xref: /sqlite-3.40.0/test/snapshot3.test (revision 6ab91a7a) 
1# 2016 September 23
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# This file implements regression tests for SQLite library. The focus
12# of this file is the sqlite3_snapshot_xxx() APIs.
13#
14
15set testdir [file dirname $argv0]
16source $testdir/tester.tcl
17ifcapable !snapshot {finish_test; return}
18set testprefix snapshot3
19
20# This test does not work with the inmemory_journal permutation. The reason
21# is that each connection opened as part of this permutation executes
22# "PRAGMA journal_mode=memory", which fails if the database is in wal mode
23# and there are one or more existing connections.
24if {[permutation]=="inmemory_journal"} {
25  finish_test
26  return
27}
28
29#-------------------------------------------------------------------------
30# This block of tests verifies that it is not possible to wrap the wal
31# file - using a writer or a "PRAGMA wal_checkpoint = TRUNCATE" - while
32# there is an open snapshot transaction (transaction opened using
33# sqlite3_snapshot_open()).
34#
35do_execsql_test 1.0 {
36  CREATE TABLE t1(y);
37  PRAGMA journal_mode = wal;
38  INSERT INTO t1 VALUES(1);
39  INSERT INTO t1 VALUES(2);
40  INSERT INTO t1 VALUES(3);
41  INSERT INTO t1 VALUES(4);
42} {wal}
43
44do_test 1.1 {
45  sqlite3 db2 test.db
46  sqlite3 db3 test.db
47
48  execsql {SELECT * FROM sqlite_master} db2
49  execsql {SELECT * FROM sqlite_master} db3
50
51  db2 trans { set snap [sqlite3_snapshot_get_blob db2 main] }
52  db2 eval { SELECT * FROM t1 }
53} {1 2 3 4}
54
55do_test 1.2 {
56  execsql BEGIN db2
57  sqlite3_snapshot_open_blob db2 main $snap
58  db2 eval { SELECT * FROM t1 }
59} {1 2 3 4}
60
61do_test 1.2 {
62  execsql END db2
63  execsql { PRAGMA wal_checkpoint }
64
65  execsql BEGIN db2
66  sqlite3_snapshot_open_blob db2 main $snap
67  db2 eval { SELECT * FROM t1 }
68} {1 2 3 4}
69
70set sz [file size test.db-wal]
71do_test 1.3 {
72  execsql { PRAGMA wal_checkpoint = truncate }
73  file size test.db-wal
74} $sz
75
76do_test 1.4 {
77  execsql BEGIN db3
78  list [catch { sqlite3_snapshot_open_blob db3 main $snap } msg] $msg
79} {0 {}}
80
81do_test 1.5 {
82  db3 eval { SELECT * FROM t1; END }
83} {1 2 3 4}
84
85do_test 1.6 {
86  db2 eval { SELECT * FROM t1; END }
87} {1 2 3 4}
88
89do_test 1.7 {
90  execsql { PRAGMA wal_checkpoint = truncate }
91  file size test.db-wal
92} 0
93
94do_test 1.8 {
95  execsql BEGIN db3
96  list [catch { sqlite3_snapshot_open_blob db3 main $snap } msg] $msg
97} {1 SQLITE_ERROR_SNAPSHOT}
98
99finish_test
100