io: use struct FileAt instead of separate FileDescriptor/path parameters

Author: MaxKellermann

src/io/FileDescriptor.cxx

@@ -2,6 +2,7 @@
 // author: Max Kellermann <max.kellermann@gmail.com>
 
 #include "FileDescriptor.hxx"
+#include "FileAt.hxx"
 #include "UniqueFileDescriptor.hxx"
 #include "system/Error.hxx"
 
@@ -65,10 +66,9 @@ FileDescriptor::IsSocket() const noexcept
 #ifdef __linux__
 
 bool
-FileDescriptor::Open(FileDescriptor dir, const char *pathname,
-		     int flags, mode_t mode) noexcept
+FileDescriptor::Open(FileAt file, int flags, mode_t mode) noexcept
 {
-	fd = ::openat(dir.Get(), pathname, flags | O_NOCTTY | O_CLOEXEC | O_NONBLOCK, mode);
+	fd = ::openat(file.directory.Get(), file.name, flags | O_NOCTTY | O_CLOEXEC | O_NONBLOCK, mode);
 	return IsDefined();
 }
 
@@ -101,9 +101,9 @@ FileDescriptor::OpenReadOnly(const char *pathname) noexcept
 #ifdef __linux__
 
 bool
-FileDescriptor::OpenReadOnly(FileDescriptor dir, const char *pathname) noexcept
+FileDescriptor::OpenReadOnly(FileAt file) noexcept
 {
-	return Open(dir, pathname, O_RDONLY);
+	return Open(file, O_RDONLY);
 }
 
 bool

src/io/FileDescriptor.hxx

@@ -16,6 +16,7 @@
 
 struct iovec;
 class UniqueFileDescriptor;
+struct FileAt;
 
 /**
  * An OO wrapper for a UNIX file descriptor.
@@ -96,8 +97,7 @@ public:
 
 #ifdef __linux__
 	[[nodiscard]]
-	bool Open(FileDescriptor dir, const char *pathname,
-		  int flags, mode_t mode=0666) noexcept;
+	bool Open(FileAt file, int flags, mode_t mode=0666) noexcept;
 #endif
 
 	[[nodiscard]]
@@ -113,8 +113,7 @@ public:
 
 #ifdef __linux__
 	[[nodiscard]]
-	bool OpenReadOnly(FileDescriptor dir,
-			  const char *pathname) noexcept;
+	bool OpenReadOnly(FileAt file) noexcept;
 
 	[[nodiscard]]
 	static bool CreatePipe(FileDescriptor &r, FileDescriptor &w,

src/io/FileOutputStream.cxx

@@ -10,6 +10,7 @@
 #endif
 
 #ifdef __linux__
+#include "FileAt.hxx"
 #include "io/linux/ProcPath.hxx"
 #include <fcntl.h>
 #endif
@@ -175,7 +176,7 @@ OpenTempFile(FileDescriptor directory_fd,
 	     FileDescriptor &fd, Path path) noexcept
 {
 	if (directory_fd != FileDescriptor(AT_FDCWD))
-		return fd.Open(directory_fd, ".", O_TMPFILE|O_WRONLY, 0666);
+		return fd.Open({directory_fd, "."}, O_TMPFILE|O_WRONLY, 0666);
 
 	const auto directory = path.GetDirectoryName();
 	if (directory.IsNull())
@@ -204,9 +205,13 @@ FileOutputStream::OpenCreate(bool visible)
 
 		if (fd.Open(
 #ifdef __linux__
-			    directory_fd,
+			    {
+				    directory_fd,
+#endif
+				    tmp_path.c_str(),
+#ifdef __linux__
+			    },
 #endif
-			    tmp_path.c_str(),
 			    O_WRONLY|O_CREAT|O_EXCL,
 			    0666))
 			return;
@@ -216,9 +221,13 @@ FileOutputStream::OpenCreate(bool visible)
 	/* fall back to plain POSIX */
 	if (!fd.Open(
 #ifdef __linux__
-		    directory_fd,
+		     {
+			    directory_fd,
+#endif
+			    GetPath().c_str(),
+#ifdef __linux__
+		    },
 #endif
-		    GetPath().c_str(),
 		    O_WRONLY|O_CREAT|O_TRUNC,
 		    0666))
 		throw FmtErrno("Failed to create {}", GetPath());
@@ -233,9 +242,14 @@ FileOutputStream::OpenAppend(bool create)
 
 	if (!fd.Open(
 #ifdef __linux__
-		     directory_fd,
+		     {
+			     directory_fd,
+#endif
+			     path.c_str(),
+#ifdef __linux__
+		     },
 #endif
-		     path.c_str(), flags))
+		     flags))
 		throw FmtErrno("Failed to append to {}", path);
 }
 

src/io/Open.cxx

@@ -6,9 +6,9 @@
 #include "lib/fmt/SystemError.hxx"
 
 #ifdef __linux__
+#include "FileAt.hxx"
 #include "system/linux/Features.h"
 #ifdef HAVE_OPENAT2
-#include "FileAt.hxx"
 #include "system/linux/openat2.h"
 #endif // HAVE_OPENAT2
 #endif // __linux__
@@ -62,41 +62,41 @@ OpenPath(const char *path, int flags)
 }
 
 UniqueFileDescriptor
-OpenPath(FileDescriptor directory, const char *name, int flags)
+OpenPath(FileAt file, int flags)
 {
 	UniqueFileDescriptor fd;
-	if (!fd.Open(directory, name, O_PATH|flags))
-		throw FmtErrno("Failed to open {:?}", name);
+	if (!fd.Open(file, O_PATH|flags))
+		throw FmtErrno("Failed to open {:?}", file.name);
 
 	return fd;
 }
 
 UniqueFileDescriptor
-OpenReadOnly(FileDescriptor directory, const char *name, int flags)
+OpenReadOnly(FileAt file, int flags)
 {
 	UniqueFileDescriptor fd;
-	if (!fd.Open(directory, name, O_RDONLY|flags))
-		throw FmtErrno("Failed to open {:?}", name);
+	if (!fd.Open(file, O_RDONLY|flags))
+		throw FmtErrno("Failed to open {:?}", file.name);
 
 	return fd;
 }
 
 UniqueFileDescriptor
-OpenWriteOnly(FileDescriptor directory, const char *name, int flags)
+OpenWriteOnly(FileAt file, int flags)
 {
 	UniqueFileDescriptor fd;
-	if (!fd.Open(directory, name, O_WRONLY|flags))
-		throw FmtErrno("Failed to open {:?}", name);
+	if (!fd.Open(file, O_WRONLY|flags))
+		throw FmtErrno("Failed to open {:?}", file.name);
 
 	return fd;
 }
 
 UniqueFileDescriptor
-OpenDirectory(FileDescriptor directory, const char *name, int flags)
+OpenDirectory(FileAt file, int flags)
 {
 	UniqueFileDescriptor fd;
-	if (!fd.Open(directory, name, O_DIRECTORY|O_RDONLY|flags))
-		throw FmtErrno("Failed to open {:?}", name);
+	if (!fd.Open(file, O_DIRECTORY|O_RDONLY|flags))
+		throw FmtErrno("Failed to open {:?}", file.name);
 
 	return fd;
 }

src/io/Open.hxx

@@ -5,6 +5,7 @@
 
 class FileDescriptor;
 class UniqueFileDescriptor;
+struct FileAt;
 
 UniqueFileDescriptor
 OpenReadOnly(const char *path, int flags=0);
@@ -25,19 +26,18 @@ UniqueFileDescriptor
 OpenPath(const char *path, int flags=0);
 
 UniqueFileDescriptor
-OpenPath(FileDescriptor directory, const char *name, int flags=0);
+OpenPath(FileAt file, int flags=0);
 
 UniqueFileDescriptor
-OpenReadOnly(FileDescriptor directory, const char *name, int flags=0);
+OpenReadOnly(FileAt file, int flags=0);
 
 UniqueFileDescriptor
-OpenWriteOnly(FileDescriptor directory, const char *name, int flags=0);
+OpenWriteOnly(FileAt file, int flags=0);
 
 UniqueFileDescriptor
-OpenDirectory(FileDescriptor directory, const char *name, int flags=0);
+OpenDirectory(FileAt file, int flags=0);
 
 struct opwn_how;
-struct FileAt;
 
 /**
  * Wrapper for openat2() which converts the returned file descriptor