feat(lnm): support HEAD requests

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
         * Allow custom & an arbitrary number of response headers
         * Better API for adding routes
         * State machine HTTP loop
+    * Auomatically support HEAD requests for all GET requests
 
 ## [0.2.0](https://git.rustybever.be/Chewing_Bever/lander/src/tag/0.2.0)
 

lnm/include/lnm/http/consts.h

@@ -11,7 +11,8 @@ typedef enum lnm_http_method {
   lnm_http_method_post,
   lnm_http_method_put,
   lnm_http_method_patch,
-  lnm_http_method_delete
+  lnm_http_method_delete,
+  lnm_http_method_head,
 } lnm_http_method;
 
 extern const char *lnm_http_status_names[][32];

lnm/src/http/lnm_http_consts.c

@@ -1,6 +1,7 @@
 #include "lnm/http/consts.h"
 
-const char *lnm_http_method_names[] = {"GET", "POST", "PUT", "PATCH", "DELETE"};
+const char *lnm_http_method_names[] = {"GET",   "POST",   "PUT",
+                                       "PATCH", "DELETE", "HEAD"};
 const size_t lnm_http_method_names_len =
     sizeof(lnm_http_method_names) / sizeof(lnm_http_method_names[0]);
 

lnm/src/http/lnm_http_loop_process.c

@@ -68,8 +68,14 @@ void lnm_http_loop_process_route(lnm_http_conn *conn) {
       break;
     }
 
-    // Remember the previous match levels
+    // GET routes also automatically route HEAD requests
-    int new_match_level = 2 * matched_path + (route->method == ctx->req.method);
+    bool matched_method = route->method == ctx->req.method ||
+                          (route->method == lnm_http_method_get &&
+                           ctx->req.method == lnm_http_method_head);
+    int new_match_level = 2 * matched_path + matched_method;
+
+    // Remember the previous match levels so we can return the correct status
+    // message
     match_level = match_level < new_match_level ? new_match_level : match_level;
   }
 
@@ -227,7 +233,11 @@ void lnm_http_loop_process_write_headers(lnm_http_conn *conn) {
     conn->w.buf[conn->w.size] = '\n';
     conn->w.size++;
 
-    ctx->state = ctx->res.body.len > 0 ? lnm_http_loop_state_write_body
+    // HEAD requests function exactly the same as GET requests, except that they
+    // skip the body writing part
+    ctx->state =
+        ctx->req.method != lnm_http_method_head && ctx->res.body.len > 0
+            ? lnm_http_loop_state_write_body
             : lnm_http_loop_state_finish;
   }
 }