iportfromfile.cpp

用于解析ts流中的各种业务信息表可以用于dvb中嘛流分析

/* Copyright (C) 1995, Tektronix Inc. All Rights Reserved.
 *
 *   Usage Restrictions
 *
 * License is granted to copy, to use, and to make and to use derivative
 * works for research and evaluation purposes only.
 *
 *   Disclaimer of Warranty
 *
 * These software programs are available to the user without any license
 * fee or royalty on an "as is" basis.  Tektronix Inc. disclaims any and
 * all warranties, whether express, implied, or statuary, including any
 * implied warranties or merchantability or of fitness for a particular
 * purpose.  In no event shall the copyright-holder be liable for any 
 * incidental, punitive, or consequential damages of any kind whatsoever
 * arising from the use of these programs.
 *
 * This disclaimer of warranty extends to the user of these programs and
 * user's customers, employees, agents, transferees, successors, and
 * assigns.
 *
 * The Tektronix Inc. does not represent or warrant that the programs
 * furnished hereunder are free of infringement of any third-party
 * patents.
*/

/* IPortFromFile implementation */

#include "IPortFromFile.H"
#include "Utilities.H"
#include "memory.h"
/*
extern "C"
{
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
int read (int, char*, int);
int write (int, char*, int);
int close (int);
}
*/
IPortFromFile::IPortFromFile (char* fileName, int flag) : InputPort()
{

	memset(fbuf, 0, sizeof(fbuf));
	flen = 0;
    // opens file and sets pos
    cycle_flag = flag;
    file_name = fileName;
//  fd = open(file_name, O_RDONLY);
//  fd = _open(file_name, _O_RDONLY);
//  fd = _open(file_name, _O_RDONLY);
	fd2 = fopen(file_name, "rb");
//test begin
/*  char bufTest[188*40];
  int itest = fread(bufTest, 1, 188*40, fd2);
  itest = fread(bufTest, 1, 188*40, fd2);
  itest = fread(bufTest, 1, 188*40, fd2);
  itest = fread(bufTest, 1, 188*40, fd2);
*/
  //test end
  if (fd2 != NULL)
  {
      pos = -1;  // forces read on first call to read_bit
  }
  else
  {
      sys_message("unable to open file in IPortFromFile::IPortFromFile");
  }
}

char IPortFromFile::input_bit ()
// returns next bit as a char or BADBIT for an error
{
  int result = inc_bit ();
   if (result) return bit2char();
  return BADBIT;
}

char IPortFromFile::input_byte ()
{
//  int result;

  if (flen == 0)
  {
      flen = fread(fbuf, 1, CacheSize, fd2);
      if (flen == 0) 
	  {
	    if (cycle_flag == NOCYCLE) sys_halt("End of Input Stream");
	    fclose(fd2);
	    fd2 = fopen(file_name, "rb");
	    if (fd2 != NULL) flen = fread(fbuf, 1, CacheSize, fd2);
	    if (flen == 0) sys_halt("Unable to Cycle on input file");
	    if (flen < 0) sys_error("error reading input file");
	  }
      else if (flen < 0) 
	  {
	    sys_error("error reading input file");
	  }
      bufpos = 0;
  }

  if (pos <= 0)
    {
      byte = fbuf[bufpos++];
      if (bufpos == flen) flen = 0;
    }
  else
    {
      sys_error("can't read_byte; not on byte boundary");
    }
    return byte;
}

int IPortFromFile::inc_bit ()
// increments pos or reads from file if necessary
{
//  int result;

  if (pos <= 0)
    {
      (void) input_byte(); // it has already set `byte'
      pos = 7;
    }
  else
    {
      pos--;
    }
  return 1;
}

char IPortFromFile::bit2char ()
// returns ONE or ZERO depending on current bit;
{
  return (byte & (1 << pos)) ? ONE : ZERO;
}