Make improvements

- Emulator can now test the αcτµαlly pδrταblε εxεcµταblε bootloader

- Whipped up a webserver named redbean. It services 150k requests per
  second on a single core. Bundling assets inside zip enables extremely
  fast serving for two reasons. The first is that zip central directory
  lookups go faster than stat() system calls. The second is that both
  zip and gzip content-encoding use DEFLATE, therefore, compressed
  responses can be served via the sendfile() system call which does an
  in-kernel copy directly from the zip executable structure. Also note
  that red bean zip executables can be deployed easily to all platforms,
  since these native executables work on Linux, Mac, BSD, and Windows.

- Address sanitizer now works very well

net/http/parsehttprequest.c

@@ -39,95 +39,84 @@ enum ParseHttpRequestState {
 };
 
 /**
- * Parses req line and headers of HTTP req.
- *
- * This parser is very lax. All decoding is ISO-8859-1. A 1mB upper
- * bound on memory is enforced.
+ * Parses HTTP request header.
  */
-int parsehttprequest(struct HttpRequest *req, FILE *f) {
-  enum ParseHttpRequestState state = METHOD;
-  int toto = 0;
-  clearhttprequest(req);
-  while (true) {
-    char ch;
-    {
-      int c = fgetc(f);
-      if (c == -1) {
-        if (toto && !ferror(f)) {
-          return ebadmsg(); /* RFC7230 § 3.4 */
-        }
-        return -1;
-      }
-      ch = (unsigned char)c;
-    }
-    if (++toto == UINT16_MAX) {
-      return ebadmsg(); /* RFC7230 § 3.2.5 */
-    }
-    switch (state) {
+int ParseHttpRequest(struct HttpRequest *req, const char *p, size_t n) {
+  int a, h, c, i, x;
+  enum ParseHttpRequestState t;
+  memset(req, 0, sizeof(*req));
+  a = h = 0;
+  t = METHOD;
+  if (n > SHRT_MAX - 1) n = SHRT_MAX - 1;
+  for (i = 0; i < n; ++i) {
+    c = p[i] & 0xFF;
+    switch (t) {
       case METHOD:
-        if (ch == '\r' || ch == '\n') break; /* RFC7230 § 3.5 */
-        if (ch == ' ') {
-          if (req->method.i == 0) return ebadmsg();
-          state = URI;
-        } else {
-          append(&req->method, &ch);
+        if (c == '\r' || c == '\n') break; /* RFC7230 § 3.5 */
+        if (c == ' ') {
+          if (!i) return ebadmsg();
+          if ((x = GetHttpMethod(p, i)) == -1) return ebadmsg();
+          req->method = x;
+          req->uri.a = i + 1;
+          t = URI;
         }
         break;
       case URI:
-        if (ch == ' ') {
-          if (req->uri.i == 0) return ebadmsg();
-          state = VERSION;
-        } else {
-          append(&req->uri, &ch);
+        if (c == ' ') {
+          req->uri.b = i;
+          req->version.a = i + 1;
+          if (req->uri.a == req->uri.b) return ebadmsg();
+          t = VERSION;
         }
         break;
       case VERSION:
-        if (ch == '\r' || ch == '\n') {
-          state = ch == '\r' ? CR1 : LF1;
-        } else {
-          append(&req->version, &ch);
+        if (c == '\r' || c == '\n') {
+          req->version.b = i;
+          t = c == '\r' ? CR1 : LF1;
         }
         break;
       case CR1:
-        if (ch != '\n') return ebadmsg();
-        state = LF1;
+        if (c != '\n') return ebadmsg();
+        t = LF1;
         break;
       case LF1:
-        if (ch == '\r') {
-          state = LF2;
+        if (c == '\r') {
+          t = LF2;
           break;
-        } else if (ch == '\n') {
+        } else if (c == '\n') {
           return 0;
-        } else if (ch == ' ' || ch == '\t') { /* line folding!!! */
-          return eprotonosupport();           /* RFC7230 § 3.2.4 */
+        } else if (c == ' ' || c == '\t') { /* line folding!!! */
+          return eprotonosupport();         /* RFC7230 § 3.2.4 */
         }
-        state = HKEY;
+        a = i;
+        t = HKEY;
         /* εpsilon transition */
       case HKEY:
-        if (ch == ':') state = HSEP;
-        ch = tolower(ch);
-        append(&req->scratch, &ch);
+        if (c == ':') {
+          h = GetHttpHeader(p + a, i - a);
+          t = HSEP;
+        }
         break;
       case HSEP:
-        if (ch == ' ' || ch == '\t') break;
-        state = HVAL;
+        if (c == ' ' || c == '\t') break;
+        a = i;
+        t = HVAL;
         /* εpsilon transition */
       case HVAL:
-        if (ch == '\r' || ch == '\n') {
-          state = ch == '\r' ? CR1 : LF1;
-          ch = '\0';
-        }
-        append(&req->scratch, &ch);
-        if (!ch) {
-          critbit0_insert(&req->headers, req->scratch.p);
-          req->scratch.i = 0;
+        if (c == '\r' || c == '\n') {
+          if (h != -1) {
+            req->headers[h].a = a;
+            req->headers[h].b = i;
+          }
+          t = c == '\r' ? CR1 : LF1;
         }
         break;
       case LF2:
-        if (ch == '\n') return 0;
+        if (c == '\n') return 0;
         return ebadmsg();
       default:
         unreachable;
     }
   }
+  return ebadmsg();
 }