Add sync option to control how much stuff to sync to disk

4 files changed, 25 insertions, 6 deletions

diff --git a/buffer.c b/buffer.c
index ad1ee55..d5532d4 100644
--- a/buffer.c
+++ b/buffer.c
@@ -3264,12 +3264,19 @@ static bool buffer_write_to_file(TextBuffer *buffer, const char *path) {
 		success = false;
 	}
 	fflush(out);
-	// make sure data is on disk before returning from this function
-	#if __unix__
-	fdatasync(fileno(out));
-	#elif _WIN32
-	_commit(_fileno(out));
-	#endif
+	const char *sync = rc_str(settings->sync, "none");
+	if (!streq(sync, "none")) {
+		// make sure data is on disk before returning from this function
+		#if __unix__
+		if (streq(sync, "data")) {
+			fdatasync(fileno(out));
+		} else {
+			fsync(fileno(out));
+		}
+		#elif _WIN32
+		_commit(_fileno(out));
+		#endif
+	}
 	if (fclose(out) != 0) {
 		if (!buffer_has_error(buffer))
 			buffer_error(buffer, "Couldn't close file %s.", path);
diff --git a/config.c b/config.c
index 7bdcc7c..12153d2 100644
--- a/config.c
+++ b/config.c
@@ -166,6 +166,7 @@ static const SettingString settings_string[] = {
 	{"comment-end", &settings_zero.comment_end, true},
 	{"font", &settings_zero.font, false},
 	{"font-bold", &settings_zero.font_bold, false},
+	{"sync", &settings_zero.sync, false},
 };
 static const SettingKeyCombo settings_key_combo[] = {
 	{"hover-key", &settings_zero.hover_key, true},
diff --git a/ted-internal.h b/ted-internal.h
index f5e3211..dd109ea 100644
--- a/ted-internal.h
+++ b/ted-internal.h
@@ -151,6 +151,11 @@ struct Settings {
 	RcStr *font;
 	/// Comma separated list of paths to bold font files.
 	RcStr *font_bold;
+	/// How to sync data when writing a file
+	/// - none - don't sync to disk
+	/// - full - sync data and metadata to disk
+	/// - data - only sync data but not metadata (on Windows this is the same as full)
+	RcStr *sync;
 	LanguageExtension *language_extensions;
 	/// dynamic array, sorted by KEY_COMBO(modifier, key)
 	KeyAction *key_actions;
diff --git a/ted.cfg b/ted.cfg
index ea59963..5a20477 100644
--- a/ted.cfg
+++ b/ted.cfg
@@ -133,6 +133,12 @@ root-identifiers = .ted-root, .ted-root.out, Cargo.toml, make.bat, CMakeLists.tx
 # writing to the file (prevents loss of data if power goes out mid-write or something).
 # the backups are deleted immediately after writing.
 save-backup = yes
+# how much data to sync to disk on :save
+# this can be one of:
+#    - none: don't sync to disk (you may lose data if power goes out)
+#    - full: sync data and metadata to disk (fsync)
+#    - data: sync data to disk but not metadata (fsyncdata) (on Windows this is the same as full)
+sync = data
 # whether to save files with \r\n line endings.
 crlf = no
 # same as crlf setting, but ignored on non-Windows operating system.