Intern CacheHeader keys and values to avoid string duplication

We found that Volley generated about 20 strings per cached item (~9000
strings for ~440 cached items) and most of these were duplicates. This
change interns the key and value strings to avoid duplication. This saved
about 500kb for our scenario (440 images cached.)

1 files changed, 2 insertions, 2 deletions

diff --git a/src/com/android/volley/toolbox/DiskBasedCache.java b/src/com/android/volley/toolbox/DiskBasedCache.java
index 75bf4d1..9559a02 100644
--- a/src/com/android/volley/toolbox/DiskBasedCache.java
+++ b/src/com/android/volley/toolbox/DiskBasedCache.java
@@ -456,8 +456,8 @@ public class DiskBasedCache implements Cache {
                     ? Collections.<String, String>emptyMap()
                     : new HashMap<String, String>(size);
             for (int i = 0; i < size; i++) {
-                String key = ois.readUTF();
-                String value = ois.readUTF();
+                String key = ois.readUTF().intern();
+                String value = ois.readUTF().intern();
                 result.put(key, value);
             }
             return result;