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
|
/*-------------------------------------------------------------------------
*
* Copyright (c) 2009, PostgreSQL Global Development Group
*
* IDENTIFICATION
* $PostgreSQL: pgjdbc/org/postgresql/core/v3/CopyOutImpl.java,v 1.1 2009/07/01 05:00:40 jurka Exp $
*
*-------------------------------------------------------------------------
*/
package org.postgresql.core.v3;
import java.sql.SQLException;
import org.postgresql.copy.CopyOut;
/**
* Anticipated flow of a COPY TO STDOUT operation:
*
* CopyManager.copyOut()
* ->QueryExecutor.startCopy()
* - sends given query to server
* ->processCopyResults():
* - receives CopyOutResponse from Server
* - creates new CopyOutImpl
* ->initCopy():
* - receives copy metadata from server
* ->CopyOutImpl.init()
* ->lock() connection for this operation
* - if query fails an exception is thrown
* - if query returns wrong CopyOperation, copyOut() cancels it before throwing exception
* <-returned: new CopyOutImpl holding lock on connection
* repeat CopyOut.readFromCopy() until null
* ->CopyOutImpl.readFromCopy()
* ->QueryExecutorImpl.readFromCopy()
* ->processCopyResults()
* - on copydata row from server
* ->CopyOutImpl.handleCopydata() stores reference to byte array
* - on CopyDone, CommandComplete, ReadyForQuery
* ->unlock() connection for use by other operations
* <-returned: byte array of data received from server or null at end.
*/
public class CopyOutImpl extends CopyOperationImpl implements CopyOut {
private byte[] currentDataRow;
public byte[] readFromCopy() throws SQLException {
currentDataRow = null;
queryExecutor.readFromCopy(this);
return currentDataRow;
}
void handleCopydata(byte[] data) {
currentDataRow = data;
}
}
|
