From c54f6d1e039f2e299aee08cb9a708fde5c78dc8f Mon Sep 17 00:00:00 2001
From: simonwep <toports@gmx.de>
Date: Thu, 8 Feb 2018 08:36:02 +0100
Subject: [PATCH] Improve ExpressFilterIml

Now the average response time is by ~30ms instead of 300ms!
---
 README.md                                     |  2 +-
 .../expressfilter/ExpressFilterImpl.java      | 57 +++++++++++++------
 2 files changed, 40 insertions(+), 19 deletions(-)

diff --git a/README.md b/README.md
index f044919..5324deb 100644
--- a/README.md
+++ b/README.md
@@ -25,7 +25,7 @@ app.listen(); // Port 80 is default
 When you create an new Express instance you can add an additional host name for example, your local network:
 ```java
 // Will bind the server to your ip-adress
-Express app  = new Express(ExpressUtils.getYourIp());
+Express app  = new Express(Utils.getYourIp());
 ```
 Default is localhost, so you can access, without setting the hostname, only from your local pc.
 
diff --git a/src/express/expressfilter/ExpressFilterImpl.java b/src/express/expressfilter/ExpressFilterImpl.java
index fed0231..1b4eead 100644
--- a/src/express/expressfilter/ExpressFilterImpl.java
+++ b/src/express/expressfilter/ExpressFilterImpl.java
@@ -18,20 +18,12 @@ public class ExpressFilterImpl implements HttpRequest {
 
   private final HttpRequest REQUEST;
   private final String REQUEST_METHOD;
-
   private final String CONTEXT;
-  private final String[] CONTEXT_PARAMS;
-  private final String CONTEXT_REGEX;
-  private final Pattern CONTEXT_PATTERN;
 
   public ExpressFilterImpl(String requestMethod, String context, HttpRequest httpRequest) {
     this.REQUEST_METHOD = requestMethod;
     this.REQUEST = httpRequest;
-
     this.CONTEXT = context;
-    this.CONTEXT_PARAMS = context.split("(/)(:|[^:]+|)(:|)");
-    this.CONTEXT_REGEX = "^\\Q" + context.replaceAll(":([^/]+)", "\\\\E([^/]+)\\\\Q") + "\\E$";
-    this.CONTEXT_PATTERN = Pattern.compile(CONTEXT_REGEX);
   }
 
   @Override
@@ -47,22 +39,51 @@ public void handle(Request req, Response res) {
     }
 
     // Parse params
+    HashMap<String, String> params = matchURL(CONTEXT, requestPath);
+    if(params == null)
+      return;
+
+    req.setParams(params);
+    REQUEST.handle(req, res);
+  }
+
+  private static HashMap<String, String> matchURL(String filter, String url) {
     HashMap<String, String> params = new HashMap<>();
-    Matcher matcher = CONTEXT_PATTERN.matcher(requestPath);
+    StringBuilder key = new StringBuilder();
+    StringBuilder val = new StringBuilder();
+    char[] uc = url.toCharArray();
+    char[] fc = filter.toCharArray();
+    int ui = 0, fi = 0;
+
 
-    // Match all params
-    if (matcher.find()) {
+    for (; fi < fc.length; fi++, ui++) {
 
-      for (int i = 1; i <= matcher.groupCount() && i < CONTEXT_PARAMS.length; i++) {
-        String g = matcher.group(i);
-        params.put(CONTEXT_PARAMS[i], g);
+      if (fc[fi] == ':') {
+        key.setLength(0);
+        val.setLength(0);
+
+        fi++;
+        while (fi < fc.length && fc[fi] != '/') {
+          key.append(fc[fi++]);
+        }
+
+        while (ui < uc.length && uc[ui] != '/') {
+          val.append(uc[ui++]);
+        }
+
+        params.put(key.toString(), val.toString());
+      } else if (fc[fi] != uc[ui]) {
+
+        // Failed
+        return null;
       }
+    }
 
-    } else {
-      return;
+    if (ui < url.length() || fi < filter.length()) {
+      return null;
     }
 
-    req.setParams(params);
-    REQUEST.handle(req, res);
+    return params;
   }
+
 }