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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282
|
package pq
import (
"database/sql/driver"
"encoding/binary"
"errors"
"fmt"
"sync"
)
var (
errCopyInClosed = errors.New("pq: copyin statement has already been closed")
errBinaryCopyNotSupported = errors.New("pq: only text format supported for COPY")
errCopyToNotSupported = errors.New("pq: COPY TO is not supported")
errCopyNotSupportedOutsideTxn = errors.New("pq: COPY is only allowed inside a transaction")
errCopyInProgress = errors.New("pq: COPY in progress")
)
// CopyIn creates a COPY FROM statement which can be prepared with
// Tx.Prepare(). The target table should be visible in search_path.
func CopyIn(table string, columns ...string) string {
stmt := "COPY " + QuoteIdentifier(table) + " ("
for i, col := range columns {
if i != 0 {
stmt += ", "
}
stmt += QuoteIdentifier(col)
}
stmt += ") FROM STDIN"
return stmt
}
// CopyInSchema creates a COPY FROM statement which can be prepared with
// Tx.Prepare().
func CopyInSchema(schema, table string, columns ...string) string {
stmt := "COPY " + QuoteIdentifier(schema) + "." + QuoteIdentifier(table) + " ("
for i, col := range columns {
if i != 0 {
stmt += ", "
}
stmt += QuoteIdentifier(col)
}
stmt += ") FROM STDIN"
return stmt
}
type copyin struct {
cn *conn
buffer []byte
rowData chan []byte
done chan bool
closed bool
sync.Mutex // guards err
err error
}
const ciBufferSize = 64 * 1024
// flush buffer before the buffer is filled up and needs reallocation
const ciBufferFlushSize = 63 * 1024
func (cn *conn) prepareCopyIn(q string) (_ driver.Stmt, err error) {
if !cn.isInTransaction() {
return nil, errCopyNotSupportedOutsideTxn
}
ci := ©in{
cn: cn,
buffer: make([]byte, 0, ciBufferSize),
rowData: make(chan []byte),
done: make(chan bool, 1),
}
// add CopyData identifier + 4 bytes for message length
ci.buffer = append(ci.buffer, 'd', 0, 0, 0, 0)
b := cn.writeBuf('Q')
b.string(q)
cn.send(b)
awaitCopyInResponse:
for {
t, r := cn.recv1()
switch t {
case 'G':
if r.byte() != 0 {
err = errBinaryCopyNotSupported
break awaitCopyInResponse
}
go ci.resploop()
return ci, nil
case 'H':
err = errCopyToNotSupported
break awaitCopyInResponse
case 'E':
err = parseError(r)
case 'Z':
if err == nil {
ci.setBad()
errorf("unexpected ReadyForQuery in response to COPY")
}
cn.processReadyForQuery(r)
return nil, err
default:
ci.setBad()
errorf("unknown response for copy query: %q", t)
}
}
// something went wrong, abort COPY before we return
b = cn.writeBuf('f')
b.string(err.Error())
cn.send(b)
for {
t, r := cn.recv1()
switch t {
case 'c', 'C', 'E':
case 'Z':
// correctly aborted, we're done
cn.processReadyForQuery(r)
return nil, err
default:
ci.setBad()
errorf("unknown response for CopyFail: %q", t)
}
}
}
func (ci *copyin) flush(buf []byte) {
// set message length (without message identifier)
binary.BigEndian.PutUint32(buf[1:], uint32(len(buf)-1))
_, err := ci.cn.c.Write(buf)
if err != nil {
panic(err)
}
}
func (ci *copyin) resploop() {
for {
var r readBuf
t, err := ci.cn.recvMessage(&r)
if err != nil {
ci.setBad()
ci.setError(err)
ci.done <- true
return
}
switch t {
case 'C':
// complete
case 'N':
// NoticeResponse
case 'Z':
ci.cn.processReadyForQuery(&r)
ci.done <- true
return
case 'E':
err := parseError(&r)
ci.setError(err)
default:
ci.setBad()
ci.setError(fmt.Errorf("unknown response during CopyIn: %q", t))
ci.done <- true
return
}
}
}
func (ci *copyin) setBad() {
ci.Lock()
ci.cn.bad = true
ci.Unlock()
}
func (ci *copyin) isBad() bool {
ci.Lock()
b := ci.cn.bad
ci.Unlock()
return b
}
func (ci *copyin) isErrorSet() bool {
ci.Lock()
isSet := (ci.err != nil)
ci.Unlock()
return isSet
}
// setError() sets ci.err if one has not been set already. Caller must not be
// holding ci.Mutex.
func (ci *copyin) setError(err error) {
ci.Lock()
if ci.err == nil {
ci.err = err
}
ci.Unlock()
}
func (ci *copyin) NumInput() int {
return -1
}
func (ci *copyin) Query(v []driver.Value) (r driver.Rows, err error) {
return nil, ErrNotSupported
}
// Exec inserts values into the COPY stream. The insert is asynchronous
// and Exec can return errors from previous Exec calls to the same
// COPY stmt.
//
// You need to call Exec(nil) to sync the COPY stream and to get any
// errors from pending data, since Stmt.Close() doesn't return errors
// to the user.
func (ci *copyin) Exec(v []driver.Value) (r driver.Result, err error) {
if ci.closed {
return nil, errCopyInClosed
}
if ci.isBad() {
return nil, driver.ErrBadConn
}
defer ci.cn.errRecover(&err)
if ci.isErrorSet() {
return nil, ci.err
}
if len(v) == 0 {
return driver.RowsAffected(0), ci.Close()
}
numValues := len(v)
for i, value := range v {
ci.buffer = appendEncodedText(&ci.cn.parameterStatus, ci.buffer, value)
if i < numValues-1 {
ci.buffer = append(ci.buffer, '\t')
}
}
ci.buffer = append(ci.buffer, '\n')
if len(ci.buffer) > ciBufferFlushSize {
ci.flush(ci.buffer)
// reset buffer, keep bytes for message identifier and length
ci.buffer = ci.buffer[:5]
}
return driver.RowsAffected(0), nil
}
func (ci *copyin) Close() (err error) {
if ci.closed { // Don't do anything, we're already closed
return nil
}
ci.closed = true
if ci.isBad() {
return driver.ErrBadConn
}
defer ci.cn.errRecover(&err)
if len(ci.buffer) > 0 {
ci.flush(ci.buffer)
}
// Avoid touching the scratch buffer as resploop could be using it.
err = ci.cn.sendSimpleMessage('c')
if err != nil {
return err
}
<-ci.done
ci.cn.inCopy = false
if ci.isErrorSet() {
err = ci.err
return err
}
return nil
}
|