*ppDb = (TestDb *)pDb;
  return 0;
}
/* 
** End wrapper for SQLite.
*************************************************************************/

/*************************************************************************

















































































































































































** Begin exported functions.
*/
static struct Lib {
  const char *zName;
  const char *zDefaultDb;
  int (*xOpen)(const char *zFilename, int bClear, TestDb **ppDb);
} aLib[] = {

  { "sqlite3",      "testdb.sqlite",    sql_open },
  { "lsm_small",    "testdb.lsm_small", test_lsm_small_open },
  { "lsm_lomem",    "testdb.lsm_lomem", test_lsm_lomem_open },
#ifdef HAVE_ZLIB
  { "lsm_zip",      "testdb.lsm_zip",   test_lsm_zip_open },
#endif
  { "lsm",          "testdb.lsm",       test_lsm_open },

  *ppDb = (TestDb *)pDb;
  return 0;
}
/* 
** End wrapper for SQLite.
*************************************************************************/

/*************************************************************************
** Begin bt wrapper.
*/
#include "bt.h"

typedef struct BtDb BtDb;
struct BtDb {
  TestDb base;
  bt_db *pBt;

  /* Space for bt_fetch() results */
  u8 *aBuffer;
  int nBuffer;
};

int bt_close(TestDb *pTestDb){
  BtDb *p = (BtDb*)pTestDb;
  free(p->aBuffer);
  return sqlite4BtClose(p->pBt);
}

int bt_write(TestDb *pTestDb, void *pK, int nK, void *pV, int nV){
  BtDb *p = (BtDb*)pTestDb;
  int iLevel;
  int rc = SQLITE4_OK;

  iLevel = sqlite4BtTransactionLevel(p->pBt);
  if( iLevel<2 ){ 
    rc = sqlite4BtBegin(p->pBt, 2); 
  }

  rc = sqlite4BtReplace(p->pBt, pK, nK, pV, nV);

  if( rc==SQLITE4_OK && iLevel<2 ){
    rc = sqlite4BtCommit(p->pBt, iLevel); 
  }

  return rc;
}

int bt_delete(TestDb *pTestDb, void *pK, int nK){
  return bt_write(pTestDb, pK, nK, 0, -1);
}

int bt_delete_range(
  TestDb *pTestDb, 
  void *pKey1, int nKey1,
  void *pKey2, int nKey2
){
  return SQLITE4_OK;
}

int bt_fetch(TestDb *pTestDb, void *pK, int nK, void **ppVal, int *pnVal){
  BtDb *p = (BtDb*)pTestDb;
  bt_cursor *pCsr = 0;
  int iLevel;
  int rc = SQLITE4_OK;

  iLevel = sqlite4BtTransactionLevel(p->pBt);
  if( iLevel==0 ){ 
    rc = sqlite4BtBegin(p->pBt, 1); 
    if( rc!=SQLITE4_OK ) return rc;
  }

  rc = sqlite4BtCsrOpen(p->pBt, 0, &pCsr);
  if( rc==SQLITE4_OK ){
    rc = sqlite4BtCsrSeek(pCsr, pK, nK, BT_SEEK_EQ);
    if( rc==SQLITE4_OK ){
      const void *pV = 0;
      int nV = 0;
      rc = sqlite4BtCsrData(pCsr, 0, -1, &pV, &nV);
      if( rc==SQLITE4_OK ){
        if( nV>p->nBuffer ){
          free(p->aBuffer);
          p->aBuffer = (u8*)malloc(nV*2);
          p->nBuffer = nV*2;
        }
        memcpy(p->aBuffer, pV, nV);
        *pnVal = nV;
        *ppVal = (void*)(p->aBuffer);
      }

    }else if( rc==SQLITE4_INEXACT || rc==SQLITE4_NOTFOUND ){
      *ppVal = 0;
      *pnVal = -1;
      rc = SQLITE4_OK;
    }
    sqlite4BtCsrClose(pCsr);
  }

  if( iLevel==0 ) sqlite4BtCommit(p->pBt, 0); 
  return rc;
}

static int bt_scan(
  TestDb *pTestDb,
  void *pCtx,
  int bReverse,
  void *pFirst, int nFirst,
  void *pLast, int nLast,
  void (*xCallback)(void *, void *, int , void *, int)
){
  BtDb *p = (BtDb*)pTestDb;
  bt_cursor *pCsr = 0;
  int rc;

  rc = sqlite4BtCsrOpen(p->pBt, 0, &pCsr);
  if( rc==SQLITE4_OK ){
    rc = sqlite4BtCsrSeek(pCsr, pFirst, nFirst, BT_SEEK_GE);
    if( rc==SQLITE4_INEXACT ) rc = SQLITE4_OK;
    while( rc==SQLITE4_OK ){
      const void *pK = 0; int nK = 0;
      const void *pV = 0; int nV = 0;

      rc = sqlite4BtCsrKey(pCsr, &pK, &nK);
      if( rc==SQLITE4_OK ){
        rc = sqlite4BtCsrData(pCsr, 0, -1, &pV, &nV);
      }

      if( pLast && rc==SQLITE4_OK ){
        int nCmp = MAX(nK, nLast);
        int res;
        res = memcmp(pLast, pK, nCmp);
        if( res<0 || (res==0 && nK>nLast) ) break;
      }

      xCallback(pCtx, (void*)pK, nK, (void*)pV, nV);
      rc = sqlite4BtCsrNext(pCsr);
    }
    if( rc==SQLITE4_NOTFOUND ) rc = SQLITE4_OK;

    sqlite4BtCsrClose(pCsr);
  }

  return rc;
}

int bt_open(const char *zFilename, int bClear, TestDb **ppDb){
  static const DatabaseMethods SqlMethods = {
    bt_close,
    bt_write,
    bt_delete,
    0,
    bt_fetch,
    bt_scan,
    0,
    0,
    0
  };
  BtDb *p = 0;
  bt_db *pBt = 0;
  int rc;
  sqlite4_env *pEnv = sqlite4_env_default();

  if( bClear && zFilename && zFilename[0] ){
    unlink(zFilename);
  }
  
  rc = sqlite4BtNew(pEnv, sizeof(BtDb), &pBt);
  if( rc==SQLITE4_OK ){
    p = (BtDb*)sqlite4BtExtra(pBt);
    p->base.pMethods = &SqlMethods;
    p->pBt = pBt;
    rc = sqlite4BtOpen(pBt, zFilename);
  }

  if( rc!=SQLITE4_OK && p ){
    bt_close(&p->base);
  }

  *ppDb = &p->base;
  return rc;
}
/* 
** End wrapper for bt.
*************************************************************************/

/*************************************************************************
** Begin exported functions.
*/
static struct Lib {
  const char *zName;
  const char *zDefaultDb;
  int (*xOpen)(const char *zFilename, int bClear, TestDb **ppDb);
} aLib[] = {
  { "bt",           "testdb.bt",        bt_open },
  { "sqlite3",      "testdb.sqlite",    sql_open },
  { "lsm_small",    "testdb.lsm_small", test_lsm_small_open },
  { "lsm_lomem",    "testdb.lsm_lomem", test_lsm_lomem_open },
#ifdef HAVE_ZLIB
  { "lsm_zip",      "testdb.lsm_zip",   test_lsm_zip_open },
#endif
  { "lsm",          "testdb.lsm",       test_lsm_open },

#define BT_PGFLAGS_INTERNAL 0x01  /* True for non-leaf nodes */

struct bt_db {
  sqlite4_env *pEnv;              /* SQLite environment */
  BtPager *pPager;                /* Underlying page-based database */
};




struct bt_cursor {
  bt_db *pDb;                     /* Database that owns this cursor */

  int nPg;                        /* Number of valid entries in apPage[] */
  int aiCell[BT_MAX_DEPTH];       /* Current cell of each apPage[] entry */
  BtPage *apPage[BT_MAX_DEPTH];   /* All pages from root to current leaf */
};
................................................................................
  static int error_cnt = 0;
  error_cnt++;
  return rc;
}
#endif

/*
** Interpret the first 4 bytes of the buffer indicated by the first parameter
** as a 32-bit unsigned big-endian integer.
*/
static u32 btGetU32(const u8 *a){
  return ((u32)a[0] << 24) + ((u32)a[1] << 16) + ((u32)a[2] << 8) + ((u32)a[3]);
}





static u16 btGetU16(const u8 *a){
  return ((u32)a[0] << 8) + (u32)a[1];
}





static void btPutU16(u8 *a, u16 i){
  a[0] = (u8)((i>>8) & 0xFF);
  a[1] = (u8)((i>>0) & 0xFF);
}





static void btPutU32(u8 *a, u32 i){
  a[0] = (u8)((i>>24) & 0xFF);
  a[1] = (u8)((i>>16) & 0xFF);
  a[2] = (u8)((i>>8) & 0xFF);
  a[3] = (u8)((i>>0) & 0xFF);
}

................................................................................
    if( rc==SQLITE4_OK ){
      pCsr->nPg++;
    }
  }
  return rc;
}






static int btCsrAscend(bt_cursor *pCsr){
  if( pCsr->nPg>0 ){
    pCsr->nPg--;
    sqlite4BtPageRelease(pCsr->apPage[pCsr->nPg]);
  }
  return (pCsr->nPg==0 ? SQLITE4_NOTFOUND : SQLITE4_OK);
}
................................................................................
    }
  }

  rc = btSetChildPgno(
      pDb, pPar, iSib+ctx.nIn-1, sqlite4BtPagePgno(ctx.apPg[ctx.nOut-1])
  );
  if( rc==SQLITE4_OK ){
    pCsr->nPg--;
    rc = btDeleteFromPage(pCsr, ctx.nIn-1);
  }
  iPg = pCsr->nPg;
  if( rc==SQLITE4_OK && ctx.nOut>1 ){
    rc = btInsertAndBalance(pCsr, ctx.nOut-1, ctx.aPCell);
  }
  if( rc==SQLITE4_OK && iPg==pCsr->nPg ){
................................................................................
  btCsrSetup(db, &csr);
  rc = btCsrSeek(&csr, pK, nK, BT_SEEK_GE, 1);
  if( rc==SQLITE4_OK ){
    /* The cursor currently points to an entry with key pK/nK. This call
    ** should therefore replace that entry. So delete it and then re-seek
    ** the cursor.  */
    rc = sqlite4BtDelete(&csr);

    if( rc==SQLITE4_OK ){
      rc = btCsrSeek(&csr, pK, nK, BT_SEEK_GE, 1);

    }
  }
  if( rc==SQLITE4_OK ) rc = btErrorBkpt(SQLITE4_CORRUPT);

  if( rc==SQLITE4_NOTFOUND || rc==SQLITE4_INEXACT ){
    /* Insert the new KV pair into the current leaf. */
    KeyValue kv;
    kv.pgno = 0;
    kv.pK = pK; kv.nK = nK;
    kv.pV = pV; kv.nV = nV;
    rc = btInsertAndBalance(&csr, 1, &kv);
  }

#define BT_PGFLAGS_INTERNAL 0x01  /* True for non-leaf nodes */

struct bt_db {
  sqlite4_env *pEnv;              /* SQLite environment */
  BtPager *pPager;                /* Underlying page-based database */
};

/*
** Database cursor handle.
*/
struct bt_cursor {
  bt_db *pDb;                     /* Database that owns this cursor */

  int nPg;                        /* Number of valid entries in apPage[] */
  int aiCell[BT_MAX_DEPTH];       /* Current cell of each apPage[] entry */
  BtPage *apPage[BT_MAX_DEPTH];   /* All pages from root to current leaf */
};
................................................................................
  static int error_cnt = 0;
  error_cnt++;
  return rc;
}
#endif

/*
** Interpret the first 4 bytes of the buffer indicated by the first 
** parameter as a 32-bit unsigned big-endian integer.
*/
static u32 btGetU32(const u8 *a){
  return ((u32)a[0] << 24) + ((u32)a[1] << 16) + ((u32)a[2] << 8) + ((u32)a[3]);
}

/*
** Interpret the first 2 bytes of the buffer indicated by the first 
** parameter as a 16-bit unsigned big-endian integer.
*/
static u16 btGetU16(const u8 *a){
  return ((u32)a[0] << 8) + (u32)a[1];
}

/*
** Write the value passed as the second argument to the buffer passed
** as the first. Formatted as an unsigned 16-bit big-endian integer.
*/
static void btPutU16(u8 *a, u16 i){
  a[0] = (u8)((i>>8) & 0xFF);
  a[1] = (u8)((i>>0) & 0xFF);
}

/*
** Write the value passed as the second argument to the buffer passed
** as the first. Formatted as an unsigned 32-bit big-endian integer.
*/
static void btPutU32(u8 *a, u32 i){
  a[0] = (u8)((i>>24) & 0xFF);
  a[1] = (u8)((i>>16) & 0xFF);
  a[2] = (u8)((i>>8) & 0xFF);
  a[3] = (u8)((i>>0) & 0xFF);
}

................................................................................
    if( rc==SQLITE4_OK ){
      pCsr->nPg++;
    }
  }
  return rc;
}

/*
** Move the cursor from the current page to the parent. Return 
** SQLITE4_NOTFOUND if the cursor already points to the root page,
** or SQLITE4_OK otherwise.
*/
static int btCsrAscend(bt_cursor *pCsr){
  if( pCsr->nPg>0 ){
    pCsr->nPg--;
    sqlite4BtPageRelease(pCsr->apPage[pCsr->nPg]);
  }
  return (pCsr->nPg==0 ? SQLITE4_NOTFOUND : SQLITE4_OK);
}
................................................................................
    }
  }

  rc = btSetChildPgno(
      pDb, pPar, iSib+ctx.nIn-1, sqlite4BtPagePgno(ctx.apPg[ctx.nOut-1])
  );
  if( rc==SQLITE4_OK ){
    btCsrAscend(pCsr);
    rc = btDeleteFromPage(pCsr, ctx.nIn-1);
  }
  iPg = pCsr->nPg;
  if( rc==SQLITE4_OK && ctx.nOut>1 ){
    rc = btInsertAndBalance(pCsr, ctx.nOut-1, ctx.aPCell);
  }
  if( rc==SQLITE4_OK && iPg==pCsr->nPg ){
................................................................................
  btCsrSetup(db, &csr);
  rc = btCsrSeek(&csr, pK, nK, BT_SEEK_GE, 1);
  if( rc==SQLITE4_OK ){
    /* The cursor currently points to an entry with key pK/nK. This call
    ** should therefore replace that entry. So delete it and then re-seek
    ** the cursor.  */
    rc = sqlite4BtDelete(&csr);

    if( rc==SQLITE4_OK && nV>=0 ){
      rc = btCsrSeek(&csr, pK, nK, BT_SEEK_GE, 1);
      if( rc==SQLITE4_OK ) rc = btErrorBkpt(SQLITE4_CORRUPT);
    }
  }


  if( nV>=0 && (rc==SQLITE4_NOTFOUND || rc==SQLITE4_INEXACT) ){
    /* Insert the new KV pair into the current leaf. */
    KeyValue kv;
    kv.pgno = 0;
    kv.pK = pK; kv.nK = nK;
    kv.pV = pV; kv.nV = nV;
    rc = btInsertAndBalance(&csr, 1, &kv);
  }