SQLite

/*
** 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 1.205 2004/11/05 00:43:12 drh 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.

/*
** Erase all information in a table and add the root of the table to
** the freelist.  Except, the root of the principle table (the one on
** page 1) is never added to the freelist.
**
** This routine will fail with SQLITE_LOCKED if there are any open
** cursors on the table.
**
** If AUTOVACUUM is enabled and the page at iTable is not the last
** root page in the database file, then the last root page 
** in the database file is moved into the slot formerly occupied by
** iTable and that last slot formerly occupied by the last root page
** is added to the freelist instead of iTable.  In this say, all
** root pages are kept at the beginning of the database file, which
** is necessary for AUTOVACUUM to work right.  *piMoved is set to the 
** page number that used to be the last root page in the file before
** the move.  If no page gets moved, *piMoved is set to 0.
** The last root page is recorded in meta[3] and the value of
** meta[3] is updated by this procedure.
*/
int sqlite3BtreeDropTable(Btree *pBt, int iTable, int *piMoved){
  int rc;
  MemPage *pPage = 0;
  BtCursor *pCur;

  if( pBt->inTrans!=TRANS_WRITE ){

  }

  rc = getPage(pBt, (Pgno)iTable, &pPage);
  if( rc ) return rc;
  rc = sqlite3BtreeClearTable(pBt, iTable);
  if( rc ) return rc;

  *piMoved = 0;

  if( iTable>1 ){
#ifdef SQLITE_OMIT_AUTOVACUUM
    rc = freePage(pPage);
    releasePage(pPage);
#else
    if( pBt->autoVacuum ){

  assert( idx>=0 && idx<=15 );
  rc = sqlite3pager_get(pBt->pPager, 1, (void**)&pP1);
  if( rc ) return rc;
  *pMeta = get4byte(&pP1[36 + idx*4]);
  sqlite3pager_unref(pP1);

  /* If autovacuumed is disabled in the implementation but we are
  ** trying to access an autovacuumed database, then make the
  ** database readonly. */
#ifdef SQLITE_OMIT_AUTOVACUUM
  if( idx==4 && *pMeta>0 ) pBt->readOnly = 1;
#endif

  return SQLITE_OK;
}

**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**     PRAGMA
**
** $Id: build.c,v 1.261 2004/11/05 00:43:12 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Check to see if the schema for the database needs

** no VDBE code was generated.
*/
void sqlite3FinishCoding(Parse *pParse){
  sqlite3 *db;
  Vdbe *v;

  if( sqlite3_malloc_failed ) return;
  if( pParse->nested ) return;

  /* Begin by generating some termination code at the end of the
  ** vdbe program
  */
  db = pParse->db;
  v = sqlite3GetVdbe(pParse);
  if( v ){

  pParse->nMem = 0;
  pParse->nSet = 0;
  pParse->nAgg = 0;
  pParse->nVar = 0;
  pParse->cookieMask = 0;
  pParse->cookieGoto = 0;
}

/*
** Run the parser and code generator recursively in order to generate
** code for the SQL statement given onto the end of the pParse context
** currently under construction.  When the parser is run recursively
** this way, the final OP_Halt is not appended and other initialization
** and finalization steps are omitted because those are handling by the
** outermost parser.
**
** Not everything is nestable.  This facility is designed to permit
** INSERT, UPDATE, and DELETE operations against SQLITE_MASTER.  Use
** care if you decide to try to use this routine for some other purpose.
*/
void sqlite3NestedParse(Parse *pParse, const char *zFormat, ...){
  va_list ap;
  char *zSql;
  int rc;
  Parse savedState;
  if( pParse->nErr ) return;
  assert( pParse->nested<10 );  /* Nesting should only be of limited depth */
  va_start(ap, zFormat);
  zSql = sqlite3VMPrintf(zFormat, ap);
  va_end(ap);
  pParse->nested++;
  savedState = *pParse;
  rc = sqlite3RunParser(pParse, zSql, 0);
  sqliteFree(zSql);
  pParse->nested--;
}

/*
** Locate the in-memory structure that describes a particular database
** table given the name of that table and (optionally) the name of the
** database containing the table.  Return NULL if not found.
**
** If zDatabase is 0, all databases are searched for the table and the

** field of the table under construction to be the index of the
** INTEGER PRIMARY KEY column.  Table.iPKey is set to -1 if there is
** no INTEGER PRIMARY KEY.
**
** If the key is not an INTEGER PRIMARY KEY, then create a unique
** index for the key.  No index is created for INTEGER PRIMARY KEYs.
*/
void sqlite3AddPrimaryKey(
  Parse *pParse,    /* Parsing context */
  ExprList *pList,  /* List of field names to be indexed */
  int onError,      /* What to do with a uniqueness conflict */
  int autoInc       /* True if the AUTOINCREMENT keyword is present */
){
  Table *pTab = pParse->pNewTable;
  char *zType = 0;
  int iCol = -1, i;
  if( pTab==0 ) goto primary_key_exit;
  if( pTab->hasPrimKey ){
    sqlite3ErrorMsg(pParse, 
      "table \"%s\" has more than one primary key", pTab->zName);

  }
  if( iCol>=0 && iCol<pTab->nCol ){
    zType = pTab->aCol[iCol].zType;
  }
  if( zType && sqlite3StrICmp(zType, "INTEGER")==0 ){
    pTab->iPKey = iCol;
    pTab->keyConf = onError;
    pTab->autoInc = autoInc;
  }else if( autoInc ){
    sqlite3ErrorMsg(pParse, "AUTOINCREMENT is only allowed on an "
       "INTEGER PRIMARY KEY");
  }else{
    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0);
    pList = 0;
  }

primary_key_exit:
  sqlite3ExprListDelete(pList);

**    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 DELETE FROM statements.
**
** $Id: delete.c,v 1.86 2004/11/05 00:43:12 drh 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.

/*
** Check to make sure the given table is writable.  If it is not
** writable, generate an error message and return 1.  If it is
** writable return 0;
*/
int sqlite3IsReadOnly(Parse *pParse, Table *pTab, int viewOk){
  if( pTab->readOnly && (pParse->db->flags & SQLITE_WriteSchema)==0
        && pParse->nested==0 ){
    sqlite3ErrorMsg(pParse, "table %s may not be modified", pTab->zName);
    return 1;
  }
  if( !viewOk && pTab->pSelect ){
    sqlite3ErrorMsg(pParse,"cannot modify %s because it is a view",pTab->zName);
    return 1;
  }

**
*************************************************************************
** This file contains SQLite's grammar for SQL.  Process this file
** using the lemon parser generator to generate C code that runs
** the parser.  Lemon will also generate a header file containing
** numeric codes for all of the tokens.
**
** @(#) $Id: parse.y,v 1.148 2004/11/05 00:43:12 drh Exp $
*/
%token_prefix TK_
%token_type {Token}
%default_type {Token}
%extra_argument {Parse *pParse}
%syntax_error {
  if( pParse->zErrMsg==0 ){

carg ::= DEFAULT NULL. 

// In addition to the type name, we also care about the primary key and
// UNIQUE constraints.
//
ccons ::= NULL onconf.
ccons ::= NOT NULL onconf(R).               {sqlite3AddNotNull(pParse, R);}
ccons ::= PRIMARY KEY sortorder onconf(R) autoinc(I).
                                     {sqlite3AddPrimaryKey(pParse,0,R,I);}
ccons ::= UNIQUE onconf(R).          {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0);}
ccons ::= CHECK LP expr RP onconf.
ccons ::= REFERENCES nm(T) idxlist_opt(TA) refargs(R).
                                {sqlite3CreateForeignKey(pParse,0,&T,TA,R);}
ccons ::= defer_subclause(D).   {sqlite3DeferForeignKey(pParse,D);}
ccons ::= COLLATE id(C).  {sqlite3AddCollateType(pParse, C.z, C.n);}

// The optional AUTOINCREMENT keyword
%type autoinc {int}
autoinc(X) ::= .         {X = 0;}
autoinc(X) ::= AUTOINC.  {X = 1;}

// The next group of rules parses the arguments to a REFERENCES clause
// that determine if the referential integrity checking is deferred or
// or immediate and which determine what action to take if a ref-integ
// check fails.
//
%type refargs {int}

//
conslist_opt ::= .
conslist_opt ::= COMMA conslist.
conslist ::= conslist COMMA tcons.
conslist ::= conslist tcons.
conslist ::= tcons.
tcons ::= CONSTRAINT nm.
tcons ::= PRIMARY KEY LP idxlist(X) RP onconf(R) autoinc(I).
                                         {sqlite3AddPrimaryKey(pParse,X,R,I);}
tcons ::= UNIQUE LP idxlist(X) RP onconf(R).
                                       {sqlite3CreateIndex(pParse,0,0,0,X,R,0,0);}
tcons ::= CHECK expr onconf.
tcons ::= FOREIGN KEY LP idxlist(FA) RP
          REFERENCES nm(T) idxlist_opt(TA) refargs(R) defer_subclause_opt(D). {
    sqlite3CreateForeignKey(pParse, FA, &T, TA, R);
    sqlite3DeferForeignKey(pParse, D);

/*
** 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 1.331 2004/11/05 00:43:12 drh Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** These #defines should enable >2GB file support on Posix if the
** underlying operating system supports it.  If the OS lacks

  int tnum;        /* Root BTree node for this table (see note above) */
  Select *pSelect; /* NULL for tables.  Points to definition if a view. */
  u8 readOnly;     /* True if this table should not be written by the user */
  u8 iDb;          /* Index into sqlite.aDb[] of the backend for this table */
  u8 isTransient;  /* True if automatically deleted when VDBE finishes */
  u8 hasPrimKey;   /* True if there exists a primary key */
  u8 keyConf;      /* What to do in case of uniqueness conflict on iPKey */
  u8 autoInc;      /* True if the integer primary key is autoincrement */
  Trigger *pTrigger; /* List of SQL triggers on this table */
  FKey *pFKey;       /* Linked list of all foreign keys in this table */
  char *zColAff;     /* String defining the affinity of each column */
};

/*
** Each foreign key constraint is an instance of the following structure.

  Vdbe *pVdbe;         /* An engine for executing database bytecode */
  u8 colNamesSet;      /* TRUE after OP_ColumnName has been issued to pVdbe */
  u8 explain;          /* True if the EXPLAIN flag is found on the query */
  u8 nameClash;        /* A permanent table name clashes with temp table name */
  u8 useAgg;           /* If true, extract field values from the aggregator
                       ** while generating expressions.  Normally false */
  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 nAgg;            /* Number of aggregate expressions */
  int nVar;            /* Number of '?' variables seen in the SQL so far */
  int nVarExpr;        /* Number of used slots in apVarExpr[] */

void sqlite3RollbackInternalChanges(sqlite3*);
void sqlite3CommitInternalChanges(sqlite3*);
Table *sqlite3ResultSetOfSelect(Parse*,char*,Select*);
void sqlite3OpenMasterTable(Vdbe *v, int);
void sqlite3StartTable(Parse*,Token*,Token*,Token*,int,int);
void sqlite3AddColumn(Parse*,Token*);
void sqlite3AddNotNull(Parse*, int);
void sqlite3AddPrimaryKey(Parse*, ExprList*, int, int);
void sqlite3AddColumnType(Parse*,Token*,Token*);
void sqlite3AddDefaultValue(Parse*,Token*,int);
void sqlite3AddCollateType(Parse*, const char*, int);
void sqlite3EndTable(Parse*,Token*,Select*);

#ifndef SQLITE_OMIT_VIEW
  void sqlite3CreateView(Parse*,Token*,Token*,Token*,Select*,int);

void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
WhereInfo *sqlite3WhereBegin(Parse*, SrcList*, Expr*, int, ExprList**);
void sqlite3WhereEnd(WhereInfo*);
void sqlite3ExprCode(Parse*, Expr*);
int sqlite3ExprCodeExprList(Parse*, ExprList*);
void sqlite3ExprIfTrue(Parse*, Expr*, int, int);
void sqlite3ExprIfFalse(Parse*, Expr*, int, int);
void sqlite3NextedParse(Parse*, const char*, ...);
Table *sqlite3FindTable(sqlite3*,const char*, const char*);
Table *sqlite3LocateTable(Parse*,const char*, const char*);
Index *sqlite3FindIndex(sqlite3*,const char*, const char*);
void sqlite3UnlinkAndDeleteTable(sqlite3*,int,const char*);
void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
void sqlite3Vacuum(Parse*, Token*);
int sqlite3RunVacuum(char**, sqlite3*);

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.56 2004/11/05 00:43:12 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "btree.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int argc,              /* Number of arguments */
  const char **argv      /* Text of each argument */
){
  Btree *pBt;
  int iTable;
  int rc;
  int notUsed1;
  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  rc = sqlite3BtreeDropTable(pBt, iTable, &notUsed1);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

**
** 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 1.424 2004/11/05 00:43:12 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include "vdbeInt.h"

/*

    }
  }
  Release(pTos);
  pTos--;
  break;
}

/* Opcode: NewRecno P1 P2 *
**
** Get a new integer record number used as the key to a table.
** The record number is not previously used as a key in the database
** table that cursor P1 points to.  The new record number is pushed 
** onto the stack.
**
** If P2>0 then P2 is a memory cell that holds the largest previously
** generated record number.  No new record numbers are allowed to be less
** than this value.  When this value reaches 0x7fffffff, a SQLITE_FULL
** error is generated.  The P2 memory cell is updated with the generated
** record number.  This P2 mechanism is used to help implement the
** AUTOINCREMENT feature.
*/
case OP_NewRecno: {
  int i = pOp->p1;
  i64 v = 0;
  Cursor *pC;
  assert( i>=0 && i<p->nCursor );
  assert( p->apCsr[i]!=0 );

          if( v==0x7fffffffffffffff ){
            pC->useRandomRowid = 1;
          }else{
            v++;
          }
        }
      }

#ifndef SQLITE_OMIT_AUTOINCREMENT
      if( pOp->p2 ){
        Mem *pMem;
        assert( pOp->p2>0 && pOp->p2<p->nMem );  /* P2 is a valid memory cell */
        pMem = &p->aMem[pOp->p2];
        assert( (pMem->flags & MEM_Int)!=0 );  /* mem(P2) holds an integer */
        if( pMem->i==0x7fffffffffffffff || pC->useRandomRowid ){
          rc = SQLITE_FULL;
          goto abort_due_to_error;
        }
        if( v<pMem->i+1 ){
          v = pMem->i + 1;
        }
        pMem->i = v;
      }
#endif

      if( v<0x7fffffffffffffff ){
        pC->nextRowidValid = 1;
        pC->nextRowid = v+1;
      }else{
        pC->nextRowidValid = 0;
      }
    }
    if( pC->useRandomRowid ){
      assert( pOp->p2==0 );  /* SQLITE_FULL must have occurred prior to this */
      v = db->priorNewRowid;
      cnt = 0;
      do{
        if( v==0 || cnt>2 ){
          sqlite3Randomness(sizeof(v), &v);
          if( cnt<5 ) v &= 0xffffff;
        }else{

** Delete an entire database table or index whose root page in the database
** file is given by P1.
**
** The table being destroyed is in the main database file if P2==0.  If
** P2==1 then the table to be clear is in the auxiliary database file
** that is used to store tables create using CREATE TEMPORARY TABLE.
**
** If AUTOVACUUM is enabled then it is possible that another root page
** might be moved into the newly deleted root page in order to keep all
** root pages contiguous at the beginning of the database.  The former
** value of the root page that moved - its value before the move occurred -
** is pushed onto the stack.  If no page movement was required (because
** the table being dropped was already the last one in the database) then
** a zero is pushed onto the stack.  If AUTOVACUUM is disabled at 
** then a zero is pushed onto the stack.
**
** See also: Clear
*/
case OP_Destroy: {
  int iMoved;
  rc = sqlite3BtreeDropTable(db->aDb[pOp->p2].pBt, pOp->p1, &iMoved);

  pTos++;
  pTos->flags = MEM_Int;
  pTos->i = iMoved;
#ifndef SQLITE_OMIT_AUTOVACUUM
  if( iMoved!=0 ){
    sqlite3RootPageMoved(&db->aDb[pOp->p2], iMoved, pOp->p1);
  }
#endif
  break;
}

  int i = pOp->p1;
  assert( i>=0 && i<p->nMem );
  pTos++;
  sqlite3VdbeMemShallowCopy(pTos, &p->aMem[i], MEM_Ephem);
  break;
}

#ifndef SQLITE_OMIT_AUTOINCREMENT
/* Opcode: MemMax P1 * *
**
** Set the value of memory cell P1 to the maximum of its current value
** and the value on the top of the stack.  The stack is unchanged.
**
** This instruction throws an error if the memory cell is not initially
** an integer.
*/
case OP_MemMax: {
  int i = pOp->p1;
  Mem *pMem;
  assert( pTos>=p->aStack );
  assert( i>=0 && i<p->nMem );
  pMem = &p->aMem[i];
  assert( pMem->flags==MEM_Int );
  Integerify(pTos);
  if( pMem->i<pTos->i){
    pMem->i = pTos->i;
  }
  break;
}
#endif /* SQLITE_OMIT_AUTOINCREMENT */

/* Opcode: MemIncr P1 P2 *
**
** Increment the integer valued memory cell P1 by 1.  If P2 is not zero
** and the result after the increment is greater than zero, then jump
** to P2.
**
** This instruction throws an error if the memory cell is not initially