libcruft-util/io_posix.cpp

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/*
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* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
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* http://www.apache.org/licenses/LICENSE-2.0
*
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* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2010-2014 Danny Robson <danny@nerdcruft.net>
*/
#include "io.hpp"
#include "debug.hpp"
#include "except.hpp"
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
using util::detail::posix::mapped_file;
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//////////////////////////////////////////////////////////////////////////////
mapped_file::mapped_file (const char *_path, int fflags, int mflags):
m_fd (_path, fflags)
{
try {
load_fd (mflags);
} catch (const errno_error &e) {
// ignore zero length mapping error
if (e.code () == EINVAL && m_size == 0)
return;
}
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}
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//----------------------------------------------------------------------------
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mapped_file::~mapped_file ()
{
CHECK (m_data != NULL);
munmap (m_data, m_size);
}
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//----------------------------------------------------------------------------
void
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mapped_file::load_fd (int mflags) {
struct stat meta;
if (fstat (m_fd, &meta) < 0)
throw errno_error ();
m_size = (size_t)meta.st_size;
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m_data = (uint8_t *)mmap (NULL, m_size, mflags, MAP_SHARED, m_fd, 0);
if (m_data == MAP_FAILED)
throw errno_error ();
}
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//----------------------------------------------------------------------------
size_t
mapped_file::size (void) const
{
return m_size;
}
//-----------------------------------------------------------------------------
bool
mapped_file::empty (void) const
{
return size () == 0;
}
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//----------------------------------------------------------------------------
uint8_t*
mapped_file::data (void) {
CHECK (m_size > 0);
CHECK (m_data != NULL);
return m_data;
}
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//----------------------------------------------------------------------------
const uint8_t*
mapped_file::data (void) const {
CHECK (m_size > 0);
CHECK (m_data != NULL);
return m_data;
}
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//----------------------------------------------------------------------------
uint8_t*
mapped_file::begin (void) {
return data ();
}
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//----------------------------------------------------------------------------
uint8_t*
mapped_file::end (void) {
return data () + size ();
}
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//----------------------------------------------------------------------------
const uint8_t*
mapped_file::cbegin (void) const {
return data ();
}
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//----------------------------------------------------------------------------
const uint8_t*
mapped_file::cend (void) const {
return data () + size ();
}