From eb8e831c956db804402e547c8a8e45d43bf6a0e7 Mon Sep 17 00:00:00 2001
From: Nathan Harold <nharold@google.com>
Date: Fri, 5 Oct 2018 18:59:18 -0700
Subject: Remove Hidden TimestampType From CellInfo

The timestamp type in CellInfo was added as an
experiment when CellInfo was first created. There
was optimism that highly precise timestamps would
be useful and available; however, in practice no
vendors are known to support precise timestamps
from the modem. Having a consistent timestap that
has a reference source available to apps is more
valuable than this flexibility. Thus, the reference
will always be nanotime since Android system boot,
and the timestamps will always be stamped by the
Android framework when the records are retrieved
from the modem.

Bug: 36971551
Test: atest FrameworksTelephonyTests

Change-Id: Ic5340b6c03ddc36aa00e7694c85b3af27128652e
---
 telephony/java/android/telephony/CellInfo.java | 70 +++++++-------------------
 1 file changed, 17 insertions(+), 53 deletions(-)

diff --git a/telephony/java/android/telephony/CellInfo.java b/telephony/java/android/telephony/CellInfo.java
index 4fe1b01007a7..94e4293806e6 100644
--- a/telephony/java/android/telephony/CellInfo.java
+++ b/telephony/java/android/telephony/CellInfo.java
@@ -22,6 +22,8 @@ import android.annotation.UnsupportedAppUsage;
 import android.os.Parcel;
 import android.os.Parcelable;
 
+import com.android.internal.annotations.VisibleForTesting;
+
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 
@@ -120,41 +122,45 @@ public abstract class CellInfo implements Parcelable {
     // Observation time stamped as type in nanoseconds since boot
     private long mTimeStamp;
 
-    // Where time stamp gets recorded.
-    // Value of TIMESTAMP_TYPE_XXXX
-    private int mTimeStampType;
-
     /** @hide */
     protected CellInfo() {
         this.mRegistered = false;
-        this.mTimeStampType = TIMESTAMP_TYPE_UNKNOWN;
         this.mTimeStamp = Long.MAX_VALUE;
     }
 
     /** @hide */
     protected CellInfo(CellInfo ci) {
         this.mRegistered = ci.mRegistered;
-        this.mTimeStampType = ci.mTimeStampType;
         this.mTimeStamp = ci.mTimeStamp;
         this.mCellConnectionStatus = ci.mCellConnectionStatus;
     }
 
-    /** True if this cell is registered to the mobile network */
+    /**
+     * True if the phone is registered to a mobile network that provides service on this cell
+     * and this cell is being used or would be used for network signaling.
+     */
     public boolean isRegistered() {
         return mRegistered;
     }
+
     /** @hide */
     public void setRegistered(boolean registered) {
         mRegistered = registered;
     }
 
-    /** Approximate time of this cell information in nanos since boot */
+    /**
+     * Approximate time this cell information was received from the modem.
+     *
+     * @return a time stamp in nanos since boot.
+     */
     public long getTimeStamp() {
         return mTimeStamp;
     }
+
     /** @hide */
-    public void setTimeStamp(long timeStamp) {
-        mTimeStamp = timeStamp;
+    @VisibleForTesting
+    public void setTimeStamp(long ts) {
+        mTimeStamp = ts;
     }
 
     /** @hide */
@@ -184,31 +190,11 @@ public abstract class CellInfo implements Parcelable {
         mCellConnectionStatus = cellConnectionStatus;
     }
 
-    /**
-     * Where time stamp gets recorded.
-     * @return one of TIMESTAMP_TYPE_XXXX
-     *
-     * @hide
-     */
-    @UnsupportedAppUsage
-    public int getTimeStampType() {
-        return mTimeStampType;
-    }
-
-    /** @hide */
-    public void setTimeStampType(int timeStampType) {
-        if (timeStampType < TIMESTAMP_TYPE_UNKNOWN || timeStampType > TIMESTAMP_TYPE_JAVA_RIL) {
-            mTimeStampType = TIMESTAMP_TYPE_UNKNOWN;
-        } else {
-            mTimeStampType = timeStampType;
-        }
-    }
-
     @Override
     public int hashCode() {
         int primeNum = 31;
         return ((mRegistered ? 0 : 1) * primeNum) + ((int)(mTimeStamp / 1000) * primeNum)
-                + (mTimeStampType * primeNum) + (mCellConnectionStatus * primeNum);
+                + (mCellConnectionStatus * primeNum);
     }
 
     @Override
@@ -223,37 +209,17 @@ public abstract class CellInfo implements Parcelable {
             CellInfo o = (CellInfo) other;
             return mRegistered == o.mRegistered
                     && mTimeStamp == o.mTimeStamp
-                    && mTimeStampType == o.mTimeStampType
                     && mCellConnectionStatus == o.mCellConnectionStatus;
         } catch (ClassCastException e) {
             return false;
         }
     }
 
-    @UnsupportedAppUsage
-    private static String timeStampTypeToString(int type) {
-        switch (type) {
-            case 1:
-                return "antenna";
-            case 2:
-                return "modem";
-            case 3:
-                return "oem_ril";
-            case 4:
-                return "java_ril";
-            default:
-                return "unknown";
-        }
-    }
-
     @Override
     public String toString() {
         StringBuffer sb = new StringBuffer();
-        String timeStampType;
 
         sb.append("mRegistered=").append(mRegistered ? "YES" : "NO");
-        timeStampType = timeStampTypeToString(mTimeStampType);
-        sb.append(" mTimeStampType=").append(timeStampType);
         sb.append(" mTimeStamp=").append(mTimeStamp).append("ns");
         sb.append(" mCellConnectionStatus=").append(mCellConnectionStatus);
 
@@ -280,7 +246,6 @@ public abstract class CellInfo implements Parcelable {
     protected void writeToParcel(Parcel dest, int flags, int type) {
         dest.writeInt(type);
         dest.writeInt(mRegistered ? 1 : 0);
-        dest.writeInt(mTimeStampType);
         dest.writeLong(mTimeStamp);
         dest.writeInt(mCellConnectionStatus);
     }
@@ -292,7 +257,6 @@ public abstract class CellInfo implements Parcelable {
      */
     protected CellInfo(Parcel in) {
         mRegistered = (in.readInt() == 1) ? true : false;
-        mTimeStampType = in.readInt();
         mTimeStamp = in.readLong();
         mCellConnectionStatus = in.readInt();
     }
-- 
cgit v1.2.3-59-g8ed1b