Add some tests for the atomic-write optimization. (CVS 4275)

FossilOrigin-Name: e2cc7b4a3476a733b2701546f6b4ec9abc18152b

test/io.test

@@ -13,11 +13,18 @@
 # IO traffic generated by SQLite (making sure SQLite is not writing out
 # more database pages than it has to, stuff like that).
 #
-# $Id: io.test,v 1.2 2007/08/22 02:56:44 drh Exp $
+# $Id: io.test,v 1.3 2007/08/23 08:06:45 danielk1977 Exp $
 
 set testdir [file dirname $argv0]
 source $testdir/tester.tcl
 
+# Test summary:
+#
+# io-1.* -  Test that quick-balance does not journal pages unnecessarily.
+# io-2.* -  Test that when the atomic-write optimisation is used no
+#           journal file is created.
+#           
+
 set ::nWrite 0
 proc nWrite {db} {
   set bt [btree_from_db $db]
@@ -29,6 +36,13 @@ proc nWrite {db} {
   set res
 }
 
+set ::nSync 0
+proc nSync {} {
+  set res [expr {$::sqlite_sync_count - $::nSync}]
+  set ::nSync $::sqlite_sync_count
+  set res
+}
+
 do_test io-1.1 {
   execsql {
     PRAGMA page_size = 1024;
@@ -75,8 +89,6 @@ do_test io-1.4 {
   lappend ret [nWrite db]
 } {2 2 2}
 
-#db eval {select * from sqlite_master} {btree_tree_dump [btree_from_db db] 2}
-
 # This insert should use the quick-balance trick to add a third leaf
 # to the b-tree used to store table abc. It should only be necessary to
 # write to 3 pages to do this: the change-counter, the root-page and
@@ -86,6 +98,174 @@ do_test io-1.5 {
   nWrite db
 } {3}
 
-#db eval {select * from sqlite_master} {btree_tree_dump [btree_from_db db] 2}
+
+
+#----------------------------------------------------------------------
+# Test cases io-2.* test the atomic-write optimization.
+#
+do_test io-2.1 {
+  execsql { DELETE FROM abc; VACUUM; }
+} {}
+
+# Clear the write and sync counts.
+nWrite db ; nSync
+
+# The following INSERT updates 2 pages and requires 4 calls to fsync():
+#
+#   1) The directory in which the journal file is created,
+#   2) The journal file (to sync the page data),
+#   3) The journal file (to sync the journal file header),
+#   4) The database file.
+#
+do_test io-2.2 {
+  execsql { INSERT INTO abc VALUES(1, 2) }
+  list [nWrite db] [nSync]
+} {2 4}
+
+# Set the device-characteristic mask to include the SQLITE_IOCAP_ATOMIC,
+# then do another INSERT similar to the one in io-2.2. This should
+# only write 1 page and require a single fsync().
+# 
+# The single fsync() is the database file. Only one page is reported as
+# written because page 1 - the change-counter page - is written using
+# an out-of-band method that bypasses the write counter.
+#
+sqlite3_simulate_device -char atomic
+do_test io-2.3 {
+  execsql { INSERT INTO abc VALUES(3, 4) }
+  list [nWrite db] [nSync]
+} {1 1}
+
+# Test that the journal file is not created and the change-counter is
+# updated when the atomic-write optimization is used.
+#
+do_test io-2.4.1 {
+  execsql {
+    BEGIN;
+    INSERT INTO abc VALUES(5, 6);
+  }
+  sqlite3 db2 test.db
+  execsql { SELECT * FROM abc } db2
+} {1 2 3 4}
+do_test io-2.4.2 {
+  file exists test.db-journal
+} {0}
+do_test io-2.4.3 {
+  execsql { COMMIT }
+  execsql { SELECT * FROM abc } db2
+} {1 2 3 4 5 6}
+db2 close
+
+# Test that the journal file is created and sync()d if the transaction
+# modifies more than one database page, even if the IOCAP_ATOMIC flag
+# is set.
+#
+do_test io-2.5.1 {
+  execsql { CREATE TABLE def(d, e) }
+  nWrite db ; nSync
+  execsql {
+    BEGIN;
+    INSERT INTO abc VALUES(7, 8);
+  }
+  file exists test.db-journal
+} {0}
+do_test io-2.5.2 {
+  execsql { INSERT INTO def VALUES('a', 'b'); }
+  file exists test.db-journal
+} {1}
+do_test io-2.5.3 {
+  execsql { COMMIT }
+  list [nWrite db] [nSync]
+} {3 4}
+
+# Test that the journal file is created and sync()d if the transaction
+# modifies a single database page and also appends a page to the file.
+# Internally, this case is handled differently to the one above. The
+# journal file is not actually created until the 'COMMIT' statement
+# is executed.
+#
+do_test io-2.6.1 {
+  execsql {
+    BEGIN;
+    INSERT INTO abc VALUES(9, randstr(1000,1000));
+  }
+  file exists test.db-journal
+} {0}
+do_test io-2.6.2 {
+  # Create a file at "test.db-journal". This will prevent SQLite from
+  # opening the journal for exclusive access. As a result, the COMMIT
+  # should fail with SQLITE_CANTOPEN and the transaction rolled back.
+  #
+  set fd [open test.db-journal w]
+  puts $fd "This is not a journal file"
+  close $fd
+  catchsql { COMMIT }
+} {1 {unable to open database file}}
+do_test io-2.6.3 {
+  file delete -force test.db-journal
+  catchsql { COMMIT }
+} {1 {cannot commit - no transaction is active}}
+do_test io-2.6.4 {
+  execsql { SELECT * FROM abc }
+} {1 2 3 4 5 6 7 8}
+
+
+# Test that if the database modification is part of multi-file commit,
+# the journal file is always created. In this case, the journal file
+# is created during execution of the COMMIT statement, so we have to
+# use the same technique to check that it is created as in the above 
+# block.
+file delete -force test2.db test2.db-journal
+do_test io-2.7.1 {
+  execsql {
+    ATTACH 'test2.db' AS aux;
+    CREATE TABLE aux.abc2(a, b);
+    BEGIN;
+    INSERT INTO abc VALUES(9, 10);
+  }
+  file exists test.db-journal
+} {0}
+do_test io-2.7.2 {
+  execsql { INSERT INTO abc2 SELECT * FROM abc }
+  file exists test2.db-journal
+} {0}
+do_test io-2.7.3 {
+  execsql { SELECT * FROM abc UNION ALL SELECT * FROM abc2 }
+} {1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10}
+do_test io-2.7.4 {
+  set fd [open test2.db-journal w]
+  puts $fd "This is not a journal file"
+  close $fd
+  catchsql { COMMIT }
+} {1 {unable to open database file}}
+do_test io-2.7.5 {
+  file delete -force test2.db-journal
+  catchsql { COMMIT }
+} {1 {cannot commit - no transaction is active}}
+do_test io-2.7.6 {
+  execsql { SELECT * FROM abc UNION ALL SELECT * FROM abc2 }
+} {1 2 3 4 5 6 7 8}
+
+# Try an explicit ROLLBACK before the journal file is created.
+#
+do_test io-2.8.1 {
+  execsql {
+    BEGIN;
+    DELETE FROM abc;
+  }
+  file exists test.db-journal
+} {0}
+do_test io-2.8.2 {
+  execsql { SELECT * FROM abc }
+} {}
+do_test io-2.8.3 {
+  execsql {
+    ROLLBACK;
+    SELECT * FROM abc;
+  }
+} {1 2 3 4 5 6 7 8}
+
+sqlite3_simulate_device -char {} -sectorsize 0
 
 finish_test
+