rf-web/vendor/bundle/gems/eventmachine-1.2.7/ext/fastfilereader/mapper.cpp
2019-10-21 10:18:17 +02:00

215 lines
4.4 KiB
C++

/*****************************************************************************
$Id: mapper.cpp 4527 2007-07-04 10:21:34Z francis $
File: mapper.cpp
Date: 02Jul07
Copyright (C) 2007 by Francis Cianfrocca. All Rights Reserved.
Gmail: garbagecat10
This program is free software; you can redistribute it and/or modify
it under the terms of either: 1) the GNU General Public License
as published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version; or 2) Ruby's License.
See the file COPYING for complete licensing information.
*****************************************************************************/
//////////////////////////////////////////////////////////////////////
// UNIX implementation
//////////////////////////////////////////////////////////////////////
#ifdef OS_UNIX
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <iostream>
#include <string>
#include <cstring>
#include <stdexcept>
#include "mapper.h"
/******************
Mapper_t::Mapper_t
******************/
Mapper_t::Mapper_t (const std::string &filename)
{
/* We ASSUME we can open the file.
* (More precisely, we assume someone else checked before we got here.)
*/
Fd = open (filename.c_str(), O_RDONLY);
if (Fd < 0)
throw std::runtime_error (strerror (errno));
struct stat st;
if (fstat (Fd, &st))
throw std::runtime_error (strerror (errno));
FileSize = st.st_size;
#ifdef OS_WIN32
MapPoint = (char*) mmap (0, FileSize, PROT_READ, MAP_SHARED, Fd, 0);
#else
MapPoint = (const char*) mmap (0, FileSize, PROT_READ, MAP_SHARED, Fd, 0);
#endif
if (MapPoint == MAP_FAILED)
throw std::runtime_error (strerror (errno));
}
/*******************
Mapper_t::~Mapper_t
*******************/
Mapper_t::~Mapper_t()
{
Close();
}
/***************
Mapper_t::Close
***************/
void Mapper_t::Close()
{
// Can be called multiple times.
// Calls to GetChunk are invalid after a call to Close.
if (MapPoint) {
#ifdef CC_SUNWspro
// TODO: The void * cast works fine on Solaris 11, but
// I don't know at what point that changed from older Solaris.
munmap ((char*)MapPoint, FileSize);
#else
munmap ((void*)MapPoint, FileSize);
#endif
MapPoint = NULL;
}
if (Fd >= 0) {
close (Fd);
Fd = -1;
}
}
/******************
Mapper_t::GetChunk
******************/
const char *Mapper_t::GetChunk (unsigned start)
{
return MapPoint + start;
}
#endif // OS_UNIX
//////////////////////////////////////////////////////////////////////
// WINDOWS implementation
//////////////////////////////////////////////////////////////////////
#ifdef OS_WIN32
#include <windows.h>
#include <iostream>
#include <string>
#include <stdexcept>
#include "mapper.h"
/******************
Mapper_t::Mapper_t
******************/
Mapper_t::Mapper_t (const std::string &filename)
{
/* We ASSUME we can open the file.
* (More precisely, we assume someone else checked before we got here.)
*/
hFile = INVALID_HANDLE_VALUE;
hMapping = NULL;
MapPoint = NULL;
FileSize = 0;
hFile = CreateFile (filename.c_str(), GENERIC_READ|GENERIC_WRITE, FILE_SHARE_DELETE|FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (hFile == INVALID_HANDLE_VALUE)
throw std::runtime_error ("File not found");
BY_HANDLE_FILE_INFORMATION i;
if (GetFileInformationByHandle (hFile, &i))
FileSize = i.nFileSizeLow;
hMapping = CreateFileMapping (hFile, NULL, PAGE_READWRITE, 0, 0, NULL);
if (!hMapping)
throw std::runtime_error ("File not mapped");
#ifdef OS_WIN32
MapPoint = (char*) MapViewOfFile (hMapping, FILE_MAP_WRITE, 0, 0, 0);
#else
MapPoint = (const char*) MapViewOfFile (hMapping, FILE_MAP_WRITE, 0, 0, 0);
#endif
if (!MapPoint)
throw std::runtime_error ("Mappoint not read");
}
/*******************
Mapper_t::~Mapper_t
*******************/
Mapper_t::~Mapper_t()
{
Close();
}
/***************
Mapper_t::Close
***************/
void Mapper_t::Close()
{
// Can be called multiple times.
// Calls to GetChunk are invalid after a call to Close.
if (MapPoint) {
UnmapViewOfFile (MapPoint);
MapPoint = NULL;
}
if (hMapping != NULL) {
CloseHandle (hMapping);
hMapping = NULL;
}
if (hFile != INVALID_HANDLE_VALUE) {
CloseHandle (hFile);
hFile = INVALID_HANDLE_VALUE;
}
}
/******************
Mapper_t::GetChunk
******************/
const char *Mapper_t::GetChunk (unsigned start)
{
return MapPoint + start;
}
#endif // OS_WINDOWS