Avoid unnecessary codec operations on in-memory subjournals.

FossilOrigin-Name: 199b2a84992823b4687588a5ba20bec9c42579887068ac21caf08df3895f41ed

manifest

@@ -1,5 +1,5 @@
-C Fix\san\sobscure\sassertion\sfault\sthat\scan\sfollow\san\sOOM.\s\s\sThe\sproblem\nwas\sintroduced\sby\scheck-in\s[a1cf44763277b6c7].
-D 2017-05-06T18:09:36.744
+C Avoid\sunnecessary\scodec\soperations\son\sin-memory\ssubjournals.
+D 2017-05-10T12:58:34.110
 F Makefile.in 1cc758ce3374a32425e4d130c2fe7b026b20de5b8843243de75f087c0a2661fb
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 6a8c838220f7c00820e1fc0ac1bccaaa8e5676067e1dbfa1bafa7a4ffecf8ae6
@@ -389,7 +389,7 @@ F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
 F src/os_unix.c 30e2c43e4955db990e5b5a81e901f8aa74cc8820
 F src/os_win.c 2a6c73eef01c51a048cc4ddccd57f981afbec18a
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
-F src/pager.c ff1232b3088a39806035ecfac4fffeb22717d80b
+F src/pager.c 80893c0860199aebc6efa4f102ab11eebde338b7fdbb0c04d4b04647c2fd62d1
 F src/pager.h f2a99646c5533ffe11afa43e9e0bea74054e4efa
 F src/parse.y 0513387ce02fea97897d8caef82d45f347818593f24f1bdc48e0c530a8af122d
 F src/pcache.c 62835bed959e2914edd26afadfecce29ece0e870
@@ -1168,6 +1168,7 @@ F test/sqllog.test 6af6cb0b09f4e44e1917e06ce85be7670302517a
 F test/stat.test f8f1279ffffabe6df825723af18cc6e0ae70a893
 F test/statfault.test f525a7bf633e50afd027700e9a486090684b1ac1
 F test/stmt.test 64844332db69cf1a735fcb3e11548557fc95392f
+F test/subjournal.test 2121a93ef3d3e83d52bf236c8a02aef4009fbf52884754104b2b6cad9a041095
 F test/subquery.test d7268d193dd33d5505df965399d3a594e76ae13f
 F test/subquery2.test 438f8a7da1457277b22e4176510f7659b286995f
 F test/subselect.test 0966aa8e720224dbd6a5e769a3ec2a723e332303
@@ -1578,7 +1579,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 198ff4c01d86d193a54745764d69376cab8e94747a4daa444690f7e1ec87800b
-R 32100f2588ee0aaab5e52c8f56365f52
+P 04e7e5650efffdce759b46999beb67c250af6cf394a7779ab861f210a84c134d d2bb0066f7c8413ef9992e6b07641cdf40ad260778074bd83cc22dcaba87860b
+R 036cd868b45040b2c72bb4968e138d5b
+T +closed d2bb0066f7c8413ef9992e6b07641cdf40ad260778074bd83cc22dcaba87860b
 U drh
-Z 5b7285d0420627775594602075610fb9
+Z 4b970db82062c1fa9f8c0e5f1157ed72

manifest.uuid

@@ -1 +1 @@
-04e7e5650efffdce759b46999beb67c250af6cf394a7779ab861f210a84c134d
+199b2a84992823b4687588a5ba20bec9c42579887068ac21caf08df3895f41ed

src/pager.c

@@ -2258,6 +2258,11 @@ static int pager_playback_one_page(
   char *aData;                  /* Temporary storage for the page */
   sqlite3_file *jfd;            /* The file descriptor for the journal file */
   int isSynced;                 /* True if journal page is synced */
+#ifdef SQLITE_HAS_CODEC
+  /* The jrnlEnc flag is true if Journal pages should be passed through
+  ** the codec.  It is false for pure in-memory journals. */
+  const int jrnlEnc = (isMainJrnl || pPager->subjInMemory==0);
+#endif
 
   assert( (isMainJrnl&~1)==0 );      /* isMainJrnl is 0 or 1 */
   assert( (isSavepnt&~1)==0 );       /* isSavepnt is 0 or 1 */
@@ -2381,14 +2386,34 @@ static int pager_playback_one_page(
     i64 ofst = (pgno-1)*(i64)pPager->pageSize;
     testcase( !isSavepnt && pPg!=0 && (pPg->flags&PGHDR_NEED_SYNC)!=0 );
     assert( !pagerUseWal(pPager) );
+
+    /* Write the data read from the journal back into the database file.
+    ** This is usually safe even for an encrypted database - as the data
+    ** was encrypted before it was written to the journal file. The exception
+    ** is if the data was just read from an in-memory sub-journal. In that
+    ** case it must be encrypted here before it is copied into the database
+    ** file.  */
+#ifdef SQLITE_HAS_CODEC
+    if( !jrnlEnc ){
+      CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT, aData);
+      rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);
+      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);
+    }else
+#endif
     rc = sqlite3OsWrite(pPager->fd, (u8 *)aData, pPager->pageSize, ofst);
+
     if( pgno>pPager->dbFileSize ){
       pPager->dbFileSize = pgno;
     }
     if( pPager->pBackup ){
-      CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);
+#ifdef SQLITE_HAS_CODEC
+      if( jrnlEnc ){
+        CODEC1(pPager, aData, pgno, 3, rc=SQLITE_NOMEM_BKPT);
+        sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);
+        CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT,aData);
+      }else
+#endif
       sqlite3BackupUpdate(pPager->pBackup, pgno, (u8*)aData);
-      CODEC2(pPager, aData, pgno, 7, rc=SQLITE_NOMEM_BKPT, aData);
     }
   }else if( !isMainJrnl && pPg==0 ){
     /* If this is a rollback of a savepoint and data was not written to
@@ -2440,7 +2465,9 @@ static int pager_playback_one_page(
     }
 
     /* Decode the page just read from disk */
-    CODEC1(pPager, pData, pPg->pgno, 3, rc=SQLITE_NOMEM_BKPT);
+#if SQLITE_HAS_CODEC
+    if( jrnlEnc ){ CODEC1(pPager, pData, pPg->pgno, 3, rc=SQLITE_NOMEM_BKPT); }
+#endif
     sqlite3PcacheRelease(pPg);
   }
   return rc;
@@ -4452,8 +4479,13 @@ static int subjournalPage(PgHdr *pPg){
       void *pData = pPg->pData;
       i64 offset = (i64)pPager->nSubRec*(4+pPager->pageSize);
       char *pData2;
-  
-      CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);
+
+#if SQLITE_HAS_CODEC   
+      if( !pPager->subjInMemory ){
+        CODEC2(pPager, pData, pPg->pgno, 7, return SQLITE_NOMEM_BKPT, pData2);
+      }else
+#endif
+      pData2 = pData;
       PAGERTRACE(("STMT-JOURNAL %d page %d\n", PAGERID(pPager), pPg->pgno));
       rc = write32bits(pPager->sjfd, offset, pPg->pgno);
       if( rc==SQLITE_OK ){

test/subjournal.test

@@ -0,0 +1,70 @@
+# 2017 May 9
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix subjournal
+
+do_execsql_test 1.0 {
+  PRAGMA temp_store = memory;
+  CREATE TABLE t1(a,b,c);
+  INSERT INTO t1 VALUES(1, 2, 3);
+} {}
+do_execsql_test 1.1 {
+  BEGIN;
+    INSERT INTO t1 VALUES(4, 5, 6);
+    SAVEPOINT one;
+      INSERT INTO t1 VALUES(7, 8, 9);
+    ROLLBACK TO one;
+    SELECT * FROM t1;
+} {1 2 3 4 5 6}
+do_execsql_test 1.2 {
+  COMMIT;
+}
+
+do_execsql_test 2.0 {
+  PRAGMA cache_size = 5;
+  CREATE TABLE t2(a BLOB);
+  CREATE INDEX i2 ON t2(a);
+  WITH s(i) AS (
+    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<100
+  ) INSERT INTO t2 SELECT randomblob(500) FROM s;
+}
+
+do_test 2.1 {
+  forcedelete test.db2
+  sqlite3 db2 test2.db
+  sqlite3_backup B db2 main db main
+  set nPage [db one {PRAGMA page_count}]
+  B step [expr $nPage-10]
+} {SQLITE_OK}
+
+do_execsql_test 2.2 {
+  BEGIN;
+    UPDATE t2 SET a=randomblob(499);
+    SAVEPOINT two;
+      UPDATE t2 SET a=randomblob(498);
+    ROLLBACK TO two;
+  COMMIT;
+  PRAGMA integrity_check;
+} {ok}
+
+do_test 2.3 {
+  B step 1000
+} {SQLITE_DONE}
+do_test 2.4 {
+  B finish
+  execsql { PRAGMA integrity_check } db2
+} {ok}
+
+finish_test
+