From b773d89eba723039d3d293df77e106c128efa878 Mon Sep 17 00:00:00 2001
From: Ingo Weinhold <ingo_weinhold@gmx.de>
Date: Sun, 29 Jun 2014 18:14:07 +0200
Subject: [PATCH] BDataIO: Add Flush()

---
 docs/user/support/DataIO.dox | 20 ++++++++++++++++++--
 headers/os/support/DataIO.h  |  3 ++-
 src/kits/support/DataIO.cpp  | 33 ++++++++++++++++++++++++++++++++-
 3 files changed, 52 insertions(+), 4 deletions(-)

diff --git a/docs/user/support/DataIO.dox b/docs/user/support/DataIO.dox
index 7a2f382385..52f2015d07 100644
--- a/docs/user/support/DataIO.dox
+++ b/docs/user/support/DataIO.dox
@@ -102,8 +102,24 @@
 
 
 /*!
-	\fn virtual status_t BDataIO::ReadExactly(void* buffer, size_t size,
-		size_t* _bytesRead)
+	\fn virtual status_t BDataIO::Flush()
+	\brief Writes pending data to underlying storage.
+
+	This method is relevant for BDataIO implementations that buffer data passed
+	to Write(). The Flush() implementation should make sure that all such data
+	are written to the underlying storage.
+
+	The default implementation is a no-op returning \c B_OK.
+
+	\return An error code indicating whether flushing the buffered data
+		succeeded.
+
+	\since Haiku R1
+*/
+
+
+/*!
+	\fn virtual status_t BDataIO::ReadExactly(void* buffer, size_t size, size_t* _bytesRead)
 	\brief Reads an exact amount of data from the object into a buffer.
 
 	This is a convenience wrapper method for Read() for code that expects the
diff --git a/headers/os/support/DataIO.h b/headers/os/support/DataIO.h
index e39bdcfd66..5e3d9bc99e 100644
--- a/headers/os/support/DataIO.h
+++ b/headers/os/support/DataIO.h
@@ -17,6 +17,8 @@ public:
 	virtual	ssize_t				Read(void* buffer, size_t size);
 	virtual	ssize_t				Write(const void* buffer, size_t size);
 
+	virtual	status_t			Flush();
+
 			status_t			ReadExactly(void* buffer, size_t size,
 									size_t* _bytesRead = NULL);
 			status_t			WriteExactly(const void* buffer, size_t size,
@@ -26,7 +28,6 @@ private:
 								BDataIO(const BDataIO&);
 			BDataIO&			operator=(const BDataIO&);
 
-	virtual	void				_ReservedDataIO1();
 	virtual	void				_ReservedDataIO2();
 	virtual	void				_ReservedDataIO3();
 	virtual	void				_ReservedDataIO4();
diff --git a/src/kits/support/DataIO.cpp b/src/kits/support/DataIO.cpp
index 90c4b8c676..55e65b40fe 100644
--- a/src/kits/support/DataIO.cpp
+++ b/src/kits/support/DataIO.cpp
@@ -40,6 +40,13 @@ BDataIO::Write(const void* buffer, size_t size)
 }
 
 
+status_t
+BDataIO::Flush()
+{
+	return B_OK;
+}
+
+
 status_t
 BDataIO::ReadExactly(void* buffer, size_t size, size_t* _bytesRead)
 {
@@ -116,8 +123,32 @@ BDataIO::operator=(const BDataIO &)
 }
 
 
+#if __GNUC__ == 2
+
+
+extern "C" status_t
+_ReservedDataIO1__7BDataIO(BDataIO* self)
+{
+	return self->BDataIO::Flush();
+}
+
+
+#else
+
+
+// TODO: RELEASE: Remove!
+
+extern "C" status_t
+_ZN7BDataIO16_ReservedDataIO1Ev(BDataIO* self)
+{
+	return self->BDataIO::Flush();
+}
+
+
+#endif
+
+
 // FBC
-void BDataIO::_ReservedDataIO1(){}
 void BDataIO::_ReservedDataIO2(){}
 void BDataIO::_ReservedDataIO3(){}
 void BDataIO::_ReservedDataIO4(){}