http handler: avoid method allocation

We limit HTTP method lengths to 32.. there are no currently defined
HTTP methods that need more than 19 bytes (including trailing zero.)

Generally most servers will not have vast numbers of handlers, so the
cost of allocating some storage up front to avoid the dynamic allocation
is worth while.

2 files changed, 29 insertions, 20 deletions

diff --git a/src/supplemental/http/http_server.c b/src/supplemental/http/http_server.c
index 64edf456..ba89626b 100644
--- a/src/supplemental/http/http_server.c
+++ b/src/supplemental/http/http_server.c
@@ -25,7 +25,7 @@
 struct nng_http_handler {
 	nni_list_node   node;
 	char           *uri;
-	char           *method;
+	char            method[32];
 	char           *host;
 	nng_sockaddr    host_addr;
 	bool            host_ip;
@@ -114,8 +114,7 @@ nni_http_handler_init(
 	if ((uri == NULL) || (strlen(uri) == 0) || (strcmp(uri, "/") == 0)) {
 		uri = "";
 	}
-	if (((h->uri = nni_strdup(uri)) == NULL) ||
-	    ((h->method = nni_strdup("GET")) == NULL)) {
+	if ((h->uri = nni_strdup(uri)) == NULL) {
 		nni_http_handler_fini(h);
 		return (NNG_ENOMEM);
 	}
@@ -126,9 +125,10 @@ nni_http_handler_init(
 	h->host           = NULL;
 	h->tree           = false;
 	h->tree_exclusive = false;
-	h->maxbody = 1024 * 1024; // By default we accept up to 1MB of body
-	h->getbody = true;
-	*hp        = h;
+	h->maxbody        = 1024 * 1024; // Up to 1MB of body
+	h->getbody        = true;
+	strcpy(h->method, "GET");
+	*hp = h;
 	return (0);
 }
 
@@ -145,7 +145,6 @@ nni_http_handler_fini(nni_http_handler *h)
 	}
 	nni_strfree(h->host);
 	nni_strfree(h->uri);
-	nni_strfree(h->method);
 	NNI_FREE_STRUCT(h);
 }
 
@@ -252,21 +251,16 @@ nni_http_handler_set_host(nni_http_handler *h, const char *host)
 int
 nni_http_handler_set_method(nni_http_handler *h, const char *method)
 {
-	char *dup;
-
 	if (nni_atomic_get_bool(&h->busy) != 0) {
 		return (NNG_EBUSY);
 	}
 	if (method == NULL) {
-		nni_strfree(h->method);
-		h->method = NULL;
-		return (0);
+		method = "";
 	}
-	if ((dup = nni_strdup(method)) == NULL) {
-		return (NNG_ENOMEM);
+	if (strlen(method) >= sizeof(h->method)) {
+		return (NNG_EINVAL);
 	}
-	nni_strfree(h->method);
-	h->method = dup;
+	(void) snprintf(h->method, sizeof(h->method), "%s", method);
 	return (0);
 }
 
@@ -663,7 +657,7 @@ http_sconn_rxdone(void *arg)
 			continue; // Some other substring, not matched.
 		}
 
-		if ((h->method == NULL) || (h->method[0] == '\0')) {
+		if (h->method[0] == '\0') {
 			// Handler wants to process *all* methods.
 			break;
 		}
@@ -1220,11 +1214,11 @@ nni_http_server_add_handler(nni_http_server *s, nni_http_handler *h)
 		    ((h->host == NULL) && (h2->host != NULL))) {
 			continue; // Host specified for just one.
 		}
-		if (((h->method == NULL) && (h2->method != NULL)) ||
-		    ((h2->method == NULL) && (h->method != NULL))) {
+		if (((h->method[0] == 0) && (h2->method[0] != 0)) ||
+		    ((h2->method[0] == 0) && (h->method[0] != 0))) {
 			continue; // Method specified for just one.
 		}
-		if ((h->method != NULL) &&
+		if ((h->method[0] != 0) &&
 		    (strcmp(h2->method, h->method) != 0)) {
 			// Different methods, so again we are fine.
 			continue;
diff --git a/src/supplemental/http/http_server_test.c b/src/supplemental/http/http_server_test.c
index 2d1e4b28..2ed04c4d 100644
--- a/src/supplemental/http/http_server_test.c
+++ b/src/supplemental/http/http_server_test.c
@@ -339,6 +339,20 @@ test_server_missing_host(void)
 }
 
 void
+test_server_method_too_long(void)
+{
+	nng_http_handler *h;
+
+	NUTS_PASS(nng_http_handler_alloc_static(
+	    &h, "/home.html", doc1, strlen(doc1), "text/html"));
+
+	NUTS_FAIL(nng_http_handler_set_method(h,
+	              "THISMETHODISFARFARTOOLONGTOBEVALIDASAMETHODASITISLONGER"
+	              "THANTHIRTYTWOBYTES"),
+	    NNG_EINVAL);
+}
+
+void
 test_server_wrong_method(void)
 {
 	struct server_test st;
@@ -898,6 +912,7 @@ NUTS_TESTS = {
 	{ "server bad version", test_server_bad_version },
 	{ "server missing host", test_server_missing_host },
 	{ "server wrong method", test_server_wrong_method },
+	{ "server method too long", test_server_method_too_long },
 	{ "server post handler", test_server_post_handler },
 	{ "server get redirect", test_server_get_redirect },
 	{ "server tree redirect", test_server_tree_redirect },