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      1 /*
      2  * Copyright 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.server.location;
     18 
     19 import android.hardware.location.ContextHubTransaction;
     20 import android.hardware.location.NanoAppState;
     21 
     22 import java.util.List;
     23 import java.util.concurrent.TimeUnit;
     24 
     25 /**
     26  * An abstract class representing transactions requested to the Context Hub Service.
     27  *
     28  * @hide
     29  */
     30 /* package */ abstract class ContextHubServiceTransaction {
     31     private final int mTransactionId;
     32     @ContextHubTransaction.Type
     33     private final int mTransactionType;
     34 
     35     /*
     36      * true if the transaction has already completed, false otherwise
     37      */
     38     private boolean mIsComplete = false;
     39 
     40     /* package */ ContextHubServiceTransaction(int id, int type) {
     41         mTransactionId = id;
     42         mTransactionType = type;
     43     }
     44 
     45     /**
     46      * Starts this transaction with a Context Hub.
     47      *
     48      * All instances of this class must implement this method by making an asynchronous request to
     49      * a hub.
     50      *
     51      * @return the synchronous error code of the transaction start
     52      */
     53     /* package */
     54     abstract int onTransact();
     55 
     56     /**
     57      * A function to invoke when the transaction completes.
     58      *
     59      * For transactions with expected contents (such as a query), the class instance should
     60      * implement the appropriate behavior (e.g. invoke onQueryResponse with an empty list).
     61      *
     62      * @param result the result of the transaction
     63      */
     64     /* package */ void onTransactionComplete(@ContextHubTransaction.Result int result) {
     65     }
     66 
     67     /**
     68      * A function to invoke when a query transaction completes.
     69      *
     70      * Only relevant for query transactions.
     71      *
     72      * @param result           the result of the query
     73      * @param nanoAppStateList the list of nanoapps given by the query response
     74      */
     75     /* package */ void onQueryResponse(
     76             @ContextHubTransaction.Result int result, List<NanoAppState> nanoAppStateList) {
     77     }
     78 
     79     /**
     80      * @return the ID of this transaction
     81      */
     82     /* package */ int getTransactionId() {
     83         return mTransactionId;
     84     }
     85 
     86     /**
     87      * @return the type of this transaction
     88      * @see ContextHubTransaction.Type
     89      */
     90     @ContextHubTransaction.Type
     91     /* package */ int getTransactionType() {
     92         return mTransactionType;
     93     }
     94 
     95     /**
     96      * Gets the timeout period as defined in IContexthub.hal
     97      *
     98      * @return the timeout of this transaction in the specified time unit
     99      */
    100     /* package */ long getTimeout(TimeUnit unit) {
    101         switch (mTransactionType) {
    102             case ContextHubTransaction.TYPE_LOAD_NANOAPP:
    103                 return unit.convert(30L, TimeUnit.SECONDS);
    104             case ContextHubTransaction.TYPE_UNLOAD_NANOAPP:
    105             case ContextHubTransaction.TYPE_ENABLE_NANOAPP:
    106             case ContextHubTransaction.TYPE_DISABLE_NANOAPP:
    107             case ContextHubTransaction.TYPE_QUERY_NANOAPPS:
    108                 // Note: query timeout is not specified at the HAL
    109             default: /* fall through */
    110                 return unit.convert(5L, TimeUnit.SECONDS);
    111         }
    112     }
    113 
    114     /**
    115      * Marks the transaction as complete.
    116      *
    117      * Should only be called as a result of a response from a Context Hub callback
    118      */
    119     /* package */ void setComplete() {
    120         mIsComplete = true;
    121     }
    122 
    123     /**
    124      * @return true if the transaction has already completed, false otherwise
    125      */
    126     /* package */ boolean isComplete() {
    127         return mIsComplete;
    128     }
    129 
    130     @Override
    131     public String toString() {
    132         return ContextHubTransaction.typeToString(mTransactionType, true /* upperCase */)
    133                 + " transaction (ID = " + mTransactionId + ")";
    134     }
    135 }
    136