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Add the schema_cookie and user_cookie pragmas. (CVS 2089)

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FossilOrigin-Name: d28d1d68e5104726e6088361dfa7bf2cdd9985c7
This commit is contained in:
danielk1977
2004-11-11 05:10:43 +00:00
parent 2df9fabf3c
commit dae2495b1f
6 changed files with 317 additions and 19 deletions
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61
src/pragma.c
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@@ -11,7 +11,7 @@
*************************************************************************
** This file contains code used to implement the PRAGMA command.
**
** $Id: pragma.c,v 1.75 2004/11/09 12:44:38 danielk1977 Exp $
** $Id: pragma.c,v 1.76 2004/11/11 05:10:44 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>
@@ -724,6 +724,65 @@ void sqlite3Pragma(
}
}
}else
/*
** PRAGMA [database.]schema_cookie
** PRAGMA [database.]schema_cookie = <integer>
**
** PRAGMA [database.]user_cookie
** PRAGMA [database.]user_cookie = <integer>
**
** The pragma's schema_cookie and user_cookie are used to set or get
** the value of the schema-cookie and user-cookie, respectively. Both
** the schema-cookie and the user-cookie are 32-bit signed integers
** stored in the database header.
**
** The schema-cookie is usually only manipulated internally by SQLite. It
** is incremented by SQLite whenever the database schema is modified (by
** creating or dropping a table or index). The schema cookie is used by
** SQLite each time a query is executed to ensure that the internal cache
** of the schema used when compiling the SQL query matches the schema of
** the database against which the compiled query is actually executed.
** Subverting this mechanism by using "PRAGMA schema_cookie" to modify
** the schema-cookie is potentially dangerous and may lead to program
** crashes or database corruption. Use with caution!
**
** The user-cookie is not used internally by SQLite. It may be used by
** applications for any purpose.
*/
if( sqlite3StrICmp(zLeft, "schema_cookie")==0 ||
sqlite3StrICmp(zLeft, "user_cookie")==0 ){
int iCookie; /* Cookie index. 0 for schema-cookie, 6 for user-cookie. */
if( zLeft[0]=='s' || zLeft[0]=='S' ){
iCookie = 0;
}else{
iCookie = 5;
}
if( zRight ){
/* Write the specified cookie value */
static const VdbeOpList setCookie[] = {
{ OP_Transaction, 0, 1, 0}, /* 0 */
{ OP_Integer, 0, 0, 0}, /* 1 */
{ OP_SetCookie, 0, 0, 0}, /* 2 */
};
int addr = sqlite3VdbeAddOpList(v, ArraySize(setCookie), setCookie);
sqlite3VdbeChangeP1(v, addr, iDb);
sqlite3VdbeChangeP1(v, addr+1, atoi(zRight));
sqlite3VdbeChangeP1(v, addr+2, iDb);
sqlite3VdbeChangeP2(v, addr+2, iCookie);
}else{
/* Read the specified cookie value */
static const VdbeOpList readCookie[] = {
{ OP_ReadCookie, 0, 0, 0}, /* 0 */
{ OP_Callback, 1, 0, 0}
};
int addr = sqlite3VdbeAddOpList(v, ArraySize(readCookie), readCookie);
sqlite3VdbeChangeP1(v, addr, iDb);
sqlite3VdbeChangeP2(v, addr, iCookie);
sqlite3VdbeSetNumCols(v, 1);
}
}
#if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
/*