/* * CFileInputStream.cpp, part of VCMI engine * * Authors: listed in file AUTHORS in main folder * * License: GNU General Public License v2.0 or later * Full text of license available in license.txt file, in main folder * */ #include "StdInc.h" #include "CFileInputStream.h" VCMI_LIB_NAMESPACE_BEGIN CFileInputStream::CFileInputStream(const boost::filesystem::path & file, si64 start, si64 size) : dataStart{start}, dataSize{size}, fileStream{file, std::ios::in | std::ios::binary} { if (fileStream.fail()) throw std::runtime_error("File " + file.string() + " isn't available."); if (dataSize == 0) { fileStream.seekg(0, std::ios::end); dataSize = tell(); } fileStream.seekg(dataStart, std::ios::beg); } si64 CFileInputStream::read(ui8 * data, si64 size) { si64 origin = tell(); si64 toRead = std::min(dataSize - origin, size); fileStream.read(reinterpret_cast(data), toRead); return fileStream.gcount(); } si64 CFileInputStream::seek(si64 position) { fileStream.seekg(dataStart + std::min(position, dataSize)); return tell(); } si64 CFileInputStream::tell() { return static_cast(fileStream.tellg()) - dataStart; } si64 CFileInputStream::skip(si64 delta) { si64 origin = tell(); //ensure that we're not seeking past the end of real data si64 toSeek = std::min(dataSize - origin, delta); fileStream.seekg(toSeek, std::ios::cur); return tell() - origin; } si64 CFileInputStream::getSize() { return dataSize; } VCMI_LIB_NAMESPACE_END