tor-browser

prstrms.cpp (10847B)

---

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
* Robin J. Maxwell 11-22-96
* Fredrik Roubert <roubert@google.com> 2010-07-23
* Matt Austern <austern@google.com> 2010-07-23
*/

#include "prstrms.h"

#include <cstdio>
#include <cstring>
#include <ios>
#include <new>

using std::ios_base;
using std::iostream;
using std::istream;
using std::nothrow;
using std::ostream;
using std::streambuf;
using std::streamsize;


PRfilebuf::PRfilebuf():
   _fd(NULL),
   _opened(false),
   _allocated(false),
   _unbuffered(false),
   _user_buf(false),
   _buf_base(NULL),
   _buf_end(NULL) { }


PRfilebuf::PRfilebuf(PRFileDesc *fd):
   _fd(fd),
   _opened(false),
   _allocated(false),
   _unbuffered(false),
   _user_buf(false),
   _buf_base(NULL),
   _buf_end(NULL) { }


PRfilebuf::PRfilebuf(PRFileDesc *fd, char_type *ptr, streamsize len):
   _fd(fd),
   _opened(false),
   _allocated(false),
   _unbuffered(false),
   _user_buf(false),
   _buf_base(NULL),
   _buf_end(NULL)
{
   setbuf(ptr, len);
}


PRfilebuf::~PRfilebuf()
{
   if (_opened) {
       close();
   } else {
       sync();
   }
   if (_allocated) {
       delete _buf_base;
   }
}


PRfilebuf *PRfilebuf::open(
   const char *name, ios_base::openmode flags, PRIntn mode)
{
   if (_fd != NULL) {
       return NULL;  // Error if already open.
   }

   // Translate flags argument.
   PRIntn prflags = 0;
   bool ate = (flags & ios_base::ate) != 0;
   flags &= ~(ios_base::ate | ios_base::binary);

   // TODO: The flag PR_CREATE_FILE should probably be used for the cases
   // (out), (out|app), (out|trunc) and (in|out|trunc) as the C++ standard
   // specifies that these cases should open files 'as if by using fopen with
   // "w"'. But adding that flag here will cause the unit test to leave files
   // behind after running (which might or might not be an error in the unit
   // test) so the matter needs further investigation before any changes are
   // made. The old prstreams implementation used the non-standard flag
   // ios::nocreate to control the use of PR_CREATE_FILE.

   if (flags == (ios_base::out)) {
       prflags = PR_WRONLY | PR_TRUNCATE;
   } else if (flags == (ios_base::out | ios_base::app)) {
       prflags = PR_RDWR | PR_APPEND;
   } else if (flags == (ios_base::out | ios_base::trunc)) {
       prflags = PR_WRONLY | PR_TRUNCATE;
   } else if (flags == (ios_base::in)) {
       prflags = PR_RDONLY;
   } else if (flags == (ios_base::in | ios_base::out)) {
       prflags = PR_RDWR;
   } else if (flags == (ios_base::in | ios_base::out | ios_base::trunc)) {
       prflags = PR_RDWR | PR_TRUNCATE;
   } else {
       return NULL;  // Unrecognized flag combination.
   }

   if ((_fd = PR_Open(name, prflags, mode)) == NULL) {
       return NULL;
   }

   _opened = true;

   if (ate &&
       seekoff(0, ios_base::end, flags) == pos_type(traits_type::eof())) {
       close();
       return NULL;
   }

   return this;
}


PRfilebuf *PRfilebuf::attach(PRFileDesc *fd)
{
   if (_fd != NULL) {
       return NULL;  // Error if already open.
   }

   _opened = false;
   _fd = fd;
   return this;
}


PRfilebuf *PRfilebuf::close()
{
   if (_fd == NULL) {
       return NULL;
   }

   int status = sync();

   if (PR_Close(_fd) == PR_FAILURE ||
       traits_type::eq_int_type(status, traits_type::eof())) {
       return NULL;
   }

   _fd = NULL;
   return this;
}


streambuf *PRfilebuf::setbuf(char_type *ptr, streamsize len)
{
   if (is_open() && _buf_end) {
       return NULL;
   }

   if (!ptr || len <= 0) {
       _unbuffered = true;
   } else {
       setb(ptr, ptr + len, false);
   }

   return this;
}


streambuf::pos_type PRfilebuf::seekoff(
   off_type offset, ios_base::seekdir dir, ios_base::openmode /*flags*/)
{
   if (PR_GetDescType(_fd) != PR_DESC_FILE) {
       return traits_type::eof();
   }

   PRSeekWhence whence;
   PRInt64 pos;

   switch (dir) {
       case ios_base::beg: whence = PR_SEEK_SET; break;
       case ios_base::cur: whence = PR_SEEK_CUR; break;
       case ios_base::end: whence = PR_SEEK_END; break;
       default:
           return traits_type::eof();  // This should never happen.
   }

   if (traits_type::eq_int_type(sync(), traits_type::eof())) {
       return traits_type::eof();
   }

   if ((pos = PR_Seek64(_fd, offset, whence)) == -1) {
       return traits_type::eof();
   }

   return pos;
}


int PRfilebuf::sync()
{
   if (_fd == NULL) {
       return traits_type::eof();
   }

   if (!_unbuffered) {
       // Sync write area.
       PRInt32 waiting;
       if ((waiting = pptr() - pbase()) != 0) {
           PRInt32 nout;
           if ((nout = PR_Write(_fd, pbase(), waiting)) != waiting) {
               if (nout > 0) {
                   // Should set _pptr -= nout.
                   pbump(-nout);
                   memmove(pbase(), pbase() + nout, waiting - nout);
               }
               return traits_type::eof();
           }
       }
       setp(NULL, NULL);  // Empty put area.

       if (PR_GetDescType(_fd) == PR_DESC_FILE) {
           // Sockets can't seek; don't need this.
           PROffset64 avail;
           if ((avail = in_avail()) > 0) {
               if (PR_Seek64(_fd, -avail, PR_SEEK_CUR) != -1) {
                   return traits_type::eof();
               }
           }
       }
       setg(NULL, NULL, NULL);  // Empty get area.
   }

   return 0;
}


streambuf::int_type PRfilebuf::underflow()
{
   PRInt32 count;
   char_type byte;

   if (gptr() != NULL && gptr() < egptr()) {
       return traits_type::to_int_type(*gptr());
   }

   // Make sure there is a reserve area.
   if (!_unbuffered && _buf_base == NULL && !allocate()) {
       return traits_type::eof();
   }

   // Sync before new buffer created below.
   if (traits_type::eq_int_type(sync(), traits_type::eof())) {
       return traits_type::eof();
   }

   if (_unbuffered) {
       if (PR_Read(_fd, &byte, 1) <= 0) {
           return traits_type::eof();
       }

       return traits_type::to_int_type(byte);
   }

   if ((count = PR_Read(_fd, _buf_base, _buf_end - _buf_base)) <= 0) {
       return traits_type::eof();  // Reached EOF.
   }

   setg(_buf_base, _buf_base, _buf_base + count);
   return traits_type::to_int_type(*gptr());
}


streambuf::int_type PRfilebuf::overflow(int_type c)
{
   // Make sure there is a reserve area.
   if (!_unbuffered && _buf_base == NULL && !allocate()) {
       return traits_type::eof();
   }

   // Sync before new buffer created below.
   if (traits_type::eq_int_type(sync(), traits_type::eof())) {
       return traits_type::eof();
   }

   if (!_unbuffered) {
       setp(_buf_base, _buf_end);
   }

   if (!traits_type::eq_int_type(c, traits_type::eof())) {
       // Extract the byte to be written.
       // (Required on big-endian architectures.)
       char_type byte = traits_type::to_char_type(c);
       if (!_unbuffered && pptr() < epptr()) {  // Guard against recursion.
           return sputc(byte);
       } else {
           if (PR_Write(_fd, &byte, 1) != 1) {
               return traits_type::eof();
           }
       }
   }

   return traits_type::not_eof(c);
}


bool PRfilebuf::allocate()
{
   char_type *buf = new(nothrow) char_type[BUFSIZ];
   if (buf == NULL) {
       return false;
   }

   setb(buf, buf + BUFSIZ, true);
   return true;
}


void PRfilebuf::setb(char_type *buf_base, char_type *buf_end, bool user_buf)
{
   if (_buf_base && !_user_buf) {
       delete[] _buf_base;
   }

   _buf_base = buf_base;
   _buf_end = buf_end;
   _user_buf = user_buf;
}


PRifstream::PRifstream():
   istream(NULL),
   _filebuf()
{
   init(&_filebuf);
}


PRifstream::PRifstream(PRFileDesc *fd):
   istream(NULL),
   _filebuf(fd)
{
   init(&_filebuf);
}


PRifstream::PRifstream(PRFileDesc *fd, char_type *ptr, streamsize len):
   istream(NULL),
   _filebuf(fd, ptr, len)
{
   init(&_filebuf);
}


PRifstream::PRifstream(const char *name, openmode flags, PRIntn mode):
   istream(NULL),
   _filebuf()
{
   init(&_filebuf);
   if (!_filebuf.open(name, flags | in, mode)) {
       setstate(failbit);
   }
}


PRifstream::~PRifstream() { }


void PRifstream::open(const char *name, openmode flags, PRIntn mode)
{
   if (is_open() || !_filebuf.open(name, flags | in, mode)) {
       setstate(failbit);
   }
}


void PRifstream::attach(PRFileDesc *fd)
{
   if (!_filebuf.attach(fd)) {
       setstate(failbit);
   }
}


void PRifstream::close()
{
   if (_filebuf.close() == NULL) {
       setstate(failbit);
   }
}


PRofstream::PRofstream():
   ostream(NULL),
   _filebuf()
{
   init(&_filebuf);
}


PRofstream::PRofstream(PRFileDesc *fd):
   ostream(NULL),
   _filebuf(fd)
{
   init(&_filebuf);
}


PRofstream::PRofstream(PRFileDesc *fd, char_type *ptr, streamsize len):
   ostream(NULL),
   _filebuf(fd, ptr, len)
{
   init(&_filebuf);
}


PRofstream::PRofstream(const char *name, openmode flags, PRIntn mode):
   ostream(NULL),
   _filebuf()
{
   init(&_filebuf);
   if (!_filebuf.open(name, flags | out, mode)) {
       setstate(failbit);
   }
}


PRofstream::~PRofstream() { }


void PRofstream::open(const char *name, openmode flags, PRIntn mode)
{
   if (is_open() || !_filebuf.open(name, flags | out, mode)) {
       setstate(failbit);
   }
}


void PRofstream::attach(PRFileDesc *fd)
{
   if (!_filebuf.attach(fd)) {
       setstate(failbit);
   }
}


void PRofstream::close()
{
   if (_filebuf.close() == NULL) {
       setstate(failbit);
   }
}


PRfstream::PRfstream():
   iostream(NULL),
   _filebuf()
{
   init(&_filebuf);
}


PRfstream::PRfstream(PRFileDesc *fd):
   iostream(NULL),
   _filebuf(fd)
{
   init(&_filebuf);
}


PRfstream::PRfstream(PRFileDesc *fd, char_type *ptr, streamsize len):
   iostream(NULL),
   _filebuf(fd, ptr, len)
{
   init(&_filebuf);
}


PRfstream::PRfstream(const char *name, openmode flags, PRIntn mode):
   iostream(NULL),
   _filebuf()
{
   init(&_filebuf);
   if (!_filebuf.open(name, flags | in | out, mode)) {
       setstate(failbit);
   }
}


PRfstream::~PRfstream() { }


void PRfstream::open(const char *name, openmode flags, PRIntn mode)
{
   if (is_open() || !_filebuf.open(name, flags | in | out, mode)) {
       setstate(failbit);
   }
}


void PRfstream::attach(PRFileDesc *fd)
{
   if (!_filebuf.attach(fd)) {
       setstate(failbit);
   }
}


void PRfstream::close()
{
   if (_filebuf.close() == NULL) {
       setstate(failbit);
   }
}