Improve the performance of Reviewing a photo.

fix: 5144370

There is two componenet in the photo page. One is the large photo and the
other is the thumbnail strip. They idenpendently load their own data and images.

This change fixes several issues here:

1. Prevent sending to many jobs to ThreadPool and block others.
   In a worse case, if the thumbnail strip send image requests first,
   it may block the ThreadPool very long.
2. Improve the performance of extracting thumbnails from local files.
   Now we try to extract the thumbnails from EXIF data first.

Change-Id: I45100d4daa025efb479f47c4f105de2b4731b498

1 files changed, 25 insertions, 0 deletions

diff --git a/src/com/android/gallery3d/data/DecodeUtils.java b/src/com/android/gallery3d/data/DecodeUtils.java
index da2d3e0ee..d2b4ebc4e 100644
--- a/src/com/android/gallery3d/data/DecodeUtils.java
+++ b/src/com/android/gallery3d/data/DecodeUtils.java
@@ -106,6 +106,31 @@ public class DecodeUtils {
                 BitmapFactory.decodeFileDescriptor(fd, null, options));
     }
 
+    /**
+     * Decodes the bitmap from the given byte array if the image size is larger than the given
+     * requirement.
+     *
+     * Note: The returned image may be resized down. However, both width and heigh must be
+     * larger than the <code>targetSize</code>.
+     */
+    public static Bitmap requestDecodeIfBigEnough(JobContext jc, byte[] data,
+            Options options, int targetSize) {
+        if (options == null) options = new Options();
+        jc.setCancelListener(new DecodeCanceller(options));
+
+        options.inJustDecodeBounds = true;
+        BitmapFactory.decodeByteArray(data, 0, data.length, options);
+        if (jc.isCancelled()) return null;
+        if (options.outWidth < targetSize || options.outHeight < targetSize) {
+            return null;
+        }
+        options.inSampleSize = BitmapUtils.computeSampleSizeLarger(
+                options.outWidth, options.outHeight, targetSize);
+        options.inJustDecodeBounds = false;
+        return ensureGLCompatibleBitmap(
+                BitmapFactory.decodeByteArray(data, 0, data.length, options));
+    }
+
     public static Bitmap requestDecode(JobContext jc,
             FileDescriptor fileDescriptor, Rect paddings, Options options) {
         if (options == null) options = new Options();