filebuf_virtuals.cc

gcc3.2.1源代码

  VERIFY( strmsz_2 == 10 );
  VERIFY( strmsz_1 == strmsz_2 ); 
  // fb_03._M_out_beg = "YZracadabras, i wanna FGHIJKLMNOPQRSTUVW"
  // fb_03._M_out_cur = "FGHIJKLMNOPQRSTUVW"
  strmsz_1 = fb_02.sputn("racadabras", 10);
  VERIFY( strmsz_1 == 10 );  
  // fb_02._M_out_beg = "YZracadabras<=>?@ABCDEFGHIJKLMNOPQRSTUVW"
  // fb_02._M_out_cur = "<=>?@ABCDEFGHIJKLMNOPQRSTUVW"
  strmsz_1 = fb_01.sputn("racadabra", 10);
  VERIFY( strmsz_1 == 0 );  

  // PUTBACK
  // int_type pbfail(int_type c)
  // called when gptr() null, gptr() == eback(), or traits::eq(*gptr, c) false
  // "pending sequence" is:
  //	1) everything as defined in underflow
  // 	2) + if (traits::eq_int_type(c, traits::eof()), then input
  // 	sequence is backed up one char before the pending sequence is
  // 	determined.
  //	3) + if (not 2) then c is prepended. Left unspecified is
  //	whether the input sequence is backedup or modified in any way
  // returns traits::eof() for failure, unspecified other value for success

  // int_type sputbackc(char_type c)
  // if in_cur not avail || ! traits::eq(c, gptr() [-1]), return pbfail
  // otherwise decrements in_cur and returns *gptr()
  c1 = fb_03.sgetc(); // -1
  c2 = fb_03.sputbackc('z');
  strmsz_2 = fb_03.in_avail();
  c3 = fb_03.sgetc();
  VERIFY( c3 == c2 );
  VERIFY( c1 != c3 );
  VERIFY( 1 == strmsz_2 );
  //test for _in_cur == _in_beg
  // fb_03._M_out_beg = "bd23456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZracada" etc
  fb_03.pubseekoff(10, std::ios_base::beg, 
		   std::ios_base::in | std::ios_base::out);
  fb_03.sputc('m');
  strmsz_1 = fb_03.in_avail(); 
  c1 = fb_03.sgetc(); 
  fb_03.snextc();
  c2 = fb_03.sputbackc('z');  
  strmsz_2 = fb_03.in_avail(); 
  c3 = fb_03.sgetc();  
  VERIFY( c1 != c2 );
  VERIFY( c3 == c2 );
  VERIFY( c1 != c3 );
  VERIFY( c2 == 'z' );
  //  VERIFY( strmsz_1 == strmsz_2 );
  // test for replacing char with identical one
  fb_03.snextc();
  fb_03.sputc('u');
  fb_03.sputc('v');
  fb_03.sputc('a');
  strmsz_1 = fb_03.in_avail();
  c2 = fb_03.sputbackc('a');
  strmsz_2 = fb_03.in_avail();
  c3 = fb_03.sgetc();
  VERIFY( c3 == c2 );
  VERIFY( strmsz_1 + 1 == strmsz_2 );
  //test for ios_base::out
  c1 = fb_02.sgetc(); // undefined
  c2 = fb_02.sputbackc('a');
  VERIFY( c1 == c2 );
  VERIFY( c1 == -1 );

  // int_type sungetc()
  // if in_cur not avail, return pbackfail(), else decrement and
  // return to_int_type(*gptr())
  // fb_03._M_out_beg = "uvaacadabras, i wannaZ[\\]^_`abcdefghijkl"
  // fb_03._M_out_cur = "aacadabras, i wannaZ[\\]^_`abcdefghijkl"
  strmsz_1 = fb_03.in_avail();
  c2 = fb_03.sungetc(); // delete the 'a'
  strmsz_2 = fb_03.in_avail();
  VERIFY( c2 == 'v' ); //  VERIFY( c2 != traits_type::eof() );
  VERIFY( strmsz_1 + 1 == strmsz_2 );
  //test for _in_cur == _in_beg
  for (int i = 50; i < 32 + 29; ++i)
    fb_02.sputc(char(i));
  fb_02.pubseekoff(0, std::ios_base::beg, std::ios_base::out);
  c1 = fb_02.sgetc(); 
  strmsz_1 = fb_02.in_avail();
  c2 = fb_02.sungetc();
  c3 = fb_02.sgetc();
  strmsz_2 = fb_02.in_avail();
  VERIFY( c1 == c2 );
  VERIFY( c2 == c3 );
  VERIFY( c1 == traits_type::eof() );
  VERIFY( strmsz_1 == strmsz_2 );
  //test for _in_cur == _in_end
  fb_03.pubseekoff(0, std::ios_base::end);
  strmsz_1 = fb_03.in_avail(); // -1 cuz at the end
  c1 = fb_03.sgetc(); 
  c2 = fb_03.sungetc();
  strmsz_2 = fb_03.in_avail(); // 1
  c3 = fb_03.sgetc();
  VERIFY( c1 != c2 );
  // VERIFY( c2 == c3 || c2 == traits_type::not_eof(int(c3)) );
  VERIFY( strmsz_2 != strmsz_1 );
  VERIFY( strmsz_2 == 1 );
  //test for ios_base::out

  // BUFFER MANAGEMENT & POSITIONING
  // int sync()
  // if a put area exists, overflow. 
  // if a get area exists, do something undefined. (like, nothing)
  strmsz_1 = fb_01.in_avail(); 
  fb_01.pubsync();
  strmsz_2 = fb_01.in_avail();
  VERIFY( strmsz_2 == strmsz_1 );
  strmsz_1 = fb_02.in_avail(); 
  fb_02.pubsync();		
  // 27filebuf-2.txt == 53 bytes after this.
  strmsz_2 = fb_02.in_avail();
  VERIFY( strmsz_2 == -1 );
  VERIFY( strmsz_2 == strmsz_1 );
  strmsz_1 = fb_03.in_avail(); 
  fb_03.pubsync();
  // 27filebuf-3.txt 
  // bd23456789mzuva?@ABCDEFGHIJKLMNOPQRSTUVWXYZracadabras, i wannaz 
  // 63 bytes.
  strmsz_2 = fb_03.in_avail();
  VERIFY( strmsz_1 == 1 );
  // VERIFY( strmsz_2 == 1 );

  // setbuf
  // pubsetbuf(char_type* s, streamsize n)
  fb_01.pubsetbuf(0,0);
  fb_02.pubsetbuf(0,0);
  fb_03.pubsetbuf(0,0);
  // Need to test unbuffered output, which means calling this on some
  // things that have just been opened.


  // seekoff
  // pubseekoff(off_type off, ios_base::seekdir way, ios_base::openmode which)
  // alters the stream position to off
  pos_type pt_1(off_type(-1));
  pos_type pt_2(off_type(0));
  off_type off_1 = 0;
  off_type off_2 = 0;
  //IN|OUT
  // 27filebuf-3.txt = bd23456789:;<=>?...
  //beg
  strmsz_1 = fb_03.in_avail(); 
  pt_1 = fb_03.pubseekoff(2, std::ios_base::beg);
  strmsz_2 = fb_03.in_avail(); 
  off_1 = pt_1;
  VERIFY( off_1 > 0 );
  c1 = fb_03.snextc(); //current in pointer +1
  VERIFY( c1 == '3' );
  c2 = fb_03.sputc('\n');  //current in pointer +1
  c3 = fb_03.sgetc();
  VERIFY( c2 != c3 ); 
  VERIFY( c3 == '4' );
  fb_03.pubsync(); 
  c1 = fb_03.sgetc();
  VERIFY( c1 == c3 );
  //cur
  // 27filebuf-3.txt = bd2\n456789:;<=>?...
  pt_2 = fb_03.pubseekoff(2, std::ios_base::cur);
  off_2 = pt_2;
  VERIFY( (off_2 == (off_1 + 2 + 1 + 1)) );
  c1 = fb_03.snextc(); //current in pointer +1
  VERIFY( c1 == '7' );
  c2 = fb_03.sputc('x');  //test current out pointer
  c3 = fb_03.sputc('\n');
  c1 = fb_03.sgetc();
  fb_03.pubsync(); 
  c3 = fb_03.sgetc();
  VERIFY( c1 == c3 );
  //end
  // 27filebuf-3.txt = "bd2\n456x\n9" 
  pt_2 = fb_03.pubseekoff(0, std::ios_base::end, 
			  std::ios_base::in|std::ios_base::out);
  off_1 = pt_2;
  VERIFY( off_1 > off_2 ); //weak, but don't know exactly where it ends
  c3 = fb_03.sputc('\n');
  strmsz_1 = fb_03.sputn("because because because. . .", 28);  
  VERIFY( strmsz_1 == 28 );
  c1 = fb_03.sungetc();
  // Defect?  retval of sungetc is not necessarily the character ungotten.
  // So re-get it.
  c1 = fb_03.sgetc();
  fb_03.pubsync(); 
  c3 = fb_03.sgetc();
  VERIFY( c1 == c3 );
  // IN
  // OUT


  // seekpos
  // pubseekpos(pos_type sp, ios_base::openmode)
  // alters the stream position to sp
  //IN|OUT
  //beg
  pt_1 = fb_03.pubseekoff(78, std::ios_base::beg);
  off_1 = pt_1;
  VERIFY( off_1 > 0 );
  c1 = fb_03.snextc(); 		//current in pointer +1
  VERIFY( c1 == ' ' );
  c2 = fb_03.sputc('\n');  	//test current out pointer
  c3 = fb_03.sgetc();
  fb_03.pubsync(); 		//resets pointers
  pt_2 = fb_03.pubseekpos(pt_1);
  off_2 = pt_2;
  VERIFY( off_1 == off_2 );
  c3 = fb_03.snextc(); 		//current in pointer +1
  VERIFY( c2 == c3 );
  pt_1 = fb_03.pubseekoff(0, std::ios_base::end);
  off_1 = pt_1;
  VERIFY( off_1 > off_2 );
  fb_03.sputn("\nof the wonderful things he does!!\nok", 37);
  fb_03.pubsync();

  // IN
  // OUT

  // VIRTUALS (indirectly tested)
  // underflow
  // if read position avail, returns *gptr()

  // pbackfail(int_type c)
  // put c back into input sequence

  // overflow
  // appends c to output seq

  // NB Have to close these suckers. . .
  // filebuf_type* close()
  fb_01.close();
  fb_02.close();
  fb_03.close();
  VERIFY( !fb_01.is_open() );
  VERIFY( !fb_02.is_open() );
  VERIFY( !fb_03.is_open() );
}

void test06()
{
  using namespace std;
  typedef istream::int_type	int_type;

  bool test = true;
  ifstream ifs(name_02);
  char buffer[] = "xxxxxxxxxx";
  int_type len1 = ifs.rdbuf()->sgetn(buffer, sizeof(buffer));
  VERIFY( len1 == sizeof(buffer) );
  VERIFY( buffer[0] == 'a' );
}

main() 
{
  test01();
  test02();
  
  test03();
  test04();
  test05();
  test06();

  return 0;
}