diff options
Diffstat (limited to 'src/common/resources/inputstreambuffer.cpp')
-rw-r--r-- | src/common/resources/inputstreambuffer.cpp | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/common/resources/inputstreambuffer.cpp b/src/common/resources/inputstreambuffer.cpp new file mode 100644 index 0000000..cfa06fb --- /dev/null +++ b/src/common/resources/inputstreambuffer.cpp @@ -0,0 +1,129 @@ +// * This file is part of the COLOBOT source code +// * Copyright (C) 2014 Polish Portal of Colobot (PPC) +// * +// * This program 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. +// * +// * This program 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 program. If not, see http://www.gnu.org/licenses/. + +#include "common/resources/inputstreambuffer.h" + +#include <stdexcept> +#include <sstream> + +CInputStreamBuffer::CInputStreamBuffer(size_t buffer_size) : m_buffer_size(buffer_size) +{ + if (buffer_size <= 0) + { + throw std::runtime_error("File buffer must be larger then 0 bytes"); + } + + m_buffer = new char[buffer_size]; + m_file = nullptr; +} + + +CInputStreamBuffer::~CInputStreamBuffer() +{ + close(); + delete m_buffer; +} + + +void CInputStreamBuffer::open(const std::string &filename) +{ + if (PHYSFS_isInit()) + m_file = PHYSFS_openRead(filename.c_str()); +} + + +void CInputStreamBuffer::close() +{ + if (is_open()) + PHYSFS_close(m_file); +} + + +bool CInputStreamBuffer::is_open() +{ + return m_file; +} + + +size_t CInputStreamBuffer::size() +{ + return PHYSFS_fileLength(m_file); +} + + +std::streambuf::int_type CInputStreamBuffer::underflow() +{ + if (gptr() < egptr()) + return traits_type::to_int_type(*gptr()); + + if (PHYSFS_eof(m_file)) + return traits_type::eof(); + + PHYSFS_sint64 read_count = PHYSFS_read(m_file, m_buffer, sizeof(char), m_buffer_size); + if (read_count <= 0) + return traits_type::eof(); + + setg(m_buffer, m_buffer, m_buffer + read_count); + + return traits_type::to_int_type(*gptr()); +} + + +std::streampos CInputStreamBuffer::seekpos(std::streampos sp, std::ios_base::openmode which) +{ + return seekoff(off_type(sp), std::ios_base::beg, which); +} + + +std::streampos CInputStreamBuffer::seekoff(std::streamoff off, std::ios_base::seekdir way, std::ios_base::openmode which) +{ + /* A bit of explanation: + We are reading file by m_buffer_size parts so our 3 internal pointers will be + * eback (not used here) - start of block + * gptr - position of read cursor in block + * egtpr - end of block + off argument is relative to way */ + + std::streamoff new_position; + + switch (way) + { + case std::ios_base::beg: + new_position = off; + break; + + case std::ios_base::cur: + // tell will give cursor at begining of block so we have to add where in block we currently are + new_position = off + static_cast<off_type>(PHYSFS_tell(m_file)) - static_cast<off_type> (egptr() - gptr()); + break; + + case std::ios_base::end: + new_position = off + static_cast<off_type>(PHYSFS_fileLength(m_file)); + break; + + default: + break; + } + + if (PHYSFS_seek(m_file, new_position)) + { + setg(m_buffer, m_buffer, m_buffer); // reset buffer + + return pos_type(new_position); + } + + return pos_type(off_type(-1)); +} |