ircd::fs: Refactor fs::read stack for fs::fd.

include/ircd/fs/read.h

@@ -16,9 +16,11 @@ namespace ircd::fs
 	struct read_opts extern const read_opts_default;
 
 	// Yields ircd::ctx for read into buffer; returns view of read portion.
+	const_buffer read(const fd &, const mutable_buffer &, const read_opts & = read_opts_default);
 	const_buffer read(const string_view &path, const mutable_buffer &, const read_opts & = read_opts_default);
 
 	// Yields ircd::ctx for read into allocated string; returns that string
+	std::string read(const fd &, const read_opts & = read_opts_default);
 	std::string read(const string_view &path, const read_opts & = read_opts_default);
 }
 

ircd/aio.cc

@@ -293,68 +293,14 @@ ircd::fs::aio::request::read::read(const int &fd,
 // ircd::fs interface
 //
 
-std::string
-ircd::fs::read__aio(const string_view &path,
-                    const read_opts &opts)
-{
-	// Path to open(2) must be null terminated;
-	static thread_local char pathstr[2048];
-	strlcpy(pathstr, path, sizeof(pathstr));
-
-	uint flags{0};
-	flags |= O_RDONLY;
-	flags |= O_CLOEXEC;
-
-	const auto fd
-	{
-		syscall(::open, pathstr, flags, 0)
-	};
-
-	const unwind cfd{[&fd]
-	{
-		syscall(::close, fd);
-	}};
-
-	struct stat stat;
-	syscall(::fstat, fd, &stat);
-	return string(stat.st_size, [&fd, &opts]
-	(const mutable_buffer &buf)
-	{
-		aio::request::read request
-		{
-			int(fd), buf, opts
-		};
-
-		return request();
-	});
-}
-
 ircd::const_buffer
-ircd::fs::read__aio(const string_view &path,
+ircd::fs::read__aio(const fd &fd,
                     const mutable_buffer &buf,
                     const read_opts &opts)
 {
-	// Path to open(2) must be null terminated;
-	static thread_local char pathstr[2048];
-	strlcpy(pathstr, path, sizeof(pathstr));
-
-	uint flags{0};
-	flags |= O_RDONLY;
-	flags |= O_CLOEXEC;
-
-	const auto fd
-	{
-		syscall(::open, pathstr, flags, 0)
-	};
-
-	const unwind cfd{[&fd]
-	{
-		syscall(::close, fd);
-	}};
-
 	aio::request::read request
 	{
-		int(fd), buf, opts
+		fd, buf, opts
 	};
 
 	const size_t bytes

ircd/aio.h

@@ -75,8 +75,7 @@ struct ircd::fs::aio::request
 namespace ircd::fs
 {
 	const_buffer write__aio(const string_view &path, const const_buffer &, const write_opts &);
-	const_buffer read__aio(const string_view &path, const mutable_buffer &, const read_opts &);
+	const_buffer read__aio(const fd &, const mutable_buffer &, const read_opts &);
-	std::string read__aio(const string_view &path, const read_opts &);
 }
 
 /// Read request control block

ircd/fs.cc

@@ -114,12 +114,6 @@ ircd::fs::stdin::readline(const mutable_buffer &buf)
 // fs/read.h
 //
 
-namespace ircd::fs
-{
-	const_buffer read__std(const string_view &path, const mutable_buffer &, const read_opts &);
-	std::string read__std(const string_view &path, const read_opts &);
-}
-
 ircd::fs::read_opts
 const ircd::fs::read_opts_default
 {};
@@ -133,12 +127,16 @@ ircd::fs::read(const string_view &path,
                const read_opts &opts)
 try
 {
-	#ifdef IRCD_USE_AIO
+	const fd fd
-	if(likely(aioctx))
+	{
-		return read__aio(path, opts);
+		path
-	#endif
+	};
 
-	return read__std(path, opts);
+	return read(fd, opts);
+}
+catch(const filesystem_error &)
+{
+	throw;
 }
 catch(const std::exception &e)
 {
@@ -148,18 +146,33 @@ catch(const std::exception &e)
 	};
 }
 
+std::string
+ircd::fs::read(const fd &fd,
+               const read_opts &opts)
+{
+	return string(size(fd), [&fd, &opts]
+	(const mutable_buffer &buf)
+	{
+		return read(fd, buf, opts);
+	});
+}
+
 ircd::const_buffer
 ircd::fs::read(const string_view &path,
                const mutable_buffer &buf,
                const read_opts &opts)
 try
 {
-	#ifdef IRCD_USE_AIO
+	const fd fd
-	if(likely(aioctx))
+	{
-		return read__aio(path, buf, opts);
+		path
-	#endif
+	};
 
-	return read__std(path, buf, opts);
+	return read(fd, buf, opts);
+}
+catch(const filesystem_error &)
+{
+	throw;
 }
 catch(const std::exception &e)
 {
@@ -169,33 +182,32 @@ catch(const std::exception &e)
 	};
 }
 
-//
-// std read
-//
-
-std::string
-ircd::fs::read__std(const string_view &path,
-                    const read_opts &opts)
-{
-	std::ifstream file{std::string{path}};
-	std::noskipws(file);
-	std::istream_iterator<char> b{file};
-	std::istream_iterator<char> e{};
-	return std::string{b, e};
-}
-
 ircd::const_buffer
-ircd::fs::read__std(const string_view &path,
+ircd::fs::read(const fd &fd,
                const mutable_buffer &buf,
                const read_opts &opts)
+try
 {
-	std::ifstream file{std::string{path}};
+	#ifdef IRCD_USE_AIO
-	file.exceptions(file.failbit | file.badbit);
+	if(likely(aioctx))
-	file.seekg(opts.offset, file.beg);
+		return read__aio(fd, buf, opts);
-	file.read(data(buf), size(buf));
+	#endif
+
 	return
 	{
-		data(buf), size_t(file.gcount())
+		data(buf),
+		size_t(syscall(::pread, fd, data(buf), size(buf), opts.offset))
+	};
+}
+catch(const filesystem_error &)
+{
+	throw;
+}
+catch(const std::exception &e)
+{
+	throw filesystem_error
+	{
+		"%s", e.what()
 	};
 }