text: /**
   * Copyright (c) 2021 OceanBase
   * OceanBase Database Proxy(ODP) is licensed under Mulan PubL v2.
   * You can use this software according to the terms and conditions of the Mulan PubL v2.
   * You may obtain a copy of Mulan PubL v2 at:
   *          http://license.coscl.org.cn/MulanPubL-2.0
   * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
   * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
   * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
   * See the Mulan PubL v2 for more details.
   */
  
  #include "lib/compress/snappy/ob_snappy_compressor.h"
  #include "lib/compress/snappy/snappy.h"
  #include "lib/ob_errno.h"
  
  namespace oceanbase
  {
  namespace common
  {
  const char *ObSnappyCompressor::compressor_name = "snappy_1.0";
  int ObSnappyCompressor::compress(const char *src_buffer,
                                   const int64_t src_data_size,
                                   char *dst_buffer,
                                   const int64_t dst_buffer_size,
                                   int64_t &dst_data_size)
  {
    int ret = OB_SUCCESS;
    int64_t max_overflow_size = 0;
    if (NULL == src_buffer
        || 0 >= src_data_size
        || NULL == dst_buffer
        || 0 >= dst_buffer_size) {
      ret = OB_INVALID_ARGUMENT;
      LIB_LOG(WARN, "invalid compress argument, ",
          K(ret), KP(src_buffer), K(src_data_size), KP(dst_buffer), K(dst_buffer_size));
    } else if (OB_FAIL(get_max_overflow_size(src_data_size, max_overflow_size))) {
      LIB_LOG(WARN, "fail to get max_overflow_size, ", K(ret), K(src_data_size));
    } else if ((src_data_size + max_overflow_size) > dst_buffer_size) {
      ret = OB_BUF_NOT_ENOUGH;
      LIB_LOG(WARN, "dst buffer not enough, ",
          K(ret), K(src_data_size), K(max_overflow_size), K(dst_buffer_size));
    } else {
      snappy::RawCompress(src_buffer, static_cast<size_t>(src_data_size), dst_buffer,
                          reinterpret_cast<size_t*>(&dst_data_size));
    }
    return ret;
  }
  
  int ObSnappyCompressor::decompress(const char *src_buffer,
                                     const int64_t src_data_size,
                                     char *dst_buffer,
                                     const int64_t dst_buffer_size,
                                     int64_t &dst_data_size)
  {
    int ret = OB_SUCCESS;
    bool flag = true;
    size_t decom_size = 0;
    if (NULL == src_buffer
        || 0 >= src_data_size
        || NULL == dst_buffer
        || 0 >= dst_buffer_size) {
      ret = OB_INVALID_ARGUMENT;
      LIB_LOG(WARN, "invalid compress argument, ",
          K(ret), KP(src_buffer), K(src_data_size), KP(dst_buffer), K(dst_buffer_size));
    } else if (!snappy::GetUncompressedLength(src_buffer,
                                              static_cast<size_t>(src_data_size),
                                              &decom_size)) {
      ret = OB_ERR_COMPRESS_DECOMPRESS_DATA;
      LIB_LOG(WARN, "fail to get uncompressed length, ",
          K(ret), KP(src_buffer), K(src_data_size));
    } else if (decom_size > static_cast<size_t>(dst_buffer_size)) {
      ret = OB_BUF_NOT_ENOUGH;
      LIB_LOG(WARN, "dst buffer not enough, ",
          K(ret), K(decom_size), K(dst_buffer_size));
    } else if (!snappy::RawUncompress(src_buffer,
                                      static_cast<size_t>(src_data_size),
                                      dst_buffer)) {
      ret = OB_ERR_COMPRESS_DECOMPRESS_DATA;
      LIB_LOG(WARN, "fail to decompress data by snappy, ",
          K(ret), KP(src_buffer), K(src_data_size));
    } else {
      dst_data_size = decom_size;
    }
  
    return ret;
  }
  
  const char *ObSnappyCompressor::get_compressor_name() const
  {
    return compressor_name;
  }
  
  int ObSnappyCompressor::get_max_overflow_size(const int64_t src_data_size,
                                                int64_t &max_overflow_size) const
  {
    int ret = OB_SUCCESS;
    if (src_data_size < 0) {
      ret = OB_INVALID_ARGUMENT;
      LIB_LOG(WARN, "invalid argument, ", K(ret), K(src_data_size));
    } else {
      max_overflow_size = 32 + src_data_size / 6;
    }
    return ret;
  }
  }//namespace common
  }//namespace oceanbase
  