static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){
  sqlite3_int64 iVal;
  *pp += sqlite3Fts3GetVarint(*pp, &iVal);
  *pVal += iVal;
}

/*




**


*/
static void fts3GetReverseDeltaVarint(
  char **pp, 
  char *pStart, 
  sqlite3_int64 *pVal
){
  sqlite3_int64 iVal;
................................................................................
}


/*
** When called, *ppPoslist must point to the byte immediately following the
** end of a position-list. i.e. ( (*ppPoslist)[-1]==POS_END ). This function
** moves *ppPoslist so that it instead points to the first byte of the
** position list.
*/
static void fts3ReversePoslist(char *pStart, char **ppPoslist){
  char *p = &(*ppPoslist)[-3];
  char c = p[1];
  while( p>=pStart && (*p & 0x80) | c ){ 
    c = *p--; 
  }

static void fts3GetDeltaVarint(char **pp, sqlite3_int64 *pVal){
  sqlite3_int64 iVal;
  *pp += sqlite3Fts3GetVarint(*pp, &iVal);
  *pVal += iVal;
}

/*
** When this function is called, *pp points to the first byte following a
** varint that is part of a doclist (or position-list, or any other list
** of varints). This function moves *pp to point to the start of that varint,
** and decrements the value stored in *pVal by the varint value.
**
** Argument pStart points to the first byte of the doclist that the
** varint is part of.
*/
static void fts3GetReverseDeltaVarint(
  char **pp, 
  char *pStart, 
  sqlite3_int64 *pVal
){
  sqlite3_int64 iVal;
................................................................................
}


/*
** When called, *ppPoslist must point to the byte immediately following the
** end of a position-list. i.e. ( (*ppPoslist)[-1]==POS_END ). This function
** moves *ppPoslist so that it instead points to the first byte of the
** same position list.
*/
static void fts3ReversePoslist(char *pStart, char **ppPoslist){
  char *p = &(*ppPoslist)[-3];
  char c = p[1];
  while( p>=pStart && (*p & 0x80) | c ){ 
    c = *p--; 
  }

** present in the FTS3 table. If it is, delete it and adjust the contents
** of subsiduary data structures accordingly.
*/
static int fts3DeleteByRowid(
  Fts3Table *p, 
  sqlite3_value *pRowid, 
  int *pnDoc,
  int *aSzDel
){
  int isEmpty = 0;
  int rc = fts3IsEmpty(p, pRowid, &isEmpty);
  if( rc==SQLITE_OK ){
    if( isEmpty ){
      /* Deleting this row means the whole table is empty. In this case
      ** delete the contents of all three tables and throw away any
      ** data in the pendingTerms hash table.  */
      rc = fts3DeleteAll(p);
      *pnDoc--;
    }else{
      sqlite3_int64 iRemove = sqlite3_value_int64(pRowid);
      rc = fts3PendingTermsDocid(p, iRemove);
      fts3DeleteTerms(&rc, p, pRowid, aSzDel);
      fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);
      if( sqlite3_changes(p->db) ) *pnDoc--;
      if( p->bHasDocsize ){
        fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, &pRowid);
      }
    }
  }

  return rc;
................................................................................
  int rc = SQLITE_OK;             /* Return Code */
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  sqlite3_int64 iRemove = 0;      /* Rowid removed by UPDATE or DELETE */
  u32 *aSzIns;                    /* Sizes of inserted documents */
  u32 *aSzDel;                    /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;
  int bReplace = 0;               /* True if on conflict mode is REPLACE */

  assert( p->pSegments==0 );

  /* Check for a "special" INSERT operation. One of the form:
  **
  **   INSERT INTO xyz(xyz) VALUES('command');
  */

** present in the FTS3 table. If it is, delete it and adjust the contents
** of subsiduary data structures accordingly.
*/
static int fts3DeleteByRowid(
  Fts3Table *p, 
  sqlite3_value *pRowid, 
  int *pnDoc,
  u32 *aSzDel
){
  int isEmpty = 0;
  int rc = fts3IsEmpty(p, pRowid, &isEmpty);
  if( rc==SQLITE_OK ){
    if( isEmpty ){
      /* Deleting this row means the whole table is empty. In this case
      ** delete the contents of all three tables and throw away any
      ** data in the pendingTerms hash table.  */
      rc = fts3DeleteAll(p);
      *pnDoc = *pnDoc - 1;
    }else{
      sqlite3_int64 iRemove = sqlite3_value_int64(pRowid);
      rc = fts3PendingTermsDocid(p, iRemove);
      fts3DeleteTerms(&rc, p, pRowid, aSzDel);
      fts3SqlExec(&rc, p, SQL_DELETE_CONTENT, &pRowid);
      if( sqlite3_changes(p->db) ) *pnDoc = *pnDoc - 1;
      if( p->bHasDocsize ){
        fts3SqlExec(&rc, p, SQL_DELETE_DOCSIZE, &pRowid);
      }
    }
  }

  return rc;
................................................................................
  int rc = SQLITE_OK;             /* Return Code */
  int isRemove = 0;               /* True for an UPDATE or DELETE */
  sqlite3_int64 iRemove = 0;      /* Rowid removed by UPDATE or DELETE */
  u32 *aSzIns;                    /* Sizes of inserted documents */
  u32 *aSzDel;                    /* Sizes of deleted documents */
  int nChng = 0;                  /* Net change in number of documents */
  int bInsertDone = 0;


  assert( p->pSegments==0 );

  /* Check for a "special" INSERT operation. One of the form:
  **
  **   INSERT INTO xyz(xyz) VALUES('command');
  */