[tor-commits] [onionoo/master] Implement caching using Last-Modified/If-Modified-Since headers.

[karsten at torproject.org]

commit 163ee8c8472ce13e6e1e589d245b102c7d684a67
Author: Karsten Loesing <karsten.loesing at gmx.net>
Date:   Fri Mar 9 13:56:35 2012 +0100

    Implement caching using Last-Modified/If-Modified-Since headers.
---
 src/org/torproject/onionoo/Main.java            |   16 ++++++++--------
 src/org/torproject/onionoo/ResourceServlet.java |    7 ++++++-
 web/index.html                                  |    8 +++-----
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/src/org/torproject/onionoo/Main.java b/src/org/torproject/onionoo/Main.java
index 8c4497d..20367d2 100644
--- a/src/org/torproject/onionoo/Main.java
+++ b/src/org/torproject/onionoo/Main.java
@@ -17,14 +17,6 @@ public class Main {
     cn.setBridgeRunningBits();
     cn.writeRelaySearchDataFile();
 
-    printStatus("Updating summary data.");
-    SummaryDataWriter sdw = new SummaryDataWriter();
-    sdw.setLastValidAfterMillis(cn.getLastValidAfterMillis());
-    sdw.setLastPublishedMillis(cn.getLastPublishedMillis());
-    sdw.setCurrentRelays(cn.getCurrentRelays());
-    sdw.setCurrentBridges(cn.getCurrentBridges());
-    sdw.writeSummaryDataFile();
-
     printStatus("Updating detail data.");
     DetailDataWriter ddw = new DetailDataWriter();
     ddw.setCurrentRelays(cn.getCurrentRelays());
@@ -42,6 +34,14 @@ public class Main {
     bdw.readExtraInfoDescriptors();
     bdw.deleteObsoleteBandwidthFiles();
 
+    printStatus("Updating summary data.");
+    SummaryDataWriter sdw = new SummaryDataWriter();
+    sdw.setLastValidAfterMillis(cn.getLastValidAfterMillis());
+    sdw.setLastPublishedMillis(cn.getLastPublishedMillis());
+    sdw.setCurrentRelays(cn.getCurrentRelays());
+    sdw.setCurrentBridges(cn.getCurrentBridges());
+    sdw.writeSummaryDataFile();
+
     printStatus("Terminating.");
   }
 
diff --git a/src/org/torproject/onionoo/ResourceServlet.java b/src/org/torproject/onionoo/ResourceServlet.java
index 016c9ef..b28eca1 100644
--- a/src/org/torproject/onionoo/ResourceServlet.java
+++ b/src/org/torproject/onionoo/ResourceServlet.java
@@ -26,7 +26,7 @@ public class ResourceServlet extends HttpServlet {
     this.readSummaryFile();
   }
 
-  long summaryFileLastModified = 0L;
+  long summaryFileLastModified = -1L;
   boolean readSummaryFile = false;
   private String relaysPublishedLine = null, bridgesPublishedLine = null;
   private List<String> relayLines = new ArrayList<String>(),
@@ -69,6 +69,11 @@ public class ResourceServlet extends HttpServlet {
     this.readSummaryFile = true;
   }
 
+  public long getLastModified(HttpServletRequest request) {
+    this.readSummaryFile();
+    return this.summaryFileLastModified;
+  }
+
   public void doGet(HttpServletRequest request,
       HttpServletResponse response) throws IOException, ServletException {
 
diff --git a/web/index.html b/web/index.html
index 27bb094..ff781f6 100755
--- a/web/index.html
+++ b/web/index.html
@@ -16,11 +16,9 @@ responds with JSON-formatted replies.</p>
 gzip"</i> header in their requests and handle gzip-compressed responses.
 Only requests starting at a certain size will be compressed by the
 server.</li>
-<li><b>Caching:</b> Clients should cache all responses for up to five
-minutes.
-A better caching strategy may be employed in the future that will be based
-on the server's information when new data is expected to be
-available.</li>
+<li><b>Caching:</b> Clients should make use of the <i>"Last-Modified"</i>
+header of responses and include that timestamp in a
+<i>"If-Modified-Since"</i> header of subsequent requests.</li>
 <li><b>Protocol changes:</b> There are plenty of reasons why we may have
 to change the protocol described here.
 Clients should be able to handle all valid JSON responses, ignoring