client: add tag_mask attribute

The "tagtypes" command now has several sub commands which can be used
to edit that mask.

src/TagPrint.cxx

@@ -40,8 +40,10 @@ tag_print(Response &r, TagType type, const char *value)
 void
 tag_print_values(Response &r, const Tag &tag)
 {
+	const auto tag_mask = r.GetTagMask();
 	for (const auto &i : tag)
-		tag_print(r, i.type, i.value);
+		if (tag_mask.Test(i.type))
+			tag_print(r, i.type, i.value);
 }
 
 void

src/client/Client.hxx

@@ -23,6 +23,7 @@
 #include "check.h"
 #include "ClientMessage.hxx"
 #include "command/CommandListBuilder.hxx"
+#include "tag/Mask.hxx"
 #include "event/FullyBufferedSocket.hxx"
 #include "event/TimeoutMonitor.hxx"
 #include "Compiler.h"
@@ -70,6 +71,11 @@ public:
 	/** idle flags that the client wants to receive */
 	unsigned idle_subscriptions;
 
+	/**
+	 * The tags this client is interested in.
+	 */
+	TagMask tag_mask = TagMask::All();
+
 	/**
 	 * A list of channel names this client is subscribed to.
 	 */

src/client/Response.cxx

@@ -23,6 +23,12 @@
 #include "util/FormatString.hxx"
 #include "util/AllocatedString.hxx"
 
+TagMask
+Response::GetTagMask() const
+{
+	return GetClient().tag_mask;
+}
+
 bool
 Response::Write(const void *data, size_t length)
 {

src/client/Response.hxx

@@ -22,11 +22,13 @@
 
 #include "check.h"
 #include "protocol/Ack.hxx"
+#include "Compiler.h"
 
 #include <stddef.h>
 #include <stdarg.h>
 
 class Client;
+class TagMask;
 
 class Response {
 	Client &client;
@@ -59,6 +61,13 @@ public:
 		return client;
 	}
 
+	/**
+	 * Accessor for Client::tag_mask.  Can be used if caller wants
+	 * to avoid including Client.hxx.
+	 */
+	gcc_pure
+	TagMask GetTagMask() const;
+
 	void SetCommand(const char *_command) {
 		command = _command;
 	}

src/command/AllCommands.cxx

@@ -187,7 +187,7 @@ static constexpr struct command commands[] = {
 	{ "subscribe", PERMISSION_READ, 1, 1, handle_subscribe },
 	{ "swap", PERMISSION_CONTROL, 2, 2, handle_swap },
 	{ "swapid", PERMISSION_CONTROL, 2, 2, handle_swapid },
-	{ "tagtypes", PERMISSION_READ, 0, 0, handle_tagtypes },
+	{ "tagtypes", PERMISSION_READ, 0, -1, handle_tagtypes },
 	{ "toggleoutput", PERMISSION_ADMIN, 1, 1, handle_toggleoutput },
 #ifdef ENABLE_DATABASE
 	{ "unmount", PERMISSION_ADMIN, 1, 1, handle_unmount },

src/command/ClientCommands.cxx

@@ -24,6 +24,8 @@
 #include "client/Client.hxx"
 #include "client/Response.hxx"
 #include "TagPrint.hxx"
+#include "tag/ParseName.hxx"
+#include "util/StringAPI.hxx"
 
 CommandResult
 handle_close(gcc_unused Client &client, gcc_unused Request args,
@@ -53,10 +55,58 @@ handle_password(Client &client, Request args, Response &r)
 	return CommandResult::OK;
 }
 
-CommandResult
-handle_tagtypes(gcc_unused Client &client, gcc_unused Request request,
-		Response &r)
+static TagMask
+ParseTagMask(Request request)
 {
-	tag_print_types(r);
-	return CommandResult::OK;
+	if (request.IsEmpty())
+		throw ProtocolError(ACK_ERROR_ARG, "Not enough arguments");
+
+	TagMask result = TagMask::None();
+
+	for (const char *name : request) {
+		auto type = tag_name_parse_i(name);
+		if (type == TAG_NUM_OF_ITEM_TYPES)
+			throw ProtocolError(ACK_ERROR_ARG, "Unknown tag type");
+
+		result |= type;
+	}
+
+	return result;
+}
+
+CommandResult
+handle_tagtypes(Client &client, Request request, Response &r)
+{
+	if (request.IsEmpty()) {
+		tag_print_types(r);
+		return CommandResult::OK;
+	}
+
+	const char *cmd = request.shift();
+	if (StringIsEqual(cmd, "all")) {
+		if (!request.IsEmpty()) {
+			r.Error(ACK_ERROR_ARG, "Too many arguments");
+			return CommandResult::ERROR;
+		}
+
+		client.tag_mask = TagMask::All();
+		return CommandResult::OK;
+	} else if (StringIsEqual(cmd, "clear")) {
+		if (!request.IsEmpty()) {
+			r.Error(ACK_ERROR_ARG, "Too many arguments");
+			return CommandResult::ERROR;
+		}
+
+		client.tag_mask = TagMask::None();
+		return CommandResult::OK;
+	} else if (StringIsEqual(cmd, "enable")) {
+		client.tag_mask |= ParseTagMask(request);
+		return CommandResult::OK;
+	} else if (StringIsEqual(cmd, "disable")) {
+		client.tag_mask &= ~ParseTagMask(request);
+		return CommandResult::OK;
+	} else {
+		r.Error(ACK_ERROR_ARG, "Unknown sub command");
+		return CommandResult::ERROR;
+	}
 }

src/command/OtherCommands.cxx

@@ -97,7 +97,8 @@ print_tag(TagType type, const char *value, void *ctx)
 {
 	auto &r = *(Response *)ctx;
 
-	tag_print(r, type, value);
+	if (r.GetClient().tag_mask.Test(type))
+		tag_print(r, type, value);
 }
 
 CommandResult

src/db/DatabasePrint.cxx

@@ -196,8 +196,9 @@ PrintUniqueTag(Response &r, TagType tag_type,
 	assert(value != nullptr);
 	tag_print(r, tag_type, value);
 
+	const auto tag_mask = r.GetTagMask();
 	for (const auto &item : tag)
-		if (item.type != tag_type)
+		if (item.type != tag_type && tag_mask.Test(item.type))
 			tag_print(r, item.type, item.value);
 }