cpp/src/compress/gzip_compressor.h

/*
 * 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.
 */

#ifndef COMPRESS_GZIP_COMPRESSOR_H
#define COMPRESS_GZIP_COMPRESSOR_H

#include <errno.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h>

#include "common/allocator/byte_stream.h"
#include "common/logger/elog.h"
#include "compressor.h"
#include "utils/errno_define.h"
#include "utils/util_define.h"

#define DEFLATE_BUFFER_SIZE 512
#define INFLATE_BUFFER_SIZE 512

namespace storage {

class GzipCompressor {
   public:
    GzipCompressor();
    ~GzipCompressor();
    int reset();
    void destroy() { end_zstream(); }
    int compress(char *uncompressed_buf, uint32_t uncompressed_buf_len,
                 char *&compressed_buf, uint32_t &compressed_buf_len);
    void after_compress(char *compressed_buf) { ::free(compressed_buf); }
    int compress_into_bytestream(char *uncompressed_buf,
                                 uint32_t uncompressed_buf_len,
                                 common::ByteStream &out);

   private:
    int init_zstream();
    int end_zstream();

   private:
    z_stream compress_stream_;
    char compressed_buf[DEFLATE_BUFFER_SIZE];
    bool zstream_valid_;
};

class GzipDeCompressor {
   public:
    GzipDeCompressor();
    ~GzipDeCompressor();
    int reset();
    void destroy() { end_zstream(); }
    int uncompress(char *compressed_buf, uint32_t compressed_buf_len,
                   char *&uncompressed_buf, uint32_t &uncompressed_buf_len);
    void after_uncompress(char *uncompressed_buf) { ::free(uncompressed_buf); }
    int decompress_into_bytestream(char *compressed_buf,
                                   uint32_t compressed_buf_len,
                                   common::ByteStream &out);

   private:
    int init_zstream();
    int end_zstream();

   private:
    z_stream decompress_stream_;
    char decompressed_buf[INFLATE_BUFFER_SIZE];
    bool zstream_valid_;
};

class GZIPCompressor : public Compressor {
   public:
    GZIPCompressor() : gzip_compressor_(), gzip_decompressor_() {}
    int reset(bool for_compress) OVERRIDE {
        if (for_compress) {
            return gzip_compressor_.reset();
        } else {
            return gzip_decompressor_.reset();
        }
    }

    void destroy() OVERRIDE {
        gzip_compressor_.destroy();
        gzip_decompressor_.destroy();
    }

    int compress(char *uncompressed_buf, uint32_t uncompressed_buf_len,
                 char *&compressed_buf, uint32_t &compressed_buf_len) OVERRIDE {
        return gzip_compressor_.compress(uncompressed_buf, uncompressed_buf_len,
                                         compressed_buf, compressed_buf_len);
    }
    void after_compress(char *compressed_buf) OVERRIDE {
        gzip_compressor_.after_compress(compressed_buf);
    }

    int uncompress(char *compressed_buf, uint32_t compressed_buf_len,
                   char *&uncompressed_buf,
                   uint32_t &uncompressed_buf_len) OVERRIDE {
        return gzip_decompressor_.uncompress(compressed_buf, compressed_buf_len,
                                             uncompressed_buf,
                                             uncompressed_buf_len);
    }
    void after_uncompress(char *uncompressed_buf) OVERRIDE {
        gzip_decompressor_.after_uncompress(uncompressed_buf);
    }

   private:
    GzipCompressor gzip_compressor_;
    GzipDeCompressor gzip_decompressor_;
};

}  // end namespace storage
   // end

#endif  // COMPRESS_GZIP_COMPRESSOR_H