Uses the "Last-Modified" header for "If-Modified-Since"

Uses the "Last-Modified" header for "If-Modified-Since"
see http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.3.4

Change-Id: I0f5e9b45f4f79d7c1b286e465f9750dcd71b6bfd
Signed-off-by: Ralph Bergmann <ralph@the4thfloor.eu>

3 files changed, 46 insertions, 1 deletions

diff --git a/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java b/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java
index 4b2955d..d9d49e9 100644
--- a/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java
+++ b/src/test/java/com/android/volley/toolbox/DiskBasedCacheTest.java
@@ -34,6 +34,7 @@ public class DiskBasedCacheTest {
         Cache.Entry e = new Cache.Entry();
         e.data = new byte[8];
         e.serverDate = 1234567L;
+        e.lastModified = 13572468L;
         e.ttl = 9876543L;
         e.softTtl = 8765432L;
         e.etag = "etag";
@@ -48,6 +49,7 @@ public class DiskBasedCacheTest {
 
         assertEquals(first.key, second.key);
         assertEquals(first.serverDate, second.serverDate);
+        assertEquals(first.lastModified, second.lastModified);
         assertEquals(first.ttl, second.ttl);
         assertEquals(first.softTtl, second.softTtl);
         assertEquals(first.etag, second.etag);
@@ -121,4 +123,43 @@ public class DiskBasedCacheTest {
         assertEquals(DiskBasedCache.readStringStringMap(bais), emptyKey);
         assertEquals(DiskBasedCache.readStringStringMap(bais), emptyValue);
     }
+
+    // Test deserializing the old format into the new one.
+    public void testCacheHeaderSerializationOldToNewFormat() throws Exception {
+
+        final int CACHE_MAGIC = 0x20140623;
+        final String key = "key";
+        final String etag = "etag";
+        final long serverDate = 1234567890l;
+        final long ttl = 1357924680l;
+        final long softTtl = 2468013579l;
+
+        Map<String, String> responseHeaders = new HashMap<String, String>();
+        responseHeaders.put("first", "thing");
+        responseHeaders.put("second", "item");
+
+        // write old sytle header (without lastModified)
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        DiskBasedCache.writeInt(baos, CACHE_MAGIC);
+        DiskBasedCache.writeString(baos, key);
+        DiskBasedCache.writeString(baos, etag == null ? "" : etag);
+        DiskBasedCache.writeLong(baos, serverDate);
+        DiskBasedCache.writeLong(baos, ttl);
+        DiskBasedCache.writeLong(baos, softTtl);
+        DiskBasedCache.writeStringStringMap(responseHeaders, baos);
+
+        // read / test new style header (with lastModified)
+        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());
+        CacheHeader cacheHeader = CacheHeader.readHeader(bais);
+
+        assertEquals(cacheHeader.key, key);
+        assertEquals(cacheHeader.etag, etag);
+        assertEquals(cacheHeader.serverDate, serverDate);
+        assertEquals(cacheHeader.ttl, ttl);
+        assertEquals(cacheHeader.softTtl, softTtl);
+        assertEquals(cacheHeader.responseHeaders, responseHeaders);
+
+        // the old format doesn't know lastModified
+        assertEquals(cacheHeader.lastModified, 0);
+    }
 }
diff --git a/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java b/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java
index b8c4847..01ff2c2 100644
--- a/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java
+++ b/src/test/java/com/android/volley/toolbox/HttpHeaderParserTest.java
@@ -40,6 +40,7 @@ public class HttpHeaderParserTest {
 
     private static long ONE_MINUTE_MILLIS = 1000L * 60;
     private static long ONE_HOUR_MILLIS = 1000L * 60 * 60;
+    private static long ONE_DAY_MILLIS = ONE_HOUR_MILLIS * 24;
 
     private NetworkResponse response;
     private Map<String, String> headers;
@@ -55,6 +56,7 @@ public class HttpHeaderParserTest {
         assertNotNull(entry);
         assertNull(entry.etag);
         assertEquals(0, entry.serverDate);
+        assertEquals(0, entry.lastModified);
         assertEquals(0, entry.ttl);
         assertEquals(0, entry.softTtl);
     }
@@ -82,6 +84,7 @@ public class HttpHeaderParserTest {
     @Test public void parseCacheHeaders_normalExpire() {
         long now = System.currentTimeMillis();
         headers.put("Date", rfc1123Date(now));
+        headers.put("Last-Modified", rfc1123Date(now - ONE_DAY_MILLIS));
         headers.put("Expires", rfc1123Date(now + ONE_HOUR_MILLIS));
 
         Cache.Entry entry = HttpHeaderParser.parseCacheHeaders(response);
@@ -89,6 +92,7 @@ public class HttpHeaderParserTest {
         assertNotNull(entry);
         assertNull(entry.etag);
         assertEqualsWithin(entry.serverDate, now, ONE_MINUTE_MILLIS);
+        assertEqualsWithin(entry.lastModified, (now - ONE_DAY_MILLIS), ONE_MINUTE_MILLIS);
         assertTrue(entry.softTtl >= (now + ONE_HOUR_MILLIS));
         assertTrue(entry.ttl == entry.softTtl);
     }
diff --git a/src/test/java/com/android/volley/utils/CacheTestUtils.java b/src/test/java/com/android/volley/utils/CacheTestUtils.java
index cd2b8e7..898d055 100644
--- a/src/test/java/com/android/volley/utils/CacheTestUtils.java
+++ b/src/test/java/com/android/volley/utils/CacheTestUtils.java
@@ -24,7 +24,7 @@ public class CacheTestUtils {
             entry.data = new byte[random.nextInt(1024)];
         }
         entry.etag = String.valueOf(random.nextLong());
-        entry.serverDate = random.nextLong();
+        entry.lastModified = random.nextLong();
         entry.ttl = isExpired ? 0 : Long.MAX_VALUE;
         entry.softTtl = needsRefresh ? 0 : Long.MAX_VALUE;
         return entry;