Add experimental API sqlite3_db_cacheflush().

FossilOrigin-Name: 65b86dc1fa4a57cc3cde86a820d9f848aa288a15

9 files changed, 391 insertions, 12 deletions

diff --git a/manifest b/manifest
index b070a768f..866a53b65 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Factor\sout\sadding\sNOT\sexpression\snodes\sin\sthe\sparser\sinto\sa\ssubroutine.
-D 2015-10-28T16:05:10.981
+C Add\sexperimental\sAPI\ssqlite3_db_cacheflush().
+D 2015-10-28T19:46:57.460
 F Makefile.in 2ea961bc09e441874eb3d1bf7398e04feb24f3ee
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 702d3e98f3afc6587a78481257f3c4c900efc3a4
@@ -305,7 +305,7 @@ F src/journal.c b4124532212b6952f42eb2c12fa3c25701d8ba8d
 F src/legacy.c ba1863ea58c4c840335a84ec276fc2b25e22bc4e
 F src/lempar.c d344a95d60c24e2f490ee59db9784b1b17439012
 F src/loadext.c 18586e45a215325f15096821e9c082035d4fb810
-F src/main.c 1cae029707c323292b5691e4d0a4c5c44561c877
+F src/main.c b9d020342b2a2b13808c6260792ef233d7af5b1d
 F src/malloc.c 337bbe9c7d436ef9b7d06b5dd10bbfc8f3025972
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c 6919bcf12f221868ea066eec27e579fed95ce98b
@@ -327,8 +327,8 @@ F src/os_setup.h c9d4553b5aaa6f73391448b265b89bed0b890faa
 F src/os_unix.c fc93d55f96bb978f0b0168c6ea7d6fc60b0e172c
 F src/os_win.c 1716291e5ec2dbfc5a1fe0b32182030f1f7d8acf
 F src/os_win.h eb7a47aa17b26b77eb97e4823f20a00b8bda12ca
-F src/pager.c 2fbeeba28f4e6d08a15bc106f36c43346a81f09e
-F src/pager.h ac213f8143ebfee6a8bfb91cf4ca02c9a83343c5
+F src/pager.c 059991ce76b1a857cb84dd2469cfcfaaae1d77fa
+F src/pager.h 1c4fa826c330040c5659a384446c7cc6e8e4200c
 F src/parse.y 11078cd8e3af00f030505b6a86a06a4536cfdeaa
 F src/pcache.c 24be750c79272e0ca7b6e007bc94999700f3e5ef
 F src/pcache.h 9968603796240cdf83da7e7bef76edf90619cea9
@@ -342,7 +342,7 @@ F src/resolve.c 1954a0f01bf65d78d7d559aea3d5c67f33376d91
 F src/rowset.c eccf6af6d620aaa4579bd3b72c1b6395d9e9fa1e
 F src/select.c 167b4e9058bc8e997d18d6b6b20ecbb0c9c457af
 F src/shell.c d25df04168d6ba5a4fa05bdbf859df667f9eb621
-F src/sqlite.h.in 070b49c253bd41607ec43505a16163aa4b537b83
+F src/sqlite.h.in e7da8d15141d0753bfe14945bd64592a42575c04
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h 4b66e3e3435da4b4c8c83696d0349f0c503b3924
 F src/sqliteInt.h b1e72ffe282c91ae30a2bf403319126dbaebd556
@@ -350,7 +350,7 @@ F src/sqliteLimit.h 216557999cb45f2e3578ed53ebefe228d779cb46
 F src/status.c 70912d7be68e9e2dbc4010c93d344af61d4c59ba
 F src/table.c 51b46b2a62d1b3a959633d593b89bab5e2c9155e
 F src/tclsqlite.c d9439b6a910985b7fff43ba6756bcef00de22649
-F src/test1.c 8fff9c5aa63d6490f516d018b70c12a9cb9a4d8a
+F src/test1.c 9ac5cbfe3c859ab7518edc5109a2959d6bf7b059
 F src/test2.c 577961fe48961b2f2e5c8b56ee50c3f459d3359d
 F src/test3.c f7ae1d6a4aa07aac257de18a43800c1199b513fc
 F src/test4.c d168f83cc78d02e8d35567bb5630e40dcd85ac1e
@@ -503,6 +503,7 @@ F test/btree02.test fe69453d474d8154d19b904157ff1db4812fed99
 F test/btreefault.test c2bcb542685eea44621275cfedbd8a13f65201e3
 F test/busy.test 76b4887f8b9160ba903c1ac22e8ff406ad6ae2f0
 F test/cache.test 13bc046b26210471ca6f2889aceb1ea52dc717de
+F test/cacheflush.test 95944e4210100c525ec301c060721e82210c33a5
 F test/capi2.test 011c16da245fdc0106a2785035de6b242c05e738
 F test/capi3.test bf6f0308bbbba1e770dac13aa08e5c2ac61c7324
 F test/capi3b.test efb2b9cfd127efa84433cd7a2d72ce0454ae0dc4
@@ -510,6 +511,7 @@ F test/capi3c.test fdc0d67a2cb8e8fc400d5b7735e330161ea057a2
 F test/capi3d.test 485048dc5cd07bc68011e4917ad035ad6047ab82
 F test/capi3e.test 3d49c01ef2a1a55f41d73cba2b23b5059ec460fe
 F test/cast.test 4c275cbdc8202d6f9c54a3596701719868ac7dc3
+F test/cffault.test 1383919788fa50db60f6119da5785c62fbc8b527
 F test/check.test 5831ddb6f2c687782eaf2e1a07b6e17f24c4f763
 F test/close.test 340bd24cc58b16c6bc01967402755027c37eb815
 F test/closure01.test b1703ba40639cfc9b295cf478d70739415eec6a4
@@ -1395,7 +1397,10 @@ F tool/vdbe_profile.tcl 246d0da094856d72d2c12efec03250d71639d19f
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P a85c2a4758c27e8d5d0395751eb3cfd9985ce696
-R fb08eb2aea7ef14b6808d0fed46a7f2e
-U drh
-Z 776eb09f5d20f370f46eb3dbeaa8d2e2
+P 001854181640bd9b088f2bc16083d84808c3da18
+R 2dbc861fa3cf60b53d3ec06b17c9981a
+T *branch * cacheflush
+T *sym-cacheflush *
+T -sym-trunk *
+U dan
+Z c07109c8cca9fe678b00367209f93a20
diff --git a/manifest.uuid b/manifest.uuid
index 0f39a0672..ac6d5b874 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-001854181640bd9b088f2bc16083d84808c3da18
\ No newline at end of file
+65b86dc1fa4a57cc3cde86a820d9f848aa288a15
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 9dd05cdf1..324415b0c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -741,6 +741,39 @@ int sqlite3_db_release_memory(sqlite3 *db){
 }
 
 /*
+** Flush any dirty pages in the pager-cache for any attached database
+** to disk.
+*/
+int sqlite3_db_cacheflush(sqlite3 *db){
+  int i;
+  int rc = SQLITE_OK;
+  int bSeenBusy = 0;
+
+#ifdef SQLITE_ENABLE_API_ARMOR
+  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
+#endif
+  sqlite3_mutex_enter(db->mutex);
+  sqlite3BtreeEnterAll(db);
+  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
+    Btree *pBt = db->aDb[i].pBt;
+    if( pBt && sqlite3BtreeIsInTrans(pBt) ){
+      Pager *pPager = sqlite3BtreePager(pBt);
+      rc = sqlite3PagerFlush(pPager);
+      if( rc==SQLITE_BUSY ){
+        bSeenBusy = 1;
+        rc = SQLITE_OK;
+      }
+    }
+  }
+  if( rc!=SQLITE_OK ){
+    sqlite3RollbackAll(db, SQLITE_ABORT_ROLLBACK);
+  }
+  sqlite3BtreeLeaveAll(db);
+  sqlite3_mutex_leave(db->mutex);
+  return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
+}
+
+/*
 ** Configuration settings for an individual database connection
 */
 int sqlite3_db_config(sqlite3 *db, int op, ...){
diff --git a/src/pager.c b/src/pager.c
index 399070af0..f21f0802b 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -4473,6 +4473,23 @@ static int pagerStress(void *p, PgHdr *pPg){
   return pager_error(pPager, rc); 
 }
 
+/*
+** Flush all unreferenced dirty pages to disk.
+*/
+int sqlite3PagerFlush(Pager *pPager){
+  int rc = SQLITE_OK;
+  PgHdr *pList = sqlite3PcacheDirtyList(pPager->pPCache);
+
+  while( rc==SQLITE_OK && pList ){
+    PgHdr *pNext = pList->pDirty;
+    if( pList->nRef==0 ){
+      rc = pagerStress((void*)pPager, pList);
+    }
+    pList = pNext;
+  }
+
+  return rc;
+}
 
 /*
 ** Allocate and initialize a new Pager object and put a pointer to it
diff --git a/src/pager.h b/src/pager.h
index 99a7aebc7..8e0e942ef 100644
--- a/src/pager.h
+++ b/src/pager.h
@@ -132,6 +132,7 @@ int sqlite3PagerGetJournalMode(Pager*);
 int sqlite3PagerOkToChangeJournalMode(Pager*);
 i64 sqlite3PagerJournalSizeLimit(Pager *, i64);
 sqlite3_backup **sqlite3PagerBackupPtr(Pager*);
+int sqlite3PagerFlush(Pager*);
 
 /* Functions used to obtain and release page references. */ 
 int sqlite3PagerAcquire(Pager *pPager, Pgno pgno, DbPage **ppPage, int clrFlag);
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index d9be3a5e6..6c04ff510 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -7792,6 +7792,36 @@ int sqlite3_stmt_scanstatus(
 */
 void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
 
+/*
+** CAPI3REF: Flush caches to disk mid-transaction
+**
+** If a write-transaction is open when this function is called, any dirty
+** pages in the pager-cache that are not currently in use are written out 
+** to disk. A dirty page may be in use if a database cursor created by an
+** active SQL statement is reading from it, or if it is page 1 of a database
+** file (page 1 is always "in use"). Dirty pages are flushed for all
+** databases - "main", "temp" and any attached databases.
+**
+** If this function needs to obtain extra database locks before dirty pages 
+** can be flushed to disk, it does so. If said locks cannot be obtained 
+** immediately and there is a busy-handler callback configured, it is invoked
+** in the usual manner. If the required lock still cannot be obtained, then
+** the database is skipped and an attempt made to flush any dirty pages
+** belonging to the next (if any) database. If any databases are skipped
+** because locks cannot be obtained, but no other error occurs, this
+** function returns SQLITE_BUSY.
+**
+** If any other error occurs while flushing dirty pages to disk (for
+** example an IO error or out-of-memory condition), then processing is
+** abandoned and an SQLite error code returned to the caller immediately.
+** In this case the open transaction may be automatically rolled back.
+**
+** Otherwise, if no error occurs, SQLITE_OK is returned.
+**
+** This function does not set the database handle error code or message
+** returned by the sqlite3_errcode() and sqlite3_errmsg() functions.
+*/
+int sqlite3_db_cacheflush(sqlite3*);
 
 /*
 ** Undo the hack that converts floating point types to integer for
diff --git a/src/test1.c b/src/test1.c
index 6c47754bf..dd190feeb 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -4689,6 +4689,34 @@ static int test_db_release_memory(
 }
 
 /*
+** Usage:  sqlite3_db_cacheflush DB
+**
+** Attempt to flush any dirty pages to disk.
+*/
+static int test_db_cacheflush(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  sqlite3 *db;
+  int rc;
+  if( objc!=2 ){
+    Tcl_WrongNumArgs(interp, 1, objv, "DB");
+    return TCL_ERROR;
+  }
+  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
+  rc = sqlite3_db_cacheflush(db);
+  if( rc ){
+    Tcl_SetResult(interp, (char *)sqlite3ErrStr(rc), TCL_STATIC);
+    return TCL_ERROR;
+  }
+
+  Tcl_ResetResult(interp);
+  return TCL_OK;
+}
+
+/*
 ** Usage:  sqlite3_db_filename DB DBNAME
 **
 ** Return the name of a file associated with a database.
@@ -6876,6 +6904,7 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
 
      { "sqlite3_release_memory",        test_release_memory,     0},
      { "sqlite3_db_release_memory",     test_db_release_memory,  0},
+     { "sqlite3_db_cacheflush",         test_db_cacheflush,      0},
      { "sqlite3_db_filename",           test_db_filename,        0},
      { "sqlite3_db_readonly",           test_db_readonly,        0},
      { "sqlite3_soft_heap_limit",       test_soft_heap_limit,    0},
diff --git a/test/cacheflush.test b/test/cacheflush.test
new file mode 100644
index 000000000..a9ee672b9
--- /dev/null
+++ b/test/cacheflush.test
@@ -0,0 +1,207 @@
+# 2011 November 16
+#
+# 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.
+#
+#***********************************************************************
+#
+# This file contains test cases for sqlite3_db_cacheflush API.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix cacheflush
+test_set_config_pagecache 0 0
+
+# Run the supplied SQL on a copy of the database currently stored on 
+# disk in file $dbfile.
+proc diskquery {dbfile sql} {
+  forcecopy $dbfile dq.db
+  sqlite3 dq dq.db
+  set res [execsql $sql dq]
+  dq close
+  set res
+}
+
+# Simplest possible test.
+#
+do_execsql_test 1.1.0 {
+  CREATE TABLE t1(a, b);
+  INSERT INTO t1 VALUES(1, 2);
+  BEGIN;
+    INSERT INTO t1 VALUES(3, 4);
+}
+do_test 1.1.1 {
+  diskquery test.db { SELECT * FROM t1 } 
+} {1 2}
+do_test 1.1.2 {
+  sqlite3_db_cacheflush db
+  diskquery test.db { SELECT * FROM t1 } 
+} {1 2 3 4}
+
+# Test that multiple pages may be flushed to disk.
+#
+do_execsql_test 1.2.0 {
+  COMMIT;
+  CREATE TABLE t2(a, b);
+  BEGIN;
+    INSERT INTO t1 VALUES(5, 6);
+    INSERT INTO t2 VALUES('a', 'b');
+}
+do_test 1.2.1 {
+  diskquery test.db { 
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+  }
+} {1 2 3 4}
+do_test 1.2.2 {
+  sqlite3_db_cacheflush db
+  diskquery test.db { 
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+  }
+} {1 2 3 4 5 6 a b}
+
+# Test that pages with nRef!=0 are not flushed to disk.
+#
+do_execsql_test 1.3.0 {
+  COMMIT;
+  CREATE TABLE t3(a, b);
+  BEGIN;
+    INSERT INTO t1 VALUES(7, 8);
+    INSERT INTO t2 VALUES('c', 'd');
+    INSERT INTO t3 VALUES('i', 'ii');
+}
+do_test 1.3.1 {
+  diskquery test.db { 
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+    SELECT * FROM t3;
+  }
+} {1 2 3 4 5 6 a b}
+do_test 1.3.2 {
+  db eval { SELECT a FROM t1 } {
+    if {$a==3} {
+      sqlite3_db_cacheflush db
+    }
+  }
+  diskquery test.db { 
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+    SELECT * FROM t3;
+  }
+} {1 2 3 4 5 6 a b c d i ii}
+do_test 1.3.2 {
+  sqlite3_db_cacheflush db
+  diskquery test.db { 
+    SELECT * FROM t1;
+    SELECT * FROM t2;
+    SELECT * FROM t3;
+  }
+} {1 2 3 4 5 6 7 8 a b c d i ii}
+
+# Check that SQLITE_BUSY is returned if pages cannot be flushed due to
+# conflicting read locks.
+#
+do_execsql_test 1.4.0 {
+  COMMIT;
+  BEGIN;
+    INSERT INTO t1 VALUES(9, 10);
+}
+do_test 1.4.1 {
+  sqlite3 db2 test.db
+  db2 eval {
+    BEGIN;
+      SELECT * FROM t1;
+  }
+  diskquery test.db { 
+    SELECT * FROM t1;
+  }
+} {1 2 3 4 5 6 7 8}
+do_test 1.4.2 {
+  list [catch { sqlite3_db_cacheflush db } msg] $msg
+} {1 {database is locked}}
+do_test 1.4.3 {
+  diskquery test.db { 
+    SELECT * FROM t1;
+  }
+} {1 2 3 4 5 6 7 8}
+do_test 1.4.4 {
+  db2 close
+  sqlite3_db_cacheflush db
+  diskquery test.db { 
+    SELECT * FROM t1;
+  }
+} {1 2 3 4 5 6 7 8 9 10}
+do_execsql_test 1.4.5 { COMMIT }
+
+#-------------------------------------------------------------------------
+# Test that ATTACHed database caches are also flushed.
+#
+forcedelete test.db2
+do_execsql_test 2.1.0 {
+  ATTACH 'test.db2' AS aux;
+  CREATE TABLE aux.t4(x, y);
+  INSERT INTO t4 VALUES('A', 'B');
+  BEGIN;
+    INSERT INTO t1 VALUES(11, 12);
+    INSERT INTO t4 VALUES('C', 'D');
+}
+do_test 2.1.1 {
+  diskquery test.db { SELECT * FROM t1; }
+} {1 2 3 4 5 6 7 8 9 10}
+do_test 2.1.2 {
+  diskquery test.db2 { SELECT * FROM t4; }
+} {A B}
+do_test 2.1.3 {
+  sqlite3_db_cacheflush db
+  diskquery test.db { SELECT * FROM t1; }
+} {1 2 3 4 5 6 7 8 9 10 11 12}
+do_test 2.1.4 {
+  sqlite3_db_cacheflush db
+  diskquery test.db2 { SELECT * FROM t4; }
+} {A B C D}
+do_execsql_test 2.1.5 { COMMIT }
+
+# And that hitting an SQLITE_BUSY when flushing "main" does not stop
+# SQLite from going on to flush "aux".
+#
+do_execsql_test 2.2.0 {
+  BEGIN;
+    INSERT INTO t1 VALUES(13, 14);
+    INSERT INTO t4 VALUES('E', 'F');
+}
+do_test 2.2.1 {
+  diskquery test.db { SELECT * FROM t1; }
+} {1 2 3 4 5 6 7 8 9 10 11 12}
+do_test 2.2.2 {
+  diskquery test.db2 { SELECT * FROM t4; }
+} {A B C D}
+do_test 2.2.3 {
+  sqlite3 db2 test.db
+  execsql {
+    BEGIN;
+      SELECT * FROM t1;
+  } db2
+  list [catch { sqlite3_db_cacheflush db } msg] $msg
+} {1 {database is locked}}
+do_test 2.2.4 {
+  diskquery test.db { SELECT * FROM t1; }
+} {1 2 3 4 5 6 7 8 9 10 11 12}
+do_test 2.2.5 {
+  diskquery test.db2 { SELECT * FROM t4; }
+} {A B C D E F}
+do_test 2.2.6 {
+  db2 close
+  sqlite3_db_cacheflush db
+  diskquery test.db { SELECT * FROM t1; }
+} {1 2 3 4 5 6 7 8 9 10 11 12 13 14}
+do_execsql_test 2.2.7 { COMMIT }
+
+test_restore_config_pagecache
+finish_test
+
diff --git a/test/cffault.test b/test/cffault.test
new file mode 100644
index 000000000..e90bbac55
--- /dev/null
+++ b/test/cffault.test
@@ -0,0 +1,57 @@
+# 2011 November 16
+#
+# 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.
+#
+#***********************************************************************
+#
+# This file contains fault-injection test cases for the 
+# sqlite3_db_cacheflush API.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+set testprefix cacheflush
+source $testdir/malloc_common.tcl
+
+# Run the supplied SQL on a copy of the database currently stored on 
+# disk in file $dbfile.
+proc diskquery {dbfile sql} {
+  forcecopy $dbfile dq.db
+  sqlite3 dq dq.db
+  set res [execsql $sql dq]
+  dq close
+  set res
+}
+
+do_execsql_test 1.0 {
+  CREATE TABLE t1(a PRIMARY KEY, b);
+  CREATE INDEX i1 ON t1(b);
+  INSERT INTO t1 VALUES(1, 2);
+  INSERT INTO t1 VALUES(3, 4);
+  INSERT INTO t1 VALUES(5, 6);
+  INSERT INTO t1 VALUES(7, 8);
+}
+faultsim_save_and_close
+
+do_faultsim_test 1 -prep {
+  faultsim_restore_and_reopen
+  db eval {
+    BEGIN;
+      UPDATE t1 SET b=b+1;
+  }
+} -body {
+  sqlite3_db_cacheflush db
+} -test {
+  faultsim_test_result {0 {}} {1 {disk I/O error}}
+  catch { db eval COMMIT }
+  faultsim_integrity_check
+}
+
+
+finish_test
+