refactor(routing): moved some stuff, added some comments

Makefile

@@ -73,7 +73,7 @@ $(BINS_TEST): %: %.c.o $(LIB)
 $(BUILD_DIR)/$(TEST_DIR)/%.c.o: $(TEST_DIR)/%.c
 	mkdir -p $(dir $@)
 	$(CC) $(_CFLAGS) -I$(TEST_DIR) \
-		-I$(dir $(@:$(BUILD_DIR)/$(TEST_DIR)/%=$(SRC_DIR)/%)) \
+		-I$(SRC_DIR)/_include \
 		-c $< -o $@
 
 # =====EXAMPLES=====

example/blocking.c

@@ -21,15 +21,19 @@ lnm_http_step_err slow_step(lnm_http_conn *conn) {
 int main() {
   lnm_http_loop *hl;
   lnm_http_step *step = NULL;
-  lnm_http_route *route;
 
   lnm_http_loop_init(&hl, NULL, ctx_init,
                      ctx_reset,
                      ctx_free);
 
-  lnm_http_step_append(&step, slow_step, true);
+  lnm_http_router *router;
-  lnm_http_route_init_literal(&route, lnm_http_method_get, "/", step);
+  lnm_http_router_init(&router);
-  lnm_http_loop_route_add(hl, route);
+
+  lnm_http_route *route;
+  lnm_http_router_add(&route, router, lnm_http_method_get, "/");
+  lnm_http_route_step_append(route, slow_step, true);
+
+  lnm_http_loop_router_set(hl, router);
 
   lnm_log_init_global();
   lnm_log_register_stdout(lnm_log_level_debug);

example/routing.c

@@ -0,0 +1,70 @@
+#include <unistd.h>
+
+#include "lnm/http/req.h"
+#include "lnm/log.h"
+#include "lnm/loop.h"
+#include "lnm/http/loop.h"
+
+lnm_err ctx_init(void **c_ctx, void *gctx) {
+  *c_ctx = NULL;
+
+  return lnm_err_ok;
+}
+
+void ctx_reset(void *c_ctx) {}
+void ctx_free(void *c_ctx) {}
+
+lnm_http_step_err print_step(lnm_http_conn *conn) {
+  lnm_http_loop_ctx *ctx = conn->ctx;
+
+  const char *key;
+  size_t key_len = lnm_http_req_route_segment(&key, &ctx->req, "key") ;
+  lnm_linfo("main", "key: %.*s", key_len, key);
+  return lnm_http_step_err_done;
+}
+
+lnm_http_step_err print_step2(lnm_http_conn *conn) {
+  lnm_http_loop_ctx *ctx = conn->ctx;
+
+  const char *key;
+  size_t key_len = lnm_http_req_route_segment(&key, &ctx->req, "key") ;
+  lnm_linfo("main", "yuhh key: %.*s", key_len, key);
+  return lnm_http_step_err_done;
+}
+
+lnm_http_step_err print_step3(lnm_http_conn *conn) {
+  lnm_http_loop_ctx *ctx = conn->ctx;
+
+  const char *key;
+  size_t key_len = lnm_http_req_route_segment(&key, &ctx->req, "cool") ;
+  lnm_linfo("main", "cool: %.*s", key_len, key);
+  return lnm_http_step_err_done;
+}
+
+
+int main() {
+  lnm_http_loop *hl;
+
+  lnm_http_loop_init(&hl, NULL, ctx_init,
+                     ctx_reset,
+                     ctx_free);
+
+  lnm_http_router *router;
+  lnm_http_router_init(&router);
+
+  lnm_http_route *route;
+  lnm_http_router_add(&route, router, lnm_http_method_get, "/emma");
+  lnm_http_router_add(&route, router, lnm_http_method_get, "/:key");
+  lnm_http_route_step_append(route, print_step, false);
+  lnm_http_router_add(&route, router, lnm_http_method_get, "/:key/two");
+  lnm_http_route_step_append(route, print_step2, false);
+  lnm_http_router_add(&route, router, lnm_http_method_get, "/*cool");
+  lnm_http_route_step_append(route, print_step3, false);
+
+  lnm_http_loop_router_set(hl, router);
+
+  lnm_log_init_global();
+  lnm_log_register_stdout(lnm_log_level_debug);
+
+  printf("res = %i\n", lnm_http_loop_run(hl, 8080, 1, 0));
+}

include/lnm/common.h

@@ -32,6 +32,9 @@ typedef enum lnm_err {
   lnm_err_not_setup,
   lnm_err_bad_regex,
   lnm_err_not_found,
+  lnm_err_already_present,
+  lnm_err_invalid_route,
+  lnm_err_overlapping_route,
 } lnm_err;
 
 typedef struct lnm_loop lnm_http_loop;
@@ -86,4 +89,12 @@ uint64_t lnm_atoi(const char *s, size_t len);
  */
 uint64_t lnm_digits(uint64_t num);
 
+/**
+ * Check whether the given nul-terminated string solely consists of ASCII
+ * characters.
+ *
+ * @param s nul-terminated string to check
+ */
+bool lnm_is_ascii(const char *s);
+
 #endif

include/lnm/http/consts.h

@@ -13,6 +13,7 @@ typedef enum lnm_http_method {
   lnm_http_method_patch,
   lnm_http_method_delete,
   lnm_http_method_head,
+  lnm_http_method_total,
 } lnm_http_method;
 
 extern const char *lnm_http_status_names[][32];

include/lnm/http/loop.h

@@ -6,15 +6,7 @@
 #include "lnm/common.h"
 #include "lnm/http/req.h"
 #include "lnm/http/res.h"
-
+#include "lnm/http/route.h"
-typedef enum lnm_http_step_err {
-  lnm_http_step_err_done = 0,
-  lnm_http_step_err_io_needed,
-  lnm_http_step_err_close,
-  lnm_http_step_err_res,
-} lnm_http_step_err;
-
-typedef lnm_http_step_err (*lnm_http_step_fn)(lnm_http_conn *conn);
 
 typedef lnm_err (*lnm_http_ctx_init_fn)(void **c_ctx, void *gctx);
 
@@ -32,47 +24,7 @@ lnm_err lnm_http_loop_init(lnm_http_loop **out, void *c_gctx,
                            lnm_http_ctx_reset_fn ctx_reset,
                            lnm_http_ctx_free_fn ctx_free);
 
-/**
+void lnm_http_loop_router_set(lnm_http_loop *hl, lnm_http_router *router);
- * Append the given step fn to the step.
- *
- * @param out both the previous step to append the new step to, and the output
- * variable to which the new step is appended
- * @param fn step function
- * @param blocking whether the step is blocking or not
- */
-lnm_err lnm_http_step_append(lnm_http_step **out, lnm_http_step_fn fn,
-                             bool blocking);
-
-/**
- * Initialize a new route of type literal.
- *
- * @param out where to store pointer to new `lnm_http_route`
- * @param path literal path to match
- * @param step step to process request with
- */
-lnm_err lnm_http_route_init_literal(lnm_http_route **out,
-                                    lnm_http_method method, const char *path,
-                                    lnm_http_step *step);
-
-/**
- * Initialize a new route of type regex.
- *
- * @param out where to store pointer to new `lnm_http_route`
- * @param pattern regex pattern
- * @param regex_group_count how many regex groups are contained in the pattern
- * @param step step to process request with
- */
-lnm_err lnm_http_route_init_regex(lnm_http_route **out, lnm_http_method method,
-                                  const char *pattern, int regex_group_count,
-                                  lnm_http_step *step);
-
-/**
- * Add a new route to the HTTP route.
- *
- * @param hl HTTP loop to modify
- * @param route route to add
- */
-lnm_err lnm_http_loop_route_add(lnm_http_loop *hl, lnm_http_route *route);
 
 lnm_err lnm_http_loop_run(lnm_http_loop *hl, uint16_t port,
                           size_t epoll_threads, size_t worker_threads);
@@ -106,10 +58,7 @@ typedef enum lnm_http_loop_state {
 } lnm_http_loop_state;
 
 typedef struct lnm_http_loop_gctx {
-  struct {
+  lnm_http_router *router;
-    lnm_http_route **arr;
-    size_t len;
-  } routes;
   lnm_http_ctx_init_fn ctx_init;
   lnm_http_ctx_reset_fn ctx_reset;
   lnm_http_ctx_free_fn ctx_free;
@@ -122,7 +71,6 @@ typedef struct lnm_http_loop_ctx {
   lnm_http_loop_state state;
   lnm_http_req req;
   lnm_http_res res;
-  lnm_http_route *route;
   lnm_http_step *cur_step;
   lnm_http_loop_gctx *g;
   void *c;

include/lnm/http/req.h

@@ -9,6 +9,7 @@
 
 #include "lnm/common.h"
 #include "lnm/http/consts.h"
+#include "lnm/http/route.h"
 
 #define LNM_HTTP_MAX_REQ_HEADERS 32
 #define LNM_HTTP_MAX_REGEX_GROUPS 4
@@ -35,6 +36,7 @@ typedef struct lnm_http_req {
   } buf;
   int minor_version;
   lnm_http_method method;
+  lnm_http_route_match route_match;
   struct {
     size_t o;
     size_t len;
@@ -108,4 +110,14 @@ lnm_err lnm_http_req_header_get(const char **out, size_t *out_len,
 lnm_err lnm_http_req_header_get_s(const char **out, size_t *out_len,
                                   lnm_http_req *req, const char *name);
 
+/**
+ * Retrieve a named key segment from the matched route.
+ *
+ * @param out where to write pointer to string
+ * @param key key of the segment
+ * @return length of the outputted char buffer, or 0 if the key doesn't exist
+ */
+size_t lnm_http_req_route_segment(const char **out, lnm_http_req *req,
+                                  const char *key);
+
 #endif

include/lnm/http/route.h

@@ -0,0 +1,97 @@
+#ifndef LNM_HTTP_ROUTE
+#define LNM_HTTP_ROUTE
+
+#include <stdlib.h>
+
+#include "lnm/common.h"
+#include "lnm/http/consts.h"
+
+#define LNM_HTTP_MAX_KEY_SEGMENTS 4
+
+typedef enum lnm_http_step_err {
+  lnm_http_step_err_done = 0,
+  lnm_http_step_err_io_needed,
+  lnm_http_step_err_close,
+  lnm_http_step_err_res,
+} lnm_http_step_err;
+
+typedef lnm_http_step_err (*lnm_http_step_fn)(lnm_http_conn *conn);
+
+typedef struct lnm_http_route lnm_http_route;
+
+typedef struct lnm_http_route_match_segment {
+  size_t start;
+  size_t len;
+} lnm_http_route_match_segment;
+
+typedef struct lnm_http_route_match {
+  const lnm_http_route *route;
+  lnm_http_method method;
+  lnm_http_route_match_segment key_segments[LNM_HTTP_MAX_KEY_SEGMENTS];
+} lnm_http_route_match;
+
+typedef struct lnm_http_router lnm_http_router;
+
+typedef enum lnm_http_route_err {
+  lnm_http_route_err_match = 0,
+  lnm_http_route_err_unknown_route = 1,
+  lnm_http_route_err_unknown_method = 2,
+} lnm_http_route_err;
+
+/**
+ * Allocate and initialize a new http_router.
+ */
+lnm_err lnm_http_router_init(lnm_http_router **out);
+
+void lnm_http_router_free(lnm_http_router *router);
+
+/**
+ * Insert a new path & method in the given router, returning a handle to the
+ * newly created route struct.
+ */
+lnm_err lnm_http_router_add(lnm_http_route **out, lnm_http_router *http_router,
+                            lnm_http_method method, const char *path);
+
+/**
+ * Checks whether the two routers have any conflicting parts.
+ */
+bool lnm_http_router_conflicts(const lnm_http_router *r1,
+                               const lnm_http_router *r2);
+
+/**
+ * Merge two routers, with the result ending up in r1. This is equivalent to
+ * nesting a router on '/'.
+ */
+lnm_err lnm_http_router_merge(lnm_http_router *r1, lnm_http_router *r2);
+
+/**
+ * Integrate the child router into the parent routing, mounting its paths on the
+ * given prefix.
+ */
+lnm_err lnm_http_router_nest(lnm_http_router *parent, lnm_http_router *child,
+                             const char *prefix);
+
+/**
+ * Route the given path & method.
+ */
+lnm_http_route_err lnm_http_router_route(lnm_http_route_match *out,
+                                         const lnm_http_router *router,
+                                         lnm_http_method method,
+                                         const char *path);
+
+/**
+ * Retrieve a path segment using its name.
+ *
+ * @return NULL if not found, otherwise pointer to the match segment struct
+ * representing the key
+ */
+const lnm_http_route_match_segment *
+lnm_http_route_match_get(lnm_http_route_match *match, const char *key);
+
+/**
+ * Append the given step function to the route's step list.
+ */
+lnm_err lnm_http_route_step_append(lnm_http_route *route, lnm_http_step_fn fn,
+                                   bool blocking);
+
+#endif

src/_include/lnm/http/loop_internal.h

@@ -5,42 +5,49 @@
 
 #include "lnm/http/loop.h"
 
+typedef struct lnm_http_route_segment_trie {
+  struct lnm_http_route_segment_trie *children[128];
+  size_t index;
+  bool represents_segment;
+} lnm_http_route_segment_trie;
+
+struct lnm_http_route {
+  lnm_http_route_segment_trie *key_segments;
+  lnm_http_step *step;
+};
+
+struct lnm_http_router {
+  struct lnm_http_router *exact_children[128];
+  struct lnm_http_router *single_segment_child;
+  lnm_http_route *multi_segment_routes[lnm_http_method_total];
+  lnm_http_route *routes[lnm_http_method_total];
+  bool represents_route;
+};
+
+lnm_err lnm_http_route_segment_trie_init(lnm_http_route_segment_trie **out);
+
+void lnm_http_route_segment_trie_free(lnm_http_route_segment_trie *trie);
+
+lnm_err lnm_http_route_key_segment_insert(lnm_http_route *route,
+                                          const char *key, size_t key_len,
+                                          size_t index);
 typedef struct lnm_http_step {
   lnm_http_step_fn fn;
   struct lnm_http_step *next;
   bool blocking;
 } lnm_http_step;
 
-typedef enum lnm_http_route_type {
-  lnm_http_route_type_literal = 0,
-  lnm_http_route_type_regex,
-} lnm_http_route_type;
-
-typedef struct lnm_http_route {
-  union {
-    regex_t *regex;
-    const char *s;
-  } route;
-  lnm_http_method method;
-  lnm_http_route_type type;
-  int regex_group_count;
-  lnm_http_step *step;
-} lnm_http_route;
-
-/**
- * Initialize a new empty route.
- *
- * @param out where to store pointer to new `lnm_http_route`
- */
-lnm_err lnm_http_route_init(lnm_http_route **out);
-
 /**
  * Initialize a first step.
  *
  * @param out where to store pointer to new `lnm_http_step`
  * @param fn step function associated with the step
  */
-lnm_err lnm_http_step_init(lnm_http_step **out, lnm_http_step_fn fn);
+lnm_err lnm_http_step_init(lnm_http_step **out);
+
+lnm_err lnm_http_route_init(lnm_http_route **out);
+
+void lnm_http_route_free(lnm_http_route *route);
 
 /**
  * Initialize a new global context object.

src/http/lnm_http_loop.c

@@ -28,94 +28,9 @@ lnm_err lnm_http_loop_init(lnm_http_loop **out, void *c_gctx,
   return lnm_err_ok;
 }
 
-lnm_err lnm_http_step_append(lnm_http_step **out, lnm_http_step_fn fn,
+void lnm_http_loop_router_set(lnm_http_loop *hl, lnm_http_router *router) {
-                             bool blocking) {
-  lnm_http_step *step = calloc(1, sizeof(lnm_http_step));
-
-  if (step == NULL) {
-    return lnm_err_failed_alloc;
-  }
-
-  step->fn = fn;
-  step->blocking = blocking;
-
-  if ((*out) != NULL) {
-    (*out)->next = step;
-  }
-
-  *out = step;
-
-  return lnm_err_ok;
-}
-
-lnm_err lnm_http_route_init(lnm_http_route **out) {
-  lnm_http_route *route = calloc(1, sizeof(lnm_http_route));
-
-  if (route == NULL) {
-    return lnm_err_failed_alloc;
-  }
-
-  *out = route;
-
-  return lnm_err_ok;
-}
-
-lnm_err lnm_http_route_init_literal(lnm_http_route **out,
-                                    lnm_http_method method, const char *path,
-                                    lnm_http_step *step) {
-  LNM_RES(lnm_http_route_init(out));
-
-  (*out)->type = lnm_http_route_type_literal;
-  (*out)->method = method;
-  (*out)->route.s = path;
-  (*out)->step = step;
-
-  return lnm_err_ok;
-}
-
-lnm_err lnm_http_route_init_regex(lnm_http_route **out, lnm_http_method method,
-                                  const char *pattern, int regex_group_count,
-                                  lnm_http_step *step) {
-  regex_t *regex = calloc(1, sizeof(regex_t));
-
-  if (regex == NULL) {
-    return lnm_err_failed_alloc;
-  }
-
-  if (regcomp(regex, pattern, REG_EXTENDED) != 0) {
-    free(regex);
-    return lnm_err_bad_regex;
-  }
-
-  LNM_RES2(lnm_http_route_init(out), free(regex));
-
-  (*out)->method = method;
-  (*out)->type = lnm_http_route_type_regex;
-  (*out)->route.regex = regex;
-  (*out)->regex_group_count = regex_group_count;
-  (*out)->step = step;
-
-  return lnm_err_ok;
-}
-
-lnm_err lnm_http_loop_route_add(lnm_http_loop *hl, lnm_http_route *route) {
   lnm_http_loop_gctx *gctx = hl->gctx;
-
+  gctx->router = router;
-  lnm_http_route **new_routes =
-      gctx->routes.len > 0
-          ? realloc(gctx->routes.arr,
-                    (gctx->routes.len + 1) * sizeof(lnm_http_route *))
-          : malloc(sizeof(lnm_http_route *));
-
-  if (new_routes == NULL) {
-    return lnm_err_failed_alloc;
-  }
-
-  new_routes[gctx->routes.len] = route;
-  gctx->routes.arr = new_routes;
-  gctx->routes.len++;
-
-  return lnm_err_ok;
 }
 
 lnm_err lnm_http_loop_run(lnm_http_loop *hl, uint16_t port,

src/http/lnm_http_loop_ctx.c

@@ -42,7 +42,6 @@ void lnm_http_loop_ctx_reset(lnm_http_loop_ctx *ctx) {
   lnm_http_req_reset(&ctx->req);
   lnm_http_res_reset(&ctx->res);
 
-  ctx->route = NULL;
   ctx->cur_step = NULL;
 }
 

src/http/lnm_http_loop_process.c

@@ -56,55 +56,22 @@ void lnm_http_loop_process_parse_req(lnm_http_conn *conn) {
 
 void lnm_http_loop_process_route(lnm_http_conn *conn) {
   lnm_http_loop_ctx *ctx = conn->ctx;
-  lnm_http_loop_gctx *gctx = ctx->g;
+  const lnm_http_loop_gctx *gctx = ctx->g;
 
-  // 0: no match
+  switch (lnm_http_router_route(&ctx->req.route_match, gctx->router,
-  // 1: matched route, but not method
+                                ctx->req.method,
-  // 2: fully matched route
+                                ctx->req.buf.s + ctx->req.path.o)) {
-  int match_level = 0;
+  case lnm_http_route_err_match:
-  lnm_http_route *route;
+    ctx->cur_step = ctx->req.route_match.route->step;
-
+    ctx->state = lnm_http_loop_state_parse_headers;
-  for (size_t i = 0; i < gctx->routes.len && match_level < 3; i++) {
-    route = gctx->routes.arr[i];
-    bool matched_path = false;
-
-    switch (route->type) {
-    case lnm_http_route_type_literal:
-      matched_path = strncmp(route->route.s, ctx->req.buf.s + ctx->req.path.o,
-                             ctx->req.path.len) == 0;
-      break;
-    case lnm_http_route_type_regex:
-      matched_path =
-          regexec(route->route.regex, ctx->req.buf.s + ctx->req.path.o,
-                  LNM_HTTP_MAX_REGEX_GROUPS, ctx->req.path.groups, 0) == 0;
-      break;
-    }
-
-    // GET routes also automatically route HEAD requests
-    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;
-  }
-
-  switch (match_level) {
-  case 0:
-  case 1:
-    ctx->res.status = lnm_http_status_not_found;
-    ctx->state = lnm_http_loop_state_first_res;
     break;
-  case 2:
+  case lnm_http_route_err_unknown_method:
     ctx->res.status = lnm_http_status_method_not_allowed;
     ctx->state = lnm_http_loop_state_first_res;
     break;
-  case 3:
+  case lnm_http_route_err_unknown_route:
-    ctx->route = route;
+    ctx->res.status = lnm_http_status_not_found;
-    ctx->cur_step = route->step;
+    ctx->state = lnm_http_loop_state_first_res;
-    ctx->state = lnm_http_loop_state_parse_headers;
     break;
   }
 }

src/http/lnm_http_req.c

@@ -112,3 +112,19 @@ lnm_err lnm_http_req_header_get_s(const char **out, size_t *out_len,
 
   return lnm_err_not_found;
 }
+
+size_t lnm_http_req_route_segment(const char **out, lnm_http_req *req,
+                                  const char *key) {
+  const lnm_http_route_match_segment *segment =
+      lnm_http_route_match_get(&req->route_match, key);
+
+  if (segment == NULL) {
+    return 0;
+  }
+
+  if (out != NULL) {
+    *out = req->buf.s + req->path.o + segment->start;
+  }
+
+  return segment->len;
+}

src/http/lnm_http_route.c

@@ -0,0 +1,128 @@
+#include "lnm/http/loop_internal.h"
+
+lnm_err lnm_http_route_init(lnm_http_route **out) {
+  lnm_http_route *route = calloc(1, sizeof(lnm_http_route));
+
+  if (route == NULL) {
+    return lnm_err_failed_alloc;
+  }
+
+  *out = route;
+
+  return lnm_err_ok;
+}
+
+void lnm_http_route_free(lnm_http_route *route) {
+  if (route == NULL) {
+    return;
+  }
+
+  lnm_http_route_segment_trie_free(route->key_segments);
+  free(route);
+}
+
+lnm_err lnm_http_route_segment_trie_init(lnm_http_route_segment_trie **out) {
+  lnm_http_route_segment_trie *trie =
+      calloc(1, sizeof(lnm_http_route_segment_trie));
+
+  if (trie == NULL) {
+    return lnm_err_failed_alloc;
+  }
+
+  *out = trie;
+
+  return lnm_err_ok;
+}
+
+void lnm_http_route_segment_trie_free(lnm_http_route_segment_trie *trie) {
+  if (trie == NULL) {
+    return;
+  }
+
+  for (size_t i = 0; i < 128; i++) {
+    lnm_http_route_segment_trie_free(trie->children[i]);
+  }
+
+  free(trie);
+}
+
+lnm_err lnm_http_route_key_segment_insert(lnm_http_route *route,
+                                          const char *key, size_t key_len,
+                                          size_t index) {
+  if (route->key_segments == NULL) {
+    LNM_RES(lnm_http_route_segment_trie_init(&route->key_segments));
+  }
+
+  lnm_http_route_segment_trie *trie = route->key_segments;
+
+  for (size_t key_index = 0; key_index < key_len; key_index++) {
+    unsigned char c = key[key_index];
+
+    if (trie->children[c] == NULL) {
+      LNM_RES(lnm_http_route_segment_trie_init(&trie->children[c]));
+    }
+
+    trie = trie->children[c];
+  }
+
+  if (trie->represents_segment) {
+    return lnm_err_already_present;
+  }
+
+  trie->represents_segment = true;
+  trie->index = index;
+
+  return lnm_err_ok;
+}
+
+const lnm_http_route_match_segment *
+lnm_http_route_match_get(lnm_http_route_match *match, const char *key) {
+  if (match->route->key_segments == NULL) {
+    return NULL;
+  }
+
+  lnm_http_route_segment_trie *trie = match->route->key_segments;
+
+  while (*key != '\0') {
+    trie = trie->children[(unsigned char)*key];
+
+    if (trie == NULL) {
+      return NULL;
+    }
+
+    key++;
+  }
+
+  if (!trie->represents_segment) {
+    return NULL;
+  }
+
+  return &match->key_segments[trie->index];
+}
+
+lnm_err lnm_http_step_init(lnm_http_step **out) {
+  lnm_http_step *step = calloc(1, sizeof(lnm_http_step));
+
+  if (step == NULL) {
+    return lnm_err_failed_alloc;
+  }
+
+  *out = step;
+
+  return lnm_err_ok;
+}
+
+lnm_err lnm_http_route_step_append(lnm_http_route *route, lnm_http_step_fn fn,
+                                   bool blocking) {
+  lnm_http_step **step_ptr = &route->step;
+
+  while (*step_ptr != NULL) {
+    step_ptr = &(*step_ptr)->next;
+  }
+
+  LNM_RES(lnm_http_step_init(step_ptr));
+  (*step_ptr)->fn = fn;
+  (*step_ptr)->blocking = blocking;
+
+  return lnm_err_ok;
+}

src/http/lnm_http_router.c

@@ -0,0 +1,347 @@
+#include <string.h>
+
+#include "lnm/common.h"
+#include "lnm/http/loop_internal.h"
+
+lnm_err lnm_http_router_init(lnm_http_router **out) {
+  lnm_http_router *router = calloc(1, sizeof(lnm_http_router));
+
+  if (router == NULL) {
+    return lnm_err_failed_alloc;
+  }
+
+  *out = router;
+
+  return lnm_err_ok;
+}
+
+void lnm_http_router_free(lnm_http_router *router) {
+  if (router == NULL) {
+    return;
+  }
+
+  for (size_t i = 0; i < 128; i++) {
+    lnm_http_router_free(router->exact_children[i]);
+  }
+
+  lnm_http_router_free(router->single_segment_child);
+
+  for (size_t i = 0; i < lnm_http_method_total; i++) {
+    lnm_http_route_free(router->routes[i]);
+    lnm_http_route_free(router->multi_segment_routes[i]);
+  }
+
+  free(router);
+}
+
+lnm_err lnm_http_router_add(lnm_http_route **out, lnm_http_router *http_router,
+                            lnm_http_method method, const char *path) {
+  if (path[0] != '/' || !lnm_is_ascii(path)) {
+    return lnm_err_invalid_route;
+  }
+
+  lnm_http_route *route;
+  LNM_RES(lnm_http_route_init(&route));
+
+  size_t key_segments_count = 0;
+  lnm_err res = lnm_err_ok;
+
+  while (*path != '\0') {
+    unsigned char c = *path;
+
+    switch (c) {
+    case ':': {
+      // Match the segment content as the variable name
+      const char *next_slash_ptr = strchr(path + 1, '/');
+
+      // Account for segment being the final part of the route
+      const char *new_path =
+          next_slash_ptr == NULL ? strchr(path + 1, '\0') : next_slash_ptr;
+      size_t key_len = new_path - (path + 1);
+
+      if (key_len == 0) {
+        res = lnm_err_invalid_route;
+
+        goto end;
+      }
+
+      res = lnm_http_route_key_segment_insert(route, path + 1, key_len,
+                                              key_segments_count);
+
+      if (res != lnm_err_ok) {
+        goto end;
+      }
+
+      key_segments_count++;
+
+      if (http_router->single_segment_child == NULL) {
+        res = lnm_http_router_init(&http_router->single_segment_child);
+
+        if (res != lnm_err_ok) {
+          goto end;
+        }
+      }
+
+      http_router = http_router->single_segment_child;
+      path = new_path;
+    } break;
+    case '*': {
+      const char *next_slash_ptr = strchr(path + 1, '/');
+
+      // Star match should be at end of route
+      if (next_slash_ptr != NULL) {
+        res = lnm_err_invalid_route;
+
+        goto end;
+      }
+
+      const char *end = strchr(path + 1, '\0');
+      size_t key_len = end - (path + 1);
+
+      if (key_len == 0) {
+        res = lnm_err_invalid_route;
+
+        goto end;
+      }
+
+      res = lnm_http_route_key_segment_insert(route, path + 1, key_len,
+                                              key_segments_count);
+
+      if (res != lnm_err_ok) {
+        goto end;
+      }
+
+      key_segments_count++;
+
+      if (http_router->multi_segment_routes[method] != NULL) {
+        res = lnm_err_overlapping_route;
+      }
+
+      http_router->multi_segment_routes[method] = route;
+      goto end;
+    } break;
+    default:
+      if (http_router->exact_children[c] == NULL) {
+        res = lnm_http_router_init(&http_router->exact_children[c]);
+
+        if (res != lnm_err_ok) {
+          goto end;
+        }
+      }
+
+      http_router = http_router->exact_children[c];
+      path++;
+
+      break;
+    }
+  }
+
+  if (http_router->routes[method] != NULL) {
+    res = lnm_err_overlapping_route;
+
+    goto end;
+  }
+
+  http_router->routes[method] = route;
+  http_router->represents_route = true;
+
+end:
+  if (res != lnm_err_ok) {
+    lnm_http_route_free(route);
+
+    return res;
+  }
+
+  if (out != NULL) {
+    *out = route;
+  }
+
+  return lnm_err_ok;
+}
+
+static lnm_http_route_err __lnm_http_router_route(lnm_http_route_match *out,
+                                                  const lnm_http_router *router,
+                                                  lnm_http_method method,
+                                                  const char *path,
+                                                  size_t path_index,
+                                                  size_t matched_key_segments) {
+  if (path[path_index] == '\0') {
+    if (!router->represents_route) {
+      return lnm_http_route_err_unknown_route;
+    }
+
+    if (out != NULL) {
+      out->route = router->routes[method];
+    }
+
+    return router->routes[method] == NULL ? lnm_http_route_err_unknown_method
+                                          : lnm_http_route_err_match;
+  }
+
+  lnm_http_route_err res = lnm_http_route_err_unknown_route;
+  const lnm_http_router *exact_router =
+      router->exact_children[(unsigned char)path[path_index]];
+
+  if (exact_router != NULL) {
+    lnm_http_route_err sub_res = __lnm_http_router_route(
+        out, exact_router, method, path, path_index + 1, matched_key_segments);
+
+    if (sub_res == lnm_http_route_err_match) {
+      return lnm_http_route_err_match;
+    }
+
+    res = LNM_MAX(res, sub_res);
+  }
+
+  const lnm_http_router *single_segment_router = router->single_segment_child;
+
+  if (single_segment_router != NULL) {
+    const char *next_slash_ptr = strchr(path + path_index, '/');
+    const char *new_path = next_slash_ptr == NULL
+                               ? strchr(path + path_index, '\0')
+                               : next_slash_ptr;
+    size_t segment_len = new_path - (path + path_index);
+
+    if (segment_len > 0) {
+      lnm_http_route_err sub_res = __lnm_http_router_route(
+          out, single_segment_router, method, path, path_index + segment_len,
+          matched_key_segments + 1);
+
+      if (sub_res == lnm_http_route_err_match) {
+        // If match succeeds down the recursion, we can correctly set the
+        // matched segments when going back up the stack
+        if (out != NULL) {
+          out->key_segments[matched_key_segments].start = path_index;
+          out->key_segments[matched_key_segments].len = segment_len;
+        }
+
+        return lnm_http_route_err_match;
+      }
+
+      res = LNM_MAX(res, sub_res);
+    }
+  }
+
+  const lnm_http_route *multi_segment_route =
+      router->multi_segment_routes[method];
+
+  if (multi_segment_route != NULL) {
+    const char *end_ptr = strchr(path + path_index, '\0');
+    size_t segment_len = end_ptr - (path + path_index);
+
+    // TODO do 405's make sense for star matches?
+
+    if (segment_len > 0) {
+      if (out != NULL) {
+        out->route = multi_segment_route;
+        out->key_segments[matched_key_segments].start = path_index;
+        out->key_segments[matched_key_segments].len = segment_len;
+      }
+
+      return lnm_http_route_err_match;
+    }
+  }
+
+  return res;
+}
+
+lnm_http_route_err lnm_http_router_route(lnm_http_route_match *out,
+                                         const lnm_http_router *router,
+                                         lnm_http_method method,
+                                         const char *path) {
+  if (!lnm_is_ascii(path)) {
+    return lnm_http_route_err_unknown_route;
+  }
+
+  return __lnm_http_router_route(out, router, method, path, 0, 0);
+}
+
+bool lnm_http_router_conflicts(const lnm_http_router *r1,
+                               const lnm_http_router *r2) {
+  // First check the literal routes for the routers
+  for (lnm_http_method m = 0; m < lnm_http_method_total; m++) {
+    if ((r1->routes[m] != NULL && r2->routes[m] != NULL) ||
+        (r1->multi_segment_routes[m] != NULL &&
+         r2->multi_segment_routes[m] != NULL)) {
+      return true;
+    }
+  }
+
+  if ((r1->single_segment_child != NULL && r2->single_segment_child != NULL) &&
+      lnm_http_router_conflicts(r1->single_segment_child,
+                                r2->single_segment_child)) {
+    return true;
+  }
+
+  for (unsigned char c = 0; c < 128; c++) {
+    if ((r1->exact_children[c] != NULL && r2->exact_children[c] != NULL) &&
+        lnm_http_router_conflicts(r1->exact_children[c],
+                                  r2->exact_children[c])) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+void __lnm_http_router_merge(lnm_http_router *r1, lnm_http_router *r2) {
+  for (lnm_http_method m = 0; m < lnm_http_method_total; m++) {
+    if (r2->routes[m] != NULL) {
+      r1->routes[m] = r2->routes[m];
+    }
+
+    if (r2->multi_segment_routes[m] != NULL) {
+      r1->multi_segment_routes[m] = r2->multi_segment_routes[m];
+    }
+  }
+
+  if (r1->single_segment_child != NULL && r2->single_segment_child != NULL) {
+    __lnm_http_router_merge(r1->single_segment_child, r2->single_segment_child);
+  } else if (r2->single_segment_child != NULL) {
+    r1->single_segment_child = r2->single_segment_child;
+  }
+
+  for (unsigned char c = 0; c < 128; c++) {
+    if (r1->exact_children[c] != NULL && r2->exact_children[c] != NULL) {
+      __lnm_http_router_merge(r1->exact_children[c], r2->exact_children[c]);
+    } else if (r2->exact_children[c] != NULL) {
+      r1->exact_children[c] = r2->exact_children[c];
+    }
+  }
+
+  r1->represents_route = r1->represents_route || r2->represents_route;
+
+  free(r2);
+}
+
+lnm_err lnm_http_router_merge(lnm_http_router *r1, lnm_http_router *r2) {
+  if (lnm_http_router_conflicts(r1, r2)) {
+    return lnm_err_overlapping_route;
+  }
+
+  __lnm_http_router_merge(r1, r2);
+
+  return lnm_err_ok;
+}
+
+lnm_err lnm_http_router_nest(lnm_http_router *parent, lnm_http_router *child,
+                             const char *prefix) {
+  if (!lnm_is_ascii(prefix) || prefix[0] != '/') {
+    return lnm_err_invalid_route;
+  }
+
+  lnm_http_router *router = parent;
+
+  while (*prefix != '\0') {
+    unsigned char c = *prefix;
+
+    if (router->exact_children[c] == NULL) {
+      LNM_RES(lnm_http_router_init(&router->exact_children[c]));
+    }
+
+    router = router->exact_children[c];
+    prefix++;
+  }
+
+  return lnm_http_router_merge(router, child);
+}

src/lnm_utils.c

@@ -55,3 +55,15 @@ uint64_t lnm_digits(uint64_t num) {
 
   return digits;
 }
+
+bool lnm_is_ascii(const char *s) {
+  bool valid = true;
+
+  while (valid && *s != '\0') {
+    valid = *s < 0;
+
+    s++;
+  }
+
+  return valid;
+}

test/routing.c

@@ -0,0 +1,111 @@
+#include "lnm/common.h"
+#include "lnm/http/route.h"
+#include "test.h"
+
+#include "lnm/http/loop.h"
+
+void test_routing_simple() {
+  lnm_http_router *router;
+  TEST_CHECK(lnm_http_router_init(&router) == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_add(NULL, router, lnm_http_method_get, "/test") == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_add(NULL, router, lnm_http_method_get, "/test/test2") == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_add(NULL, router, lnm_http_method_get, "/test/:hello") == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_add(NULL, router, lnm_http_method_get, "/test/:hello/:second") == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_route(NULL, router, lnm_http_method_get, "/test") == lnm_http_route_err_match);
+  TEST_CHECK(lnm_http_router_route(NULL, router, lnm_http_method_get, "/test2/t/e") == lnm_http_route_err_unknown_route);
+  TEST_CHECK(lnm_http_router_route(NULL, router, lnm_http_method_head, "/test/test2") == lnm_http_route_err_unknown_method);
+  TEST_CHECK(lnm_http_router_route(NULL, router, lnm_http_method_get, "/test/test2") == lnm_http_route_err_match);
+
+  lnm_http_route_match match;
+  TEST_CHECK(lnm_http_router_route(&match, router, lnm_http_method_get, "/test/test_var") == lnm_http_route_err_match);
+  TEST_CHECK(match.key_segments[0].start == 6);
+  TEST_CHECK(match.key_segments[0].len == 8);
+
+  TEST_CHECK(lnm_http_router_route(NULL, router, lnm_http_method_get, "/test/") == lnm_http_route_err_unknown_route);
+
+  TEST_CHECK(lnm_http_router_route(&match, router, lnm_http_method_get, "/test/test_var/secondvar") == lnm_http_route_err_match);
+  TEST_CHECK(match.key_segments[0].start == 6);
+  TEST_CHECK(match.key_segments[0].len == 8);
+  TEST_CHECK(match.key_segments[1].start == 15);
+  TEST_CHECK(match.key_segments[1].len == 9);
+
+  const lnm_http_route_match_segment *segment;
+  TEST_CHECK((segment = lnm_http_route_match_get(&match, "second")) != NULL);
+  TEST_CHECK(segment->start == 15);
+  TEST_CHECK(segment->len == 9);
+  TEST_CHECK((segment = lnm_http_route_match_get(&match, "yuhh")) == NULL);
+  TEST_CHECK((segment = lnm_http_route_match_get(&match, "hello")) != NULL);
+  TEST_CHECK(segment->start == 6);
+  TEST_CHECK(segment->len == 8);
+
+  lnm_http_router_free(router);
+}
+
+void test_routing_star() {
+  lnm_http_router *router;
+  TEST_CHECK(lnm_http_router_init(&router) == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_add(NULL, router, lnm_http_method_get, "/*key") == lnm_err_ok);
+
+  lnm_http_route_match match;
+  TEST_CHECK(lnm_http_router_route(&match, router, lnm_http_method_get, "/hello/world") == lnm_http_route_err_match);
+  TEST_CHECK(match.key_segments[0].start == 1);
+  TEST_CHECK(match.key_segments[0].len == 11);
+
+  lnm_http_router_free(router);
+}
+
+void test_routing_merge() {
+  lnm_http_router *rtr1, *rtr2;
+  lnm_http_route *rt1, *rt2;
+  lnm_http_route_match match;
+
+  TEST_CHECK(lnm_http_router_init(&rtr1) == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_init(&rtr2) == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_add(&rt1, rtr1, lnm_http_method_get, "/*key") == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_add(NULL, rtr1, lnm_http_method_get, "/:key/hello") == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_add(&rt2, rtr2, lnm_http_method_get, "/test2") == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_add(NULL, rtr2, lnm_http_method_get, "/:key/hello2") == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_merge(rtr1, rtr2) == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_route(&match, rtr1, lnm_http_method_get, "/some/thing") == lnm_http_route_err_match);
+  TEST_CHECK(match.route == rt1);
+
+  TEST_CHECK(lnm_http_router_route(&match, rtr1, lnm_http_method_get, "/test2") == lnm_http_route_err_match);
+  TEST_CHECK(match.route == rt2);
+
+  lnm_http_router_free(rtr1);
+}
+
+void test_routing_nest() {
+  lnm_http_router *r1, *r2;
+  lnm_http_route_match match;
+
+  TEST_CHECK(lnm_http_router_init(&r1) == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_init(&r2) == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_add(NULL, r1, lnm_http_method_get, "/*key") == lnm_err_ok);
+  TEST_CHECK(lnm_http_router_add(NULL, r2, lnm_http_method_get, "/test/test2") == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_nest(r2, r1, "/test") == lnm_err_ok);
+
+  TEST_CHECK(lnm_http_router_route(&match, r2, lnm_http_method_get, "/test/test_var/secondvar") == lnm_http_route_err_match);
+  TEST_CHECK(match.key_segments[0].start == 6);
+  TEST_CHECK(match.key_segments[0].len == 18);
+
+  TEST_CHECK(lnm_http_router_route(&match, r2, lnm_http_method_get, "/test/test2") == lnm_http_route_err_match);
+
+  lnm_http_router_free(r2);
+}
+
+TEST_LIST = {
+  { "routing simple", test_routing_simple },
+  { "routing star", test_routing_star },
+  { "routing merge", test_routing_merge },
+  { "routing nest", test_routing_nest },
+  { NULL, NULL }
+};