File size: 3,724 Bytes
b110593
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
//                           _       _
// __      _____  __ ___   ___  __ _| |_ ___
// \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
//  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
//   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
//
//  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
//
//  CONTACT: [email protected]
//

package lsmkv

import (
	"bufio"
	"encoding/binary"
	"os"
	"sync/atomic"

	"github.com/pkg/errors"
	"github.com/weaviate/weaviate/adapters/repos/db/lsmkv/roaringset"
)

type commitLogger struct {
	file   *os.File
	writer *bufio.Writer
	n      atomic.Int64
	path   string

	// e.g. when recovering from an existing log, we do not want to write into a
	// new log again
	paused bool
}

type CommitType uint16

const (
	CommitTypeReplace CommitType = iota // replace strategy

	// collection strategy - this can handle all cases as updates and deletes are
	// only appends in a collection strategy
	CommitTypeCollection
	CommitTypeRoaringSet
)

func (ct CommitType) String() string {
	switch ct {
	case CommitTypeReplace:
		return "replace"
	case CommitTypeCollection:
		return "collection"
	case CommitTypeRoaringSet:
		return "roaringset"
	default:
		return "unknown"
	}
}

func (ct CommitType) Is(checkedCommitType CommitType) bool {
	return ct == checkedCommitType
}

func newCommitLogger(path string) (*commitLogger, error) {
	out := &commitLogger{
		path: path + ".wal",
	}

	f, err := os.Create(out.path)
	if err != nil {
		return nil, err
	}

	out.file = f

	out.writer = bufio.NewWriter(f)
	return out, nil
}

func (cl *commitLogger) put(node segmentReplaceNode) error {
	if cl.paused {
		return nil
	}

	// TODO: do we need a timestamp? if so, does it need to be a vector clock?
	if err := binary.Write(cl.writer, binary.LittleEndian, CommitTypeReplace); err != nil {
		return err
	}
	n := 1

	if ki, err := node.KeyIndexAndWriteTo(cl.writer); err != nil {
		return err
	} else {
		n += ki.ValueEnd - ki.ValueStart
	}

	cl.n.Add(int64(n))

	return nil
}

func (cl *commitLogger) append(node segmentCollectionNode) error {
	if cl.paused {
		return nil
	}

	// TODO: do we need a timestamp? if so, does it need to be a vector clock?
	if err := binary.Write(cl.writer, binary.LittleEndian, CommitTypeCollection); err != nil {
		return err
	}
	n := 1

	if ki, err := node.KeyIndexAndWriteTo(cl.writer); err != nil {
		return err
	} else {
		n += ki.ValueEnd - ki.ValueStart
	}

	cl.n.Add(int64(n))

	return nil
}

func (cl *commitLogger) add(node *roaringset.SegmentNode) error {
	if cl.paused {
		return nil
	}

	if err := binary.Write(cl.writer, binary.LittleEndian, CommitTypeRoaringSet); err != nil {
		return err
	}
	n := 1

	if ki, err := node.KeyIndexAndWriteTo(cl.writer, 0); err != nil {
		return err
	} else {
		n += ki.ValueEnd - ki.ValueStart
	}

	cl.n.Add(int64(n))

	return nil
}

// Size returns the amount of data that has been written since the commit
// logger was initialized. After a flush a new logger is initialized which
// automatically resets the logger.
func (cl *commitLogger) Size() int64 {
	return cl.n.Load()
}

func (cl *commitLogger) close() error {
	if cl.paused {
		return errors.Errorf("attempting to close a paused commit logger")
	}

	if err := cl.writer.Flush(); err != nil {
		return err
	}

	return cl.file.Close()
}

func (cl *commitLogger) pause() {
	cl.paused = true
}

func (cl *commitLogger) unpause() {
	cl.paused = false
}

func (cl *commitLogger) delete() error {
	return os.Remove(cl.path)
}

func (cl *commitLogger) flushBuffers() error {
	return cl.writer.Flush()
}