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/* -*- C++ -*- */
// $Id$
// ============================================================================
//
// = LIBRARY
// examples/Web_Crawler
//
// = FILENAME
// Mem_Map_Stream.h
//
// = AUTHOR
// Douglas C. Schmidt <schmidt@cs.wustl.edu>
//
// ============================================================================
#ifndef _MEM_MAP_STREAM_H
#define _MEM_MAP_STREAM_H
#include /**/ "ace/pre.h"
#include "ace/SOCK_Stream.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
#pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
#include "ace/Mem_Map.h"
#include "ace/SOCK_Connector.h"
#include "ace/Connector.h"
#include "ace/Svc_Handler.h"
#include "ace/Strategies_T.h"
class Mem_Map_Stream
{
// = TITLE
// Provides a memory-mapped stream abstraction to simplify parsing
// of tokens.
//
// = DESCRIPTION
// This class makes it possible to treat an connection as a stream
// of bytes, similar to the C library stdio streams. The contents
// of the connection are buffered incrementally in a memory-mapped
// file. This class maintains pointers to two positions in the
// stream:
//
// 1. The <recv> position, which keeps track of the beginning of a
// token that is in the stream.
//
// 2. The <get> position, which moves along character-by-character
// until the end of the token is reached.
//
// Once a token has been located, it can be extracted from the
// stream by calling the <recv>. The length of the token, i.e.,
// the <recv_len>, is the length in bytes between the <get>
// position and the <recv> position. Once the token has been
// extracted, the <recv> and <get> positions can be updated by the
// <seek> method.
public:
typedef ACE_Svc_Handler<ACE_SOCK_STREAM, ACE_NULL_SYNCH> Svc_Handler;
typedef ACE_Strategy_Connector<Svc_Handler,
ACE_SOCK_CONNECTOR>
STRAT_CONNECTOR;
// Mem_Map_Stream (void);
// constructor added:KIRTHIKA
virtual int open (STRAT_CONNECTOR *connector,
const ACE_INET_Addr &);
// Initialize this object.
virtual ~Mem_Map_Stream (void);
// Destructor.
// = Accessor.
ACE_SOCK_Stream &stream (void);
// Returns the underlying <ACE_SOCK_Stream>.
// = I/O methods.
virtual ssize_t send_n (const void *buf,
size_t size,
ACE_Time_Value *tv = 0);
// Send <size> bytes in <buf> to the connected peer. This is a
// completely unbuffered call.
virtual int get_char (void);
// Return the next character in the stream and advance the <get>
// position. Returns EOF when the <get> position reaches the end of
// the HTTP stream.
virtual const char *recv (size_t &len);
// Returns a pointer to array of at most <len> characters starting
// at the <recv> position. If the <recv> position + <len> extends
// past the EOF then <len> is set to the number of characters
// between the <recv> position and the EOF and both the <get> and
// <recv> positions are advanced by <len>. Returns 0 if the <recv>
// position is at the EOF.
virtual const char *recv (void) const;
// Returns a pointer to array of characters starting at the <recv>
// position.
virtual size_t recv_len (void) const;
// Returns the length in bytes between the <get> position and the
// <recv> position.
virtual int rewind (void);
// Resets the <get> and <recv> positions to the beginning of the
// stream. This works since all the data has been cached in the
// memory-mapped backing store.
virtual int peek_char (size_t offset);
// Returns the nth character <offset> from the <get> position in the
// stream without advancing the <get> position. Automatically
// extends the backing store if necessary. Returns EOF if <offset>
// is past the end of the stream.
virtual const char *peek_str (size_t offset, size_t size);
// Return a pointer to an array of <size> characters starting at
// <offset> characters from the <get> position in the stream without
// advancing the <get> position. Automatically extends the backing
// store if necessary. Returns 0 if <offset> or <offset + size> is
// past the end of the stream.
virtual off_t seek (off_t offset, int whence = SEEK_CUR);
// Sets the <get> and <recv> positions as follows:
// o If <whence> is <SEEK_SET>, the positions are set to <offset>
// bytes from the start of the stream.
//
// o If <whence> is <SEEK_CUR>, the positions are set to the
// current <get> position plus <offset>.
//
// o If <whence> is <SEEK_END>, the positions are set to the size
// of the stream plus <offset>.
virtual int eof (void) const;
// Returns 1 if we're at the end of the HTTP stream, else 0.
/*
typedef ACE_NOOP_Creation_Strategy<Svc_Handler>
NULL_CREATION_STRATEGY;
typedef ACE_NOOP_Concurrency_Strategy<Svc_Handler>
NULL_ACTIVATION_STRATEGY;
typedef ACE_Cached_Connect_Strategy<Svc_Handler,
ACE_SOCK_CONNECTOR,
ACE_SYNCH_NULL_MUTEX>
CACHED_CONNECT_STRATEGY;*/
Svc_Handler *svc_handler (void);
private:
int grow_file_and_remap (void);
// Grow the file by reading another chunk from the HTTP socket and
// extend the mapping to cover this chunk. Returns -1 on failure or
// EOF, else 0.
//ACE_SOCK_Stream stream_;
Svc_Handler *svc_handler_;
// Connection to peer. The granularity is at the Svc_Handler level.
// The Svc_Handler has an SOCK_Stream.
/*
NULL_CREATION_STRATEGY creation_strategy_;
NULL_ACTIVATION_STRATEGY activation_strategy_;
// Configure the Strategy Connector with a strategy that caches
// connection.
CACHED_CONNECT_STRATEGY caching_connect_strategy_;
STRAT_CONNECTOR *strat_connector_; */
ACE_Mem_Map mem_map_;
// Memory-mapped file that we're iterating over.
char *recv_pos_;
// Pointer to the address where the next <recv> method will start.
char *get_pos_;
// Pointer to the address where the next <get_char> method will
// start.
char *end_of_mapping_plus1_;
// Address at the end of the file mapping.
};
#include /**/ "ace/post.h"
#endif /* _MEM_MAP_STREAM_H */
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