SQLite

  if( rc ){
    *pzErr = sqlite3_mprintf("lsm_open failed with %d", rc);
    rc = SQLITE_ERROR;
    goto connect_failed;
  }

/* Column numbers */
#define LSM1_COLUMN_KEY         0
#define LSM1_COLUMN_BLOBKEY     1
#define LSM1_COLUMN_VALUE       2
#define LSM1_COLUMN_BLOBVALUE   3
#define LSM1_COLUMN_COMMAND     4

  rc = sqlite3_declare_vtab(db,
     "CREATE TABLE x("
     "  key,"              /* The primary key.  Any non-NULL */
     "  blobkey,"          /* Pure BLOB primary key */
     "  value,"            /* The value associated with key.  Any non-NULL */
     "  blobvalue,"        /* Pure BLOB value */
     "  command hidden"    /* Insert here for control operations */
     ");"
  );
connect_failed:
  if( rc!=SQLITE_OK ){
    if( pNew ){
      if( pNew->pDb ) lsm_close(pNew->pDb);
      sqlite3_free(pNew);
    }
    *ppVtab = 0;

** Return TRUE if the cursor has been moved off of the last
** row of output.
*/
static int lsm1Eof(sqlite3_vtab_cursor *cur){
  lsm1_cursor *pCur = (lsm1_cursor*)cur;
  return pCur->atEof;
}

/*
** Rowids are not supported by the underlying virtual table.  So always
** return 0 for the rowid.
*/
static int lsm1Rowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  *pRowid = 0;
  return SQLITE_OK;
}

/*
** Type prefixes on LSM keys
*/
#define LSM1_TYPE_NEGATIVE   0
#define LSM1_TYPE_POSITIVE   1
#define LSM1_TYPE_TEXT       2
#define LSM1_TYPE_BLOB       3

/*
** Generate a key encoding for pValue such that all keys compare in
** lexicographical order.  Return an SQLite error code or SQLITE_OK.
**
** The key encoding is *pnKey bytes in length written into *ppKey.
** Space to hold the key is taken from pSpace if sufficient, or else
** from sqlite3_malloc().  The caller is responsible for freeing malloced
** space.
*/
static int lsm1EncodeKey(
  sqlite3_value *pValue,     /* Value to be encoded */
  unsigned char **ppKey,     /* Write the encoding here */
  int *pnKey,                /* Write the size of the encoding here */
  unsigned char *pSpace,     /* Use this space if it is large enough */
  int nSpace                 /* Size of pSpace[] */
){
  int eType = sqlite3_value_type(pValue);
  *ppKey = 0;
  *pnKey = 0;
  switch( eType ){
    default: {
      return SQLITE_ERROR;  /* We cannot handle NULL keys */
    }
    case SQLITE_BLOB:
    case SQLITE_TEXT: {
      int nVal = sqlite3_value_bytes(pValue);
      const void *pVal;
      if( eType==SQLITE_BLOB ){
        eType = LSM1_TYPE_BLOB;
        pVal = sqlite3_value_blob(pValue);
      }else{
        eType = LSM1_TYPE_TEXT;
        pVal = (const void*)sqlite3_value_text(pValue);
        if( pVal==0 ) return SQLITE_NOMEM;
      }
      if( nVal+1>nSpace ){
        pSpace = sqlite3_malloc( nVal+1 );
        if( pSpace==0 ) return SQLITE_NOMEM;
      }
      pSpace[0] = eType;
      memcpy(&pSpace[1], pVal, nVal);
      *ppKey = pSpace;
      *pnKey = nVal+1;
      break;
    }
  }
  return SQLITE_OK;
}

/*
** Return values of columns for the row at which the lsm1_cursor
** is currently pointing.
*/
static int lsm1Column(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  lsm1_cursor *pCur = (lsm1_cursor*)cur;
  switch( i ){
    case LSM1_COLUMN_BLOBKEY: {
      const void *pVal;
      int nVal;
      if( lsm_csr_key(pCur->pLsmCur, &pVal, &nVal)==LSM_OK ){
        sqlite3_result_blob(ctx, pVal, nVal, SQLITE_TRANSIENT);
      }
      break;
    }
    case LSM1_COLUMN_KEY: {
      const unsigned char *pVal;
      int nVal;
      if( lsm_csr_key(pCur->pLsmCur, (const void**)&pVal, &nVal)==LSM_OK
       && nVal>=1
      ){
        if( pVal[0]==LSM1_TYPE_BLOB ){
          sqlite3_result_blob(ctx, (const void*)&pVal[1],nVal-1,
                              SQLITE_TRANSIENT);
        }else if( pVal[0]==LSM1_TYPE_TEXT ){
          sqlite3_result_text(ctx, (const char*)&pVal[1],nVal-1,
                              SQLITE_TRANSIENT);
        }
      }
      break;
    }
    case LSM1_COLUMN_BLOBVALUE: {
      const void *pVal;
      int nVal;
      if( lsm_csr_value(pCur->pLsmCur, (const void**)&pVal, &nVal)==LSM_OK ){
        sqlite3_result_blob(ctx, pVal, nVal, SQLITE_TRANSIENT);
      }
      break;
    }
    case LSM1_COLUMN_VALUE: {
      const unsigned char *aVal;
      int nVal;
      if( lsm_csr_value(pCur->pLsmCur, (const void**)&aVal, &nVal)==LSM_OK
          && nVal>=1
      ){
        switch( aVal[0] ){
          case SQLITE_FLOAT:
          case SQLITE_INTEGER: {
            sqlite3_uint64 x = 0;
            int j;
            for(j=1; j<nVal; j++){
              x = (x<<8) | aVal[j];
            }
            if( aVal[0]==SQLITE_INTEGER ){
              sqlite3_result_int64(ctx, *(sqlite3_int64*)&x);
            }else{
              sqlite3_result_double(ctx, *(double*)&x);
            }

      }
      break;
    }
    default: {
      break;
    }
  }









  return SQLITE_OK;
}

/* Move to the first row to return.
*/
static int lsm1Filter(
  sqlite3_vtab_cursor *pVtabCursor, 

  return rc==LSM_OK ? SQLITE_OK : SQLITE_ERROR;
}

/*
** Only comparisons against the key are allowed.  The idxNum defines
** which comparisons are available:
**
**     0        Full table scan only
**   bit 1      key==?1  single argument for ?1
**   bit 2      key>?1
**   bit 3      key>=?1
**   bit 4      key<?N   (N==1 if bits 2,3 clear, or 2 if bits2,3 set)
**   bit 5      key<=?N  (N==1 if bits 2,3 clear, or 2 if bits2,3 set)
**   bit 6      Use blobkey instead of key
**
** To put it another way:
**
**     0        Full table scan.
**     1        key==?1
**     2        key>?1
**     4        key>=?1
**     8        key<?1
**     10       key>?1 AND key<?2
**     12       key>=?1 AND key<?2
**     16       key<=?1
**     18       key>?1 AND key<=?2
**     20       key>=?1 AND key<=?2
**     33..52   Use blobkey in place of key...
*/
static int lsm1BestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;                 /* Loop over constraints */
  int idxNum = 0;        /* The query plan bitmask */

){
  lsm1_vtab *p = (lsm1_vtab*)pVTab;
  const void *pKey;
  int nKey;
  int eType;
  int rc;
  sqlite3_value *pValue;
  const unsigned char *pVal;
  unsigned char *pData;
  int nVal;
  unsigned char pSpace[100];

  if( argc==1 ){
    pVTab->zErrMsg = sqlite3_mprintf("cannot DELETE");
    return SQLITE_ERROR;
  }
  if( sqlite3_value_type(argv[0])!=SQLITE_NULL ){
    pVTab->zErrMsg = sqlite3_mprintf("cannot UPDATE");
    return SQLITE_ERROR;
  }

  /* "INSERT INTO tab(command) VALUES('....')" is used to implement
  ** special commands.
  */
  if( sqlite3_value_type(argv[2+LSM1_COLUMN_COMMAND])!=SQLITE_NULL ){
    return SQLITE_OK;
  }
  if( sqlite3_value_type(argv[2+LSM1_COLUMN_BLOBKEY])==SQLITE_BLOB ){
    /* Use the blob key exactly as supplied */
    pKey = sqlite3_value_blob(argv[2+LSM1_COLUMN_BLOBKEY]);
    nKey = sqlite3_value_bytes(argv[2+LSM1_COLUMN_BLOBKEY]);
  }else{
    /* Use a key encoding that sorts in lexicographical order */
    rc = lsm1EncodeKey(argv[2+LSM1_COLUMN_KEY],
                       (unsigned char**)&pKey,&nKey,
                       pSpace,sizeof(pSpace));
    if( rc ) return rc;
  }
  if( sqlite3_value_type(argv[2+LSM1_COLUMN_BLOBVALUE])==SQLITE_BLOB ){
    pVal = sqlite3_value_blob(argv[2+LSM1_COLUMN_BLOBVALUE]);
    nVal = sqlite3_value_bytes(argv[2+LSM1_COLUMN_BLOBVALUE]);
    rc = lsm_insert(p->pDb, pKey, nKey, pVal, nVal);
  }else{
    pValue = argv[2+LSM1_COLUMN_VALUE];
    eType = sqlite3_value_type(pValue);
    switch( eType ){
      case SQLITE_NULL: {
        rc = lsm_delete(p->pDb, pKey, nKey);
        break;
      }
      case SQLITE_BLOB:
      case SQLITE_TEXT: {



        if( eType==SQLITE_TEXT ){
          pVal = sqlite3_value_text(pValue);
        }else{
          pVal = (unsigned char*)sqlite3_value_blob(pValue);
        }
        nVal = sqlite3_value_bytes(pValue);
        pData = sqlite3_malloc( nVal+1 );
        if( pData==0 ){
          rc = SQLITE_NOMEM;
        }else{
          pData[0] = eType;
          memcpy(&pData[1], pVal, nVal);
          rc = lsm_insert(p->pDb, pKey, nKey, pData, nVal+1);
          sqlite3_free(pData);
        }
        break;
      }
      case SQLITE_INTEGER:
      case SQLITE_FLOAT: {
        sqlite3_uint64 x;
        unsigned char aVal[9];
        int i;
        if( eType==SQLITE_INTEGER ){
          *(sqlite3_int64*)&x = sqlite3_value_int64(pValue);
        }else{
          *(double*)&x = sqlite3_value_double(pValue);
        }
        for(i=8; x>0 && i>=1; i--){
          aVal[i] = x & 0xff;
          x >>= 8;
        }
        aVal[i] = eType;
        rc = lsm_insert(p->pDb, pKey, nKey, &aVal[i], 9-i);
        break;
      }
    }
  }
  if( pKey!=(const void*)pSpace ) sqlite3_free((void*)pKey);
  return rc==LSM_OK ? SQLITE_OK : SQLITE_ERROR;
}      

/* Begin a transaction
*/
static int lsm1Begin(sqlite3_vtab *pVtab){
  lsm1_vtab *p = (lsm1_vtab*)pVtab;