loki/pkg/logproto/sketch.proto

syntax = "proto3";

package logproto;

import "pkg/logproto/logproto.proto";

option go_package = "github.com/grafana/loki/pkg/logproto";

message QuantileSketchMatrix {
  repeated QuantileSketchVector values = 1;
}

message QuantileSketchVector {
  repeated QuantileSketchSample samples = 1;
}

message QuantileSketchSample {
  QuantileSketch f = 1;
  int64 timestamp_ms = 2;
  repeated LabelPair metric = 3;
}

message QuantileSketch {
  oneof sketch {
    TDigest tdigest = 1;
    bytes ddsketch = 2; // Use binary encoding for DDSketch.
  }
}

// "Large" bytes format from https://github.com/tdunning/t-digest
message TDigest {
  double min = 1;
  double max = 2;
  double compression = 3;

  message Centroid {
    double mean = 1;
    double weight = 2;
  }
  repeated Centroid processed = 4;
}

message CountMinSketch {
  uint32 depth = 1;
  uint32 width = 2;

  // counters is a matrix of depth * width.
  repeated uint32 counters = 3;
}

message TopK {
  CountMinSketch cms = 1;

  message Pair {
    string event = 1;
    uint32 count = 2;
  }
  repeated Pair list = 2;

  bytes hyperloglog = 3;
}

message TopKMatrix {
  message Vector {
    TopK topk = 1;
    int64 timestamp_ms = 2;
  }

  repeated Vector values = 1;
}