From 60ef28853e4aca8b227f533c4b95c03de6574e02 Mon Sep 17 00:00:00 2001
From: Fredrik Tolf <fredrik@dolda2000.com>
Date: Tue, 13 Oct 2009 06:48:20 +0200
Subject: [PATCH] Made cache checking easier.

---
 src/dolda/jsvc/util/Cache.java         | 28 ++++++++++++++++++++++++++++
 src/dolda/jsvc/util/Restarts.java      |  7 +++++++
 src/dolda/jsvc/util/StaticContent.java | 17 +----------------
 3 files changed, 36 insertions(+), 16 deletions(-)
 create mode 100644 src/dolda/jsvc/util/Cache.java

diff --git a/src/dolda/jsvc/util/Cache.java b/src/dolda/jsvc/util/Cache.java
new file mode 100644
index 0000000..6fd7d7a
--- /dev/null
+++ b/src/dolda/jsvc/util/Cache.java
@@ -0,0 +1,28 @@
+package dolda.jsvc.util;
+
+import dolda.jsvc.*;
+import java.util.*;
+
+public class Cache {
+    public static void checkmtime(Request req, long mtime) {
+	/* Since the HTTP time format is (reasonably enough) precise
+	 * only to seconds, any extra milliseconds must be trimmed
+	 * off, or the mtime will almost certainly not match. */
+	Date mdate = new Date((mtime / 1000) * 1000);
+	String ims = req.inheaders().get("If-Modified-Since");
+	if(ims != null) {
+	    Date cldate;
+	    try {
+		cldate = Http.parsedate(ims);
+	    } catch(java.text.ParseException e) {
+		throw(Restarts.stdresponse(400, "The If-Modified-Since header is not parseable."));
+	    }
+	    if(mdate.compareTo(cldate) <= 0) {
+		req.status(304);
+		req.outheaders().put("Content-Length", "0");
+		throw(Restarts.done());
+	    }
+	}
+	req.outheaders().put("Last-Modified", Http.fmtdate(mdate));
+    }
+}
diff --git a/src/dolda/jsvc/util/Restarts.java b/src/dolda/jsvc/util/Restarts.java
index 7725f28..d4aab70 100644
--- a/src/dolda/jsvc/util/Restarts.java
+++ b/src/dolda/jsvc/util/Restarts.java
@@ -77,4 +77,11 @@ public class Restarts {
     public static RequestRestart stdresponse(int code) {
 	return(stdresponse(code, "An error occurred", Misc.statustext(code)));
     }
+    
+    public static RequestRestart done() {
+	return(new RequestRestart() {
+		public void respond(Request req) {
+		}
+	    });
+    }
 }
diff --git a/src/dolda/jsvc/util/StaticContent.java b/src/dolda/jsvc/util/StaticContent.java
index 0d4208e..685669c 100644
--- a/src/dolda/jsvc/util/StaticContent.java
+++ b/src/dolda/jsvc/util/StaticContent.java
@@ -36,25 +36,10 @@ public class StaticContent implements Responder {
 	}
 	if(in == null)
 	    throw(Restarts.stdresponse(404));
-	String ims = req.inheaders().get("If-Modified-Since");
-	Date mtime = new Date((req.ctx().starttime() / 1000) * 1000);
-	if(ims != null) {
-	    Date d;
-	    try {
-		d = Http.parsedate(ims);
-	    } catch(java.text.ParseException e) {
-		throw(Restarts.stdresponse(400));
-	    }
-	    if(mtime.compareTo(d) <= 0) {
-		req.status(304);
-		req.outheaders().put("Content-Length", "0");
-		return;
-	    }
-	}
+	Cache.checkmtime(req, req.ctx().starttime());
 	try {
 	    try {
 		req.outheaders().put("Content-Type", mimetype);
-		req.outheaders().put("Last-Modified", Http.fmtdate(mtime));
 		Misc.cpstream(in, req.output());
 	    } finally {
 		in.close();
-- 
2.11.0