1 files changed, 132 insertions, 0 deletions
diff --git a/src/common/resources/inputstreambuffer.cpp b/src/common/resources/inputstreambuffer.cpp
new file mode 100644
index 0000000..7059d60
--- /dev/null
+++ b/src/common/resources/inputstreambuffer.cpp
@@ -0,0 +1,132 @@
+/*
+ * This file is part of the Colobot: Gold Edition source code
+ * Copyright (C) 2001-2014, Daniel Roux, EPSITEC SA & TerranovaTeam
+ * http://epsiteс.ch; http://colobot.info; http://github.com/colobot
+ *
+ * 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://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));
+}