ircd::fs: Break apart / improve make_iov() related stack / cleanup typedefs.

include/ircd/fs/iov.h

@@ -18,17 +18,23 @@ extern "C"
 
 namespace ircd::fs
 {
+	using const_iovec_view = vector_view<const struct ::iovec>;
+	using iovec_view = vector_view<struct ::iovec>;
 	using const_buffers = vector_view<const const_buffer>;
 	using mutable_buffers = vector_view<const mutable_buffer>;
 
 	// utility; count the total bytes of an iov.
-	size_t bytes(const vector_view<const struct ::iovec> &);
+	size_t bytes(const const_iovec_view &);
+
+	// Transforms our buffers to struct iovec ones.
+	const_iovec_view make_iov(const iovec_view &, const const_buffers &);
+	const_iovec_view make_iov(const iovec_view &, const mutable_buffers &);
 
 	// Transforms our buffers to struct iovec ones. This is done using an
 	// internal thread_local array of IOV_MAX. The returned view is of that
 	// array. We get away with using a single buffer because the synchronous
 	// readv()/writev() calls block the thread and for AIO the iov is copied out
 	// of userspace on io_submit().
-	vector_view<const struct ::iovec> make_iov(const const_buffers &);
+	const_iovec_view make_iov(const const_buffers &);
-	vector_view<const struct ::iovec> make_iov(const mutable_buffers &);
+	const_iovec_view make_iov(const mutable_buffers &);
 }

ircd/aio.cc

@@ -84,7 +84,7 @@ ircd::fs::aio::fdsync(const fd &fd,
 //
 
 ircd::fs::aio::request::read::read(const int &fd,
-                                   const vector_view<const struct ::iovec> &iov,
+                                   const const_iovec_view &iov,
                                    const read_opts &opts)
 :request{fd}
 {
@@ -129,7 +129,7 @@ ircd::fs::aio::read(const fd &fd,
 //
 
 ircd::fs::aio::request::write::write(const int &fd,
-                                     const vector_view<const struct ::iovec> &iov,
+                                     const const_iovec_view &iov,
                                      const write_opts &opts)
 :request{fd}
 {
@@ -548,7 +548,7 @@ catch(const ctx::terminated &)
 	throw;
 }
 
-ircd::vector_view<const struct ::iovec>
+ircd::fs::const_iovec_view
 ircd::fs::aio::request::iovec()
 const
 {

ircd/aio.h

@@ -17,8 +17,8 @@ namespace ircd::fs::aio
 	struct request;
 
 	void prefetch(const fd &, const size_t &, const read_opts &);
-	size_t write(const fd &, const vector_view<const const_buffer> &, const write_opts &);
+	size_t write(const fd &, const const_buffers &, const write_opts &);
-	size_t read(const fd &, const vector_view<const mutable_buffer> &, const read_opts &);
+	size_t read(const fd &, const mutable_buffers &, const read_opts &);
 	void fdsync(const fd &, const fsync_opts &);
 	void fsync(const fd &, const fsync_opts &);
 }
@@ -74,7 +74,7 @@ struct ircd::fs::aio::request
 	ssize_t errcode {0};
 
   public:
-	vector_view<const struct ::iovec> iovec() const;
+	const_iovec_view iovec() const;
 
 	size_t operator()();
 	void cancel();
@@ -87,14 +87,14 @@ struct ircd::fs::aio::request
 struct ircd::fs::aio::request::read
 :request
 {
-	read(const int &fd, const vector_view<const struct ::iovec> &, const read_opts &);
+	read(const int &fd, const const_iovec_view &, const read_opts &);
 };
 
 /// Write request control block
 struct ircd::fs::aio::request::write
 :request
 {
-	write(const int &fd, const vector_view<const struct ::iovec> &, const write_opts &);
+	write(const int &fd, const const_iovec_view &, const write_opts &);
 };
 
 /// fdsync request control block

ircd/fs.cc

@@ -1138,58 +1138,72 @@ namespace ircd::fs
 	thread_local std::array<struct ::iovec, IOV_MAX> _iov_;
 }
 
-ircd::vector_view<const struct ::iovec>
+ircd::fs::const_iovec_view
 ircd::fs::make_iov(const mutable_buffers &bufs)
 {
-	if(unlikely(bufs.size() > IOV_MAX))
+	if(unlikely(bufs.size() > _iov_.size()))
 		throw error
 		{
 			make_error_code(std::errc::invalid_argument),
-			"Buffer count of %zu excheeds IOV_MAX of %zu",
+			"Buffer count of %zu exceeds IOV_MAX of %zu",
 			bufs.size(),
-			IOV_MAX
+			_iov_.size()
 		};
 
+	return make_iov(iovec_view(_iov_.data(), _iov_.size()), bufs);
+}
+
+ircd::fs::const_iovec_view
+ircd::fs::make_iov(const const_buffers &bufs)
+{
+	if(unlikely(bufs.size() > _iov_.size()))
+		throw error
+		{
+			make_error_code(std::errc::invalid_argument),
+			"Buffer count of %zu exceeds IOV_MAX of %zu",
+			bufs.size(),
+			_iov_.size()
+		};
+
+	return make_iov(iovec_view(_iov_.data(), _iov_.size()), bufs);
+}
+
+ircd::fs::const_iovec_view
+ircd::fs::make_iov(const iovec_view &iov,
+                   const mutable_buffers &bufs)
+{
 	size_t i(0);
-	for(; i < bufs.size(); ++i)
+	for(; i < bufs.size() && i < iov.size(); ++i)
 		_iov_.at(i) =
 		{
 			buffer::data(bufs[i]), buffer::size(bufs[i])
 		};
 
-	return
+	return const_iovec_view
 	{
-		_iov_.data(), i
+		iov.data(), i
 	};
 }
 
-ircd::vector_view<const struct ::iovec>
+ircd::fs::const_iovec_view
-ircd::fs::make_iov(const const_buffers &bufs)
+ircd::fs::make_iov(const iovec_view &iov,
+                   const const_buffers &bufs)
 {
-	if(unlikely(bufs.size() > IOV_MAX))
-		throw error
-		{
-			make_error_code(std::errc::invalid_argument),
-			"Buffer count of %zu excheeds IOV_MAX of %zu",
-			bufs.size(),
-			IOV_MAX
-		};
-
 	size_t i(0);
-	for(; i < bufs.size(); ++i)
+	for(; i < bufs.size() && i < iov.size(); ++i)
-		_iov_.at(i) =
+		iov.at(i) =
 		{
 			const_cast<char *>(buffer::data(bufs[i])), buffer::size(bufs[i])
 		};
 
-	return
+	return const_iovec_view
 	{
-		_iov_.data(), i
+		iov.data(), i
 	};
 }
 
 size_t
-ircd::fs::bytes(const vector_view<const struct ::iovec> &iov)
+ircd::fs::bytes(const const_iovec_view &iov)
 {
 	return std::accumulate(begin(iov), end(iov), size_t(0), []
 	(auto ret, const auto &iov)