SQLite

  $(TOP)/src/where.c

# Source code to the test files.
#
TESTSRC = \
  $(TOP)/src/test1.c \
  $(TOP)/src/test2.c \
  $(TOP)/src/test3.c \
  $(TOP)/src/md5.c

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	sqlite.h libsqlite.a sqlite 

# Generate the file "last_change" which contains the date of change

** Boston, MA  02111-1307, USA.
**
** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** $Id: btree.c,v 1.19 2001/07/01 22:12:01 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.

        if( rc ) return rc;
        memcpy(pPage, pChild, SQLITE_PAGE_SIZE);
        pPage->isInit = 0;
        initPage(pPage, sqlitepager_pagenumber(pPage), 0);
        reparentChildPages(pBt->pPager, pPage);
        freePage(pBt, pChild, pgnoChild);
        sqlitepager_unref(pChild);
      }else{
        relinkCellList(pPage);
      }
      return SQLITE_OK;
    }
    if( !pPage->isOverfull ){
      /* It is OK for the root page to be less than half full.
      */
      relinkCellList(pPage);

*/
char *sqliteBtreeSanityCheck(Btree *pBt, int *aRoot, int nRoot){
  int i;
  int nRef;
  SanityCheck sCheck;

  nRef = *sqlitepager_stats(pBt->pPager);
  if( lockBtree(pBt)!=SQLITE_OK ){
    return sqliteStrDup("Unable to acquire a read lock on the database");
  }
  sCheck.pBt = pBt;
  sCheck.pPager = pBt->pPager;
  sCheck.nPage = sqlitepager_pagecount(sCheck.pPager);
  sCheck.anRef = sqliteMalloc( (sCheck.nPage+1)*sizeof(sCheck.anRef[0]) );
  sCheck.anRef[1] = 1;
  for(i=2; i<=sCheck.nPage; i++){ sCheck.anRef[i] = 0; }
  sCheck.zErrMsg = 0;

      sprintf(zBuf, "Page %d is never used", i);
      checkAppendMsg(&sCheck, zBuf, 0);
    }
  }

  /* Make sure this analysis did not leave any unref() pages
  */
  unlockBtree(pBt);
  if( nRef != *sqlitepager_stats(pBt->pPager) ){
    char zBuf[100];
    sprintf(zBuf, 
      "Outstanding page count goes from %d to %d during this analysis",
      nRef, *sqlitepager_stats(pBt->pPager)
    );
    checkAppendMsg(&sCheck, zBuf, 0);

/*
** SQLite uses this code for testing only.  It is not a part of
** the SQLite library.  This file implements two new TCL commands
** "md5" and "md5file" that compute md5 checksums on arbitrary text
** and on complete files.  These commands are used by the "testfixture"
** program to help verify the correct operation of the SQLite library.
**
** The original use of these TCL commands was to test the ROLLBACK
** feature of SQLite.  First compute the MD5-checksum of the database.
** Then make some changes but rollback the changes rather than commit
** them.  Compute a second MD5-checksum of the file and verify that the
** two checksums are the same.  Such is the original use of this code.
** New uses may have been added since this comment was written.
*/
/*
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 */
#include <tcl.h>
#include <string.h>

/*
 * If compiled on a machine that doesn't have a 32-bit integer,
 * you just set "uint32" to the appropriate datatype for an
 * unsigned 32-bit integer.  For example:
 *
 *       cc -Duint32='unsigned long' md5.c
 *
 */
#ifndef uint32
#  define uint32 unsigned int
#endif

struct Context {
  uint32 buf[4];
  uint32 bits[2];
  unsigned char in[64];
};
typedef char MD5Context[88];

/*
 * Note: this code is harmless on little-endian machines.
 */
static void byteReverse (unsigned char *buf, unsigned longs){
	uint32 t;
	do {
		t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
		            ((unsigned)buf[1]<<8 | buf[0]);
		*(uint32 *)buf = t;
		buf += 4;
	} while (--longs);
}
/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
static void MD5Transform(uint32 buf[4], const uint32 in[16]){
	register uint32 a, b, c, d;

	a = buf[0];
	b = buf[1];
	c = buf[2];
	d = buf[3];

	MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
	MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
	MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
	MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
	MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
	MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
	MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
	MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
	MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
	MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
	MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
	MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
	MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
	MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
	MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
	MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);

	MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
	MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
	MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
	MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
	MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
	MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
	MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
	MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
	MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
	MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
	MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
	MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
	MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
	MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
	MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
	MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);

	MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
	MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
	MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
	MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
	MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
	MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
	MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
	MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
	MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
	MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
	MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
	MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
	MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
	MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
	MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
	MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);

	MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
	MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
	MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
	MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
	MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
	MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
	MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
	MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
	MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
	MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
	MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
	MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
	MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
	MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
	MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
	MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);

	buf[0] += a;
	buf[1] += b;
	buf[2] += c;
	buf[3] += d;
}

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
static void MD5Init(MD5Context *pCtx){
        struct Context *ctx = (struct Context *)pCtx;
	ctx->buf[0] = 0x67452301;
	ctx->buf[1] = 0xefcdab89;
	ctx->buf[2] = 0x98badcfe;
	ctx->buf[3] = 0x10325476;
	ctx->bits[0] = 0;
	ctx->bits[1] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
static 
void MD5Update(MD5Context *pCtx, const unsigned char *buf, unsigned int len){
        struct Context *ctx = (struct Context *)pCtx;
	uint32 t;

	/* Update bitcount */

	t = ctx->bits[0];
	if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
		ctx->bits[1]++;	/* Carry from low to high */
	ctx->bits[1] += len >> 29;

	t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */

	/* Handle any leading odd-sized chunks */

	if ( t ) {
		unsigned char *p = (unsigned char *)ctx->in + t;

		t = 64-t;
		if (len < t) {
			memcpy(p, buf, len);
			return;
		}
		memcpy(p, buf, t);
		byteReverse(ctx->in, 16);
		MD5Transform(ctx->buf, (uint32 *)ctx->in);
		buf += t;
		len -= t;
	}

	/* Process data in 64-byte chunks */

	while (len >= 64) {
		memcpy(ctx->in, buf, 64);
		byteReverse(ctx->in, 16);
		MD5Transform(ctx->buf, (uint32 *)ctx->in);
		buf += 64;
		len -= 64;
	}

	/* Handle any remaining bytes of data. */

	memcpy(ctx->in, buf, len);
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern 
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
static void MD5Final(unsigned char digest[16], MD5Context *pCtx){
        struct Context *ctx = (struct Context *)pCtx;
	unsigned count;
	unsigned char *p;

	/* Compute number of bytes mod 64 */
	count = (ctx->bits[0] >> 3) & 0x3F;

	/* Set the first char of padding to 0x80.  This is safe since there is
	   always at least one byte free */
	p = ctx->in + count;
	*p++ = 0x80;

	/* Bytes of padding needed to make 64 bytes */
	count = 64 - 1 - count;

	/* Pad out to 56 mod 64 */
	if (count < 8) {
		/* Two lots of padding:  Pad the first block to 64 bytes */
		memset(p, 0, count);
		byteReverse(ctx->in, 16);
		MD5Transform(ctx->buf, (uint32 *)ctx->in);

		/* Now fill the next block with 56 bytes */
		memset(ctx->in, 0, 56);
	} else {
		/* Pad block to 56 bytes */
		memset(p, 0, count-8);
	}
	byteReverse(ctx->in, 14);

	/* Append length in bits and transform */
	((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
	((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];

	MD5Transform(ctx->buf, (uint32 *)ctx->in);
	byteReverse((unsigned char *)ctx->buf, 4);
	memcpy(digest, ctx->buf, 16);
	memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
}

/*
** Convert a digest into base-16.  digest should be declared as
** "unsigned char digest[16]" in the calling function.  The MD5
** digest is stored in the first 16 bytes.  zBuf should
** be "char zBuf[33]".
*/
static void DigestToBase16(unsigned char *digest, char *zBuf){
  static char const zEncode[] = "0123456789abcdef";
  int i, j;

  for(j=i=0; i<16; i++){
    int a = digest[i];
    zBuf[j++] = zEncode[(a>>4)&0xf];
    zBuf[j++] = zEncode[a & 0xf];
  }
  zBuf[j] = 0;
}

/*
** A TCL command for md5.  The argument is the text to be hashed.  The
** Result is the hash in base64.  
*/
static int md5_cmd(ClientData cd, Tcl_Interp *interp, int argc, char **argv){
  MD5Context ctx;
  unsigned char digest[16];

  if( argc!=2 ){
    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0], 
        " TEXT\"", 0);
    return TCL_ERROR;
  }
  MD5Init(&ctx);
  MD5Update(&ctx, (unsigned char*)argv[1], (unsigned)strlen(argv[1]));
  MD5Final(digest, &ctx);
  DigestToBase16(digest, interp->result);
  return TCL_OK;
}

/*
** A TCL command to take the md5 hash of a file.  The argument is the
** name of the file.
*/
static int md5file_cmd(ClientData cd, Tcl_Interp*interp, int argc, char **argv){
  FILE *in;
  MD5Context ctx;
  unsigned char digest[16];
  char zBuf[10240];

  if( argc!=2 ){
    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0], 
        " FILENAME\"", 0);
    return TCL_ERROR;
  }
  in = fopen(argv[1],"rb");
  if( in==0 ){
    Tcl_AppendResult(interp,"unable to open file \"", argv[1], 
         "\" for reading", 0);
    return TCL_ERROR;
  }
  MD5Init(&ctx);
  for(;;){
    int n;
    n = fread(zBuf, 1, sizeof(zBuf), in);
    if( n<=0 ) break;
    MD5Update(&ctx, (unsigned char*)zBuf, (unsigned)n);
  }
  fclose(in);
  MD5Final(digest, &ctx);
  DigestToBase16(digest, interp->result);
  return TCL_OK;
}

/*
** Register the two TCL commands above with the TCL interpreter.
*/
int Md5_Init(Tcl_Interp *interp){
  Tcl_CreateCommand(interp, "md5", md5_cmd, 0, 0);
  Tcl_CreateCommand(interp, "md5file", md5file_cmd, 0, 0);
  return TCL_OK;
}

** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** A TCL Interface to SQLite
**
** $Id: tclsqlite.c,v 1.20 2001/07/01 22:12:02 drh Exp $
*/
#ifndef NO_TCL     /* Omit this whole file if TCL is unavailable */

#include "sqlite.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

  interp = Tcl_CreateInterp();
  Sqlite_Init(interp);
#ifdef SQLITE_TEST
  {
    extern int Sqlitetest1_Init(Tcl_Interp*);
    extern int Sqlitetest2_Init(Tcl_Interp*);
    extern int Sqlitetest3_Init(Tcl_Interp*);
    extern int Md5_Init(Tcl_Interp*);
    Sqlitetest1_Init(interp);
    Sqlitetest2_Init(interp);
    Sqlitetest3_Init(interp);
    Md5_Init(interp);
  }
#endif
  if( argc>=2 ){
    int i;
    Tcl_SetVar(interp,"argv0",argv[1],TCL_GLOBAL_ONLY);
    Tcl_SetVar(interp,"argv", "", TCL_GLOBAL_ONLY);
    for(i=2; i<argc; i++){

**   http://www.hwaci.com/drh/
**
*************************************************************************
** 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 1.6 2001/07/01 22:12:02 drh Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "btree.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM\"", 0);
    return TCL_ERROR;
  }
  if( Tcl_GetInt(interp, argv[1], (int*)&pBt) ) return TCL_ERROR;
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  rc = sqliteBtreeDropTable(pBt, iTable);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

/*
** Usage:   btree_clear_table ID TABLENUM
**
** Remove all entries from the given table but keep the table around.
*/
static int btree_clear_table(
  void *NotUsed,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int argc,              /* Number of arguments */
  char **argv            /* Text of each argument */
){
  Btree *pBt;
  int iTable;
  int rc;
  if( argc!=3 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID TABLENUM\"", 0);
    return TCL_ERROR;
  }
  if( Tcl_GetInt(interp, argv[1], (int*)&pBt) ) return TCL_ERROR;
  if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
  rc = sqliteBtreeClearTable(pBt, iTable);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, errorName(rc), 0);
    return TCL_ERROR;
  }
  return TCL_OK;
}

  Tcl_CreateCommand(interp, "btree_close", btree_close, 0, 0);
  Tcl_CreateCommand(interp, "btree_begin_transaction",
      btree_begin_transaction, 0, 0);
  Tcl_CreateCommand(interp, "btree_commit", btree_commit, 0, 0);
  Tcl_CreateCommand(interp, "btree_rollback", btree_rollback, 0, 0);
  Tcl_CreateCommand(interp, "btree_create_table", btree_create_table, 0, 0);
  Tcl_CreateCommand(interp, "btree_drop_table", btree_drop_table, 0, 0);
  Tcl_CreateCommand(interp, "btree_clear_table", btree_clear_table, 0, 0);
  Tcl_CreateCommand(interp, "btree_get_meta", btree_get_meta, 0, 0);
  Tcl_CreateCommand(interp, "btree_update_meta", btree_update_meta, 0, 0);
  Tcl_CreateCommand(interp, "btree_page_dump", btree_page_dump, 0, 0);
  Tcl_CreateCommand(interp, "btree_pager_stats", btree_pager_stats, 0, 0);
  Tcl_CreateCommand(interp, "btree_pager_ref_dump", btree_pager_ref_dump, 0, 0);
  Tcl_CreateCommand(interp, "btree_cursor", btree_cursor, 0, 0);
  Tcl_CreateCommand(interp, "btree_close_cursor", btree_close_cursor, 0, 0);

# Copyright (c) 1999, 2000 D. Richard Hipp
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
# 
# You should have received a copy of the GNU General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA  02111-1307, USA.
#
# Author contact information:
#   drh@hwaci.com
#   http://www.hwaci.com/drh/
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this script is btree database backend
#
# $Id: btree2.test,v 1.1 2001/07/01 22:12:02 drh Exp $


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

if {$dbprefix!="memory:" && [info commands btree_open]!=""} {

# Create a new database file containing no entries.  The database should
# contain 5 tables:
#
#     2   The descriptor table
#     3   The foreground table
#     4   The background table
#     5   The long key table
#     6   The long data table
#
# An explanation for what all these tables are used for is provided below.
#
do_test btree2-1.1 {
  file delete -force test2.bt
  file delete -force test2.bt-journal
  set ::b [btree_open test2.bt]
  btree_begin_transaction $::b
  btree_create_table $::b
} {3}
do_test btree2-1.2 {
  btree_create_table $::b
} {4}
do_test btree2-1.3 {
  btree_create_table $::b
} {5}
do_test btree2-1.4 {
  btree_create_table $::b
} {6}
do_test btree2-1.5 {
  set ::c2 [btree_cursor $::b 2]
  btree_insert $::c2 {one} {1}
  btree_delete $::c2
  btree_close_cursor $::c2
  btree_commit $::b
  btree_sanity_check $::b 2 3 4 5 6
} {}

# This test module works by making lots of pseudo-random changes to a
# database while simultaneously maintaining an invariant on that database.
# Periodically, the script does a sanity check on the database and verifies
# that the invariant is satisfied.
#
# The invariant is as follows:
#
#   1.  The descriptor table always contains 2 enters.  An entry keyed by
#       "N" is the number of elements in the foreground and background tables
#       combined.  The entry keyed by "L" is the number of digits in the keys
#       for foreground and background tables.
#
#   2.  The union of the foreground an background tables consists of N entries
#       where each entry an L-digit key.  (Actually, some keys can be longer 
#       than L characters, but they always start with L digits.)  The keys
#       cover all integers between 1 and N.  Whenever an entry is added to
#       the foreground it is removed form the background and vice versa.
#
#   3.  Some entries in the foreground and background tables have keys that
#       begin with an L-digit number but are followed by additional characters.
#       For each such entry there is a corresponding entry in the long key
#       table.  The long key table entry has a key which is just the L-digit
#       number and data which is the length of the key in the foreground and
#       background tables.
#
#   4.  The data for both foreground and background entries is usually a
#       short string.  But some entries have long data strings.  For each
#       such entries there is an entry in the long data type.  The key to
#       long data table is an L-digit number.  (The extension on long keys
#       is omitted.)  The data is the number of charaters in the data of the
#       foreground or background entry.
#
# The following function builds a database that satisfies all of the above
# invariants.
#
proc build_db {N L} {
  for {set i 2} {$i<=6} {incr i} {
    catch {btree_close_cursor [set ::c$i]}
    btree_clear_table $::b $i
    set ::c$i [btree_cursor $::b $i]
  }
  btree_insert $::c2 N $N
  btree_insert $::c2 L $L
  set format %0${L}d
  for {set i 1} {$i<=$N} {incr i} { 
    set key [format $format $i]
    set data $key
    btree_insert $::c3 $key $data
  }
}

# Given a base key number and a length, construct the full text of the key
# or data.
#
proc make_payload {keynum L len} {
  set key [format %0${L}d $keynum]
  set r $key
  set i 1
  while {[string length $r]<$len} {
    append r " ($i) $key"
    incr i
  }
  return [string range $r 0 [expr {$len-1}]]
}

# Verify the invariants on the database.  Return an empty string on 
# success or an error message if something is amiss.
#
proc check_invariants {} {
  btree_move_to $::c3 {}
  btree_move_to $::c4 {}
  btree_move_to $::c2 N
  set N [btree_data $::c2]
  btree_move_to $::c2 L
  set L [btree_data $::c2]
  set LM1 [expr {$L-1}]
  for {set i 1} {$i<=$N} {incr i} {
    set key [btree_key $::c3]
    scan $key %d k
    if {$k!=$i} {
      set key [btree_key $::c4]
      scan $key %d k
      if {$k!=$i} {
         return "Key $i is missing from both foreground and backgroun"
      }
      set data [btree_data $::c4]
      btree_next $::c4
    } else {
      set data [btree_data $::c3]
      btree_next $::c3
    }
    set skey [string range $key 0 $LM1]
    if {[btree_move_to $::c5 $skey]==0} {
      set keylen [btree_data $::c5]
    } else {
      set keylen $L
    }
    if {[string length $key]!=$keylen} {
      return "Key $i is the wrong size.\
              Is \"$key\" but should be \"[make_payload $k $L $keylen]\""
    }
    if {[make_payload $k $L $keylen]!=$key} {
      return "Key $i has an invalid extension"
    }
    if {[btree_move_to $::c6 $skey]==0} {
      set datalen [btree_data $::c6]
    } else {
      set datalen $L
    }
    if {[string length $data]!=$datalen} {
      return "Data for $i is the wrong size.\
              Is [string length $data] but should be $datalen"
    }
    if {[make_payload $k $L $datalen]!=$data} {
      return "Entry $i has an incorrect data"
    }
  }
}

# Make random changes to the database such that each change preserves
# the invariants.  The number of changes is $n*N where N is the parameter
# from the descriptor table.  Each changes begins with a random key.
# the entry with that key is put in the foreground table with probability
# $I and it is put in background with probability (1.0-$I).  It gets
# a long key with probability $K and long data with probability $D.  
# 
proc random_changes {n I K D} {
  set N [btree_data $::c2]
  btree_move_to $::c2 L
  set L [btree_data $::c2]
  set LM1 [expr {$L-1}]
  set total [expr {int($N*$n)}]
  set format %0${L}d
  for {set i 0} {$i<$total} {incr i} {
    set k [expr {int(rand()*$N)}]
    set insert [expr {rand()<=$I}]
    set longkey [expr {rand()<=$K}]
    set longdata [expr {rand()<=$D}]
    if {$longkey} {
      set x [expr {rand()}]
      set keylen [expr {int($x*$x*$x*$x*3000)}]
    } else {
      set keylen $L
    }
    set key [make_payload $k $L $keylen]
    if {$longdata} {
      set x [expr {rand()}]
      set datalen [expr {int($x*$x*$x*$x*3000)}]
    } else {
      set datalen $L
    }
    set data [make_payload $k $L $datalen]
    set basekey [format $format $k]
    if {$insert} {
      btree_move_to $::c4 $basekey
      if {[scan [btree_key $::c4] %d kx]<1} {set kx -1}
      if {$kx==$k} {
        btree_delete $::c4
      }
      btree_insert $::c3 $key $data
    } else {
      btree_move_to $::c3 $basekey
      if {[scan [btree_key $::c4] %d kx]<1} {set kx -1}
      if {$kx==$k} {
        btree_delete $::c3
      }
      btree_insert $::c4 $key $data
    }
    if {$longkey} {
      btree_insert $::c5 $basekey $keylen
    } elseif {[btree_move_to $::c5 $basekey]==0} {
      btree_delete $::c5
    }
    if {$longdata} {
      btree_insert $::c6 $basekey $datalen
    } elseif {[btree_move_to $::c6 $basekey]==0} {
      btree_delete $::c6
    }
  }
  return [btree_sanity_check $::b 2 3 4 5 6]
}

# Repeat this test sequence on database of various sizes
#
set testno 2
foreach {N L} {
  10 2
} {
  puts "**** N=$N L=$L ****"
  set hash [md5file test2.bt]
  do_test btree2-$testno.1 [subst -nocommands {
    set ::c2 [btree_cursor $::b 2]
    set ::c3 [btree_cursor $::b 3]
    set ::c4 [btree_cursor $::b 4]
    set ::c5 [btree_cursor $::b 5]
    set ::c6 [btree_cursor $::b 6]
    btree_begin_transaction $::b
    build_db $N $L
    check_invariants
  }] {}
  do_test btree2-$testno.2 {
    btree_close_cursor $::c2
    btree_close_cursor $::c3
    btree_close_cursor $::c4
    btree_close_cursor $::c5
    btree_close_cursor $::c6
    btree_rollback $::b
    md5file test2.bt
  } $hash
  do_test btree2-$testno.3 [subst -nocommands {
    btree_begin_transaction $::b
    set ::c2 [btree_cursor $::b 2]
    set ::c3 [btree_cursor $::b 3]
    set ::c4 [btree_cursor $::b 4]
    set ::c5 [btree_cursor $::b 5]
    set ::c6 [btree_cursor $::b 6]
    build_db $N $L
    check_invariants
  }] {}
  do_test btree2-$testno.4 {
    btree_commit $::b
    check_invariants
  } {}
  do_test btree2-$testno.5  {
    lindex [btree_pager_stats $::b] 1
  } {6}
  do_test btree2-$testno.6  {
    btree_close_cursor $::c2
    btree_close_cursor $::c3
    btree_close_cursor $::c4
    btree_close_cursor $::c5
    btree_close_cursor $::c6
    lindex [btree_pager_stats $::b] 1
  } {0}
  do_test btree2-$testno.7 {
    btree_close $::b
    set ::b [btree_open test2.bt]
    check_invariants
  } {}

  # For each database size, run various changes tests.
  #
  set num2 1
  foreach {n I K D} {
    0.5 0.5 0.5 0.5
  } {
    set testid btree2-$testno.8.$num2
    do_test $testid.1 {
      set ::c2 [btree_cursor $::b 2]
      set ::c3 [btree_cursor $::b 3]
      set ::c4 [btree_cursor $::b 4]
      set ::c5 [btree_cursor $::b 5]
      set ::c6 [btree_cursor $::b 6]
      btree_begin_transaction $::b
      lindex [btree_pager_stats $::b] 1
    } {6}   
    set hash [md5file test2.bt]
    do_test $testid.2 [subst -nocommands {
      random_changes $n $I $K $D
      check_invariants
    }] {}
    do_test $testid.3 {
      btree_close_cursor $::c2
      btree_close_cursor $::c3
      btree_close_cursor $::c4
      btree_close_cursor $::c5
      btree_close_cursor $::c6
      btree_rollback $::b
      md5file test2.bt
    } $hash
    do_test $testid.4 [subst -nocommands {
      btree_begin_transaction $::b
      set ::c2 [btree_cursor $::b 2]
      set ::c3 [btree_cursor $::b 3]
      set ::c4 [btree_cursor $::b 4]
      set ::c5 [btree_cursor $::b 5]
      set ::c6 [btree_cursor $::b 6]
      random_changes $n $I $K $D
      check_invariants
    }] {}
    do_test $testid.5 {
      btree_commit $::b
      check_invariants
    } {}
    set hash [md5file test2.bt]
    do_test $testid.6 {
      btree_close_cursor $::c2
      btree_close_cursor $::c3
      btree_close_cursor $::c4
      btree_close_cursor $::c5
      btree_close_cursor $::c6
      btree_close $::b
      set ::b [btree_open test2.bt]
      check_invariants
    } {}
    incr num2
  }
  incr testno
}  

# Testing is complete.  Shut everything down.
#
do_test btree-999.1 {
  lindex [btree_pager_stats $::b] 1
} {0}
do_test btree-999.2 {
  btree_close $::b
} {}
do_test btree-999.3 {
  file delete -force test2.bt
  file exists test2.bt-journal
} {0}

} ;# end if( not mem: and has pager_open command );

finish_test