SQLite

/*
** 2005 July 8
**
** 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 code associated with the ANALYZE command.
**
** @(#) $Id: analyze.c,v 1.13 2006/01/07 13:21:04 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_ANALYZE
#include "sqliteInt.h"

/*
** This routine generates code that opens the sqlite_stat1 table on cursor
** iStatCur.

    iRootPage = pStat->tnum;
  }else{
    /* The sqlite_stat1 table already exists.  Delete all rows. */
    iRootPage = pStat->tnum;
    sqlite3VdbeAddOp(v, OP_Clear, pStat->tnum, iDb);
  }

  /* Open the sqlite_stat1 table for writing. Unless it was created
  ** by this vdbe program, lock it for writing at the shared-cache level. 
  ** If this vdbe did create the sqlite_stat1 table, then it must have 
  ** already obtained a schema-lock, making the write-lock redundant.
  */
  if( iRootPage>0 ){
    sqlite3TableLock(pParse, iDb, iRootPage, 1, "sqlite_stat1");
  }
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenWrite, iStatCur, iRootPage);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, iStatCur, 3);
}

/*
** Generate code to do an analysis of all indices associated with

  assert( iDb>=0 );
#ifndef SQLITE_OMIT_AUTHORIZATION
  if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0,
      pParse->db->aDb[iDb].zName ) ){
    return;
  }
#endif

  /* Establish a read-lock on the table at the shared-cache level. */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);

  iIdxCur = pParse->nTab;
  for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
    /* Open a cursor to the index to be analyzed
    */
    assert( iDb==sqlite3SchemaToIndex(pParse->db, pIdx->pSchema) );
    sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);

/*
** 2004 April 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.
**
*************************************************************************
** $Id: btree.c,v 1.285 2006/01/07 13:21:04 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

      return SQLITE_READONLY;
    }
    if( checkReadLocks(pBt, iTable, 0) ){
      return SQLITE_LOCKED;
    }
  }








  if( pBt->pPage1==0 ){
    rc = lockBtreeWithRetry(p);
    if( rc!=SQLITE_OK ){
      return rc;
    }
  }
  pCur = sqliteMalloc( sizeof(*pCur) );
  if( pCur==0 ){
    rc = SQLITE_NOMEM;
    goto create_cursor_exception;
  }
  pCur->pgnoRoot = (Pgno)iTable;
  pCur->pPage = 0;  /* For exit-handler, in case getAndInitPage() fails. */
  if( iTable==1 && sqlite3pager_pagecount(pBt->pPager)==0 ){
    rc = SQLITE_EMPTY;
    goto create_cursor_exception;
  }
  rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->pPage, 0);
  if( rc!=SQLITE_OK ){







    goto create_cursor_exception;
  }

  /* Now that no other errors can occur, finish filling in the BtCursor
  ** variables, link the cursor into the BtShared list and set *ppCur (the
  ** output argument to this function).
  */

/*
** Return true if another user of the same shared btree as the argument
** handle holds an exclusive lock on the sqlite_master table.
*/
int sqlite3BtreeSchemaLocked(Btree *p){
  return (queryTableLock(p, MASTER_ROOT, READ_LOCK)!=SQLITE_OK);
}

int sqlite3BtreeLockTable(Btree *p, int iTab, u8 isWriteLock){
  u8 lockType = (isWriteLock?WRITE_LOCK:READ_LOCK);
  int rc = queryTableLock(p, iTab, lockType);
  if( rc==SQLITE_OK ){
    rc = lockTable(p, iTab, lockType);
  }
  return rc;
}

#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** Enable the shared pager and schema features.
*/
int sqlite3_enable_shared_cache(int enable){
  SqliteTsd *pTsd = sqlite3Tsd();

**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the sqlite B-Tree file
** subsystem.  See comments in the source code for a detailed description
** of what each interface routine does.
**
** @(#) $Id: btree.h,v 1.69 2006/01/07 13:21:04 danielk1977 Exp $
*/
#ifndef _BTREE_H_
#define _BTREE_H_

/* TODO: This definition is just included so other modules compile. It
** needs to be revisited.
*/

int sqlite3BtreeRollbackStmt(Btree*);
int sqlite3BtreeCreateTable(Btree*, int*, int flags);
int sqlite3BtreeIsInTrans(Btree*);
int sqlite3BtreeIsInStmt(Btree*);
int sqlite3BtreeSync(Btree*, const char *zMaster);
void *sqlite3BtreeSchema(Btree *, int, void(*)(void *));
int sqlite3BtreeSchemaLocked(Btree *);
int sqlite3BtreeLockTable(Btree *, int, u8);

const char *sqlite3BtreeGetFilename(Btree *);
const char *sqlite3BtreeGetDirname(Btree *);
const char *sqlite3BtreeGetJournalname(Btree *);
int sqlite3BtreeCopyFile(Btree *, Btree *);

/* The flags parameter to sqlite3BtreeCreateTable can be the bitwise OR

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.369 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
*/
void sqlite3BeginParse(Parse *pParse, int explainFlag){
  pParse->explain = explainFlag;
  pParse->nVar = 0;
}

#ifndef SQLITE_OMIT_SHARED_CACHE
/*
** The TableLock structure is only used by the sqlite3TableLock() and
** codeTableLocks() functions.
*/
struct TableLock {
  int iDb;
  int iTab;
  u8 isWriteLock;
  const char *zName;
};

/*
** Have the compiled statement lock the table with rootpage iTab in database
** iDb at the shared-cache level when executed. The isWriteLock argument 
** is zero for a read-lock, or non-zero for a write-lock.
**
** The zName parameter should point to the unqualified table name. This is
** used to provide a more informative error message should the lock fail.
*/
void sqlite3TableLock(
  Parse *pParse, 
  int iDb, 
  int iTab, 
  u8 isWriteLock,  
  const char *zName
){
  int i;
  int nBytes;
  TableLock *p;
  SqliteTsd *pTsd = sqlite3Tsd();

  if( 0==pTsd->useSharedData ){
    return;
  }

  for(i=0; i<pParse->nTableLock; i++){
    p = &pParse->aTableLock[i];
    if( p->iDb==iDb && p->iTab==iTab ){
      p->isWriteLock = (p->isWriteLock || isWriteLock);
      return;
    }
  }

  nBytes = sizeof(TableLock) * (pParse->nTableLock+1);
  sqliteReallocOrFree((void **)&pParse->aTableLock, nBytes);
  if( pParse->aTableLock ){
    p = &pParse->aTableLock[pParse->nTableLock++];
    p->iDb = iDb;
    p->iTab = iTab;
    p->isWriteLock = isWriteLock;
    p->zName = zName;
  }
}

/*
** Code an OP_TableLock instruction for each table locked by the
** statement (configured by calls to sqlite3TableLock()).
*/
static void codeTableLocks(Parse *pParse){
  int i;
  Vdbe *pVdbe; 
  assert( sqlite3Tsd()->useSharedData || pParse->nTableLock==0 );

  if( 0==(pVdbe = sqlite3GetVdbe(pParse)) ){
    return;
  }

  for(i=0; i<pParse->nTableLock; i++){
    TableLock *p = &pParse->aTableLock[i];
    int p1 = p->iDb;
    if( p->isWriteLock ){
      p1 = -1*(p1+1);
    }
    sqlite3VdbeOp3(pVdbe, OP_TableLock, p1, p->iTab, p->zName, P3_STATIC);
  }
}
#else
  #define codeTableLocks(x)
#endif

/*
** This routine is called after a single SQL statement has been
** parsed and a VDBE program to execute that statement has been
** prepared.  This routine puts the finishing touches on the
** VDBE program and resets the pParse structure for the next
** parse.

    /* The cookie mask contains one bit for each database file open.
    ** (Bit 0 is for main, bit 1 is for temp, and so forth.)  Bits are
    ** set for each database that is used.  Generate code to start a
    ** transaction on each used database and to verify the schema cookie
    ** on each used database.
    */
    assert( pParse->cookieGoto>0 || pParse->nTableLock==0 );
    if( pParse->cookieGoto>0 ){
      u32 mask;
      int iDb;
      sqlite3VdbeJumpHere(v, pParse->cookieGoto-1);
      for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
        if( (mask & pParse->cookieMask)==0 ) continue;
        sqlite3VdbeAddOp(v, OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
        sqlite3VdbeAddOp(v, OP_VerifyCookie, iDb, pParse->cookieValue[iDb]);
      }

      /* Once all the cookies have been verified and transactions opened, 
      ** obtain the required table-locks. This is a no-op unless the 
      ** shared-cache feature is enabled.
      */
      codeTableLocks(pParse);
      sqlite3VdbeAddOp(v, OP_Goto, 0, pParse->cookieGoto);
    }

#ifndef SQLITE_OMIT_TRACE
    /* Add a No-op that contains the complete text of the compiled SQL
    ** statement as its P3 argument.  This does not change the functionality
    ** of the program. 

  return zName;
}

/*
** Open the sqlite_master table stored in database number iDb for
** writing. The table is opened using cursor 0.
*/
void sqlite3OpenMasterTable(Parse *p, int iDb){
  Vdbe *v = sqlite3GetVdbe(p);
  sqlite3TableLock(p, iDb, MASTER_ROOT, 1, SCHEMA_TABLE(iDb));
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  sqlite3VdbeAddOp(v, OP_OpenWrite, 0, MASTER_ROOT);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, 0, 5); /* sqlite_master has 5 columns */
}

/*
** The token *pName contains the name of a database (either "main" or

    if( isView ){
      sqlite3VdbeAddOp(v, OP_Integer, 0, 0);
    }else
#endif
    {
      sqlite3VdbeAddOp(v, OP_CreateTable, iDb, 0);
    }
    sqlite3OpenMasterTable(pParse, iDb);
    sqlite3VdbeAddOp(v, OP_NewRowid, 0, 0);
    sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
    sqlite3VdbeAddOp(v, OP_Null, 0, 0);
    sqlite3VdbeAddOp(v, OP_Insert, 0, 0);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeAddOp(v, OP_Pull, 1, 0);
  }

    /* If this is a CREATE TABLE xx AS SELECT ..., execute the SELECT
    ** statement to populate the new table. The root-page number for the
    ** new table is on the top of the vdbe stack.
    **
    ** Once the SELECT has been coded by sqlite3Select(), it is in a
    ** suitable state to query for the column names and types to be used
    ** by the new table.
    **
    ** A shared-cache write-lock is not required to write to the new table,
    ** as a schema-lock must have already been obtained to create it. Since
    ** a schema-lock excludes all other database users, the write-lock would
    ** be redundant.
    */
    if( pSelect ){
      Table *pSelTab;
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
      sqlite3VdbeAddOp(v, OP_OpenWrite, 1, 0);
      pParse->nTab = 2;

  ** routine will invoke the collation-needed callback if necessary (and
  ** if one has been registered).
  */
  if( sqlite3CheckIndexCollSeq(pParse, pIndex) ){
    return;
  }

  /* Require a write-lock on the table to perform this operation */
  sqlite3TableLock(pParse, iDb, pTab->tnum, 1, pTab->zName);

  v = sqlite3GetVdbe(pParse);
  if( v==0 ) return;
  if( memRootPage>=0 ){
    sqlite3VdbeAddOp(v, OP_MemLoad, memRootPage, 0);
    tnum = 0;
  }else{
    tnum = pIndex->tnum;
    sqlite3VdbeAddOp(v, OP_Clear, tnum, iDb);
  }
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  sqlite3VdbeOp3(v, OP_OpenWrite, iIdx, tnum,
                    (char*)&pIndex->keyInfo, P3_KEYINFO);
  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
  addr1 = sqlite3VdbeAddOp(v, OP_Rewind, iTab, 0);
  sqlite3GenerateIndexKey(v, pIndex, iTab);
  if( pIndex->onError!=OE_None ){
    int curaddr = sqlite3VdbeCurrentAddr(v);
    int addr2 = curaddr+4;
    sqlite3VdbeChangeP2(v, curaddr-1, addr2);
    sqlite3VdbeAddOp(v, OP_Rowid, iTab, 0);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** in order to generate code for DELETE FROM statements.
**
** $Id: delete.c,v 1.115 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Look up every table that is named in pSrc.  If any table is not found,
** add an error message to pParse->zErrMsg and return NULL.  If all tables
** are found, return a pointer to the last table.

#endif
  return 0;
}

/*
** Generate code that will open a table for reading.
*/
void sqlite3OpenTable(
  Parse *p,       /* Generate code into this VDBE */
  int iCur,       /* The cursor number of the table */
  int iDb,        /* The database index in sqlite3.aDb[] */
  Table *pTab,    /* The table to be opened */
  int opcode      /* OP_OpenRead or OP_OpenWrite */
){
  Vdbe *v = sqlite3GetVdbe(p);
  assert( opcode==OP_OpenWrite || opcode==OP_OpenRead );
  sqlite3TableLock(p, iDb, pTab->tnum, (opcode==OP_OpenWrite), pTab->zName);
  sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
  VdbeComment((v, "# %s", pTab->zName));
  sqlite3VdbeAddOp(v, opcode, iCur, pTab->tnum);
  sqlite3VdbeAddOp(v, OP_SetNumColumns, iCur, pTab->nCol);
}


/*
** Generate code for a DELETE FROM statement.
**

  if( pWhere==0 && !triggers_exist ){
    if( db->flags & SQLITE_CountRows ){
      /* If counting rows deleted, just count the total number of
      ** entries in the table. */
      int endOfLoop = sqlite3VdbeMakeLabel(v);
      int addr;
      if( !isView ){
        sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
      }
      sqlite3VdbeAddOp(v, OP_Rewind, iCur, sqlite3VdbeCurrentAddr(v)+2);
      addr = sqlite3VdbeAddOp(v, OP_AddImm, 1, 0);
      sqlite3VdbeAddOp(v, OP_Next, iCur, addr);
      sqlite3VdbeResolveLabel(v, endOfLoop);
      sqlite3VdbeAddOp(v, OP_Close, iCur, 0);
    }

    /* This is the beginning of the delete loop when there are
    ** row triggers.
    */
    if( triggers_exist ){
      addr = sqlite3VdbeAddOp(v, OP_FifoRead, 0, end);
      if( !isView ){
        sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
        sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
      }
      sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);
      sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
      sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);
      sqlite3VdbeAddOp(v, OP_Insert, oldIdx, 0);
      if( !isView ){
        sqlite3VdbeAddOp(v, OP_Close, iCur, 0);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements in SQLite.
**
** $Id: insert.c,v 1.153 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** Set P3 of the most recently inserted opcode to a column affinity
** string for index pIdx. A column affinity string has one character
** for each column in the table, according to the affinity of the column:

  ** counterRowid.
  */
  if( pTab->autoInc ){
    int iCur = pParse->nTab;
    int base = sqlite3VdbeCurrentAddr(v);
    counterRowid = pParse->nMem++;
    counterMem = pParse->nMem++;

    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenRead);

    sqlite3VdbeAddOp(v, OP_Rewind, iCur, base+13);
    sqlite3VdbeAddOp(v, OP_Column, iCur, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp(v, OP_Ne, 0x100, base+12);
    sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
    sqlite3VdbeAddOp(v, OP_MemStore, counterRowid, 1);
    sqlite3VdbeAddOp(v, OP_Column, iCur, 1);

  /* Update the sqlite_sequence table by storing the content of the
  ** counter value in memory counterMem back into the sqlite_sequence
  ** table.
  */
  if( pTab->autoInc ){
    int iCur = pParse->nTab;
    int base = sqlite3VdbeCurrentAddr(v);

    sqlite3OpenTable(pParse, iCur, iDb, pDb->pSchema->pSeqTab, OP_OpenWrite);

    sqlite3VdbeAddOp(v, OP_MemLoad, counterRowid, 0);
    sqlite3VdbeAddOp(v, OP_NotNull, -1, base+7);
    sqlite3VdbeAddOp(v, OP_Pop, 1, 0);
    sqlite3VdbeAddOp(v, OP_NewRowid, iCur, 0);
    sqlite3VdbeOp3(v, OP_String8, 0, 0, pTab->zName, 0);
    sqlite3VdbeAddOp(v, OP_MemLoad, counterMem, 0);
    sqlite3VdbeAddOp(v, OP_MakeRecord, 2, 0);

  int op           /* OP_OpenRead or OP_OpenWrite */
){
  int i;
  int iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  Index *pIdx;
  Vdbe *v = sqlite3GetVdbe(pParse);
  assert( v!=0 );


  sqlite3OpenTable(pParse, base, iDb, pTab, op);

  for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
    assert( pIdx->pSchema==pTab->pSchema );
    sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
    VdbeComment((v, "# %s", pIdx->zName));
    sqlite3VdbeOp3(v, op, i+base, pIdx->tnum,
                   (char*)&pIdx->keyInfo, P3_KEYINFO);
  }
  if( pParse->nTab<=base+i ){
    pParse->nTab = base+i;
  }
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle SELECT statements in SQLite.
**
** $Id: select.c,v 1.286 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"


/*
** Allocate a new Select structure and return a pointer to that
** structure.

  }else{
    return 0;
  }
  pExpr = pList->a[0].pExpr;
  if( pExpr->op!=TK_COLUMN ) return 0;
  iCol = pExpr->iColumn;
  pTab = pSrc->a[0].pTab;


  /* If we get to here, it means the query is of the correct form.
  ** Check to make sure we have an index and make pIdx point to the
  ** appropriate index.  If the min() or max() is on an INTEGER PRIMARY
  ** key column, no index is necessary so set pIdx to NULL.  If no
  ** usable index is found, return 0.
  */

  /* Generating code to find the min or the max.  Basically all we have
  ** to do is find the first or the last entry in the chosen index.  If
  ** the min() or max() is on the INTEGER PRIMARY KEY, then find the first
  ** or last entry in the main table.
  */
  iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
  sqlite3CodeVerifySchema(pParse, iDb);
  sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
  base = pSrc->a[0].iCursor;
  brk = sqlite3VdbeMakeLabel(v);
  computeLimitRegisters(pParse, p, brk);
  if( pSrc->a[0].pSelect==0 ){
    sqlite3OpenTable(pParse, base, iDb, pTab, OP_OpenRead);
  }
  if( pIdx==0 ){
    sqlite3VdbeAddOp(v, seekOp, base, 0);
  }else{
    /* Even though the cursor used to open the index here is closed
    ** as soon as a single value has been read from it, allocate it
    ** using (pParse->nTab++) to prevent the cursor id from being 

/*
** 2001 September 15
**
** 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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.453 2006/01/07 13:21:04 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Extra interface definitions for those who need them
*/

** pointer arithmetic.
*/
#define Addr(X)  ((uptr)X)

#ifdef SQLITE_MEMDEBUG
/*
** The following global variables are used for testing and debugging
** only.  They only work if SQLITE_MEMDEBUG is defined.
*/
extern int sqlite3_nMalloc;      /* Number of sqliteMalloc() calls */
extern int sqlite3_nFree;        /* Number of sqliteFree() calls */
extern int sqlite3_iMallocFail;  /* Fail sqliteMalloc() after this many calls */
extern int sqlite3_iMallocReset; /* Set iMallocFail to this when it reaches 0 */
#define ENTER_MALLOC (\
  sqlite3Tsd()->zFile = __FILE__, sqlite3Tsd()->iLine = __LINE__ \
)
#define sqliteMalloc(x)          (ENTER_MALLOC, sqlite3Malloc(x))
#define sqliteMallocRaw(x)       (ENTER_MALLOC, sqlite3MallocRaw(x))
#define sqliteRealloc(x,y)       (ENTER_MALLOC, sqlite3Realloc(x,y))
#define sqliteStrDup(x)          (ENTER_MALLOC, sqlite3StrDup(x))
#define sqliteStrNDup(x,y)       (ENTER_MALLOC, sqlite3StrNDup(x,y))
#define sqliteReallocOrFree(x,y) (ENTER_MALLOC, sqlite3ReallocOrFree(x,y))

#else

#define sqliteMalloc(x)          sqlite3Malloc(x)
#define sqliteMallocRaw(x)       sqlite3MallocRaw(x)
#define sqliteRealloc(x,y)       sqlite3Realloc(x,y)
#define sqliteStrDup(x)          sqlite3StrDup(x)
#define sqliteStrNDup(x,y)       sqlite3StrNDup(x,y)
#define sqliteReallocOrFree(x,y) sqlite3ReallocOrFree(x,y)

#endif

#define sqliteFree(x)          sqlite3FreeX(x)
#define sqliteAllocSize(x)     sqlite3AllocSize(x)

/*

typedef struct KeyInfo KeyInfo;
typedef struct NameContext NameContext;
typedef struct Parse Parse;
typedef struct Select Select;
typedef struct SrcList SrcList;
typedef struct SqliteTsd SqliteTsd;
typedef struct Table Table;
typedef struct TableLock TableLock;
typedef struct Token Token;
typedef struct TriggerStack TriggerStack;
typedef struct TriggerStep TriggerStep;
typedef struct Trigger Trigger;
typedef struct WhereInfo WhereInfo;
typedef struct WhereLevel WhereLevel;

** the parser and down into all the parser action routine in order to
** carry around information that is global to the entire parse.
**
** The structure is divided into two parts.  When the parser and code
** generate call themselves recursively, the first part of the structure
** is constant but the second part is reset at the beginning and end of
** each recursion.
**
** The nTableLock and aTableLock variables are only used if the shared-cache 
** feature is enabled (if sqlite3Tsd()->useSharedData is true). They are
** used to store the set of table-locks required by the statement being
** compiled. Function sqlite3TableLock() is used to add entries to the
** list.
*/
struct Parse {
  sqlite3 *db;         /* The main database structure */
  int rc;              /* Return code from execution */
  char *zErrMsg;       /* An error message */
  Vdbe *pVdbe;         /* An engine for executing database bytecode */
  u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
  u8 nameClash;        /* A permanent table name clashes with temp table name */
  u8 checkSchema;      /* Causes schema cookie check after an error */
  u8 nested;           /* Number of nested calls to the parser/code generator */
  int nErr;            /* Number of errors seen */
  int nTab;            /* Number of previously allocated VDBE cursors */
  int nMem;            /* Number of memory cells used so far */
  int nSet;            /* Number of sets used so far */
  int ckOffset;        /* Stack offset to data used by CHECK constraints */
  u32 writeMask;       /* Start a write transaction on these databases */
  u32 cookieMask;      /* Bitmask of schema verified databases */
  int cookieGoto;      /* Address of OP_Goto to cookie verifier subroutine */
  int cookieValue[MAX_ATTACHED+2];  /* Values of cookies to verify */
#ifndef SQLITE_OMIT_SHARED_CACHE
  int nTableLock;        /* Number of locks in aTableLock */
  TableLock *aTableLock; /* Required table locks for shared-cache mode */
#endif

  /* Above is constant between recursions.  Below is reset before and after
  ** each recursion */

  int nVar;            /* Number of '?' variables seen in the SQL so far */
  int nVarExpr;        /* Number of used slots in apVarExpr[] */
  int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */

int sqlite3InitCallback(void*, int, char**, char**);
void sqlite3Pragma(Parse*,Token*,Token*,Token*,int);
void sqlite3ResetInternalSchema(sqlite3*, int);
void sqlite3BeginParse(Parse*,int);
void sqlite3RollbackInternalChanges(sqlite3*);
void sqlite3CommitInternalChanges(sqlite3*);
Table *sqlite3ResultSetOfSelect(Parse*,char*,Select*);
void sqlite3OpenMasterTable(Parse *, int);
void sqlite3StartTable(Parse*,Token*,Token*,Token*,int,int,int);
void sqlite3AddColumn(Parse*,Token*);
void sqlite3AddNotNull(Parse*, int);
void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int, int);
void sqlite3AddCheckConstraint(Parse*, Expr*);
void sqlite3AddColumnType(Parse*,Token*);
void sqlite3AddDefaultValue(Parse*,Expr*);

int sqlite3Select(Parse*, Select*, int, int, Select*, int, int*, char *aff);
Select *sqlite3SelectNew(ExprList*,SrcList*,Expr*,ExprList*,Expr*,ExprList*,
                        int,Expr*,Expr*);
void sqlite3SelectDelete(Select*);
void sqlite3SelectUnbind(Select*);
Table *sqlite3SrcListLookup(Parse*, SrcList*);
int sqlite3IsReadOnly(Parse*, Table*, int);
void sqlite3OpenTable(Parse*, int iCur, int iDb, Table*, int);

void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, ExprList**);
void sqlite3WhereEnd(WhereInfo*);
void sqlite3ExprCode(Parse*, Expr*);
void sqlite3ExprCodeAndCache(Parse*, Expr*);
int sqlite3ExprCodeExprList(Parse*, ExprList*);

int sqlite3IsLikeFunction(sqlite3*,Expr*,int*,char*);
SqliteTsd *sqlite3Tsd();
void sqlite3AttachFunctions(sqlite3 *);
void sqlite3MinimumFileFormat(Parse*, int, int);
void sqlite3SchemaFree(void *);
DbSchema *sqlite3SchemaGet(Btree *);
int sqlite3SchemaToIndex(sqlite3 *db, DbSchema *);

#ifndef SQLITE_OMIT_SHARED_CACHE
  void sqlite3TableLock(Parse *, int, int, u8, const char *);
#else
  #define sqlite3TableLock(v,w,x,y,z)
#endif

void sqlite3MallocClearFailed();
#ifdef NDEBUG
  #define sqlite3MallocDisallow()
  #define sqlite3MallocAllow()
#else
  void sqlite3MallocDisallow();

*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
** $Id: tokenize.c,v 1.111 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*

    pParse->zErrMsg = 0;
    if( !nErr ) nErr++;
  }
  if( pParse->pVdbe && pParse->nErr>0 && pParse->nested==0 ){
    sqlite3VdbeDelete(pParse->pVdbe);
    pParse->pVdbe = 0;
  }
#ifndef SQLITE_OMIT_SHARED_CACHE
  if( pParse->nested==0 ){
    sqliteFree(pParse->aTableLock);
    pParse->aTableLock = 0;
    pParse->nTableLock = 0;
  }
#endif
  sqlite3DeleteTable(pParse->db, pParse->pNewTable);
  sqlite3DeleteTrigger(pParse->pNewTrigger);
  sqliteFree(pParse->apVarExpr);
  if( nErr>0 && (pParse->rc==SQLITE_OK || pParse->rc==SQLITE_DONE) ){
    pParse->rc = SQLITE_ERROR;
  }
  return nErr;
}

    int addr;
    Vdbe *v;

    /* Make an entry in the sqlite_master table */
    v = sqlite3GetVdbe(pParse);
    if( v==0 ) goto triggerfinish_cleanup;
    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    addr = sqlite3VdbeAddOpList(v, ArraySize(insertTrig), insertTrig);
    sqlite3VdbeChangeP3(v, addr+2, pTrig->name, 0); 
    sqlite3VdbeChangeP3(v, addr+3, pTrig->table, 0); 
    sqlite3VdbeChangeP3(v, addr+6, (char*)pAll->z, pAll->n);
    sqlite3ChangeCookie(db, v, iDb);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0, 

      { OP_Column,     0, 0,        0},
      { OP_Ne,         0, ADDR(8),  0},
      { OP_Delete,     0, 0,        0},
      { OP_Next,       0, ADDR(1),  0}, /* 8 */
    };

    sqlite3BeginWriteOperation(pParse, 0, iDb);
    sqlite3OpenMasterTable(pParse, iDb);
    base = sqlite3VdbeAddOpList(v,  ArraySize(dropTrigger), dropTrigger);
    sqlite3VdbeChangeP3(v, base+1, pTrigger->name, 0);
    sqlite3ChangeCookie(db, v, iDb);
    sqlite3VdbeAddOp(v, OP_Close, 0, 0);
    sqlite3VdbeOp3(v, OP_DropTrigger, iDb, 0, pTrigger->name, 0);
  }
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.116 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The most recently coded instruction was an OP_Column to retrieve the
** i-th column of table pTab. This routine sets the P3 parameter of the 
** OP_Column to the default value, if any.

    if( !isView ){
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      sqlite3VdbeAddOp(v, OP_Dup, 0, 0);
      /* Open a cursor and make it point to the record that is
      ** being updated.
      */
      sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenRead);
    }
    sqlite3VdbeAddOp(v, OP_MoveGe, iCur, 0);

    /* Generate the OLD table
    */
    sqlite3VdbeAddOp(v, OP_Rowid, iCur, 0);
    sqlite3VdbeAddOp(v, OP_RowData, iCur, 0);

  if( !isView ){
    /* 
    ** Open every index that needs updating.  Note that if any
    ** index could potentially invoke a REPLACE conflict resolution 
    ** action, then we need to open all indices because we might need
    ** to be deleting some records.
    */

    sqlite3OpenTable(pParse, iCur, iDb, pTab, OP_OpenWrite); 

    if( onError==OE_Replace ){
      openAll = 1;
    }else{
      openAll = 0;
      for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
        if( pIdx->onError==OE_Replace ){
          openAll = 1;

**
** Various scripts scan this source file in order to generate HTML
** documentation, headers files, or other derived files.  The formatting
** of the code in this file is, therefore, important.  See other comments
** 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 1.514 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

    sqlite3ExpirePreparedStatements(db);
  }else{
    p->expired = 1;
  }
  break;
}

#ifndef SQLITE_OMIT_SHARED_CACHE
/* Opcode: TableLock P1 P2 P3
**
** Obtain a lock on a particular table. This instruction is only used when
** the shared-cache feature is enabled. 
**
** If P1 is not negative, then it is the index of the index of the database
** in sqlite3.aDb[] and a read-lock is required. If P1 is negative, a 
** write-lock is required. In this case the index of the database is the 
** absolute value of P1 minus one (iDb = abs(P1) - 1;) and a write-lock is
** required. 
**
** P2 contains the root-page of the table to lock.
**
** P3 contains a pointer to the name of the table being locked. This is only
** used to generate an error message if the lock cannot be obtained.
*/
case OP_TableLock: {        /* no-push */
  int p1 = pOp->p1; 
  u8 isWriteLock = (p1<0);
  if( isWriteLock ){
    p1 = (-1*p1)-1;
  }
  rc = sqlite3BtreeLockTable(db->aDb[p1].pBt, pOp->p2, isWriteLock);
  if( rc==SQLITE_LOCKED ){
    const char *z = (const char *)pOp->p3;
    sqlite3SetString(&p->zErrMsg, "database table is locked: ", z, (char*)0);
  }
  break;
}
#endif /* SHARED_OMIT_SHARED_CACHE */

/* An other opcode is illegal...
*/
default: {
  assert( 0 );
  break;
}

** This module contains C code that generates VDBE code used to process
** the WHERE clause of SQL statements.  This module is reponsible for
** generating the code that loops through a table looking for applicable
** rows.  Indices are selected and used to speed the search when doing
** so is applicable.  Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.191 2006/01/07 13:21:04 danielk1977 Exp $
*/
#include "sqliteInt.h"

/*
** The number of bits in a Bitmask.  "BMS" means "BitMask Size".
*/
#define BMS  (sizeof(Bitmask)*8)

    }
#endif /* SQLITE_OMIT_EXPLAIN */
    pTabItem = &pTabList->a[pLevel->iFrom];
    pTab = pTabItem->pTab;
    iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
    if( pTab->isTransient || pTab->pSelect ) continue;
    if( (pLevel->flags & WHERE_IDX_ONLY)==0 ){
      sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, OP_OpenRead);
    }else{
      sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
    }
    pLevel->iTabCur = pTabItem->iCursor;
    if( (pIx = pLevel->pIdx)!=0 ){
      assert( pIx->pSchema==pTab->pSchema );
      sqlite3VdbeAddOp(v, OP_Integer, iDb, 0);
      VdbeComment((v, "# %s", pIx->zName));
      sqlite3VdbeOp3(v, OP_OpenRead, iIdxCur, pIx->tnum,

# 2005 December 30
#
# 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.  The
# focus of this file is testing the SELECT statement.
#
# $Id: shared.test,v 1.6 2006/01/07 13:21:04 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl
db close

ifcapable !shared_cache {
  finish_test

# shared-2.*: Test that a read transaction can co-exist with a 
#             write-transaction, including a simple test to ensure the 
#             external locking protocol is still working.
# shared-3.*: Simple test of read-uncommitted mode.
# shared-4.*: Check that the schema is locked and unlocked correctly.
# shared-5.*: Test that creating/dropping schema items works when databases
#             are attached in different orders to different handles.
# shared-6.*: Locking, UNION ALL queries and sub-queries.
#

do_test shared-1.1 {
  # Open a second database on the file test.db. It should use the same pager
  # cache and schema as the original connection. Verify that only 1 file is 
  # opened.
  sqlite3 db2 test.db

do_test shared-1.4 {
  # Try to insert a row into abc via connection 2. This should fail because
  # of the read-lock connection 1 is holding on table abc (obtained in the
  # previous test case).
  catchsql {
    INSERT INTO abc VALUES(4, 5, 6);
  } db2
} {1 {database table is locked: abc}}
do_test shared-1.5 {
  # Using connection 2 (the one without the open transaction), try to create
  # a new table. This should fail because of the open read transaction 
  # held by connection 1.
  catchsql {
    CREATE TABLE def(d, e, f);
  } db2
} {1 {database table is locked: sqlite_master}}
do_test shared-1.6 {
  # Upgrade connection 1's transaction to a write transaction. Create
  # a new table - def - and insert a row into it. Because the connection 1
  # transaction modifies the schema, it should not be possible for 
  # connection 2 to access the database at all until the connection 1 
  # has finished the transaction.
  execsql {

  execsql {
    BEGIN;
    SELECT * FROM abc;
  } db2
  catchsql {
    INSERT INTO abc VALUES(1, 2, 3);
  } db2
} {1 {database table is locked: abc}}
do_test shared-2.3 {
  # Turn db's transaction into a write-transaction. db3 should still be
  # able to read from table def (but will not see the new row). Connection
  # db2 should not be able to read def (because of the write-lock).

# Todo: The failed "INSERT INTO abc ..." statement in the above test
# has started a write-transaction on db2 (should this be so?). This 

    INSERT INTO def VALUES('VII', 'VIII', 'IX');
  }
  concat [
    catchsql { SELECT * FROM def; } db3
  ] [
    catchsql { SELECT * FROM def; } db2
  ]
} {0 {IV V VI} 1 {database table is locked: def}}
do_test shared-2.4 {
  # Commit the open transaction on db. db2 still holds a read-transaction.
  # This should prevent db3 from writing to the database, but not from 
  # reading.
  execsql {
    COMMIT;
  }

    SELECT * FROM test.abc;
  } db2
} {i ii iii}
do_test shared-4.3.2 {
  catchsql {
    INSERT INTO abc VALUES('iv', 'v', 'vi');
  }
} {1 {database table is locked: abc}}
do_test shared-4.3.3 {
  catchsql {
    CREATE TABLE ghi(g, h, i);
  }
} {1 {database table is locked: sqlite_master}}
do_test shared-4.3.3 {
  catchsql {
    INSERT INTO def VALUES('IV', 'V', 'VI');
  }
} {0 {}}
do_test shared-4.3.4 {
  # Cleanup: commit the transaction opened by db2.

  } db2
} {}
do_test shared-5.1.2 {
  execsql {
    SELECT * FROM sqlite_master UNION ALL SELECT * FROM test1.sqlite_master
  } db1
} {}

#--------------------------------------------------------------------------
# Tests shared-6.* test that a query obtains all the read-locks it needs
# before starting execution of the query. This means that there is no chance
# some rows of data will be returned before a lock fails and SQLITE_LOCK
# is returned.
#
do_test shared-6.1.1 {
  execsql {
    CREATE TABLE t1(a, b);
    CREATE TABLE t2(a, b);
    INSERT INTO t1 VALUES(1, 2);
    INSERT INTO t2 VALUES(3, 4);
  } db1
  execsql {
    SELECT * FROM t1 UNION ALL SELECT * FROM t2;
  } db2
} {1 2 3 4}
do_test shared-6.1.2 {
  # Establish a write lock on table t2 via connection db2. Then make a 
  # UNION all query using connection db1 that first accesses t1, followed 
  # by t2. If the locks are grabbed at the start of the statement (as 
  # they should be), no rows are returned. If (as was previously the case)
  # they are grabbed as the tables are accessed, the t1 rows will be 
  # returned before the query fails.
  #
  execsql {
    BEGIN;
    INSERT INTO t2 VALUES(5, 6);
  } db2
  set ret [list]
  catch {
    db1 eval {SELECT * FROM t1 UNION ALL SELECT * FROM t2} {
      lappend ret $a $b
    }
  }
  set ret
} {}
do_test shared-6.1.3 {
  execsql {
    COMMIT;
    BEGIN;
    INSERT INTO t1 VALUES(7, 8);
  } db2
  set ret [list]
  catch {
    db1 eval {
      SELECT (CASE WHEN a>4 THEN (SELECT a FROM t1) ELSE 0 END) AS d FROM t2;
    } {
      lappend ret $d
    }
  }
  set ret
} {}

catch {db1 close}
catch {db2 close}

finish_test
sqlite3_enable_shared_cache $::enable_shared_cache