Allow prefetch for cache, reducing priority for prefetched images.

 Bug 8446191
 Required for I86cfa59f448daa4e7b9fd7ea9ada2d69357e1f63

Change-Id: I7cccfffc539988d26fc751e16726b05fb2ba21bd

1 files changed, 27 insertions, 3 deletions

diff --git a/src/com/android/photos/data/MediaCache.java b/src/com/android/photos/data/MediaCache.java
index 9cf69d643..0952a4017 100644
--- a/src/com/android/photos/data/MediaCache.java
+++ b/src/com/android/photos/data/MediaCache.java
@@ -107,6 +107,8 @@ public class MediaCache {
         void notifyReady();
 
         void setFile(File file) throws FileNotFoundException;
+
+        boolean isPrefetch();
     }
 
     private static class NotifyOriginalReady implements NotifyReady {
@@ -119,13 +121,20 @@ public class MediaCache {
 
         @Override
         public void notifyReady() {
-            mCallback.originalReady(mFile);
+            if (mCallback != null) {
+                mCallback.originalReady(mFile);
+            }
         }
 
         @Override
         public void setFile(File file) {
             mFile = file;
         }
+
+        @Override
+        public boolean isPrefetch() {
+            return mCallback == null;
+        }
     }
 
     private static class NotifyImageReady implements NotifyReady {
@@ -138,7 +147,9 @@ public class MediaCache {
 
         @Override
         public void notifyReady() {
-            mCallback.imageReady(mInputStream);
+            if (mCallback != null) {
+                mCallback.imageReady(mInputStream);
+            }
         }
 
         @Override
@@ -149,6 +160,11 @@ public class MediaCache {
         public void setBytes(byte[] bytes) {
             mInputStream = new ByteArrayInputStream(bytes);
         }
+
+        @Override
+        public boolean isPrefetch() {
+            return mCallback == null;
+        }
     }
 
     /** A media item to be retrieved and its notifications. */
@@ -496,7 +512,15 @@ public class MediaCache {
             }
             synchronized (tasks) {
                 ProcessingJob job = new ProcessingJob(uri, size, complete, lowResolution);
-                tasks.add(job);
+                if (complete.isPrefetch()) {
+                    tasks.add(job);
+                } else {
+                    int index = tasks.size() - 1;
+                    while (index >= 0 && tasks.get(index).complete.isPrefetch()) {
+                        index--;
+                    }
+                    tasks.add(index + 1, job);
+                }
                 tasks.notifyAll();
             }
         }