blob: a242ab8e98fd4aba4f92e243e0bd7cf89ce60338 [file] [log] [blame]
Scott Baker2c1c4822019-10-16 11:02:41 -07001/*
2 * Copyright 2018-present Open Networking Foundation
3
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7
8 * http://www.apache.org/licenses/LICENSE-2.0
9
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package model
18
19import (
20 "github.com/opencord/voltha-lib-go/pkg/common/log"
21 "sync"
22)
23
24// TODO: implement weak references or something equivalent
25// TODO: missing proper logging
26
27// Branch structure is used to classify a collection of transaction based revisions
28type Branch struct {
29 mutex sync.RWMutex
30 Node *node
31 Txid string
32 Origin Revision
33 Revisions map[string]Revision
34 LatestLock sync.RWMutex
35 Latest Revision
36}
37
38// NewBranch creates a new instance of the Branch structure
39func NewBranch(node *node, txid string, origin Revision, autoPrune bool) *Branch {
40 b := &Branch{}
41 b.Node = node
42 b.Txid = txid
43 b.Origin = origin
44 b.Revisions = make(map[string]Revision)
45 b.Latest = origin
46
47 return b
48}
49
50// Utility function to extract all children names for a given revision (mostly for debugging purposes)
51func (b *Branch) retrieveChildrenNames(revision Revision) []string {
52 var childrenNames []string
53
54 for _, child := range revision.GetChildren("devices") {
55 childrenNames = append(childrenNames, child.GetName())
56 }
57
58 return childrenNames
59}
60
61// Utility function to compare children names and report the missing ones (mostly for debugging purposes)
62func (b *Branch) findMissingChildrenNames(previousNames, latestNames []string) []string {
63 var missingNames []string
64
65 for _, previousName := range previousNames {
66 found := false
67
68 if len(latestNames) == 0 {
69 break
70 }
71
72 for _, latestName := range latestNames {
73 if previousName == latestName {
74 found = true
75 break
76 }
77 }
78 if !found {
79 missingNames = append(missingNames, previousName)
80 }
81 }
82
83 return missingNames
84}
85
86// SetLatest assigns the latest revision for this branch
87func (b *Branch) SetLatest(latest Revision) {
88 b.mutex.Lock()
89 defer b.mutex.Unlock()
90
91 if b.Latest != nil {
92 log.Debugw("updating-latest-revision", log.Fields{"current": b.Latest.GetHash(), "new": latest.GetHash()})
93
94 // Go through list of children names in current revision and new revision
95 // and then compare the resulting outputs to ensure that we have not lost any entries.
96
97 if level, _ := log.GetPackageLogLevel(); level == log.DebugLevel {
98 var previousNames, latestNames, missingNames []string
99
100 if previousNames = b.retrieveChildrenNames(b.Latest); len(previousNames) > 0 {
101 log.Debugw("children-of-previous-revision", log.Fields{"hash": b.Latest.GetHash(), "names": previousNames})
102 }
103
104 if latestNames = b.retrieveChildrenNames(b.Latest); len(latestNames) > 0 {
105 log.Debugw("children-of-latest-revision", log.Fields{"hash": latest.GetHash(), "names": latestNames})
106 }
107
108 if missingNames = b.findMissingChildrenNames(previousNames, latestNames); len(missingNames) > 0 {
109 log.Debugw("children-missing-in-latest-revision", log.Fields{"hash": latest.GetHash(), "names": missingNames})
110 }
111 }
112
113 } else {
114 log.Debugw("setting-latest-revision", log.Fields{"new": latest.GetHash()})
115 }
116
117 b.Latest = latest
118}
119
120// GetLatest retrieves the latest revision of the branch
121func (b *Branch) GetLatest() Revision {
122 b.mutex.RLock()
123 defer b.mutex.RUnlock()
124
125 return b.Latest
126}
127
128// GetOrigin retrieves the original revision of the branch
129func (b *Branch) GetOrigin() Revision {
130 b.mutex.RLock()
131 defer b.mutex.RUnlock()
132
133 return b.Origin
134}
135
136// AddRevision inserts a new revision to the branch
137func (b *Branch) AddRevision(revision Revision) {
138 if revision != nil && b.GetRevision(revision.GetHash()) == nil {
139 b.SetRevision(revision.GetHash(), revision)
140 }
141}
142
143// GetRevision pulls a revision entry at the specified hash
144func (b *Branch) GetRevision(hash string) Revision {
145 b.mutex.RLock()
146 defer b.mutex.RUnlock()
147
148 if revision, ok := b.Revisions[hash]; ok {
149 return revision
150 }
151
152 return nil
153}
154
155// SetRevision updates a revision entry at the specified hash
156func (b *Branch) SetRevision(hash string, revision Revision) {
157 b.mutex.Lock()
158 defer b.mutex.Unlock()
159
160 b.Revisions[hash] = revision
161}
162
163// DeleteRevision removes a revision with the specified hash
164func (b *Branch) DeleteRevision(hash string) {
165 b.mutex.Lock()
166 defer b.mutex.Unlock()
167
168 if _, ok := b.Revisions[hash]; ok {
169 delete(b.Revisions, hash)
170 }
171}