From fdd34239fc386f72b7be7210a647cca5ac467f21 Mon Sep 17 00:00:00 2001
From: "C. McEnroe" <june@causal.agency>
Date: Thu, 26 Dec 2019 15:49:29 -0500
Subject: Use bsearch to find handler

The code is a bit cleaner this way I think, and performance would be
better if the list of handlers ever got very long, and it was sorted
anyway.

However, I would prefer if there were a way to enforce the list being
sorted at compile-time.
---
 litterbox.c | 27 ++++++++++++++++-----------
 1 file changed, 16 insertions(+), 11 deletions(-)

(limited to 'litterbox.c')

diff --git a/litterbox.c b/litterbox.c
index 3a54bf5..57d30cb 100644
--- a/litterbox.c
+++ b/litterbox.c
@@ -443,7 +443,7 @@ static void handleError(struct Message *msg) {
 	errx(EX_UNAVAILABLE, "%s", msg->params[0]);
 }
 
-static const struct {
+static const struct Handler {
 	const char *cmd;
 	bool transaction;
 	Handler *fn;
@@ -469,18 +469,23 @@ static const struct {
 	{ "TOPIC", true, handleTopic },
 };
 
+static int compar(const void *cmd, const void *_handler) {
+	const struct Handler *handler = _handler;
+	return strcmp(cmd, handler->cmd);
+}
+
 static void handle(struct Message msg) {
 	if (!msg.cmd) return;
-	for (size_t i = 0; i < ARRAY_LEN(Handlers); ++i) {
-		if (strcmp(msg.cmd, Handlers[i].cmd)) continue;
-		if (Handlers[i].transaction) {
-			dbExec(SQL(BEGIN TRANSACTION;));
-			Handlers[i].fn(&msg);
-			dbExec(SQL(COMMIT TRANSACTION;));
-		} else {
-			Handlers[i].fn(&msg);
-		}
-		break;
+	const struct Handler *handler = bsearch(
+		msg.cmd, Handlers, ARRAY_LEN(Handlers), sizeof(*handler), compar
+	);
+	if (!handler) return;
+	if (handler->transaction) {
+		dbExec(SQL(BEGIN TRANSACTION;));
+		handler->fn(&msg);
+		dbExec(SQL(COMMIT TRANSACTION;));
+	} else {
+		handler->fn(&msg);
 	}
 }
 
-- 
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