop-lz4 decompress, input_len=$0", input_len));

        }

        uint32_t remaining_decompressed_large_block_len = BigEndian::Load32(input_ptr);

        input_ptr += sizeof(uint32_t);

        input_len -= sizeof(uint32_t);

        std::size_t remaining_output_len = output_max_len - *decompressed_len;

        if (remaining_output_len < remaining_decompressed_large_block_len) {

            // Need more output buffer

            *more_output_bytes = remaining_decompressed_large_block_len - remaining_output_len;

            input_ptr = large_block_input_ptr;

            output_ptr = large_block_output_ptr;

            break;

        }

        std::size_t decompressed_large_block_len = 0;

        while (remaining_decompressed_large_block_len > 0) {

            // Check that input length should not be negative.

            if (input_len < sizeof(uint32_t)) {

                *more_input_bytes = sizeof(uint32_t) - input_len;

                break;

            }

            // Read the length of the next lz4 compressed block.

            size_t compressed_small_block_len = BigEndian::Load32(input_ptr);

            input_ptr += sizeof(uint32_t);

            input_len -= sizeof(uint32_t);

            if (compressed_small_block_len == 0) {

                continue;

            }

            if (compressed_small_block_len > input_len) {

                // Need more input buffer

                *more_input_bytes = compressed_small_block_len - input_len;

                break;

            }

            // Decompress this block.

            auto decompressed_small_block_len = LZ4_decompress_safe(

                    reinterpret_cast<const char*>(input_ptr), reinterpret_cast<char*>(output_ptr),

                    compressed_small_block_len, remaining_output_len);

            if (decompressed_small_block_len < 0) {

                return Status::InvalidArgument("fail to do LZ4 decompress, error = {}",

                                               LZ4F_getErrorName(decompressed_small_block_len));

            }

            input_ptr += compressed_small_block_len;

            input_len -= compressed_small_block_len;

            output_ptr += decompressed_small_block_len;

            remaining_decompressed_large_block_len -= decompressed_small_block_len;

            decompressed_large_block_len += decompressed_small_block_len;

        };

        if (*more_input_bytes != 0) {

            // Need more input buffer

            input_ptr = large_block_input_ptr;

            output_ptr = large_block_output_ptr;

            break;

        }

        *decompressed_len += decompressed_large_block_len;

    }

    *input_bytes_read += (input_ptr - input);

    // If no more input and output need, means this is the end of a compressed block

    *stream_end = (*more_input_bytes == 0 && *more_output_bytes == 0);

    return Status::OK();

}

std::string Lz4BlockDecompressor::debug_info() {

    std::stringstream ss;

    ss << "Lz4BlockDecompressor.";

    return ss.str();

}

/// SnappyBlockDecompressor

Status SnappyBlockDecompressor::init() {

    return Status::OK();

}

// Hadoop snappycodec source :

// https://github.com/apache/hadoop/blob/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-nativetask/src/main/native/src/codec/SnappyCodec.cc

// Example:

// OriginData(The original data will be divided into several large data block.) :

//      large data block1 | large data block2 | large data block3 | ....

// The large data block will be divided into several small data block.

// Suppose a large data block is divided into three small blocks:

// large data block1:            | small block1 | small block2 | small block3 |

// CompressData:   <A [B1 compress(small block1) ] [B2 compress(small block1) ] [B3 compress(small block1)]>

//

// A : original length of the current block of large data block.

// sizeof(A) = 4 bytes.

// A = length(small block1) + length(small block2) + length(small block3)

// Bx : length of  small data block bx.

// sizeof(Bx) = 4 bytes.

// Bx = length(compress(small blockx))

Status SnappyBlockDecompressor::decompress(uint8_t* input, size_t input_len,

                                           size_t* input_bytes_read, uint8_t* output,

                                           size_t output_max_len, size_t* decompressed_len,

                                           bool* stream_end, size_t* more_input_bytes,

                                           size_t* more_output_bytes) {

    auto* input_ptr = input;

    auto* output_ptr = output;

    while (input_len > 0) {

        //if faild ,  fall back to large block begin

        auto* large_block_input_ptr = input_ptr;

        auto* large_block_output_ptr = output_ptr;

        if (input_len < sizeof(uint32_t)) {

            return Status::InvalidArgument(strings::Substitute(

                    "fail to do hadoop-snappy decompress, input_len=$0", input_len));

        }

        uint32_t remaining_decompressed_large_block_len = BigEndian::Load32(input_ptr);

        input_ptr += sizeof(uint32_t);

        input_len -= sizeof(uint32_t);

        std::size_t remaining_output_len = output_max_len - *decompressed_len;

        if (remaining_output_len < remaining_decompressed_large_block_len) {

            // Need more output buffer

            *more_output_bytes = remaining_decompressed_large_block_len - remaining_output_len;

            input_ptr = large_block_input_ptr;

            output_ptr = large_block_output_ptr;

            break;

        }

        std::size_t decompressed_large_block_len = 0;

        while (remaining_decompressed_large_block_len > 0) {

            // Check that input length should not be negative.

            if (input_len < sizeof(uint32_t)) {

                *more_input_bytes = sizeof(uint32_t) - input_len;

                break;

            }

            // Read the length of the next snappy compressed block.

            size_t compressed_small_block_len = BigEndian::Load32(input_ptr);

            input_ptr += sizeof(uint32_t);

            input_len -= sizeof(uint32_t);

            if (compressed_small_block_len == 0) {

                continue;

            }

            if (compressed_small_block_len > input_len) {

                // Need more input buffer

                *more_input_bytes = compressed_small_block_len - input_len;

                break;

            }

            // Decompress this block.

            size_t decompressed_small_block_len;

            if (!snappy::GetUncompressedLength(reinterpret_cast<const char*>(input_ptr),

                                               compressed_small_block_len,

                                               &decompressed_small_block_len)) {

                return Status::InternalError(

                        "snappy block decompress failed to get uncompressed len");

            }

            if (!snappy::RawUncompress(reinterpret_cast<const char*>(input_ptr),

                                       compressed_small_block_len,

                                       reinterpret_cast<char*>(output_ptr))) {

                return Status::InternalError(

                        "snappy block decompress failed. uncompressed_len: {}, compressed_len: {}",

                        decompressed_small_block_len, compressed_small_block_len);

            }

            input_ptr += compressed_small_block_len;

            input_len -= compressed_small_block_len;

            output_ptr += decompressed_small_block_len;

            remaining_decompressed_large_block_len -= decompressed_small_block_len;

            decompressed_large_block_len += decompressed_small_block_len;

        };

        if (*more_input_bytes != 0) {

            // Need more input buffer

            input_ptr = large_block_input_ptr;

            output_ptr = large_block_output_ptr;

            break;

        }

        *decompressed_len += decompressed_large_block_len;

    }

    *input_bytes_read += (input_ptr - input);

    // If no more input and output need, means this is the end of a compressed block

    *stream_end = (*more_input_bytes == 0 && *more_output_bytes == 0);

    return Status::OK();

}

std::string SnappyBlockDecompressor::debug_info() {

    std::stringstream ss;

    ss << "SnappyBlockDecompressor.";

    return ss.str();

}

} // namespace doris