/
vfs.go
187 lines (154 loc) · 3.99 KB
/
vfs.go
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
179
180
181
182
183
184
185
186
187
package examples_lib
import (
"encoding/binary"
"fmt"
"math"
"os"
"unsafe"
tiledb "github.com/TileDB-Inc/TileDB-Go"
)
var vfsFileName = "tiledb_vfs.bin"
func dirsFiles() {
// Create a TileDB context.
ctx, err := tiledb.NewContext(nil)
checkError(err)
defer ctx.Free()
// Create config object
config, err := tiledb.NewConfig()
checkError(err)
defer config.Free()
// Create TileDB VFS.
vfs, err := tiledb.NewVFS(ctx, config)
checkError(err)
defer vfs.Free()
isDir, err := vfs.IsDir("dir_A")
checkError(err)
if !isDir {
err = vfs.CreateDir("dir_A")
checkError(err)
fmt.Println("Created 'dir_A'")
} else {
fmt.Println("'dir_A' already exists")
}
// Creating an (empty) file
isFile, err := vfs.IsFile("dir_A/file_A")
checkError(err)
if !isFile {
err = vfs.Touch("dir_A/file_A")
checkError(err)
fmt.Println("Created empty file 'dir_A/file_A'")
} else {
fmt.Println("'dir_A/file_A' already exists")
}
// Getting the file size
fileSize, err := vfs.FileSize("dir_A/file_A")
checkError(err)
fmt.Printf("Size of file 'dir_A/file_A': %d\n", fileSize)
// Moving files (moving directories is similar)
fmt.Println("Moving file 'dir_A/file_A' to 'dir_A/file_B'")
err = vfs.MoveFile("dir_A/file_A", "dir_A/file_B")
checkError(err)
// Deleting files and directories
fmt.Println("Deleting 'dir_A/file_B' and 'dir_A'")
err = vfs.RemoveFile("dir_A/file_B")
checkError(err)
err = vfs.RemoveDir("dir_A")
checkError(err)
}
func float32FromBytes(bytes []byte) float32 {
bits := binary.LittleEndian.Uint32(bytes)
float := math.Float32frombits(bits)
return float
}
func float32ToBytes(float float32) []byte {
bits := math.Float32bits(float)
bytes := make([]byte, 4)
binary.LittleEndian.PutUint32(bytes, bits)
return bytes
}
func write() {
// Create TileDB context
ctx, err := tiledb.NewContext(nil)
checkError(err)
defer ctx.Free()
// Create config object
config, err := tiledb.NewConfig()
checkError(err)
defer config.Free()
// Create TileDB VFS.
vfs, err := tiledb.NewVFS(ctx, config)
checkError(err)
defer vfs.Free()
// Write binary data
fh1, err := vfs.Open(vfsFileName, tiledb.TILEDB_VFS_WRITE)
defer vfs.Close(fh1)
if err != nil {
fmt.Printf("Error opening file '%s'\n", vfsFileName)
}
var f1 float32 = 153.0
s1 := "abcd"
err = vfs.Write(fh1, float32ToBytes(f1))
checkError(err)
err = vfs.Write(fh1, []byte(s1))
checkError(err)
// Write binary data again - this will overwrite the previous file
fh2, err := vfs.Open("tiledb_vfs.bin", tiledb.TILEDB_VFS_WRITE)
defer vfs.Close(fh2)
if err != nil {
fmt.Printf("Error opening file '%s' for write.\n", vfsFileName)
}
var f2 float32 = 153.1
s2 := "abcdef"
err = vfs.Write(fh2, float32ToBytes(f2))
checkError(err)
err = vfs.Write(fh2, []byte(s2))
checkError(err)
// Append binary data to existing file (this will NOT work on S3)
fh3, err := vfs.Open("tiledb_vfs.bin", tiledb.TILEDB_VFS_APPEND)
defer vfs.Close(fh3)
if err != nil {
fmt.Printf("Error opening file '%s' for append.\n", vfsFileName)
}
s3 := "ghijkl"
err = vfs.Write(fh3, []byte(s3))
checkError(err)
}
func read() {
// Create TileDB context
ctx, err := tiledb.NewContext(nil)
checkError(err)
defer ctx.Free()
// Create config object
config, err := tiledb.NewConfig()
checkError(err)
defer config.Free()
// Create TileDB VFS.
vfs, err := tiledb.NewVFS(ctx, config)
checkError(err)
defer vfs.Free()
// Read binary data
fh, err := vfs.Open("tiledb_vfs.bin", tiledb.TILEDB_VFS_READ)
defer vfs.Close(fh)
if err != nil {
fmt.Printf("Error opening file '%s'\n", vfsFileName)
}
sizefFile, err := vfs.FileSize(vfsFileName)
checkError(err)
var f float32 = 0.0
sizeOfFloat32 := uint64(unsafe.Sizeof(f))
f1, err := vfs.Read(fh, 0, sizeOfFloat32)
checkError(err)
s1, err := vfs.Read(fh, sizeOfFloat32, sizefFile-sizeOfFloat32)
checkError(err)
fmt.Println("Binary read:")
fmt.Println(float32FromBytes(f1))
fmt.Println(string(s1))
// Clean up
err = os.RemoveAll(vfsFileName)
checkError(err)
}
func RunVfs() {
dirsFiles()
write()
read()
}