feat: allow matching regex routes

include/http.h

@@ -1,12 +1,14 @@
 #ifndef HTTP
 #define HTTP
 
+#include <regex.h>
 #include <stdbool.h>
 #include <stdlib.h>
 
 #include "picohttpparser.h"
 
 #define HTTP_MAX_ALLOWED_HEADERS 16
+#define HTTP_MAX_REGEX_GROUPS 4
 
 extern const char *http_response_type_names[5][32];
 extern const char *http_header_names[];
@@ -33,6 +35,7 @@ typedef struct http_request {
   size_t path_len;
   const char *query;
   size_t query_len;
+  regmatch_t regex_groups[HTTP_MAX_REGEX_GROUPS];
   struct phr_header headers[HTTP_MAX_ALLOWED_HEADERS];
 } http_request;
 

include/http_loop.h

@@ -105,4 +105,6 @@ void http_loop_res_add_header(http_loop_ctx *ctx, http_header type,
  */
 event_loop *http_loop_init(http_loop_gctx *gctx);
 
+void http_loop_run(event_loop *el, int port);
+
 #endif

src/http_loop/http_loop.c

@@ -1,5 +1,8 @@
-#include "http_loop.h"
+#include <regex.h>
+
 #include "http.h"
+#include "http_loop.h"
+#include "log.h"
 
 bool http_loop_handle_request(event_loop_conn *conn) {
   // Prevents the request handler function from looping indefinitely without
@@ -54,3 +57,28 @@ event_loop *http_loop_init(http_loop_gctx *gctx) {
 
   return el;
 }
+
+void http_loop_run(event_loop *el, int port) {
+  debug("Compiling RegEx routes");
+
+  http_loop_gctx *gctx = el->gctx;
+  http_route *route;
+
+  for (size_t i = 0; i < gctx->route_count; i++) {
+    route = &gctx->routes[i];
+
+    if (route->type == http_route_regex) {
+      regex_t *r = calloc(sizeof(regex_t), 1);
+
+      if (regcomp(r, route->path, 0) != 0) {
+        critical(1, "RegEx expression '%s' failed to compile", route->path);
+      }
+
+      route->regex = r;
+    }
+  }
+
+  debug("RegEx routes compiled successfully");
+
+  event_loop_run(el, port);
+}

src/http_loop/http_loop_req.c

@@ -12,11 +12,14 @@ http_parse_error http_loop_parse_request(event_loop_conn *conn) {
 
   const char *method;
   size_t method_len;
+  char *path;
+  size_t path_len;
 
-  int res = phr_parse_request(
-      (const char *)&conn->rbuf[conn->rbuf_read],
-      conn->rbuf_size - conn->rbuf_read, &method, &method_len, &req->path,
-      &req->path_len, &req->minor_version, req->headers, &num_headers, 0);
+  int res =
+      phr_parse_request((const char *)&conn->rbuf[conn->rbuf_read],
+                        conn->rbuf_size - conn->rbuf_read, &method, &method_len,
+                        (const char **)&path, &path_len, &req->minor_version,
+                        req->headers, &num_headers, 0);
 
   if (res == -1) {
     return http_parse_error_invalid;
@@ -45,16 +48,16 @@ http_parse_error http_loop_parse_request(event_loop_conn *conn) {
   i = 0;
   bool no_query = true;
 
-  while (no_query && i < req->path_len) {
-    if (req->path[i] == '?') {
+  while (no_query && i < path_len) {
+    if (path[i] == '?') {
       // Ensure we don't store an invalid pointer if the request simply ends
       // with '?'
       if (i + 1 < req->path_len) {
-        req->query = &req->path[i + 1];
-        req->query_len = req->path_len - (i + 1);
+        req->query = &path[i + 1];
+        req->query_len = path_len - (i + 1);
       }
 
-      req->path_len = i;
+      path_len = i;
 
       no_query = false;
     }
@@ -62,6 +65,15 @@ http_parse_error http_loop_parse_request(event_loop_conn *conn) {
     i++;
   }
 
+  // The path needs to be NULL-terminated in order for regex routes to be
+  // matched properly. We know we can overwrite this char because it's either
+  // '?' if there's a query, or '\n' because we know the buf contains a valid
+  // HTTP rqeuest
+  path[path_len] = '\0';
+
+  req->path = path;
+  req->path_len = path_len;
+
   // Ensure we clear the old request's query
   if (no_query) {
     req->query = NULL;
@@ -80,6 +92,7 @@ void http_loop_route_request(event_loop_conn *conn) {
 
   http_route *route;
   bool path_matched = false;
+  char c;
 
   for (size_t i = 0; i < gctx->route_count; i++) {
     route = &gctx->routes[i];
@@ -95,8 +108,17 @@ void http_loop_route_request(event_loop_conn *conn) {
         }
       }
       break;
-    // TODO
-    case http_route_regex:;
+    case http_route_regex:
+      if (regexec(route->regex, ctx->req.path, HTTP_MAX_REGEX_GROUPS,
+                  ctx->req.regex_groups, 0) == 0) {
+        path_matched = true;
+
+        if (ctx->req.method == route->method) {
+          ctx->route = route;
+          return;
+        }
+      }
+      break;
     }
   }
 

src/main.c

@@ -25,10 +25,26 @@ bool lander_get_index(event_loop_conn *conn) {
   return true;
 }
 
+bool lander_get_entry(event_loop_conn *conn) {
+  http_loop_ctx *ctx = conn->ctx;
+
+  size_t match_len =
+      ctx->req.regex_groups[1].rm_eo - ctx->req.regex_groups[1].rm_so;
+  info("matched: %.*s", match_len,
+       &ctx->req.path[ctx->req.regex_groups[1].rm_so]);
+  conn->state = event_loop_conn_state_res;
+
+  return true;
+}
+
 http_route routes[] = {{.type = http_route_literal,
                         .method = http_get,
                         .path = "/",
-                        .steps = {lander_get_index, NULL}}};
+                        .steps = {lander_get_index, NULL}},
+                       {.type = http_route_regex,
+                        .method = http_get,
+                        .path = "^/\\([^/]\\+\\)$",
+                        .steps = {lander_get_entry, NULL}}};
 
 int main() {
   setvbuf(stdout, NULL, _IONBF, 0);
@@ -50,5 +66,5 @@ int main() {
   gctx->route_count = sizeof(routes) / sizeof(routes[0]);
   event_loop *el = http_loop_init(gctx);
 
-  event_loop_run(el, 8000);
+  http_loop_run(el, 8000);
 }