readfile.cpp

Go to the documentation of this file.

/* xoreos - A reimplementation of BioWare's Aurora engine
 *
 * xoreos is the legal property of its developers, whose names
 * can be found in the AUTHORS file distributed with this source
 * distribution.
 *
 * xoreos 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 3
 * of the License, or (at your option) any later version.
 *
 * xoreos 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 xoreos. If not, see <http://www.gnu.org/licenses/>.
 */

#include <cassert>

#include "src/common/readfile.h"
#include "src/common/error.h"
#include "src/common/ustring.h"
#include "src/common/platform.h"

namespace Common {

ReadFile::ReadFile() : _handle(0), _size(kSizeInvalid) {
}

ReadFile::ReadFile(const UString &fileName) : _handle(0), _size(kSizeInvalid) {
    if (!open(fileName))
        throw Exception("Can't open file \"%s\"", fileName.c_str());
}

ReadFile::~ReadFile() {
    close();
}

static long getInitialSize(std::FILE *handle) {
    if (!handle)
        return -1;

    if (std::fseek(handle, 0, SEEK_END) != 0)
        return -1;

    long fileSize = std::ftell(handle);

    if (std::fseek(handle, 0, SEEK_SET) != 0)
        return -1;

    return fileSize;
}

bool ReadFile::open(const UString &fileName) {
    close();

    long fileSize = -1;
    if (!(_handle  = Platform::openFile(fileName, Platform::kFileModeRead)) ||
        ((fileSize = getInitialSize(_handle)) < 0)) {

        close();
        return false;
    }

    if ((uint64)((unsigned long)fileSize) > (uint64)0x7FFFFFFFULL) {
        warning("ReadFile \"%s\" is too big", fileName.c_str());

        close();
        return false;
    }

    _size = (size_t)fileSize;

    return true;
}

void ReadFile::close() {
    if (_handle)
        std::fclose(_handle);

    _handle = 0;
    _size   = kSizeInvalid;
}

bool ReadFile::isOpen() const {
    return _handle != 0;
}

bool ReadFile::eos() const {
    if (!_handle)
        return true;

    return std::feof(_handle) != 0;
}

size_t ReadFile::pos() const {
    if (!_handle)
        return kPositionInvalid;

    return (size_t)std::ftell(_handle);
}

size_t ReadFile::size() const {
    return _size;
}

size_t ReadFile::seek(ptrdiff_t offset, Origin whence) {
    static const int kSeekToWhence[kOriginMAX] = { SEEK_SET, SEEK_CUR, SEEK_END };
    if (((size_t) whence) >= kOriginMAX)
        throw Exception(kSeekError);

    if (!_handle)
        throw Exception(kSeekError);

    size_t oldPos = pos();

    if (std::fseek(_handle, offset, kSeekToWhence[whence]) != 0)
        throw Exception(kSeekError);

    long p = std::ftell(_handle);
    if ((p < 0) || ((size_t)p > _size))
        throw Exception(kSeekError);

    return oldPos;
}

size_t ReadFile::read(void *dataPtr, size_t dataSize) {
    if (!_handle)
        return 0;

    assert(dataPtr);
    return std::fread(dataPtr, 1, dataSize, _handle);
}

} // End of namespace Common