-
Notifications
You must be signed in to change notification settings - Fork 2
/
datapipe.go
226 lines (176 loc) · 4.75 KB
/
datapipe.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
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
package main
import (
"database/sql"
"fmt"
"os"
"strconv"
"time"
_ "github.com/denisenkom/go-mssqldb"
_ "github.com/lib/pq"
"github.com/juju/errors"
"github.com/literatesnow/go-datapipe/bulk"
)
type Config struct {
maxRowBufSz int //Maximum number of rows to buffer at a time
maxRowTxCommit int //Maximum number of rows to process before committing the database transaction
srcDbDriver string //Source database driver name
srcDbUri string //Source database driver URI
srcSelectSql string //Source database select SQL statement
dstDbDriver string //Destination database driver name
dstDbUri string //Destination database driver URI
dstSchema string
dstTable string //Destination database table name
showStackTrace bool //Display stack traces on error
}
type Insert interface {
Append(rows *sql.Rows) (err error)
Flush() (totalRowCount int, err error)
Close() (err error)
}
func (c *Config) Init() (err error) {
if os.Getenv("SHOW_STACK_TRACE") != "" {
c.showStackTrace = true
}
c.maxRowBufSz, _ = c.EnvInt("MAX_ROW_BUF_SZ", 100)
c.maxRowTxCommit, _ = c.EnvInt("MAX_ROW_TX_COMMIT", 500)
if c.srcDbDriver, err = c.EnvStr("SRC_DB_DRIVER"); err != nil {
return errors.Trace(err)
}
if c.srcDbUri, err = c.EnvStr("SRC_DB_URI"); err != nil {
return errors.Trace(err)
}
if c.srcSelectSql, err = c.EnvStr("SRC_DB_SELECT_SQL"); err != nil {
return errors.Trace(err)
}
if c.dstDbDriver, err = c.EnvStr("DST_DB_DRIVER"); err != nil {
return errors.Trace(err)
}
if c.dstDbUri, err = c.EnvStr("DST_DB_URI"); err != nil {
return errors.Trace(err)
}
if c.dstSchema, err = c.EnvStr("DST_DB_SCHEMA"); err != nil {
return errors.Trace(err)
}
if c.dstTable, err = c.EnvStr("DST_DB_TABLE"); err != nil {
return errors.Trace(err)
}
return nil
}
func (c *Config) EnvStr(envName string) (dst string, err error) {
dst = os.Getenv(envName)
if dst == "" {
err = errors.Errorf("Missing ENV variable: %s", envName)
}
return dst, err
}
func (c *Config) EnvInt(envName string, defaultValue int) (dst int, err error) {
if dst, err = strconv.Atoi(os.Getenv(envName)); err != nil {
dst = defaultValue
}
return dst, nil
}
func main() {
cfg := &Config{}
if err := cfg.Init(); err != nil {
showError(cfg, err)
os.Exit(2)
} else if err := run(cfg); err != nil {
showError(cfg, err)
os.Exit(1)
}
}
func run(cfg *Config) (err error) {
var srcDb, dstDb *sql.DB
if srcDb, err = sql.Open(cfg.srcDbDriver, cfg.srcDbUri); err != nil {
return errors.Trace(err)
}
defer srcDb.Close()
if dstDb, err = sql.Open(cfg.dstDbDriver, cfg.dstDbUri); err != nil {
return errors.Trace(err)
}
defer dstDb.Close()
if err = clearTable(dstDb, cfg); err != nil {
return errors.Trace(err)
}
if err = copyTable(srcDb, dstDb, cfg); err != nil {
return errors.Trace(err)
}
return nil
}
func clearTable(dstDb *sql.DB, cfg *Config) (err error) {
if _, err = dstDb.Exec("TRUNCATE TABLE " + cfg.dstSchema + "." + cfg.dstTable); err != nil {
return errors.Trace(err)
}
return nil
}
func copyTable(srcDb *sql.DB, dstDb *sql.DB, cfg *Config) (err error) {
var ir Insert
var rows *sql.Rows
var rowCount int
var columns []string
readStart := time.Now()
if rows, err = srcDb.Query(cfg.srcSelectSql); err != nil {
return errors.Trace(err)
}
defer rows.Close()
if columns, err = rows.Columns(); err != nil {
return errors.Trace(err)
}
readEnd := time.Since(readStart)
writeStart := time.Now()
switch cfg.dstDbDriver {
case "postgres":
if ir, err = bulk.NewCopyIn(dstDb, columns, cfg.dstSchema, cfg.dstTable); err != nil {
return errors.Trace(err)
}
default:
if ir, err = bulk.NewBulk(
dstDb, columns,
cfg.dstSchema, cfg.dstTable,
cfg.maxRowBufSz, cfg.maxRowTxCommit); err != nil {
return errors.Trace(err)
}
}
rowCount, err = copyBulkRows(dstDb, rows, ir, cfg)
if err != nil {
return errors.Trace(err)
}
if err = ir.Close(); err != nil {
return errors.Trace(err)
}
writeEnd := time.Since(writeStart)
fmt.Printf("%d rows queried in %s and inserted in %s\n",
rowCount,
readEnd.String(),
writeEnd.String())
return errors.Trace(rows.Err())
}
func copyBulkRows(dstDb *sql.DB, rows *sql.Rows, ir Insert, cfg *Config) (rowCount int, err error) {
var totalRowCount int
const dotLimit = 1000
i := 1
for rows.Next() {
if err = ir.Append(rows); err != nil {
return 0, errors.Trace(err)
}
if i%dotLimit == 0 {
fmt.Print(".")
i = 1
}
i++
}
if totalRowCount, err = ir.Flush(); err != nil {
return 0, errors.Trace(err)
}
if totalRowCount > dotLimit {
fmt.Println()
}
return totalRowCount, errors.Trace(rows.Err())
}
func showError(cfg *Config, err error) {
if cfg.showStackTrace {
fmt.Fprintf(os.Stderr, "%s\n", errors.ErrorStack(err))
} else {
fmt.Fprintf(os.Stderr, "%s\n", err)
}
}