Line data    Source code

       1             : #pragma once
       2             : 
       3             : #include "envoy/compression/decompressor/decompressor.h"
       4             : #include "envoy/stats/scope.h"
       5             : #include "envoy/stats/stats_macros.h"
       6             : 
       7             : #include "source/common/common/logger.h"
       8             : #include "source/extensions/compression/gzip/common/base.h"
       9             : 
      10             : #include "zlib.h"
      11             : 
      12             : namespace Envoy {
      13             : namespace Extensions {
      14             : namespace Compression {
      15             : namespace Gzip {
      16             : namespace Decompressor {
      17             : 
      18             : /**
      19             :  * All zlib decompressor stats. @see stats_macros.h
      20             :  */
      21             : #define ALL_ZLIB_DECOMPRESSOR_STATS(COUNTER)                                                       \
      22         758 :   COUNTER(zlib_errno)                                                                              \
      23         758 :   COUNTER(zlib_stream_error)                                                                       \
      24         758 :   COUNTER(zlib_data_error)                                                                         \
      25         758 :   COUNTER(zlib_mem_error)                                                                          \
      26         758 :   COUNTER(zlib_buf_error)                                                                          \
      27         758 :   COUNTER(zlib_version_error)
      28             : 
      29             : /**
      30             :  * Struct definition for zlib decompressor stats. @see stats_macros.h
      31             :  */
      32             : struct ZlibDecompressorStats {
      33             :   ALL_ZLIB_DECOMPRESSOR_STATS(GENERATE_COUNTER_STRUCT)
      34             : };
      35             : 
      36             : /**
      37             :  * Implementation of decompressor's interface.
      38             :  */
      39             : class ZlibDecompressorImpl : public Common::Base,
      40             :                              public Envoy::Compression::Decompressor::Decompressor,
      41             :                              public Logger::Loggable<Logger::Id::decompression> {
      42             : public:
      43             :   /**
      44             :    * Constructor that allows setting the size of decompressor's output buffer. It
      45             :    * should be called whenever a buffer size different than the 4096 bytes, normally set by the
      46             :    * default constructor, is desired. If memory is available and it makes sense to output large
      47             :    * chunks of compressed data, zlib documentation suggests buffers sizes on the order of 128K or
      48             :    * 256K bytes. @see http://zlib.net/zlib_how.html
      49             :    * @param chunk_size amount of memory reserved for the decompressor output.
      50             :    */
      51             :   ZlibDecompressorImpl(Stats::Scope& scope, const std::string& stats_prefix, uint64_t chunk_size,
      52             :                        uint64_t max_inflate_ratio);
      53             : 
      54             :   /**
      55             :    * Init must be called in order to initialize the decompressor. Once decompressor is initialized,
      56             :    * it cannot be initialized again. Init should run before decompressing any data.
      57             :    * @param window_bits sets the size of the history buffer. It must be greater than or equal to
      58             :    * the window_bits value provided when data was compressed (zlib manual).
      59             :    */
      60             :   void init(int64_t window_bits);
      61             : 
      62             :   // Compression::Decompressor::Decompressor
      63             :   void decompress(const Buffer::Instance& input_buffer, Buffer::Instance& output_buffer) override;
      64             : 
      65             :   // Flag to track whether error occurred during decompression.
      66             :   // When an error occurs, the error code (a negative int) will be stored in this variable.
      67             :   int decompression_error_{0};
      68             : 
      69             : private:
      70             :   // TODO: clean up friend class. This is here to allow coverage of chargeErrorStats as it isn't
      71             :   // completely straightforward
      72             :   // to cause zlib's inflate function to return all the error codes necessary to hit all the cases
      73             :   // in the switch statement.
      74             :   friend class ZlibDecompressorStatsTest;
      75         758 :   static ZlibDecompressorStats generateStats(const std::string& prefix, Stats::Scope& scope) {
      76         758 :     return ZlibDecompressorStats{ALL_ZLIB_DECOMPRESSOR_STATS(POOL_COUNTER_PREFIX(scope, prefix))};
      77         758 :   }
      78             : 
      79             :   bool inflateNext();
      80             :   void chargeErrorStats(const int result);
      81             : 
      82             :   const ZlibDecompressorStats stats_;
      83             :   const uint64_t max_inflate_ratio_;
      84             : };
      85             : 
      86             : } // namespace Decompressor
      87             : } // namespace Gzip
      88             : } // namespace Compression
      89             : } // namespace Extensions
      90             : } // namespace Envoy