simian/diskindexstore.go at master · mandykoh/simian · GitHub

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
package simian

import (
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"os"
	"path"

	"github.com/mandykoh/keva"
)

const nodeFingerprintFile = "fingerprint"
const nodeEntriesDir = "entries"
const thumbnailsDir = "thumbnails"

type DiskIndexStore struct {
	rootPath string
	nodes    *keva.Store
}

func (s *DiskIndexStore) AddEntry(entry *IndexEntry, node *IndexNode, nodeFingerprint Fingerprint) error {
	err := entry.saveThumbnail(s.pathForThumbnail(entry))
	if err != nil {
		return err
	}

	node.registerEntry(entry)

	fmt.Printf("AddEntry - Saving [%s] %d %d\n", nodeFingerprint.String(), len(node.childFingerprints), len(node.entries))
	return s.nodes.Put(nodeFingerprint.String(), node)
}

func (s *DiskIndexStore) Close() error {
	return s.nodes.Close()
}

func (s *DiskIndexStore) GetChild(f Fingerprint, parent *IndexNode) (*IndexNode, error) {
	var node IndexNode

	err := s.nodes.Get(f.String(), &node)
	if err == keva.ErrValueNotFound {
		return nil, nil

	} else if err == nil {
		err = s.loadThumbnails(&node)
		if err != nil {
			return nil, err
		}

	} else {
		return nil, err
	}

	return &node, nil
}

func (s *DiskIndexStore) GetOrCreateChild(f Fingerprint, parent *IndexNode, parentFingerprint Fingerprint) (*IndexNode, error) {
	fmt.Printf("GetOrCreateChild() %s\n", f.String())

	nodeKey := f.String()

	var node IndexNode
	err := s.nodes.Get(nodeKey, &node)

	if err == keva.ErrValueNotFound {
		fmt.Printf("Creating child\n")

		node = IndexNode{
			childFingerprintsByString: make(map[string]*Fingerprint),
		}

		fmt.Printf("GetOrCreateChild - Saving [%s] %d %d\n", nodeKey, len(node.childFingerprints), len(node.entries))
		err = s.nodes.Put(nodeKey, &node)
		if err != nil {
			return nil, err
		}

		parent.registerChild(f)
		fmt.Printf("GetOrCreateChild - Parent - Saving [%s] %d %d\n", parentFingerprint.String(), len(parent.childFingerprints), len(parent.entries))
		err = s.nodes.Put(parentFingerprint.String(), parent)
		if err != nil {
			return nil, err
		}

	} else if err == nil {
		err = s.loadThumbnails(&node)
		if err != nil {
			return nil, err
		}

	} else {
		return nil, err
	}

	return &node, nil
}

func (s *DiskIndexStore) GetRoot() (*IndexNode, error) {
	var rootKey = Fingerprint{}.String()

	var root IndexNode
	err := s.nodes.Get(rootKey, &root)

	if err == keva.ErrValueNotFound {
		fmt.Printf("Root node not found - creating it\n")
		root = IndexNode{
			childFingerprintsByString: make(map[string]*Fingerprint),
		}

	} else if err == nil {
		fmt.Printf("Found root node with %d children and %d entries\n", len(root.childFingerprints), len(root.entries))

		err = s.loadThumbnails(&root)
		if err != nil {
			return nil, err
		}

	} else {
		return nil, err
	}

	return &root, nil
}

func (s *DiskIndexStore) RemoveEntries(node *IndexNode, nodeFingerprint Fingerprint) error {
	node.removeEntries()
	fmt.Printf("RemoveEntries - Saving [%s] %d %d\n", nodeFingerprint.String(), len(node.childFingerprints), len(node.entries))
	return s.nodes.Put(nodeFingerprint.String(), node)
}

func (s *DiskIndexStore) loadThumbnails(n *IndexNode) error {
	return n.withEachEntry(func(entry *IndexEntry) error {
		return entry.loadThumbnail(s.pathForThumbnail(entry))
	})
}

func (s *DiskIndexStore) pathForThumbnail(entry *IndexEntry) string {
	thumbnailHash := sha256.Sum256(entry.MaxFingerprint.Bytes())
	thumbnailHex := hex.EncodeToString(thumbnailHash[:])
	return path.Join(s.rootPath, thumbnailsDir, thumbnailHex[0:2], thumbnailHex[2:4], thumbnailHex[4:])
}

func NewDiskIndexStore(rootPath string) (*DiskIndexStore, error) {
	thumbnailsDir := path.Join(rootPath, thumbnailsDir)
	os.MkdirAll(thumbnailsDir, os.FileMode(0700))

	nodeStore, err := keva.NewStore(path.Join(rootPath, "nodes"))
	if err != nil {
		return nil, err
	}

	return &DiskIndexStore{
		rootPath: rootPath,
		nodes:    nodeStore,
	}, nil
}