Add private class BFdIO

Simple BPositionIO implementation using the POSIX API on a FD. In effect
similar to BFile, but more easily ported to kernel and boot loader (and
the FD is reusable).

headers/build/private/storage/FdIO.h

@@ -0,0 +1 @@
+#include <../private/storage/FdIO.h>

headers/private/storage/FdIO.h

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2014, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _FD_IO_H_
+#define _FD_IO_H_
+
+
+#include <DataIO.h>
+
+
+class BFdIO : public BPositionIO {
+public:
+								BFdIO();
+								BFdIO(int fd, bool keepFd);
+	virtual						~BFdIO();
+
+			void				SetTo(int fd, bool keepFd);
+			void				Unset();
+
+	virtual	ssize_t				Read(void* buffer, size_t size);
+	virtual	ssize_t				Write(const void* buffer, size_t size);
+
+	virtual	ssize_t				ReadAt(off_t position, void* buffer,
+									size_t size);
+	virtual	ssize_t				WriteAt(off_t position, const void* buffer,
+									size_t size);
+
+	virtual	off_t				Seek(off_t position, uint32 seekMode);
+	virtual	off_t				Position() const;
+
+	virtual	status_t			SetSize(off_t size);
+	virtual	status_t			GetSize(off_t* _size) const;
+
+private:
+								BFdIO(const BFdIO& other);
+			BFdIO&				operator=(const BFdIO& other);
+
+private:
+			int					fFd;
+			bool				fOwnsFd;
+};
+
+
+#endif	// _FD_IO_H_

src/build/libbe/storage/Jamfile

@@ -14,6 +14,7 @@ BuildPlatformMergeObjectPIC <libbe_build>storage_kit.o :
 	DriverSettings.cpp
 	Entry.cpp
 	EntryList.cpp
+	FdIO.cpp
 	File.cpp
 	FileIO.cpp
 	FindDirectory.cpp

src/kits/storage/FdIO.cpp

@@ -0,0 +1,122 @@
+/*
+ * Copyright 2014, Ingo Weinhold, ingo_weinhold@gmx.de.
+ * Distributed under the terms of the MIT License.
+ */
+
+
+#include <FdIO.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+
+BFdIO::BFdIO()
+	:
+	BPositionIO(),
+	fFd(-1),
+	fOwnsFd(false)
+{
+}
+
+
+BFdIO::BFdIO(int fd, bool keepFd)
+	:
+	BPositionIO(),
+	fFd(fd),
+	fOwnsFd(keepFd)
+{
+}
+
+
+BFdIO::~BFdIO()
+{
+	Unset();
+}
+
+
+void
+BFdIO::SetTo(int fd, bool keepFd)
+{
+	Unset();
+
+	fFd = fd;
+	fOwnsFd = keepFd;
+}
+
+
+void
+BFdIO::Unset()
+{
+	if (fOwnsFd && fFd >= 0)
+		close(fFd);
+
+	fFd = -1;
+	fOwnsFd = false;
+}
+
+
+ssize_t
+BFdIO::Read(void* buffer, size_t size)
+{
+	ssize_t bytesRead = read(fFd, buffer, size);
+	return bytesRead >= 0 ? bytesRead : errno;
+}
+
+
+ssize_t
+BFdIO::Write(const void* buffer, size_t size)
+{
+	ssize_t bytesWritten = write(fFd, buffer, size);
+	return bytesWritten >= 0 ? bytesWritten : errno;
+}
+
+
+ssize_t
+BFdIO::ReadAt(off_t position, void* buffer, size_t size)
+{
+	ssize_t bytesRead = pread(fFd, buffer, size, position);
+	return bytesRead >= 0 ? bytesRead : errno;
+}
+
+
+ssize_t
+BFdIO::WriteAt(off_t position, const void* buffer, size_t size)
+{
+	ssize_t bytesWritten = pwrite(fFd, buffer, size, position);
+	return bytesWritten >= 0 ? bytesWritten : errno;
+}
+
+
+off_t
+BFdIO::Seek(off_t position, uint32 seekMode)
+{
+	off_t newPosition = lseek(fFd, position, seekMode);
+	return newPosition >= 0 ? newPosition : errno;
+}
+
+
+off_t
+BFdIO::Position() const
+{
+	return const_cast<BFdIO*>(this)->BFdIO::Seek(0, SEEK_CUR);
+}
+
+
+status_t
+BFdIO::SetSize(off_t size)
+{
+	return ftruncate(fFd, size) == 0 ? B_OK : errno;
+}
+
+
+status_t
+BFdIO::GetSize(off_t* _size) const
+{
+	struct stat st;
+	if (fstat(fFd, &st) != 0)
+		return errno;
+
+	*_size = st.st_size;
+	return B_OK;
+}

src/kits/storage/Jamfile

@@ -27,6 +27,7 @@ for architectureObject in [ MultiArchSubDirSetup ] {
 			Entry.cpp
 			EntryList.cpp
 			EntryOperationEngineBase.cpp
+			FdIO.cpp
 			File.cpp
 			FileDescriptorIO.cpp
 			FileIO.cpp