swibufferedinputstream.hpp

OSB-PIK-OpenVXI-3.0.0源代码 “中国XML论坛 - 专业的XML技术讨论区--XML在语音技术中的应用”

#ifndef SWIBUFFEREDINPUTSTREAM_HPP
 #define SWIBUFFEREDINPUTSTREAM_HPP
 

 /****************License************************************************
  *
  * Copyright 2000-2003.  ScanSoft, Inc.    
  *
  * Use of this software is subject to notices and obligations set forth 
  * in the SpeechWorks Public License - Software Version 1.2 which is 
  * included with this software. 
  *
  * ScanSoft is a registered trademark of ScanSoft, Inc., and OpenSpeech, 
  * SpeechWorks and the SpeechWorks logo are registered trademarks or 
  * trademarks of SpeechWorks International, Inc. in the United States 
  * and other countries.
  *
  ***********************************************************************/
 

 #include "SWIfilterInputStream.hpp"
 
 class SWIUTIL_API_CLASS SWIbufferedInputStream: public SWIfilterInputStream
 {
   // ................. CONSTRUCTORS, DESTRUCTOR  ............
   //
   // ------------------------------------------------------------
   /**
    * Provides buffering for non-buffered stream.
    *
    * @param stream The stream that is being wrapped.
    * @param bufSize the size of the internal buffer.  This is also the size that will be used to call
    * the stream's read operation.
    * @param lookAhead The amount of look ahead characters that can be looked further.
    * @param ownStream  If <code>true</code>, then the stream is deleted when this reader is deleted.
    *
    **/
  public:
   SWIbufferedInputStream(SWIinputStream * stream,
             int bufSize = 1024,
             int lookAhead = 10,
             bool ownStream = true);
 
   /**
    * Destructor.
    **/
  public:
   virtual ~SWIbufferedInputStream();
 
   /**
    * Reads one character from the stream.
 
    * Returns either a positive number that can be cast to a char or a negative
    * number representing an error.  See SWIstream.hpp for error codes.
    **/
  public:
   virtual int read();
 
   /**
    * Reads the specified number of bytes into the specified buffer.
    *
    * Returns the number of bytes stored in the buffer.
    **/
  public:
   virtual int readBytes(void *buffer, int bufSize);
 
   /**
    * Reads a line of text.  A line is considered to be terminated by any one
    * of a line feed ('\n'), a carriage return ('\r'), or a carriage return
    * followed immediately by a linefeed.  The carriage return and line feed
    * are extracted from the stream but not stored.
    *
    * returns the number of characters in the string, or a negative number
    * representing the cause of the error. See SWIstream.hpp for error codes.
    * Note that function is lost in the case where the value returned is exactly
    * <code>bufSize - 1</code>.  In this case, it is impossible to know whether the reading stopped
    * because of a line-termination or because the buffer is full.
    *
    **/
  public:
   virtual int readLine(char *buffer, int bufSize);
 
   /**
    * Reads a line of text and store the result into an OutputStream.
    *
    * Returns the number of characters that have been successfully put into the stream.
    **/
   virtual int readLine(SWIoutputStream& out);
 
   /**
    * Looks at the stream for look-ahead character.
    *
    * @param offset The offset compared to the current read position in the stream.  A value of 0 means
    * the character that would be returned by the next read().
    *
    * @return    Returns either a positive number that can be cast to a char or a negative
    * number representing an error.  See SWIstream.hpp for error codes.
    **/
   virtual int peek(int offset = 0) const;
 
   virtual bool isBuffered() const;
 
   virtual int getLookAhead() const;
 
  public:
   virtual Result close();
 
  public:
   virtual Result waitReady(long timeoutMs = -1);
 
   /**
    * Disabled copy constructor.
    **/
  private:
   SWIbufferedInputStream(const SWIbufferedInputStream&);
 
   /**
    * Disabled assignment operator.
    **/
  private:
   SWIbufferedInputStream& operator=(const SWIbufferedInputStream&);
 
  private:
   int fillBuffer(int lowBound = 0);
 
  private:
   SWIinputStream *_stream;
   int _readSize;
   int _lookAhead;
   bool _ownStream;
   unsigned char *_buffer;
   unsigned char * _end;
   unsigned char *_pos;
   bool _eofSeen;
 };
 #endif