1// Copyright 2015 The etcd Authors
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package raft
16
17import (
18	"fmt"
19
20	pb "go.etcd.io/etcd/raft/raftpb"
21	"go.etcd.io/etcd/raft/tracker"
22)
23
24// Status contains information about this Raft peer and its view of the system.
25// The Progress is only populated on the leader.
26type Status struct {
27	BasicStatus
28	Config   tracker.Config
29	Progress map[uint64]tracker.Progress
30}
31
32// BasicStatus contains basic information about the Raft peer. It does not allocate.
33type BasicStatus struct {
34	ID uint64
35
36	pb.HardState
37	SoftState
38
39	Applied uint64
40
41	LeadTransferee uint64
42}
43
44func getProgressCopy(r *raft) map[uint64]tracker.Progress {
45	m := make(map[uint64]tracker.Progress)
46	r.prs.Visit(func(id uint64, pr *tracker.Progress) {
47		var p tracker.Progress
48		p = *pr
49		p.Inflights = pr.Inflights.Clone()
50		pr = nil
51
52		m[id] = p
53	})
54	return m
55}
56
57func getBasicStatus(r *raft) BasicStatus {
58	s := BasicStatus{
59		ID:             r.id,
60		LeadTransferee: r.leadTransferee,
61	}
62	s.HardState = r.hardState()
63	s.SoftState = *r.softState()
64	s.Applied = r.raftLog.applied
65	return s
66}
67
68// getStatus gets a copy of the current raft status.
69func getStatus(r *raft) Status {
70	var s Status
71	s.BasicStatus = getBasicStatus(r)
72	if s.RaftState == StateLeader {
73		s.Progress = getProgressCopy(r)
74	}
75	s.Config = r.prs.Config.Clone()
76	return s
77}
78
79// MarshalJSON translates the raft status into JSON.
80// TODO: try to simplify this by introducing ID type into raft
81func (s Status) MarshalJSON() ([]byte, error) {
82	j := fmt.Sprintf(`{"id":"%x","term":%d,"vote":"%x","commit":%d,"lead":"%x","raftState":%q,"applied":%d,"progress":{`,
83		s.ID, s.Term, s.Vote, s.Commit, s.Lead, s.RaftState, s.Applied)
84
85	if len(s.Progress) == 0 {
86		j += "},"
87	} else {
88		for k, v := range s.Progress {
89			subj := fmt.Sprintf(`"%x":{"match":%d,"next":%d,"state":%q},`, k, v.Match, v.Next, v.State)
90			j += subj
91		}
92		// remove the trailing ","
93		j = j[:len(j)-1] + "},"
94	}
95
96	j += fmt.Sprintf(`"leadtransferee":"%x"}`, s.LeadTransferee)
97	return []byte(j), nil
98}
99
100func (s Status) String() string {
101	b, err := s.MarshalJSON()
102	if err != nil {
103		raftLogger.Panicf("unexpected error: %v", err)
104	}
105	return string(b)
106}
107