syntax = "proto3";

package envoy.extensions.compression.gzip.compressor.v3;

import "google/protobuf/wrappers.proto";

import "udpa/annotations/status.proto";
import "validate/validate.proto";

option java_package = "io.envoyproxy.envoy.extensions.compression.gzip.compressor.v3";
option java_outer_classname = "GzipProto";
option java_multiple_files = true;
option (udpa.annotations.file_status).package_version_status = ACTIVE;

// [#protodoc-title: Gzip Compressor]
// [#extension: envoy.compression.gzip.compressor]

// [#next-free-field: 6]
message Gzip {
  // All the values of this enumeration translate directly to zlib's compression strategies.
  // For more information about each strategy, please refer to zlib manual.
  enum CompressionStrategy {
    DEFAULT_STRATEGY = 0;
    FILTERED = 1;
    HUFFMAN_ONLY = 2;
    RLE = 3;
    FIXED = 4;
  }

  enum CompressionLevel {
    option allow_alias = true;

    DEFAULT_COMPRESSION = 0;
    BEST_SPEED = 1;
    COMPRESSION_LEVEL_1 = 1;
    COMPRESSION_LEVEL_2 = 2;
    COMPRESSION_LEVEL_3 = 3;
    COMPRESSION_LEVEL_4 = 4;
    COMPRESSION_LEVEL_5 = 5;
    COMPRESSION_LEVEL_6 = 6;
    COMPRESSION_LEVEL_7 = 7;
    COMPRESSION_LEVEL_8 = 8;
    COMPRESSION_LEVEL_9 = 9;
    BEST_COMPRESSION = 9;
  }

  // Value from 1 to 9 that controls the amount of internal memory used by zlib. Higher values
  // use more memory, but are faster and produce better compression results. The default value is 5.
  google.protobuf.UInt32Value memory_level = 1 [(validate.rules).uint32 = {lte: 9 gte: 1}];

  // A value used for selecting the zlib compression level. This setting will affect speed and
  // amount of compression applied to the content. "BEST_COMPRESSION" provides higher compression
  // at the cost of higher latency and is equal to "COMPRESSION_LEVEL_9". "BEST_SPEED" provides
  // lower compression with minimum impact on response time, the same as "COMPRESSION_LEVEL_1".
  // "DEFAULT_COMPRESSION" provides an optimal result between speed and compression. According
  // to zlib's manual this level gives the same result as "COMPRESSION_LEVEL_6".
  // This field will be set to "DEFAULT_COMPRESSION" if not specified.
  CompressionLevel compression_level = 2 [(validate.rules).enum = {defined_only: true}];

  // A value used for selecting the zlib compression strategy which is directly related to the
  // characteristics of the content. Most of the time "DEFAULT_STRATEGY" will be the best choice,
  // which is also the default value for the parameter, though there are situations when
  // changing this parameter might produce better results. For example, run-length encoding (RLE)
  // is typically used when the content is known for having sequences which same data occurs many
  // consecutive times. For more information about each strategy, please refer to zlib manual.
  CompressionStrategy compression_strategy = 3 [(validate.rules).enum = {defined_only: true}];

  // Value from 9 to 15 that represents the base two logarithmic of the compressor's window size.
  // Larger window results in better compression at the expense of memory usage. The default is 12
  // which will produce a 4096 bytes window. For more details about this parameter, please refer to
  // zlib manual > deflateInit2.
  google.protobuf.UInt32Value window_bits = 4 [(validate.rules).uint32 = {lte: 15 gte: 9}];

  // Value for Zlib's next output buffer. If not set, defaults to 4096.
  // See https://www.zlib.net/manual.html for more details. Also see
  // https://github.com/envoyproxy/envoy/issues/8448 for context on this filter's performance.
  google.protobuf.UInt32Value chunk_size = 5 [(validate.rules).uint32 = {lte: 65536 gte: 4096}];
}