Improve TrafficStats UID APIs.

Deprecate transport layer statistics, leaving only the summarized
network layer statistics.

Improve documentation to be clear about layers where measurements
occur, and their behavior since boot.  Under the hood, move to using
xt_qtaguid UID statistics.

Bug: 6818637, 7013662
Change-Id: I9f26992e5fcdebd88c671e5765bd91229e7b0016

1 files changed, 113 insertions, 117 deletions

diff --git a/core/java/android/net/TrafficStats.java b/core/java/android/net/TrafficStats.java
index a014cec..a282910 100644
--- a/core/java/android/net/TrafficStats.java
+++ b/core/java/android/net/TrafficStats.java
@@ -424,161 +424,156 @@ public class TrafficStats {
     }
 
     /**
-     * Get the number of bytes sent through the network for this UID.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
+     * Return number of bytes transmitted by the given UID since device boot.
+     * Counts packets across all network interfaces, and always increases
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @see android.os.Process#myUid()
+     * @see android.content.pm.ApplicationInfo#uid
      */
-    public static native long getUidTxBytes(int uid);
+    public static long getUidTxBytes(int uid) {
+        return nativeGetUidStat(uid, TYPE_TX_BYTES);
+    }
 
     /**
-     * Get the number of bytes received through the network for this UID.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
+     * Return number of bytes received by the given UID since device boot.
+     * Counts packets across all network interfaces, and always increases
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes
+     * @see android.os.Process#myUid()
+     * @see android.content.pm.ApplicationInfo#uid
      */
-    public static native long getUidRxBytes(int uid);
+    public static long getUidRxBytes(int uid) {
+        return nativeGetUidStat(uid, TYPE_RX_BYTES);
+    }
 
     /**
-     * Get the number of packets (TCP segments + UDP) sent through
-     * the network for this UID.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
+     * Return number of packets transmitted by the given UID since device boot.
+     * Counts packets across all network interfaces, and always increases
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * @param uid The UID of the process to examine.
-     * @return number of packets.
-     * If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @see android.os.Process#myUid()
+     * @see android.content.pm.ApplicationInfo#uid
      */
-    public static native long getUidTxPackets(int uid);
+    public static long getUidTxPackets(int uid) {
+        return nativeGetUidStat(uid, TYPE_TX_PACKETS);
+    }
 
     /**
-     * Get the number of packets (TCP segments + UDP) received through
-     * the network for this UID.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
+     * Return number of packets received by the given UID since device boot.
+     * Counts packets across all network interfaces, and always increases
+     * monotonically since device boot. Statistics are measured at the network
+     * layer, so they include both TCP and UDP usage.
+     * <p>
+     * Before {@link android.os.Build.VERSION_CODES#K}, this may return
+     * {@link #UNSUPPORTED} on devices where statistics aren't available.
      *
-     * @param uid The UID of the process to examine.
-     * @return number of packets
+     * @see android.os.Process#myUid()
+     * @see android.content.pm.ApplicationInfo#uid
      */
-    public static native long getUidRxPackets(int uid);
+    public static long getUidRxPackets(int uid) {
+        return nativeGetUidStat(uid, TYPE_RX_PACKETS);
+    }
 
     /**
-     * Get the number of TCP payload bytes sent for this UID.
-     * This total does not include protocol and control overheads at
-     * the transport and the lower layers of the networking stack.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidTxBytes(int)
      */
-    public static native long getUidTcpTxBytes(int uid);
+    @Deprecated
+    public static long getUidTcpTxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of TCP payload bytes received for this UID.
-     * This total does not include protocol and control overheads at
-     * the transport and the lower layers of the networking stack.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidRxBytes(int)
      */
-    public static native long getUidTcpRxBytes(int uid);
+    @Deprecated
+    public static long getUidTcpRxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP payload bytes sent for this UID.
-     * This total does not include protocol and control overheads at
-     * the transport and the lower layers of the networking stack.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidTxBytes(int)
      */
-    public static native long getUidUdpTxBytes(int uid);
+    @Deprecated
+    public static long getUidUdpTxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP payload bytes received for this UID.
-     * This total does not include protocol and control overheads at
-     * the transport and the lower layers of the networking stack.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of bytes.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidRxBytes(int)
      */
-    public static native long getUidUdpRxBytes(int uid);
+    @Deprecated
+    public static long getUidUdpRxBytes(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of TCP segments sent for this UID.
-     * Does not include TCP control packets (SYN/ACKs/FIN/..).
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of TCP segments.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidTxPackets(int)
      */
-    public static native long getUidTcpTxSegments(int uid);
+    @Deprecated
+    public static long getUidTcpTxSegments(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of TCP segments received for this UID.
-     * Does not include TCP control packets (SYN/ACKs/FIN/..).
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of TCP segments.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidRxPackets(int)
      */
-    public static native long getUidTcpRxSegments(int uid);
+    @Deprecated
+    public static long getUidTcpRxSegments(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP packets sent for this UID.
-     * Includes DNS requests.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of packets.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidTxPackets(int)
      */
-    public static native long getUidUdpTxPackets(int uid);
+    @Deprecated
+    public static long getUidUdpTxPackets(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
-     * Get the number of UDP packets received for this UID.
-     * Includes DNS responses.
-     * The statistics are across all interfaces.
-     *
-     * {@see android.os.Process#myUid()}.
-     *
-     * @param uid The UID of the process to examine.
-     * @return number of packets.  If the statistics are not supported by this device,
-     * {@link #UNSUPPORTED} will be returned.
+     * @deprecated Starting in {@link android.os.Build.VERSION_CODES#K},
+     *             transport layer statistics are no longer available, and will
+     *             always return {@link #UNSUPPORTED}.
+     * @see #getUidRxPackets(int)
      */
-    public static native long getUidUdpRxPackets(int uid);
+    @Deprecated
+    public static long getUidUdpRxPackets(int uid) {
+        return UNSUPPORTED;
+    }
 
     /**
      * Return detailed {@link NetworkStats} for the current UID. Requires no
@@ -616,4 +611,5 @@ public class TrafficStats {
 
     private static native long nativeGetTotalStat(int type);
     private static native long nativeGetIfaceStat(String iface, int type);
+    private static native long nativeGetUidStat(int uid, int type);
 }