SQLite

CollSeq *sqlite3FindCollSeq(
  sqlite3 *db,          /* Database connection to search */
  u8 enc,               /* Desired text encoding */
  const char *zName,    /* Name of the collating sequence.  Might be NULL */
  int create            /* True to create CollSeq if doesn't already exist */
){
  CollSeq *pColl;
  assert( SQLITE_UTF8==1 && SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 );
  assert( enc>=SQLITE_UTF8 && enc<=SQLITE_UTF16BE );
  if( zName ){
    pColl = findCollSeqEntry(db, zName, create);
    if( pColl ) pColl += enc-1;
  }else{
    pColl = db->pDfltColl;
  }



  return pColl;
}

/*
** Change the text encoding for a database connection. This means that
** the pDfltColl must change as well.
*/
void sqlite3SetTextEncoding(sqlite3 *db, u8 enc){
  assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE );
  db->enc = enc;
  /* EVIDENCE-OF: R-08308-17224 The default collating function for all
  ** strings is BINARY. 
  */
  db->pDfltColl = sqlite3FindCollSeq(db, enc, sqlite3StrBINARY, 0);
}

/*
** This function is responsible for invoking the collation factory callback
** or substituting a collation sequence of a different encoding when the
** requested collation sequence is not available in the desired encoding.
** 
** If it is not NULL, then pColl must point to the database native encoding 

  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
  createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
  if( db->mallocFailed ){
    goto opendb_out;
  }






  /* Parse the filename/URI argument
  **
  ** Only allow sensible combinations of bits in the flags argument.  
  ** Throw an error if any non-sense combination is used.  If we
  ** do not block illegal combinations here, it could trigger
  ** assert() statements in deeper layers.  Sensible combinations

      rc = SQLITE_NOMEM_BKPT;
    }
    sqlite3Error(db, rc);
    goto opendb_out;
  }
  sqlite3BtreeEnter(db->aDb[0].pBt);
  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
  if( !db->mallocFailed ){
    sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
  }
  sqlite3BtreeLeave(db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  /* The default safety_level for the main database is FULL; for the temp
  ** database it is OFF. This matches the pager layer defaults.  
  */
  db->aDb[0].zDbSName = "main";

        ){
          canChangeEnc = 0;
        }
      }
      if( canChangeEnc ){
        for(pEnc=&encnames[0]; pEnc->zName; pEnc++){
          if( 0==sqlite3StrICmp(zRight, pEnc->zName) ){

            u8 enc = pEnc->enc ? pEnc->enc : SQLITE_UTF16NATIVE;
            SCHEMA_ENC(db) = enc;
            sqlite3SetTextEncoding(db, enc);
            break;
          }
        }
        if( !pEnc->zName ){
          sqlite3ErrorMsg(pParse, "unsupported encoding: %s", zRight);
        }
      }

  /* If opening a non-empty database, check the text encoding. For the
  ** main database, set sqlite3.enc to the encoding of the main database.
  ** For an attached db, it is an error if the encoding is not the same
  ** as sqlite3.enc.
  */
  if( meta[BTREE_TEXT_ENCODING-1] ){  /* text encoding */
    if( iDb==0 ){

      u8 encoding;
#ifndef SQLITE_OMIT_UTF16
      /* If opening the main database, set ENC(db). */
      encoding = (u8)meta[BTREE_TEXT_ENCODING-1] & 3;
      if( encoding==0 ) encoding = SQLITE_UTF8;

#else
      encoding = SQLITE_UTF8;
#endif
      sqlite3SetTextEncoding(db, encoding);
    }else{
      /* If opening an attached database, the encoding much match ENC(db) */
      if( meta[BTREE_TEXT_ENCODING-1]!=ENC(db) ){
        sqlite3SetString(pzErrMsg, db, "attached databases must use the same"
            " text encoding as main database");
        rc = SQLITE_ERROR;
        goto initone_error_out;

/*
** Each database connection is an instance of the following structure.
*/
struct sqlite3 {
  sqlite3_vfs *pVfs;            /* OS Interface */
  struct Vdbe *pVdbe;           /* List of active virtual machines */
  CollSeq *pDfltColl;           /* BINARY collseq for the database encoding */
  sqlite3_mutex *mutex;         /* Connection mutex */
  Db *aDb;                      /* All backends */
  int nDb;                      /* Number of backends currently in use */
  u32 mDbFlags;                 /* flags recording internal state */
  u64 flags;                    /* flags settable by pragmas. See below */
  i64 lastRowid;                /* ROWID of most recent insert (see above) */
  i64 szMmap;                   /* Default mmap_size setting */

#endif

const char *sqlite3ErrStr(int);
int sqlite3ReadSchema(Parse *pParse);
CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int);
int sqlite3IsBinary(const CollSeq*);
CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName);
void sqlite3SetTextEncoding(sqlite3 *db, u8);
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr);
CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr);
int sqlite3ExprCollSeqMatch(Parse*,Expr*,Expr*);
Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int);
Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*);
Expr *sqlite3ExprSkipCollate(Expr*);
Expr *sqlite3ExprSkipCollateAndLikely(Expr*);