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      1 package com.android.server.location;
      2 
      3 import android.util.Log;
      4 
      5 import com.android.internal.annotations.VisibleForTesting;
      6 
      7 /**
      8  * Manages GNSS Batching operations.
      9  *
     10  * <p>This class is not thread safe (It's client's responsibility to make sure calls happen on
     11  * the same thread).
     12  */
     13 public class GnssBatchingProvider {
     14 
     15     private static final String TAG = "GnssBatchingProvider";
     16     private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
     17 
     18     private final GnssBatchingProviderNative mNative;
     19     private boolean mEnabled;
     20     private boolean mStarted;
     21     private long mPeriodNanos;
     22     private boolean mWakeOnFifoFull;
     23 
     24     GnssBatchingProvider() {
     25         this(new GnssBatchingProviderNative());
     26     }
     27 
     28     @VisibleForTesting
     29     GnssBatchingProvider(GnssBatchingProviderNative gnssBatchingProviderNative) {
     30         mNative = gnssBatchingProviderNative;
     31     }
     32 
     33     /**
     34      * Returns the GNSS batching size
     35      */
     36     public int getBatchSize() {
     37         return mNative.getBatchSize();
     38     }
     39 
     40     /** Enable GNSS batching. */
     41     public void enable() {
     42         mEnabled = mNative.initBatching();
     43         if (!mEnabled) {
     44             Log.e(TAG, "Failed to initialize GNSS batching");
     45         }
     46     }
     47 
     48     /**
     49      * Starts the hardware batching operation
     50      */
     51     public boolean start(long periodNanos, boolean wakeOnFifoFull) {
     52         if (!mEnabled) {
     53             throw new IllegalStateException();
     54         }
     55         if (periodNanos <= 0) {
     56             Log.e(TAG, "Invalid periodNanos " + periodNanos +
     57                     " in batching request, not started");
     58             return false;
     59         }
     60         mStarted = mNative.startBatch(periodNanos, wakeOnFifoFull);
     61         if (mStarted) {
     62             mPeriodNanos = periodNanos;
     63             mWakeOnFifoFull = wakeOnFifoFull;
     64         }
     65         return mStarted;
     66     }
     67 
     68     /**
     69      * Forces a flush of existing locations from the hardware batching
     70      */
     71     public void flush() {
     72         if (!mStarted) {
     73             Log.w(TAG, "Cannot flush since GNSS batching has not started.");
     74             return;
     75         }
     76         mNative.flushBatch();
     77     }
     78 
     79     /**
     80      * Stops the batching operation
     81      */
     82     public boolean stop() {
     83         boolean stopped = mNative.stopBatch();
     84         if (stopped) {
     85             mStarted = false;
     86         }
     87         return stopped;
     88     }
     89 
     90     /** Disable GNSS batching. */
     91     public void disable() {
     92         stop();
     93         mNative.cleanupBatching();
     94         mEnabled = false;
     95     }
     96 
     97     // TODO(b/37460011): Use this with death recovery logic.
     98     void resumeIfStarted() {
     99         if (DEBUG) {
    100             Log.d(TAG, "resumeIfStarted");
    101         }
    102         if (mStarted) {
    103             mNative.startBatch(mPeriodNanos, mWakeOnFifoFull);
    104         }
    105     }
    106 
    107     @VisibleForTesting
    108     static class GnssBatchingProviderNative {
    109         public int getBatchSize() {
    110             return native_get_batch_size();
    111         }
    112 
    113         public boolean startBatch(long periodNanos, boolean wakeOnFifoFull) {
    114             return native_start_batch(periodNanos, wakeOnFifoFull);
    115         }
    116 
    117         public void flushBatch() {
    118             native_flush_batch();
    119         }
    120 
    121         public boolean stopBatch() {
    122             return native_stop_batch();
    123         }
    124 
    125         public boolean initBatching() {
    126             return native_init_batching();
    127         }
    128 
    129         public void cleanupBatching() {
    130             native_cleanup_batching();
    131         }
    132     }
    133 
    134     private static native int native_get_batch_size();
    135 
    136     private static native boolean native_start_batch(long periodNanos, boolean wakeOnFifoFull);
    137 
    138     private static native void native_flush_batch();
    139 
    140     private static native boolean native_stop_batch();
    141 
    142     private static native boolean native_init_batching();
    143 
    144     private static native void native_cleanup_batching();
    145 }
    146