VACUUM works even on an empty database. Ticket #1512. (CVS 2760)

FossilOrigin-Name: 1b6bf4188e8ebf55cf1972b7081f6d31bf525555

src/os_common.h

@@ -88,6 +88,7 @@ static unsigned int elapse;
 ** is used for testing the I/O recovery logic.
 */
 #ifdef SQLITE_TEST
+int sqlite3_io_error_hit = 0;
 int sqlite3_io_error_pending = 0;
 int sqlite3_diskfull_pending = 0;
 int sqlite3_diskfull = 0;
@@ -95,7 +96,7 @@ int sqlite3_diskfull = 0;
    if( sqlite3_io_error_pending ) \
      if( sqlite3_io_error_pending-- == 1 ){ local_ioerr(); return A; }
 static void local_ioerr(){
-  sqlite3_io_error_pending = 0;  /* Really just a place to set a breakpoint */
+  sqlite3_io_error_hit = 1;  /* Really just a place to set a breakpoint */
 }
 #define SimulateDiskfullError \
    if( sqlite3_diskfull_pending ){ \

src/pager.c

@@ -18,7 +18,7 @@
 ** file simultaneously, or one process from reading the database while
 ** another is writing.
 **
-** @(#) $Id: pager.c,v 1.215 2005/09/17 15:20:27 drh Exp $
+** @(#) $Id: pager.c,v 1.216 2005/11/04 22:03:30 drh Exp $
 */
 #ifndef SQLITE_OMIT_DISKIO
 #include "sqliteInt.h"
@@ -1738,6 +1738,34 @@ int sqlite3pager_set_pagesize(Pager *pPager, int pageSize){
   return pPager->pageSize;
 }
 
+/*
+** The following set of routines are used to disable the simulated
+** I/O error mechanism.  These routines are used to avoid simulated
+** errors in places where we do not care about errors.
+**
+** Unless -DSQLITE_TEST=1 is used, these routines are all no-ops
+** and generate no code.
+*/
+#ifdef SQLITE_TEST
+extern int sqlite3_io_error_pending;
+extern int sqlite3_io_error_hit;
+static int saved_cnt;
+void clear_simulated_io_error(){
+  sqlite3_io_error_hit = 0;
+}
+void disable_simulated_io_errors(void){
+  saved_cnt = sqlite3_io_error_pending;
+  sqlite3_io_error_pending = -1;
+}
+void enable_simulated_io_errors(void){
+  sqlite3_io_error_pending = saved_cnt;
+}
+#else
+# define clear_simulated_io_error(X)
+# define disable_simulated_io_errors(X)
+# define enable_simulated_io_errors(X)
+#endif
+
 /*
 ** Read the first N bytes from the beginning of the file into memory
 ** that pDest points to.  No error checking is done.
@@ -1747,6 +1775,7 @@ void sqlite3pager_read_fileheader(Pager *pPager, int N, unsigned char *pDest){
   if( MEMDB==0 ){
     sqlite3OsSeek(&pPager->fd, 0);
     sqlite3OsRead(&pPager->fd, pDest, N);
+    clear_simulated_io_error();
   }
 }
 
@@ -1961,15 +1990,9 @@ int sqlite3pager_close(Pager *pPager){
       ** operation. So disable IO error simulation so that testing
       ** works more easily.
       */
-#if defined(SQLITE_TEST) && (defined(OS_UNIX) || defined(OS_WIN))
-      extern int sqlite3_io_error_pending;
-      int ioerr_cnt = sqlite3_io_error_pending;
-      sqlite3_io_error_pending = -1;
-#endif
+      disable_simulated_io_errors();
       sqlite3pager_rollback(pPager);
-#if defined(SQLITE_TEST) && (defined(OS_UNIX) || defined(OS_WIN))
-      sqlite3_io_error_pending = ioerr_cnt;
-#endif
+      enable_simulated_io_errors();
       if( !MEMDB ){
         sqlite3OsUnlock(&pPager->fd, NO_LOCK);
       }
@@ -2535,6 +2558,7 @@ int sqlite3pager_get(Pager *pPager, Pgno pgno, void **ppPage){
           sqlite3pager_unref(PGHDR_TO_DATA(pPg));
           return rc;
         }else{
+          clear_simulated_io_error();
           memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
         }
       }else{

src/test2.c

@@ -13,7 +13,7 @@
 ** is not included in the SQLite library.  It is used for automated
 ** testing of the SQLite library.
 **
-** $Id: test2.c,v 1.34 2005/09/16 10:13:42 danielk1977 Exp $
+** $Id: test2.c,v 1.35 2005/11/04 22:03:30 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -560,6 +560,7 @@ static int fake_big_file(
 */
 int Sqlitetest2_Init(Tcl_Interp *interp){
   extern int sqlite3_io_error_pending;
+  extern int sqlite3_io_error_hit;
   extern int sqlite3_diskfull_pending;
   extern int sqlite3_diskfull;
   static struct {
@@ -592,6 +593,8 @@ int Sqlitetest2_Init(Tcl_Interp *interp){
   }
   Tcl_LinkVar(interp, "sqlite_io_error_pending",
      (char*)&sqlite3_io_error_pending, TCL_LINK_INT);
+  Tcl_LinkVar(interp, "sqlite_io_error_hit",
+     (char*)&sqlite3_io_error_hit, TCL_LINK_INT);
   Tcl_LinkVar(interp, "sqlite_diskfull_pending",
      (char*)&sqlite3_diskfull_pending, TCL_LINK_INT);
   Tcl_LinkVar(interp, "sqlite_diskfull",

src/vacuum.c

@@ -14,7 +14,7 @@
 ** Most of the code in this file may be omitted by defining the
 ** SQLITE_OMIT_VACUUM macro.
 **
-** $Id: vacuum.c,v 1.46 2005/11/03 02:15:04 drh Exp $
+** $Id: vacuum.c,v 1.47 2005/11/04 22:03:30 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -100,6 +100,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   Btree *pMain;           /* The database being vacuumed */
   Btree *pTemp;
   char *zSql = 0;
+  int rc2;  
   int saved_flags;       /* Saved value of the db->flags */
 
   /* Save the current value of the write-schema flag before setting it. */
@@ -176,7 +177,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
 #endif
 
   /* Begin a transaction */
-  rc = execSql(db, "BEGIN;");
+  rc = execSql(db, "BEGIN EXCLUSIVE;");
   if( rc!=SQLITE_OK ) goto end_of_vacuum;
 
   /* Query the schema of the main database. Create a mirror schema
@@ -247,7 +248,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** opened for writing. This way, the SQL transaction used to create the
   ** temporary database never needs to be committed.
   */
-  if( sqlite3BtreeIsInTrans(pTemp) ){
+  if( rc==SQLITE_OK ){
     u32 meta;
     int i;
 
@@ -264,19 +265,21 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
        6, 0,    /* Preserve the user version */
     };
 
-    assert( 0==sqlite3BtreeIsInTrans(pMain) );
-    rc = sqlite3BtreeBeginTrans(pMain, 1);
-    if( rc!=SQLITE_OK ) goto end_of_vacuum;
+    assert( 1==sqlite3BtreeIsInTrans(pTemp) );
+    assert( 1==sqlite3BtreeIsInTrans(pMain) );
 
     /* Copy Btree meta values */
     for(i=0; i<sizeof(aCopy)/sizeof(aCopy[0]); i+=2){
       rc = sqlite3BtreeGetMeta(pMain, aCopy[i], &meta);
       if( rc!=SQLITE_OK ) goto end_of_vacuum;
       rc = sqlite3BtreeUpdateMeta(pTemp, aCopy[i], meta+aCopy[i+1]);
+      if( rc!=SQLITE_OK ) goto end_of_vacuum;
     }
 
     rc = sqlite3BtreeCopyFile(pMain, pTemp);
     if( rc!=SQLITE_OK ) goto end_of_vacuum;
+    rc = sqlite3BtreeCommit(pTemp);
+    if( rc!=SQLITE_OK ) goto end_of_vacuum;
     rc = sqlite3BtreeCommit(pMain);
   }
 
@@ -292,16 +295,15 @@ end_of_vacuum:
   ** is closed by the DETACH.
   */
   db->autoCommit = 1;
+  rc2 = execSql(db, "DETACH vacuum_db;");
   if( rc==SQLITE_OK ){
-    rc = execSql(db, "DETACH vacuum_db;");
-  }else{
-    execSql(db, "DETACH vacuum_db;");
+    rc = rc2;
   }
   if( zTemp ){
     sqlite3OsDelete(zTemp);
     sqliteFree(zTemp);
   }
-  if( zSql ) sqliteFree( zSql );
+  sqliteFree( zSql );
   sqlite3ResetInternalSchema(db, 0);
 #endif