ircd::fs: Consolidate support tests and indications into namespace.

include/ircd/fs/fs.h

@@ -88,6 +88,7 @@ enum ircd::fs::index
 #include "write.h"
 #include "fsync.h"
 #include "stdin.h"
+#include "support.h"
 
 struct ircd::fs::init
 {

include/ircd/fs/support.h

@@ -0,0 +1,23 @@
+// Matrix Construct
+//
+// Copyright (C) Matrix Construct Developers, Authors & Contributors
+// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice is present in all copies. The
+// full license for this software is available in the LICENSE file.
+
+#pragma once
+#define HAVE_IRCD_FS_SUPPORT_H
+
+namespace ircd::fs::support
+{
+	// Indicator lights for AIO
+	extern const bool aio;             // Any AIO support.
+	extern const bool aio_fsync;       // Kernel supports CMD_FSYNC
+	extern const bool aio_fdsync;      // Kernel supports CMD_FDSYNC
+
+	// Test if O_DIRECT supported at target path
+	bool direct_io(const string_view &path);
+}

ircd/db.cc

@@ -255,7 +255,7 @@ try
 		direct_io_test_file_path()
 	};
 
-	if(fs::direct_io_support(test_file_path))
+	if(fs::support::direct_io(test_file_path))
 		log::debug
 		{
 			log, "Detected Direct-IO works by opening test file at `%s'",

ircd/fs.cc

@@ -227,30 +227,6 @@ catch(const filesystem::filesystem_error &e)
 	throw error{e};
 }
 
-bool
-ircd::fs::direct_io_support(const string_view &path)
-try
-{
-	fd::opts opts{std::ios::out};
-	opts.direct = true;
-	fd{path, opts};
-	return true;
-}
-catch(const std::system_error &e)
-{
-	const auto &ec(e.code());
-	if(system_category(ec)) switch(ec.value())
-	{
-		case int(std::errc::invalid_argument):
-			return false;
-
-		default:
-			break;
-	}
-
-	throw;
-}
-
 size_t
 ircd::fs::size(const string_view &path)
 {
@@ -332,6 +308,62 @@ ircd::fs::path(std::string s)
 	return filesystem::path(std::move(s));
 }
 
+///////////////////////////////////////////////////////////////////////////////
+//
+// fs/support.h
+//
+
+bool
+ircd::fs::support::direct_io(const string_view &path)
+try
+{
+	fd::opts opts{std::ios::out};
+	opts.direct = true;
+	fd{path, opts};
+	return true;
+}
+catch(const std::system_error &e)
+{
+	const auto &ec(e.code());
+	if(system_category(ec)) switch(ec.value())
+	{
+		case int(std::errc::invalid_argument):
+			return false;
+
+		default:
+			break;
+	}
+
+	throw;
+}
+
+/// True if AIO is supported by this build and runtime.
+decltype(ircd::fs::support::aio)
+ircd::fs::support::aio
+{
+	#ifdef IRCD_USE_AIO
+		true
+	#else
+		false
+	#endif
+};
+
+/// True if IOCB_CMD_FSYNC is supported by AIO. If this is false then
+/// fs::fsync_opts::async=true flag is ignored.
+decltype(ircd::fs::support::aio_fsync)
+ircd::fs::support::aio_fsync
+{
+	false //TODO: Detect kernel support
+};
+
+/// True if IOCB_CMD_FDSYNC is supported by AIO. If this is false then
+/// fs::fsync_opts::async=true flag is ignored.
+decltype(ircd::fs::support::aio_fdsync)
+ircd::fs::support::aio_fdsync
+{
+	false //TODO: Detect kernel support
+};
+
 ///////////////////////////////////////////////////////////////////////////////
 //
 // fs/stdin.h
@@ -406,7 +438,7 @@ ircd::fs::fsync(const fd &fd,
 try
 {
 	#ifdef IRCD_USE_AIO
-	if(aio::context && opts.async && aio::available_fsync)
+	if(aio::context && opts.async && support::aio_fsync)
 		return aio::fsync(fd, opts);
 	#endif
 
@@ -434,7 +466,7 @@ ircd::fs::fdsync(const fd &fd,
 try
 {
 	#ifdef IRCD_USE_AIO
-	if(aio::context && opts.async && aio::available_fdsync)
+	if(aio::context && opts.async && support::aio_fdsync)
 		return aio::fdsync(fd, opts);
 	#endif
 
@@ -901,22 +933,6 @@ ircd::fs::aio::stats;
 decltype(ircd::fs::aio::context)
 ircd::fs::aio::context;
 
-/// True if IOCB_CMD_FSYNC is supported by AIO. If this is false then
-/// fs::fsync_opts::async=true flag is ignored.
-decltype(ircd::fs::aio::available_fsync)
-ircd::fs::aio::available_fsync
-{
-	false //TODO: Detect kernel support
-};
-
-/// True if IOCB_CMD_FDSYNC is supported by AIO. If this is false then
-/// fs::fsync_opts::async=true flag is ignored.
-decltype(ircd::fs::aio::available_fdsync)
-ircd::fs::aio::available_fdsync
-{
-	false //TODO: Detect kernel support
-};
-
 //
 // init
 //