backend: add parser char skipper

backend/http.c

@@ -1,26 +1,55 @@
 #include "http.h"
+#include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+
+typedef struct {
+    const char* message;
+    size_t message_size;
+    size_t i;
+} HttpRequestHeaderParser;
+
+HttpMethod parse_method(HttpRequestHeaderParser* parser)
+{
+    if (parser->i + 3 < parser->message_size && strncmp(&parser->message[0], "GET", 3)) {
+        parser->i += 3;
+        return HttpMethodGet;
+    } else if (parser->i + 4 < parser->message_size && strncmp(&parser->message[0], "POST", 4)) {
+        parser->i += 4;
+        return HttpMethodPost;
+    } else {
+        printf("error: http parser: failed to parse http method\n");
+        exit(1);
+    }
+}
+
+void skip_char(HttpRequestHeaderParser* parser, char value)
+{
+    if (parser->message[parser->i] != value) {
+        printf("error: http parser: unexpected character, expected ' '\n");
+        exit(1);
+    }
+    parser->i += 1;
+    if (parser->i >= parser->message_size) {
+        printf("error: http parser: unexpected end\n");
+        exit(1);
+    }
+}
+
+typedef struct {
+    size_t begin, length;
+} PathSpan;
 
 HttpRequestHeader parse_http_request_header(const char* message, size_t message_size)
 {
-    size_t i = 0;
-
-    // parse method
-    HttpMethod method;
-    if (i + 3 < message_size && strncmp(&message[0], "GET", 3)) {
-        method = HttpMethodGet;
-        i += 3;
-    } else if (i + 4 < message_size && strncmp(&message[0], "POST", 4)) {
-        method = HttpMethodPost;
-        i += 4;
-    } else {
-        printf("error: header parse fail #1\n");
-        exit(1);
-    }
-
-    // skip space
-    i += 1;
-    if (i >= message_size) { }
+    HttpRequestHeaderParser parser = (HttpRequestHeaderParser) {
+        .message = message,
+        .message_size = message_size,
+        .i = 0,
+    };
+    HttpMethod method = parse_method(&parser);
+    skip_char(&parser, ' ');
 
     return (HttpRequestHeader) { 0 };
 }

backend/http_request_example.txt

@@ -0,0 +1,28 @@
+starting server...
+listening on port 8000
+waiting for client...
+client connected
+recieved:
+GET / HTTP/1.1
+Host: localhost:8000
+User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:109.0) Gecko/20100101 Firefox/109
+.0
+Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/w
+ebp,*/*;q=0.8
+Accept-Language: en-US,en;q=0.5
+Accept-Encoding: gzip, deflate, br
+Connection: keep-alive
+Upgrade-Insecure-Requests: 1
+Sec-Fetch-Dest: document
+Sec-Fetch-Mode: navigate
+Sec-Fetch-Site: none
+Sec-Fetch-User: ?1
+
+
+disconnecting client
+error: could not recieve
+waiting for client...
+client connected
+client disconnected
+waiting for client...
+