SQLite

/*
** 2003 Feb 4
**
** 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_rb.c,v 1.17 2003/10/22 22:15:28 drh Exp $
**
** This file implements an in-core database using Red-Black balanced
** binary trees.
** 
** It was contributed to SQLite by anonymous on 2003-Feb-04 23:24:49 UTC.
*/
#include "btree.h"

  /* Make sure some other cursor isn't trying to read this same table */
  if( checkReadLocks(pCur) ){
    return SQLITE_LOCKED; /* The table pCur points to has a read lock */
  }

  /* Take a copy of the input data now, in case we need it for the 
   * replace case */
  pData = sqliteMallocRaw(nData);
  memcpy(pData, pDataInput, nData);

  /* Move the cursor to a node near the key to be inserted. If the key already
   * exists in the table, then (match == 0). In this case we can just replace
   * the data associated with the entry, we don't need to manipulate the tree.
   * 
   * If there is no exact match, then the cursor points at what would be either
   * the predecessor (match == -1) or successor (match == 1) of the
   * searched-for key, were it to be inserted. The new node becomes a child of
   * this node.
   * 
   * The new node is initially red.
   */
  memRbtreeMoveto( pCur, pKey, nKey, &match);
  if( match ){
    BtRbNode *pNode = sqliteMalloc(sizeof(BtRbNode));
    pNode->nKey = nKey;
    pNode->pKey = sqliteMallocRaw(nKey);
    memcpy(pNode->pKey, pKey, nKey);
    pNode->nData = nData;
    pNode->pData = pData; 
    if( pCur->pNode ){
      switch( match ){
        case -1:
          assert( !pCur->pNode->pRight );

    /* Set up a rollback-op in case we have to roll this operation back */
    if( pCur->pRbtree->eTransState != TRANS_ROLLBACK ){
      BtRollbackOp *pOp = sqliteMalloc( sizeof(BtRollbackOp) );
      pOp->eOp = ROLLBACK_DELETE;
      pOp->iTab = pCur->iTree;
      pOp->nKey = pNode->nKey;
      pOp->pKey = sqliteMallocRaw( pOp->nKey );
      memcpy( pOp->pKey, pNode->pKey, pOp->nKey );
      btreeLogRollbackOp(pCur->pRbtree, pOp);
    }

  }else{ 
    /* No need to insert a new node in the tree, as the key already exists.
     * Just clobber the current nodes data. */

    /* Set up a rollback-op in case we have to roll this operation back */
    if( pCur->pRbtree->eTransState != TRANS_ROLLBACK ){
      BtRollbackOp *pOp = sqliteMalloc( sizeof(BtRollbackOp) );
      pOp->iTab = pCur->iTree;
      pOp->nKey = pCur->pNode->nKey;
      pOp->pKey = sqliteMallocRaw( pOp->nKey );
      memcpy( pOp->pKey, pCur->pNode->pKey, pOp->nKey );
      pOp->nData = pCur->pNode->nData;
      pOp->pData = pCur->pNode->pData;
      pOp->eOp = ROLLBACK_INSERT;
      btreeLogRollbackOp(pCur->pRbtree, pOp);
    }else{
      sqliteFree( pCur->pNode->pData );

    }
    else {
      BtRbNode *pTmp = pNode->pParent;
      if( tree->eTransState == TRANS_ROLLBACK ){
        sqliteFree( pNode->pKey );
        sqliteFree( pNode->pData );
      }else{
        BtRollbackOp *pRollbackOp = sqliteMallocRaw(sizeof(BtRollbackOp));
        pRollbackOp->eOp = ROLLBACK_INSERT;
        pRollbackOp->iTab = n;
        pRollbackOp->nKey = pNode->nKey;
        pRollbackOp->pKey = pNode->pKey;
        pRollbackOp->nData = pNode->nData;
        pRollbackOp->pData = pNode->pData;
        btreeLogRollbackOp(tree, pRollbackOp);

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.68 2003/10/22 22:15:28 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

/*
** If malloc() ever fails, this global variable gets set to 1.

/*
** Allocate new memory and set it to zero.  Return NULL if
** no memory is available.  See also sqliteMallocRaw().
*/
void *sqliteMalloc(int n){
  void *p;

  if( (p = malloc(n))==0 ){

    sqlite_malloc_failed++;

  }else{
    memset(p, 0, n);
  }
  return p;
}

/*
** Allocate new memory but do not set it to zero.  Return NULL if
** no memory is available.  See also sqliteMalloc().
*/
void *sqliteMallocRaw(int n){
  void *p;

  if( (p = malloc(n))==0 ){

    sqlite_malloc_failed++;

  }
  return p;
}

/*
** Free memory previously obtained from sqliteMalloc()
*/

#define YY_ERROR_ACTION   (YYNSTATE+YYNRULE)

/* Next are that tables used to determine what action to take based on the
** current state and lookahead token.  These tables are used to implement
** functions that take a state number and lookahead value and return an
** action integer.  
**
** Suppose the action integer is N.  Then the action is determined as
** follows
**
**   0 <= N < YYNSTATE                  Shift N.  That is, push the lookahead
**                                      token onto the stack and goto state N.
**
**   YYNSTATE <= N < YYNSTATE+YYNRULE   Reduce by rule N-YYNSTATE.
**
**   N == YYNSTATE+YYNRULE              A syntax error has occurred.
**
**   N == YYNSTATE+YYNRULE+1            The parser accepts its input.
**
**   N == YYNSTATE+YYNRULE+2            No such action.  Denotes unused
**                                      slots in the yy_action[] table.
**
** The action table is constructed as a single large table named yy_action[].
** Given state S and lookahead X, the action is computed as

**
**      yy_action[ yy_shift_ofst[S] + X ]
**
** If the index value yy_shift_ofst[S]+X is out of range or if the value
** yy_lookahead[yy_shift_ofst[S]+X] is not equal to X or if yy_shift_ofst[S]
** is equal to YY_SHIFT_USE_DFLT, it means that the action is not in the table
** and that yy_default[S] should be used instead.  
**
** The formula above is for computing the action when the lookahead is
** a terminal symbol.  If the lookahead is a non-terminal (as occurs after
** a reduce action) then the yy_reduce_ofst[] array is used in place of

#
# Run this TCL script to generate HTML for the index.html file.
#
set rcsid {$Id: index.tcl,v 1.79 2003/10/22 22:15:28 drh Exp $}

puts {<html>
<head><title>SQLite: An Embeddable SQL Database Engine</title></head>
<body bgcolor=white>
<h1 align=center>SQLite<br>An Embeddable SQL Database Engine</h1>
<p align=center>}
puts "This page was last modified on [lrange $rcsid 3 4] UTC<br>"

    Bindings for many other languages 
    <a href="http://www.sqlite.org/cvstrac/wiki?p=SqliteWrappers">
    available separately.</a></li>
<li>Simple, well-commented source code.</li>
<li>Automated test suite provides near 100% code coverage.</li>
<li>Self-contained: no external dependencies.</li>
<li>Built and tested under Linux and Windows.</li>
<li>Sources are in the <a href="copyright.html">public domain</a>.
    Use for any purpose.</li>
</ul>
</p>
}

puts {<h2>Current Status</h2>

<p>A <a href="changes.html">Change Summary</a> is available on this

<p>The SQLite source code is 30% comment.  These comments are
another important source of information.  </p>

}

puts {







<a name="mailinglist" />
<h2>Mailing List</h2>
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SQLite design issues or for asking questions about SQLite.
To subscribe send an email to
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If you would prefer to get digests rather than individual
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For additional information about operating and using this
mailing list, send a message to
<a href="mailto:sqlite-users-help@sqlite.org">
sqlite-users-help@sqlite.org</a> and instructions will be
sent by to you by return email.
</p>
}

puts {<h2>Professional Support and Custom Modifications</h2>}

puts {
<p>
If you would like professional support for SQLite