Merge "AudioFormat: Make member variables final for immutable class"
diff --git a/media/java/android/media/AudioFormat.java b/media/java/android/media/AudioFormat.java
index 3e3e651..24d2725 100644
--- a/media/java/android/media/AudioFormat.java
+++ b/media/java/android/media/AudioFormat.java
@@ -670,27 +670,43 @@
     }
 
     /**
-     * Private constructor with an ignored argument to differentiate from the removed default ctor
-     * @param ignoredArgument
-     */
-    private AudioFormat(int ignoredArgument) {
-    }
-
-    /**
      * Constructor used by the JNI.  Parameters are not checked for validity.
      */
     // Update sound trigger JNI in core/jni/android_hardware_SoundTrigger.cpp when modifying this
     // constructor
     @UnsupportedAppUsage
     private AudioFormat(int encoding, int sampleRate, int channelMask, int channelIndexMask) {
-        mEncoding = encoding;
-        mSampleRate = sampleRate;
-        mChannelMask = channelMask;
-        mChannelIndexMask = channelIndexMask;
-        mPropertySetMask = AUDIO_FORMAT_HAS_PROPERTY_ENCODING |
-                AUDIO_FORMAT_HAS_PROPERTY_SAMPLE_RATE |
-                AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_MASK |
-                AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_INDEX_MASK;
+        this(
+             AUDIO_FORMAT_HAS_PROPERTY_ENCODING
+             | AUDIO_FORMAT_HAS_PROPERTY_SAMPLE_RATE
+             | AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_MASK
+             | AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_INDEX_MASK,
+             encoding, sampleRate, channelMask, channelIndexMask
+             );
+    }
+
+    private AudioFormat(int propertySetMask,
+            int encoding, int sampleRate, int channelMask, int channelIndexMask) {
+        mPropertySetMask = propertySetMask;
+        mEncoding = (propertySetMask & AUDIO_FORMAT_HAS_PROPERTY_ENCODING) != 0
+                ? encoding : ENCODING_INVALID;
+        mSampleRate = (propertySetMask & AUDIO_FORMAT_HAS_PROPERTY_SAMPLE_RATE) != 0
+                ? sampleRate : SAMPLE_RATE_UNSPECIFIED;
+        mChannelMask = (propertySetMask & AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_MASK) != 0
+                ? channelMask : CHANNEL_INVALID;
+        mChannelIndexMask = (propertySetMask & AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_INDEX_MASK) != 0
+                ? channelIndexMask : CHANNEL_INVALID;
+
+        // Compute derived values.
+
+        final int channelIndexCount = Integer.bitCount(getChannelIndexMask());
+        int channelCount = channelCountFromOutChannelMask(getChannelMask());
+        if (channelCount == 0) {
+            channelCount = channelIndexCount;
+        } else if (channelCount != channelIndexCount && channelIndexCount != 0) {
+            channelCount = 0; // position and index channel count mismatch
+        }
+        mChannelCount = channelCount;
     }
 
     /** @hide */
@@ -704,14 +720,20 @@
     /** @hide */
     public final static int AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_INDEX_MASK = 0x1 << 3;
 
+    // This is an immutable class, all member variables are final.
+
+    // Essential values.
     @UnsupportedAppUsage
-    private int mEncoding;
+    private final int mEncoding;
     @UnsupportedAppUsage
-    private int mSampleRate;
+    private final int mSampleRate;
     @UnsupportedAppUsage
-    private int mChannelMask;
-    private int mChannelIndexMask;
-    private int mPropertySetMask;
+    private final int mChannelMask;
+    private final int mChannelIndexMask;
+    private final int mPropertySetMask;
+
+    // Derived values computed in the constructor, cached here.
+    private final int mChannelCount;
 
     /**
      * Return the encoding.
@@ -721,9 +743,6 @@
      * {@link AudioFormat#ENCODING_INVALID} if not set.
      */
     public int getEncoding() {
-        if ((mPropertySetMask & AUDIO_FORMAT_HAS_PROPERTY_ENCODING) == 0) {
-            return ENCODING_INVALID;
-        }
         return mEncoding;
     }
 
@@ -745,9 +764,6 @@
      * {@link AudioFormat#CHANNEL_INVALID} if not set.
      */
     public int getChannelMask() {
-        if ((mPropertySetMask & AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_MASK) == 0) {
-            return CHANNEL_INVALID;
-        }
         return mChannelMask;
     }
 
@@ -760,9 +776,6 @@
      * {@link AudioFormat#CHANNEL_INVALID} if not set or an invalid mask was used.
      */
     public int getChannelIndexMask() {
-        if ((mPropertySetMask & AUDIO_FORMAT_HAS_PROPERTY_CHANNEL_INDEX_MASK) == 0) {
-            return CHANNEL_INVALID;
-        }
         return mChannelIndexMask;
     }
 
@@ -772,14 +785,7 @@
      * Zero is returned if both the channel position mask and the channel index mask are not set.
      */
     public int getChannelCount() {
-        final int channelIndexCount = Integer.bitCount(getChannelIndexMask());
-        int channelCount = channelCountFromOutChannelMask(getChannelMask());
-        if (channelCount == 0) {
-            channelCount = channelIndexCount;
-        } else if (channelCount != channelIndexCount && channelIndexCount != 0) {
-            channelCount = 0; // position and index channel count mismatch
-        }
-        return channelCount;
+        return mChannelCount;
     }
 
     /** @hide */
@@ -790,7 +796,7 @@
     /** @hide */
     public String toLogFriendlyString() {
         return String.format("%dch %dHz %s",
-                getChannelCount(), mSampleRate, toLogFriendlyEncoding(mEncoding));
+                mChannelCount, mSampleRate, toLogFriendlyEncoding(mEncoding));
     }
 
     /**
@@ -839,14 +845,13 @@
          * @return a new {@link AudioFormat} object
          */
         public AudioFormat build() {
-            AudioFormat af = new AudioFormat(1980/*ignored*/);
-            af.mEncoding = mEncoding;
-            // not calling setSampleRate is equivalent to calling
-            // setSampleRate(SAMPLE_RATE_UNSPECIFIED)
-            af.mSampleRate = mSampleRate;
-            af.mChannelMask = mChannelMask;
-            af.mChannelIndexMask = mChannelIndexMask;
-            af.mPropertySetMask = mPropertySetMask;
+            AudioFormat af = new AudioFormat(
+                    mPropertySetMask,
+                    mEncoding,
+                    mSampleRate,
+                    mChannelMask,
+                    mChannelIndexMask
+                    );
             return af;
         }
 
@@ -1049,11 +1054,13 @@
     }
 
     private AudioFormat(Parcel in) {
-        mPropertySetMask = in.readInt();
-        mEncoding = in.readInt();
-        mSampleRate = in.readInt();
-        mChannelMask = in.readInt();
-        mChannelIndexMask = in.readInt();
+        this(
+             in.readInt(), // propertySetMask
+             in.readInt(), // encoding
+             in.readInt(), // sampleRate
+             in.readInt(), // channelMask
+             in.readInt()  // channelIndexMask
+            );
     }
 
     public static final Parcelable.Creator<AudioFormat> CREATOR =