tag/Handler: convert to class with virtual methods

2 files changed, 27 insertions, 28 deletions

diff --git a/src/command/FileCommands.cxx b/src/command/FileCommands.cxx
index 488c6a798..744db8619 100644
--- a/src/command/FileCommands.cxx
+++ b/src/command/FileCommands.cxx
@@ -137,25 +137,24 @@ IsValidValue(const char *p) noexcept
 	return true;
 }
 
-static void
-print_pair(const char *key, const char *value, void *ctx)
-{
-	auto &r = *(Response *)ctx;
+class PrintCommentHandler final : public NullTagHandler {
+	Response &response;
 
-	if (IsValidName(key) && IsValidValue(value))
-		r.Format("%s: %s\n", key, value);
-}
+public:
+	explicit PrintCommentHandler(Response &_response) noexcept
+		:NullTagHandler(WANT_PAIR), response(_response) {}
 
-static constexpr TagHandler print_comment_handler = {
-	nullptr,
-	nullptr,
-	print_pair,
+	void OnPair(const char *key, const char *value) noexcept override {
+		if (IsValidName(key) && IsValidValue(value))
+			response.Format("%s: %s\n", key, value);
+	}
 };
 
 static CommandResult
 read_stream_comments(Response &r, const char *uri)
 {
-	if (!tag_stream_scan(uri, print_comment_handler, &r)) {
+	PrintCommentHandler h(r);
+	if (!tag_stream_scan(uri, h)) {
 		r.Error(ACK_ERROR_NO_EXIST, "Failed to load file");
 		return CommandResult::ERROR;
 	}
@@ -167,12 +166,13 @@ read_stream_comments(Response &r, const char *uri)
 static CommandResult
 read_file_comments(Response &r, const Path path_fs)
 {
-	if (!tag_file_scan(path_fs, print_comment_handler, &r)) {
+	PrintCommentHandler h(r);
+	if (!tag_file_scan(path_fs, h)) {
 		r.Error(ACK_ERROR_NO_EXIST, "Failed to load file");
 		return CommandResult::ERROR;
 	}
 
-	ScanGenericTags(path_fs, print_comment_handler, &r);
+	ScanGenericTags(path_fs, h);
 
 	return CommandResult::OK;
 
diff --git a/src/command/OtherCommands.cxx b/src/command/OtherCommands.cxx
index b748ce2ff..b08468aca 100644
--- a/src/command/OtherCommands.cxx
+++ b/src/command/OtherCommands.cxx
@@ -93,15 +93,6 @@ handle_kill(gcc_unused Client &client, gcc_unused Request request,
 	return CommandResult::KILL;
 }
 
-static void
-print_tag(TagType type, const char *value, void *ctx)
-{
-	auto &r = *(Response *)ctx;
-
-	if (r.GetClient().tag_mask.Test(type))
-		tag_print(r, type, value);
-}
-
 CommandResult
 handle_listfiles(Client &client, Request args, Response &r)
 {
@@ -149,16 +140,24 @@ handle_listfiles(Client &client, Request args, Response &r)
 	gcc_unreachable();
 }
 
-static constexpr TagHandler print_tag_handler = {
-	nullptr,
-	print_tag,
-	nullptr,
+class PrintTagHandler final : public NullTagHandler {
+	Response &response;
+
+public:
+	explicit PrintTagHandler(Response &_response) noexcept
+		:NullTagHandler(WANT_TAG), response(_response) {}
+
+	void OnTag(TagType type, const char *value) noexcept override {
+		if (response.GetClient().tag_mask.Test(type))
+			tag_print(response, type, value);
+	}
 };
 
 static CommandResult
 handle_lsinfo_absolute(Response &r, const char *uri)
 {
-	if (!tag_stream_scan(uri, print_tag_handler, &r)) {
+	PrintTagHandler h(r);
+	if (!tag_stream_scan(uri, h)) {
 		r.Error(ACK_ERROR_NO_EXIST, "No such file");
 		return CommandResult::ERROR;
 	}