io/FileDescriptor: pass std::span to Full{Read,Write}()

src/io/FileDescriptor.cxx

@@ -249,38 +249,32 @@ FileDescriptor::GetSize() const noexcept
 }
 
 void
-FileDescriptor::FullRead(void *_buffer, std::size_t length) const
+FileDescriptor::FullRead(std::span<std::byte> dest) const
 {
-	auto buffer = (std::byte *)_buffer;
-
-	while (length > 0) {
-		ssize_t nbytes = Read(buffer, length);
+	while (!dest.empty()) {
+		ssize_t nbytes = Read(dest.data(), dest.size());
 		if (nbytes <= 0) {
 			if (nbytes < 0)
 				throw MakeErrno("Failed to read");
 			throw std::runtime_error("Unexpected end of file");
 		}
 
-		buffer += nbytes;
-		length -= nbytes;
+		dest = dest.subspan(nbytes);
 	}
 }
 
 void
-FileDescriptor::FullWrite(const void *_buffer, std::size_t length) const
+FileDescriptor::FullWrite(std::span<const std::byte> src) const
 {
-	auto buffer = (const std::byte *)_buffer;
-
-	while (length > 0) {
-		ssize_t nbytes = Write(buffer, length);
+	while (!src.empty()) {
+		ssize_t nbytes = Write(src.data(), src.size());
 		if (nbytes <= 0) {
 			if (nbytes < 0)
 				throw MakeErrno("Failed to write");
 			throw std::runtime_error("Failed to write");
 		}
 
-		buffer += nbytes;
-		length -= nbytes;
+		src = src.subspan(nbytes);
 	}
 }
 

src/io/FileDescriptor.hxx

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <cstddef>
+#include <span>
 #include <utility>
 
 #include <unistd.h>
@@ -224,7 +225,7 @@ public:
 	 * Read until all of the given buffer has been filled.  Throws
 	 * on error.
 	 */
-	void FullRead(void *buffer, std::size_t length) const;
+	void FullRead(std::span<std::byte> dest) const;
 
 	ssize_t Write(const void *buffer, std::size_t length) const noexcept {
 		return ::write(fd, buffer, length);
@@ -234,7 +235,7 @@ public:
 	 * Write until all of the given buffer has been written.
 	 * Throws on error.
 	 */
-	void FullWrite(const void *buffer, std::size_t length) const;
+	void FullWrite(std::span<const std::byte> src) const;
 
 #ifndef _WIN32
 	int Poll(short events, int timeout) const noexcept;

test/ReadFrames.cxx

@@ -28,7 +28,7 @@ ReadFrames(FileDescriptor fd, void *_buffer, std::size_t size,
 	const size_t modulo = nbytes % frame_size;
 	if (modulo > 0) {
 		size_t rest = frame_size - modulo;
-		fd.FullRead(buffer + nbytes, rest);
+		fd.FullRead({(std::byte *)buffer + nbytes, rest});
 		nbytes += rest;
 	}
 

test/run_convert.cxx

@@ -116,15 +116,15 @@ RunConvert(PcmConvert &convert, size_t in_frame_size,
 		buffer.Consume(src.size());
 
 		auto output = convert.Convert(src);
-		out_fd.FullWrite(output.data(), output.size());
+		out_fd.FullWrite(output);
 	}
 
 	while (true) {
 		auto output = convert.Flush();
 		if (output.data() == nullptr)
 			break;
 
-		out_fd.FullWrite(output.data(), output.size());
+		out_fd.FullWrite(output);
 	}
 }
 

test/run_filter.cxx

@@ -87,14 +87,14 @@ try {
 			break;
 
 		auto dest = filter->FilterPCM(std::span{buffer}.first(nbytes));
-		output_fd.FullWrite(dest.data(), dest.size());
+		output_fd.FullWrite(dest);
 	}
 
 	while (true) {
 		auto dest = filter->Flush();
 		if (dest.data() == nullptr)
 			break;
-		output_fd.FullWrite(dest.data(), dest.size());
+		output_fd.FullWrite(dest);
 	}
 
 	/* cleanup and exit */

test/run_input.cxx

@@ -170,13 +170,13 @@ dump_input_stream(InputStream &is, FileDescriptor out,
 			}
 		}
 
-		char buffer[MAX_CHUNK_SIZE];
+		std::byte buffer[MAX_CHUNK_SIZE];
 		assert(chunk_size <= sizeof(buffer));
 		size_t num_read = is.Read(lock, buffer, chunk_size);
 		if (num_read == 0)
 			break;
 
-		out.FullWrite(buffer, num_read);
+		out.FullWrite({buffer, num_read});
 	}
 
 	is.Check();