template<typename _CharT, typename _Traits>
streamsize
basic_filebuf<_CharT, _Traits>::
+ xsgetn(_CharT* __s, streamsize __n)
+ {
+ // Clear out pback buffer before going on to the real deal...
+ streamsize __ret = 0;
+ if (this->_M_pback_init)
+ {
+ if (__n > 0 && this->gptr() == this->eback())
+ {
+ *__s++ = *this->gptr();
+ this->gbump(1);
+ __ret = 1;
+ --__n;
+ }
+ _M_destroy_pback();
+ }
+
+ // Optimization in the always_noconv() case, to be generalized in the
+ // future: when __n > __buflen we read directly instead of using the
+ // buffer repeatedly.
+ const bool __testin = this->_M_mode & ios_base::in;
+ const streamsize __buflen = this->_M_buf_size > 1 ? this->_M_buf_size - 1
+ : 1;
+ if (__n > __buflen && __check_facet(_M_codecvt).always_noconv()
+ && __testin && !_M_writing)
+ {
+ // First, copy the chars already present in the buffer.
+ const streamsize __avail = this->egptr() - this->gptr();
+ if (__avail == 1)
+ *__s = *this->gptr();
+ else if (__avail > 1)
+ traits_type::move(__s, this->gptr(), __avail);
+ __s += __avail;
+ this->gbump(__avail);
+ __ret += __avail;
+ __n -= __avail;
+
+ const streamsize __len = _M_file.xsgetn(reinterpret_cast<char*>(__s),
+ __n);
+ if (__len == -1)
+ __throw_ios_failure(__N("basic_filebuf::xsgetn "
+ "error reading the file"));
+ __ret += __len;
+ if (__len == __n)
+ {
+ _M_set_buffer(0);
+ _M_reading = true;
+ }
+ else if (__len == 0)
+ {
+ // If end of file is reached, set 'uncommitted'
+ // mode, thus allowing an immediate write without
+ // an intervening seek.
+ _M_set_buffer(-1);
+ _M_reading = false;
+ }
+ }
+ else
+ __ret += __streambuf_type::xsgetn(__s, __n);
+
+ return __ret;
+ }
+
+ template<typename _CharT, typename _Traits>
+ streamsize
+ basic_filebuf<_CharT, _Traits>::
xsputn(const _CharT* __s, streamsize __n)
{
// Optimization in the always_noconv() case, to be generalized in the
// using the buffer.
streamsize __ret = 0;
const bool __testout = this->_M_mode & ios_base::out;
- if (__testout && !_M_reading
- && __check_facet(_M_codecvt).always_noconv())
+ if (__check_facet(_M_codecvt).always_noconv()
+ && __testout && !_M_reading)
{
// Measurement would reveal the best choice.
const streamsize __chunk = 1ul << 10;
--- /dev/null
+// Copyright (C) 2004 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 2, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING. If not, write to the Free
+// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
+// USA.
+
+// As a special exception, you may use this file as part of a free software
+// library without restriction. Specifically, if other files instantiate
+// templates or use macros or inline functions from this file, or you compile
+// this file and link it with other files to produce an executable, this
+// file does not by itself cause the resulting executable to be covered by
+// the GNU General Public License. This exception does not however
+// invalidate any other reasons why the executable file might be covered by
+// the GNU General Public License.
+
+#include <cstdio>
+#include <fstream>
+#include <testsuite_performance.h>
+
+// libstdc++/11722
+int main()
+{
+ using namespace std;
+ using namespace __gnu_test;
+
+ time_counter time;
+ resource_counter resource;
+
+ const int iterations = 500000;
+ const int chunksize = 100;
+
+ char* chunk = new char[chunksize];
+ const char* name = "/usr/share/dict/linux.words";
+
+ // C
+ FILE* file = fopen(name, "r");
+ setvbuf(file, 0, _IONBF, 0);
+ start_counters(time, resource);
+ for (int i = 0; i < iterations; ++i)
+ if (fread(chunk, 1, chunksize, file) < chunksize)
+ fseek(file, 0, SEEK_SET);
+ stop_counters(time, resource);
+ fclose(file);
+ report_performance(__FILE__, "C", time, resource);
+ clear_counters(time, resource);
+
+ // C unlocked
+ file = fopen(name, "r");
+ setvbuf(file, 0, _IONBF, 0);
+ start_counters(time, resource);
+ for (int i = 0; i < iterations; ++i)
+ if (fread_unlocked(chunk, 1, chunksize, file) < chunksize)
+ fseek(file, 0, SEEK_SET);
+ stop_counters(time, resource);
+ fclose(file);
+ report_performance(__FILE__, "C unlocked", time, resource);
+ clear_counters(time, resource);
+
+ // C++
+ filebuf buf;
+ buf.pubsetbuf(0, 0);
+ buf.open(name, ios_base::in);
+ start_counters(time, resource);
+ for (int i = 0; i < iterations; ++i)
+ if (buf.sgetn(chunk, chunksize) < chunksize)
+ buf.pubseekoff(0, ios::beg);
+ stop_counters(time, resource);
+ report_performance(__FILE__, "C++", time, resource);
+
+ delete [] chunk;
+
+ return 0;
+}
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