// Copyright 2013 Prometheus Team
// Licensed 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.

package dto;

message LabelPair {
  optional string name = 1;
  optional string value = 2;
}

message LabelName {
  optional string name = 1;
}

message Metric {
  repeated LabelPair label_pair = 1;
}

message Fingerprint {
  optional string signature = 1;
}

message FingerprintCollection {
  repeated Fingerprint member = 1;
}

message LabelSet {
  repeated LabelPair member = 1;
}

// The default LevelDB comparator sorts not only lexicographically, but also by
// key length (which takes precedence). Thus, no variable-length fields may be
// introduced into the key definition below.
message SampleKey {
  optional Fingerprint fingerprint    = 1;
  optional bytes       timestamp      = 2;
  optional sfixed64    last_timestamp = 3;
  optional fixed32     sample_count   = 4;
}

message SampleValueSeries {
  message Value {
    optional int64 timestamp = 1;
    optional float value     = 2;
  }
  repeated Value value = 1;
}

message MembershipIndexValue {
}

message MetricHighWatermark {
  optional int64 timestamp = 1;
}

// CurationKey models the state of curation for a given metric fingerprint and
// its associated samples.  The time series database only knows about compaction
// and resampling behaviors that are explicitly defined to it in its runtime
// configuration, meaning it never scans on-disk tables for CurationKey
// policies; rather, it looks up via the CurationKey tuple to find out what the
// effectuation state for a given metric fingerprint is.
//
// For instance, how far along as a rule for (Fingerprint A, Samples Older Than
// B, and Grouped Together in Size of C) has been effectuated on-disk.
message CurationKey {
  // fingerprint identifies the fingerprint for the given policy.
  optional Fingerprint fingerprint        = 1;
  // older_than represents in seconds relative to when curation cycle starts
  // into the past when the curator should stop operating on a given metric
  // fingerprint's samples:
  //
  // [Oldest Sample Time, time.Now().Sub(time.Second * older_than))
  optional int64       older_than         = 2;
  // minimum_group_size identifies how minimally samples should be grouped
  // together to write a new SampleValueSeries chunk.
  optional uint32      minimum_group_size = 3;
}

// CurationValue models the progress for a given CurationKey.
message CurationValue {
  // last_completion_timestamp represents the seconds since the epoch UTC at
  // which the curator last completed its duty cycle for a given metric
  // fingerprint.
  optional int64 last_completion_timestamp = 1;
}