Add the "(database.)freelist_count" PRAGMA. For querying the size of the

database free-list. (CVS 4112)

FossilOrigin-Name: 1fb4251a707d0b79d250d6ea2022913b371d5f14

manifest

@@ -1,5 +1,5 @@
-C When\sexpanding\s'*'\sin\sthe\sresult\sset\sof\sa\sSELECT,\squote\sthe\sexpanded\sidentifiers.\sFix\sfor\s#2450.\s(CVS\s4111)
-D 2007-06-24T06:32:18
+C Add\sthe\s"(database.)freelist_count"\sPRAGMA.\sFor\squerying\sthe\ssize\sof\sthe\ndatabase\sfree-list.\s(CVS\s4112)
+D 2007-06-24T08:00:43
 F Makefile.in 7f7485a4cc039476a42e534b3f26ec90e2f9753e
 F Makefile.linux-gcc 2d8574d1ba75f129aba2019f0b959db380a90935
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -99,7 +99,7 @@ F src/os_win.h 41a946bea10f61c158ce8645e7646b29d44f122b
 F src/pager.c 39352b58ee840cae715a4f0d20e446aa5e1445fe
 F src/pager.h 94110a5570dca30d54a883e880a3633b2e4c05ae
 F src/parse.y ad2ce25665be7f7303137f774a4e3e72e0d036ff
-F src/pragma.c 0d25dad58bdfd6789943a10f1b9663c2eb85b96d
+F src/pragma.c d2e6f5da991594e1c2c7636927f6be7cf66e81bd
 F src/prepare.c 87c23644986b5e41a58bc76f05abebd899e00089
 F src/printf.c 9b3048d270e8bb2f8b910b491ac3aadece6cfab2
 F src/random.c 6119474a6f6917f708c1dee25b9a8e519a620e88
@@ -137,7 +137,7 @@ F src/update.c 3359041db390a8f856d67272f299600e2104f350
 F src/utf.c 01b2aba02b10d12903e9e1ff897215c9faf6b662
 F src/util.c 80cdf6b68d03b8f0ab3237a390842e039cff66c6
 F src/vacuum.c 8bd895d29e7074e78d4e80f948e35ddc9cf2beef
-F src/vdbe.c a7407f045ecc35fc2a9ddeffdd06145e402a7685
+F src/vdbe.c 219cfe39555e6144d0b2b902832aaee18c9e0f0e
 F src/vdbe.h 001c5b257567c1d3de7feb2203aac71d0d7b16a3
 F src/vdbeInt.h 7d2bf163d6d4e815724a457f2216dd8e38c3955c
 F src/vdbeapi.c 7930b9a188ab385287ca3eb3840af7225cb43549
@@ -330,6 +330,7 @@ F test/pager3.test 2323bf27fd5bd887b580247e5bce500ceee994b4
 F test/pageropt.test b4b38eb3cf76be2be444326856248898bb0e3fc9
 F test/pagesize.test e0a8b3fe80f8b8e808d94a00734c7a18c76c407e
 F test/pragma.test b0e73879206934a835856a8b8c4cc884cd8562f3
+F test/pragma2.test 6639e9e53fd91b2f1b58a5cf3d86fbe2fc9a70f5
 F test/printf.test 69d8cb0771a1a5e4d9d5dece12fc2c16179ac5e5
 F test/progress.test 5b075c3c790c7b2a61419bc199db87aaf48b8301 x
 F test/ptrchng.test 1c712dd6516e1377471744fa765e41c79a357da6
@@ -501,7 +502,7 @@ F www/opcode.tcl 5bd68059416b223515a680d410a9f7cb6736485f
 F www/optimizer.tcl d6812a10269bd0d7c488987aac0ad5036cace9dc
 F www/optimizing.tcl f0b2538988d1bbad16cbfe63ec6e8f48c9eb04e5
 F www/optoverview.tcl 815df406a38c9f69b27d37e8f7ede004c6d9f19e
-F www/pragma.tcl 394028988b9c22c23439a67a21be9e1fb818d258
+F www/pragma.tcl bb3ae44a9c4a3e1047c07657954dd4ea18911194
 F www/quickstart.tcl 8708a4ca83fbf55c66af1782992626f20c3df095
 F www/shared.gif 265bae80c5b311c5a86e47662821076ffaf5c6ea
 F www/sharedcache.tcl 3ebec81110e606af6fd65a3c4c19562cb173b29c
@@ -513,7 +514,7 @@ F www/tclsqlite.tcl 8be95ee6dba05eabcd27a9d91331c803f2ce2130
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl 890248cf7b70e60c383b0e84d77d5132b3ead42b
 F www/whentouse.tcl fc46eae081251c3c181bd79c5faef8195d7991a5
-P f35e20e19633d7b114fdf145820ca5d61b5aa925
-R 0028662710d587da4e5d82de686d252d
+P d5b7224f37db1729dd042d48765d7a79247e1bde
+R 68c93754de3917a7a2bfaeb6e4eb9132
 U danielk1977
-Z 13d4831b99a0601e7fdfc2a1c76b4c67
+Z 04ec3282e5bef0f3d8094230d12c6499

manifest.uuid

@@ -1 +1 @@
-d5b7224f37db1729dd042d48765d7a79247e1bde
+1fb4251a707d0b79d250d6ea2022913b371d5f14

src/pragma.c

@@ -11,7 +11,7 @@
 *************************************************************************
 ** This file contains code used to implement the PRAGMA command.
 **
-** $Id: pragma.c,v 1.139 2007/05/23 13:50:24 danielk1977 Exp $
+** $Id: pragma.c,v 1.140 2007/06/24 08:00:43 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -1006,17 +1006,27 @@ void sqlite3Pragma(
   ** The user-version is not used internally by SQLite. It may be used by
   ** applications for any purpose.
   */
-  if( sqlite3StrICmp(zLeft, "schema_version")==0 ||
-      sqlite3StrICmp(zLeft, "user_version")==0 ){
+  if( sqlite3StrICmp(zLeft, "schema_version")==0 
+   || sqlite3StrICmp(zLeft, "user_version")==0 
+   || sqlite3StrICmp(zLeft, "freelist_count")==0 
+  ){
 
     int iCookie;   /* Cookie index. 0 for schema-cookie, 6 for user-cookie. */
-    if( zLeft[0]=='s' || zLeft[0]=='S' ){
+    switch( zLeft[0] ){
+      case 's': case 'S':
         iCookie = 0;
-    }else{
+        break;
+      case 'f': case 'F':
+        iCookie = 1;
+        iDb = (-1*(iDb+1));
+        assert(iDb<=0);
+        break;
+      default:
         iCookie = 5;
+        break;
     }
 
-    if( zRight ){
+    if( zRight && iDb>=0 ){
       /* Write the specified cookie value */
       static const VdbeOpList setCookie[] = {
         { OP_Transaction,    0,  1,  0},    /* 0 */

src/vdbe.c

@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.627 2007/06/20 15:29:25 drh Exp $
+** $Id: vdbe.c,v 1.628 2007/06/24 08:00:43 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -2515,9 +2515,16 @@ case OP_Transaction: {       /* no-push */
 */
 case OP_ReadCookie: {
   int iMeta;
+  int iDb = pOp->p1;
+  int iCookie = pOp->p2;
+
   assert( pOp->p2<SQLITE_N_BTREE_META );
-  assert( pOp->p1>=0 && pOp->p1<db->nDb );
-  assert( db->aDb[pOp->p1].pBt!=0 );
+  if( iDb<0 ){
+    iDb = (-1*(iDb+1));
+    iCookie *= -1;
+  }
+  assert( iDb>=0 && iDb<db->nDb );
+  assert( db->aDb[iDb].pBt!=0 );
   /* The indexing of meta values at the schema layer is off by one from
   ** the indexing in the btree layer.  The btree considers meta[0] to
   ** be the number of free pages in the database (a read-only value)
@@ -2525,7 +2532,7 @@ case OP_ReadCookie: {
   ** meta[1] to be the schema cookie.  So we have to shift the index
   ** by one in the following statement.
   */
-  rc = sqlite3BtreeGetMeta(db->aDb[pOp->p1].pBt, 1 + pOp->p2, (u32 *)&iMeta);
+  rc = sqlite3BtreeGetMeta(db->aDb[iDb].pBt, 1 + iCookie, (u32 *)&iMeta);
   pTos++;
   pTos->u.i = iMeta;
   pTos->flags = MEM_Int;

test/pragma2.test

@@ -0,0 +1,115 @@
+# 2002 March 6
+#
+# 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 implements regression tests for SQLite library.
+#
+# This file implements tests for the PRAGMA command.
+#
+# $Id: pragma2.test,v 1.1 2007/06/24 08:00:44 danielk1977 Exp $
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+# Test organization:
+#
+# pragma2-1.*: Test freelist_count pragma on the main database.
+# pragma2-2.*: Test freelist_count pragma on an attached database.
+# pragma2-3.*: Test trying to write to the freelist_count is a no-op.
+#
+
+ifcapable !pragma {
+  finish_test
+  return
+}
+
+# Delete the preexisting database to avoid the special setup
+# that the "all.test" script does.
+#
+db close
+file delete test.db test.db-journal
+file delete test3.db test3.db-journal
+sqlite3 db test.db; set DB [sqlite3_connection_pointer db]
+
+do_test pragma2-1.1 {
+  execsql {
+    PRAGMA freelist_count;
+  }
+} {0}
+do_test pragma2-1.2 {
+  execsql {
+    CREATE TABLE abc(a, b, c);
+    PRAGMA freelist_count;
+  }
+} {0}
+do_test pragma2-1.3 {
+  execsql {
+    DROP TABLE abc;
+    PRAGMA freelist_count;
+  }
+} {1}
+do_test pragma2-1.4 {
+  execsql {
+    PRAGMA main.freelist_count;
+  }
+} {1}
+
+file delete -force test2.db
+file delete -force test2.db-journal
+
+do_test pragma2-2.1 {
+  execsql {
+    ATTACH 'test2.db' AS aux;
+    PRAGMA aux.freelist_count;
+  }
+} {0}
+do_test pragma2-2.2 {
+  execsql {
+    CREATE TABLE aux.abc(a, b, c);
+    PRAGMA aux.freelist_count;
+  }
+} {0}
+do_test pragma2-2.3 {
+  set ::val [string repeat 0123456789 1000]
+  execsql {
+    INSERT INTO aux.abc VALUES(1, 2, $::val);
+    PRAGMA aux.freelist_count;
+  }
+} {0}
+do_test pragma2-2.4 {
+  expr {[file size test2.db] / 1024}
+} {11}
+do_test pragma2-2.5 {
+  execsql {
+    DELETE FROM aux.abc;
+    PRAGMA aux.freelist_count;
+  }
+} {9}
+
+do_test pragma2-3.1 {
+  execsql {
+    PRAGMA aux.freelist_count;
+    PRAGMA main.freelist_count;
+    PRAGMA freelist_count;
+  }
+} {9 1 1}
+do_test pragma2-3.2 {
+  execsql {
+    PRAGMA freelist_count = 500;
+    PRAGMA freelist_count;
+  }
+} {1 1}
+do_test pragma2-3.3 {
+  execsql {
+    PRAGMA aux.freelist_count = 500;
+    PRAGMA aux.freelist_count;
+  }
+} {9 9}
+
+finish_test

www/pragma.tcl

@@ -1,7 +1,7 @@
 #
 # Run this Tcl script to generate the pragma.html file.
 #
-set rcsid {$Id: pragma.tcl,v 1.25 2007/06/18 12:22:43 drh Exp $}
+set rcsid {$Id: pragma.tcl,v 1.26 2007/06/24 08:00:44 danielk1977 Exp $}
 source common.tcl
 header {Pragma statements supported by SQLite}
 
@@ -526,6 +526,13 @@ puts {
     foreign key. The callback function will be invoked once for each
     column in each foreign key.</p></li>
 
+<a name="pragma_freelist_count"></a>
+<li><p><b>PRAGMA [database].freelist_count;</b></p>
+    <p>Return the number of unused pages in the database file. Running
+    a <a href="#pragma_incremental_vacuum">"PRAGMA incremental_vaccum(N);"</a> 
+    command with a large value of N will shrink the database file by this
+    number of pages. </p></li>
+
 <a name="pragma_index_info"></a>
 <li><p><b>PRAGMA index_info(</b><i>index-name</i><b>);</b></p>
     <p>For each column that the named index references, invoke the