Imported Upstream version 0.26.0

components/files/lowlevelfile.cpp

@@ -0,0 +1,299 @@
+#include "lowlevelfile.hpp"
+
+#include <stdexcept>
+#include <sstream>
+#include <cassert>
+
+#if FILE_API == FILE_API_POSIX
+#include <sys/types.h>
+#include <unistd.h>
+#include <fcntl.h>
+#endif
+
+#if FILE_API == FILE_API_STDIO
+/*
+ *
+ *	Implementation of LowLevelFile methods using c stdio
+ *
+ */
+
+LowLevelFile::LowLevelFile ()
+{
+	mHandle = NULL;
+}
+
+LowLevelFile::~LowLevelFile ()
+{
+	if (mHandle != NULL)
+		fclose (mHandle);
+}
+
+void LowLevelFile::open (char const * filename)
+{
+	assert (mHandle == NULL);
+
+	mHandle = fopen (filename, "rb");
+
+	if (mHandle == NULL)
+	{
+		std::ostringstream os;
+		os << "Failed to open '" << filename << "' for reading.";
+		throw std::runtime_error (os.str ());
+	}
+}
+
+void LowLevelFile::close ()
+{
+	assert (mHandle != NULL);
+
+	fclose (mHandle);
+
+	mHandle = NULL;
+}
+
+size_t LowLevelFile::size ()
+{
+	assert (mHandle != NULL);
+
+	long oldPosition = ftell (mHandle);
+
+	if (oldPosition == -1)
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	if (fseek (mHandle, 0, SEEK_END) != 0)
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	long Size = ftell (mHandle);
+
+	if (Size == -1)
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	if (fseek (mHandle, oldPosition, SEEK_SET) != 0)
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	return size_t (Size);
+}
+
+void LowLevelFile::seek (size_t Position)
+{
+	assert (mHandle != NULL);
+
+	if (fseek (mHandle, Position, SEEK_SET) != 0)
+		throw std::runtime_error ("A seek operation on a file failed.");
+}
+
+size_t LowLevelFile::tell ()
+{
+	assert (mHandle != NULL);
+
+	long Position = ftell (mHandle);
+
+	if (Position == -1)
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	return size_t (Position);
+}
+
+size_t LowLevelFile::read (void * data, size_t size)
+{
+	assert (mHandle != NULL);
+
+	int amount = fread (data, 1, size, mHandle);
+
+	if (amount == 0 && ferror (mHandle))
+		throw std::runtime_error ("A read operation on a file failed.");
+
+	return amount;
+}
+
+#elif FILE_API == FILE_API_POSIX
+/*
+ *
+ *	Implementation of LowLevelFile methods using posix IO calls
+ *
+ */
+
+LowLevelFile::LowLevelFile ()
+{
+	mHandle = -1;
+}
+
+LowLevelFile::~LowLevelFile ()
+{
+	if (mHandle != -1)
+		::close (mHandle);
+}
+
+void LowLevelFile::open (char const * filename)
+{
+	assert (mHandle == -1);
+
+#ifdef O_BINARY
+	static const int openFlags = O_RDONLY | O_BINARY;
+#else
+	static const int openFlags = O_RDONLY;
+#endif
+
+	mHandle = ::open (filename, openFlags, 0);
+
+	if (mHandle == -1)
+	{
+		std::ostringstream os;
+		os << "Failed to open '" << filename << "' for reading.";
+		throw std::runtime_error (os.str ());
+	}
+}
+
+void LowLevelFile::close ()
+{
+	assert (mHandle != -1);
+
+	::close (mHandle);
+
+	mHandle = -1;
+}
+
+size_t LowLevelFile::size ()
+{
+	assert (mHandle != -1);
+
+	size_t oldPosition = ::lseek (mHandle, 0, SEEK_CUR);
+
+	if (oldPosition == size_t (-1))
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	size_t Size = ::lseek (mHandle, 0, SEEK_END);
+
+	if (Size == size_t (-1))
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	if (lseek (mHandle, oldPosition, SEEK_SET) == -1)
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	return Size;
+}
+
+void LowLevelFile::seek (size_t Position)
+{
+	assert (mHandle != -1);
+
+	if (::lseek (mHandle, Position, SEEK_SET) == -1)
+		throw std::runtime_error ("A seek operation on a file failed.");
+}
+
+size_t LowLevelFile::tell ()
+{
+	assert (mHandle != -1);
+
+	size_t Position = ::lseek (mHandle, 0, SEEK_CUR);
+
+	if (Position == size_t (-1))
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	return Position;
+}
+
+size_t LowLevelFile::read (void * data, size_t size)
+{
+	assert (mHandle != -1);
+
+	int amount = ::read (mHandle, data, size);
+
+	if (amount == -1)
+		throw std::runtime_error ("A read operation on a file failed.");
+
+	return amount;
+}
+
+#elif FILE_API == FILE_API_WIN32
+/*
+ *
+ *	Implementation of LowLevelFile methods using Win32 API calls
+ *
+ */
+
+LowLevelFile::LowLevelFile ()
+{
+	mHandle = INVALID_HANDLE_VALUE;
+}
+
+LowLevelFile::~LowLevelFile ()
+{
+	if (mHandle == INVALID_HANDLE_VALUE)
+		CloseHandle (mHandle);
+}
+
+void LowLevelFile::open (char const * filename)
+{
+	assert (mHandle == INVALID_HANDLE_VALUE);
+
+	HANDLE handle = CreateFileA (filename, GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, 0, 0);
+
+	if (handle == NULL)
+	{
+		std::ostringstream os;
+		os << "Failed to open '" << filename << "' for reading.";
+		throw std::runtime_error (os.str ());
+	}
+
+	mHandle = handle;
+}
+
+void LowLevelFile::close ()
+{
+	assert (mHandle != INVALID_HANDLE_VALUE);
+
+	CloseHandle (mHandle);
+
+	mHandle = INVALID_HANDLE_VALUE;
+}
+
+size_t LowLevelFile::size ()
+{
+	assert (mHandle != INVALID_HANDLE_VALUE);
+
+	BY_HANDLE_FILE_INFORMATION info;
+
+	if (!GetFileInformationByHandle (mHandle, &info))
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	if (info.nFileSizeHigh != 0)
+		throw std::runtime_error ("Files greater that 4GB are not supported.");
+
+	return info.nFileSizeLow;
+}
+
+void LowLevelFile::seek (size_t Position)
+{
+	assert (mHandle != INVALID_HANDLE_VALUE);
+
+	if (SetFilePointer (mHandle, Position, NULL, SEEK_SET) == INVALID_SET_FILE_POINTER)
+		if (GetLastError () != NO_ERROR)
+			throw std::runtime_error ("A seek operation on a file failed.");
+}
+
+size_t LowLevelFile::tell ()
+{
+	assert (mHandle != INVALID_HANDLE_VALUE);
+
+	DWORD value = SetFilePointer (mHandle, 0, NULL, SEEK_CUR);
+
+	if (value == INVALID_SET_FILE_POINTER && GetLastError () != NO_ERROR)
+		throw std::runtime_error ("A query operation on a file failed.");
+
+	return value;
+}
+
+size_t LowLevelFile::read (void * data, size_t size)
+{
+	assert (mHandle != INVALID_HANDLE_VALUE);
+
+	DWORD read;
+
+	if (!ReadFile (mHandle, data, size, &read, NULL))
+		throw std::runtime_error ("A read operation on a file failed.");
+
+	return read;
+}
+
+#endif