system/FileDescriptor: add method FullWrite()

src/system/FileDescriptor.cxx

@@ -298,6 +298,24 @@ FileDescriptor::FullRead(void *_buffer, size_t length)
 	}
 }
 
+void
+FileDescriptor::FullWrite(const void *_buffer, size_t length)
+{
+	const uint8_t *buffer = (const uint8_t *)_buffer;
+
+	while (length > 0) {
+		ssize_t nbytes = Write(buffer, length);
+		if (nbytes <= 0) {
+			if (nbytes < 0)
+				throw MakeErrno("Failed to write");
+			throw std::runtime_error("Failed to write");
+		}
+
+		buffer += nbytes;
+		length -= nbytes;
+	}
+}
+
 #ifndef _WIN32
 
 int

src/system/FileDescriptor.hxx

@@ -237,6 +237,12 @@ public:
 		return ::write(fd, buffer, length);
 	}
 
+	/**
+	 * Write until all of the given buffer has been written.
+	 * Throws on error.
+	 */
+	void FullWrite(const void *buffer, size_t length);
+
 #ifndef _WIN32
 	int Poll(short events, int timeout) const noexcept;
 

test/run_filter.cxx

@@ -70,34 +70,6 @@ ReadOrThrow(FileDescriptor fd, void *buffer, size_t size)
 	return nbytes;
 }
 
-static size_t
-WriteOrThrow(FileDescriptor fd, const void *buffer, size_t size)
-{
-	auto nbytes = fd.Write(buffer, size);
-	if (nbytes < 0)
-		throw MakeErrno("Write failed");
-
-	return nbytes;
-}
-
-static void
-FullWrite(FileDescriptor fd, ConstBuffer<uint8_t> src)
-{
-	while (!src.empty()) {
-		size_t nbytes = WriteOrThrow(fd, src.data, src.size);
-		if (nbytes == 0)
-			throw std::runtime_error("Write failed");
-
-		src.skip_front(nbytes);
-	}
-}
-
-static void
-FullWrite(FileDescriptor fd, ConstBuffer<void> src)
-{
-	FullWrite(fd, ConstBuffer<uint8_t>::FromVoid(src));
-}
-
 static size_t
 ReadFrames(FileDescriptor fd, void *_buffer, size_t size, size_t frame_size)
 {
@@ -166,14 +138,14 @@ try {
 			break;
 
 		auto dest = filter->FilterPCM({(const void *)buffer, (size_t)nbytes});
-		FullWrite(output_fd, dest);
+		output_fd.FullWrite(dest.data, dest.size);
 	}
 
 	while (true) {
 		auto dest = filter->Flush();
 		if (dest.IsNull())
 			break;
-		FullWrite(output_fd, dest);
+		output_fd.FullWrite(dest.data, dest.size);
 	}
 
 	/* cleanup and exit */