More battery stats improvements.
We now write to the parcel using deltas. For common situations,
it only takes 4 bytes to write a delta (new command, time delta,
significant state changes, flags indicating additional state that
follows).
Increasing the buffer size to 128K, this give us 32,768 samples
if they all fit in the smallest delta. A device that is doing
something every minute (like acquiring a wake lock or doing a
wifi scan) for our max target battery life of 30 days would
generate 43,200 samples.
Also some turning to the maximum time between samples at which
we decide to completely collapse two samples.
Change-Id: I074a698d27ccf9389f9585abfc983af2f5ba7a54
diff --git a/core/java/android/os/BatteryStats.java b/core/java/android/os/BatteryStats.java
index d7483ba..b0f3ac3 100644
--- a/core/java/android/os/BatteryStats.java
+++ b/core/java/android/os/BatteryStats.java
@@ -26,6 +26,7 @@
import android.telephony.SignalStrength;
import android.util.Log;
import android.util.Printer;
+import android.util.Slog;
import android.util.SparseArray;
import android.util.TimeUtils;
@@ -408,16 +409,19 @@
}
public final static class HistoryItem implements Parcelable {
+ static final String TAG = "HistoryItem";
+ static final boolean DEBUG = false;
+
public HistoryItem next;
public long time;
- public static final byte CMD_NULL = -1;
- public static final byte CMD_UPDATE = 0;
- public static final byte CMD_START = 1;
- public static final byte CMD_OVERFLOW = 2;
+ public static final byte CMD_NULL = 0;
+ public static final byte CMD_UPDATE = 1;
+ public static final byte CMD_START = 2;
+ public static final byte CMD_OVERFLOW = 3;
- public byte cmd;
+ public byte cmd = CMD_NULL;
public byte batteryLevel;
public byte batteryStatus;
@@ -428,33 +432,38 @@
public char batteryVoltage;
// Constants from SCREEN_BRIGHTNESS_*
- public static final int STATE_BRIGHTNESS_MASK = 0x000000f;
+ public static final int STATE_BRIGHTNESS_MASK = 0x0000000f;
public static final int STATE_BRIGHTNESS_SHIFT = 0;
// Constants from SIGNAL_STRENGTH_*
- public static final int STATE_SIGNAL_STRENGTH_MASK = 0x00000f0;
+ public static final int STATE_SIGNAL_STRENGTH_MASK = 0x000000f0;
public static final int STATE_SIGNAL_STRENGTH_SHIFT = 4;
// Constants from ServiceState.STATE_*
- public static final int STATE_PHONE_STATE_MASK = 0x0000f00;
+ public static final int STATE_PHONE_STATE_MASK = 0x00000f00;
public static final int STATE_PHONE_STATE_SHIFT = 8;
// Constants from DATA_CONNECTION_*
- public static final int STATE_DATA_CONNECTION_MASK = 0x000f000;
+ public static final int STATE_DATA_CONNECTION_MASK = 0x0000f000;
public static final int STATE_DATA_CONNECTION_SHIFT = 12;
- public static final int STATE_BATTERY_PLUGGED_FLAG = 1<<30;
- public static final int STATE_SCREEN_ON_FLAG = 1<<29;
+ // These states always appear directly in the first int token
+ // of a delta change; they should be ones that change relatively
+ // frequently.
+ public static final int STATE_WAKE_LOCK_FLAG = 1<<30;
+ public static final int STATE_SENSOR_ON_FLAG = 1<<29;
public static final int STATE_GPS_ON_FLAG = 1<<28;
- public static final int STATE_PHONE_IN_CALL_FLAG = 1<<27;
- public static final int STATE_PHONE_SCANNING_FLAG = 1<<26;
- public static final int STATE_WIFI_ON_FLAG = 1<<25;
- public static final int STATE_WIFI_RUNNING_FLAG = 1<<24;
- public static final int STATE_WIFI_FULL_LOCK_FLAG = 1<<23;
- public static final int STATE_WIFI_SCAN_LOCK_FLAG = 1<<22;
- public static final int STATE_WIFI_MULTICAST_ON_FLAG = 1<<21;
- public static final int STATE_BLUETOOTH_ON_FLAG = 1<<20;
- public static final int STATE_AUDIO_ON_FLAG = 1<<19;
- public static final int STATE_VIDEO_ON_FLAG = 1<<18;
- public static final int STATE_WAKE_LOCK_FLAG = 1<<17;
- public static final int STATE_SENSOR_ON_FLAG = 1<<16;
+ public static final int STATE_PHONE_SCANNING_FLAG = 1<<27;
+ public static final int STATE_WIFI_RUNNING_FLAG = 1<<26;
+ public static final int STATE_WIFI_FULL_LOCK_FLAG = 1<<25;
+ public static final int STATE_WIFI_SCAN_LOCK_FLAG = 1<<24;
+ public static final int STATE_WIFI_MULTICAST_ON_FLAG = 1<<23;
+ // These are on the lower bits used for the command; if they change
+ // we need to write another int of data.
+ public static final int STATE_AUDIO_ON_FLAG = 1<<22;
+ public static final int STATE_VIDEO_ON_FLAG = 1<<21;
+ public static final int STATE_SCREEN_ON_FLAG = 1<<20;
+ public static final int STATE_BATTERY_PLUGGED_FLAG = 1<<19;
+ public static final int STATE_PHONE_IN_CALL_FLAG = 1<<18;
+ public static final int STATE_WIFI_ON_FLAG = 1<<17;
+ public static final int STATE_BLUETOOTH_ON_FLAG = 1<<16;
public static final int MOST_INTERESTING_STATES =
STATE_BATTERY_PLUGGED_FLAG | STATE_SCREEN_ON_FLAG
@@ -487,10 +496,6 @@
dest.writeInt(bat);
dest.writeInt(states);
}
-
- public void writeDelta(Parcel dest, HistoryItem last) {
- writeToParcel(dest, 0);
- }
private void readFromParcel(Parcel src) {
int bat = src.readInt();
@@ -505,11 +510,161 @@
states = src.readInt();
}
- public void readDelta(Parcel src, HistoryItem last) {
- time = src.readLong();
- readFromParcel(src);
+ // Part of initial delta int that specifies the time delta.
+ static final int DELTA_TIME_MASK = 0x3ffff;
+ static final int DELTA_TIME_ABS = 0x3fffd; // Following is an entire abs update.
+ static final int DELTA_TIME_INT = 0x3fffe; // The delta is a following int
+ static final int DELTA_TIME_LONG = 0x3ffff; // The delta is a following long
+ // Part of initial delta int holding the command code.
+ static final int DELTA_CMD_MASK = 0x3;
+ static final int DELTA_CMD_SHIFT = 18;
+ // Flag in delta int: a new battery level int follows.
+ static final int DELTA_BATTERY_LEVEL_FLAG = 1<<20;
+ // Flag in delta int: a new full state and battery status int follows.
+ static final int DELTA_STATE_FLAG = 1<<21;
+ static final int DELTA_STATE_MASK = 0xffc00000;
+
+ public void writeDelta(Parcel dest, HistoryItem last) {
+ if (last == null || last.cmd != CMD_UPDATE) {
+ dest.writeInt(DELTA_TIME_ABS);
+ writeToParcel(dest, 0);
+ return;
+ }
+
+ final long deltaTime = time - last.time;
+ final int lastBatteryLevelInt = last.buildBatteryLevelInt();
+ final int lastStateInt = last.buildStateInt();
+
+ int deltaTimeToken;
+ if (deltaTime < 0 || deltaTime > Integer.MAX_VALUE) {
+ deltaTimeToken = DELTA_TIME_LONG;
+ } else if (deltaTime >= DELTA_TIME_ABS) {
+ deltaTimeToken = DELTA_TIME_INT;
+ } else {
+ deltaTimeToken = (int)deltaTime;
+ }
+ int firstToken = deltaTimeToken
+ | (cmd<<DELTA_CMD_SHIFT)
+ | (states&DELTA_STATE_MASK);
+ final int batteryLevelInt = buildBatteryLevelInt();
+ final boolean batteryLevelIntChanged = batteryLevelInt != lastBatteryLevelInt;
+ if (batteryLevelIntChanged) {
+ firstToken |= DELTA_BATTERY_LEVEL_FLAG;
+ }
+ final int stateInt = buildStateInt();
+ final boolean stateIntChanged = stateInt != lastStateInt;
+ if (stateIntChanged) {
+ firstToken |= DELTA_STATE_FLAG;
+ }
+ dest.writeInt(firstToken);
+ if (DEBUG) Slog.i(TAG, "WRITE DELTA: firstToken=0x" + Integer.toHexString(firstToken)
+ + " deltaTime=" + deltaTime);
+
+ if (deltaTimeToken >= DELTA_TIME_INT) {
+ if (deltaTimeToken == DELTA_TIME_INT) {
+ if (DEBUG) Slog.i(TAG, "WRITE DELTA: int deltaTime=" + (int)deltaTime);
+ dest.writeInt((int)deltaTime);
+ } else {
+ if (DEBUG) Slog.i(TAG, "WRITE DELTA: long deltaTime=" + deltaTime);
+ dest.writeLong(deltaTime);
+ }
+ }
+ if (batteryLevelIntChanged) {
+ dest.writeInt(batteryLevelInt);
+ if (DEBUG) Slog.i(TAG, "WRITE DELTA: batteryToken=0x"
+ + Integer.toHexString(batteryLevelInt)
+ + " batteryLevel=" + batteryLevel
+ + " batteryTemp=" + (int)batteryTemperature
+ + " batteryVolt=" + (int)batteryVoltage);
+ }
+ if (stateIntChanged) {
+ dest.writeInt(stateInt);
+ if (DEBUG) Slog.i(TAG, "WRITE DELTA: stateToken=0x"
+ + Integer.toHexString(stateInt)
+ + " batteryStatus=" + batteryStatus
+ + " batteryHealth=" + batteryHealth
+ + " batteryPlugType=" + batteryPlugType
+ + " states=0x" + Integer.toHexString(states));
+ }
+ }
+
+ private int buildBatteryLevelInt() {
+ return ((((int)batteryLevel)<<24)&0xff000000)
+ | ((((int)batteryTemperature)<<14)&0x00ffc000)
+ | (((int)batteryVoltage)&0x00003fff);
+ }
+
+ private int buildStateInt() {
+ return ((((int)batteryStatus)<<28)&0xf0000000)
+ | ((((int)batteryHealth)<<24)&0x0f000000)
+ | ((((int)batteryPlugType)<<22)&0x00c00000)
+ | (states&(~DELTA_STATE_MASK));
+ }
+
+ public void readDelta(Parcel src) {
+ int firstToken = src.readInt();
+ int deltaTimeToken = firstToken&DELTA_TIME_MASK;
+ cmd = (byte)((firstToken>>DELTA_CMD_SHIFT)&DELTA_CMD_MASK);
+ if (DEBUG) Slog.i(TAG, "READ DELTA: firstToken=0x" + Integer.toHexString(firstToken)
+ + " deltaTimeToken=" + deltaTimeToken);
+
+ if (deltaTimeToken < DELTA_TIME_ABS) {
+ time += deltaTimeToken;
+ } else if (deltaTimeToken == DELTA_TIME_ABS) {
+ time = src.readLong();
+ readFromParcel(src);
+ return;
+ } else if (deltaTimeToken == DELTA_TIME_INT) {
+ int delta = src.readInt();
+ time += delta;
+ if (DEBUG) Slog.i(TAG, "READ DELTA: time delta=" + delta + " new time=" + time);
+ } else {
+ long delta = src.readLong();
+ if (DEBUG) Slog.i(TAG, "READ DELTA: time delta=" + delta + " new time=" + time);
+ time += delta;
+ }
+
+ if ((firstToken&DELTA_BATTERY_LEVEL_FLAG) != 0) {
+ int batteryLevelInt = src.readInt();
+ batteryLevel = (byte)((batteryLevelInt>>24)&0xff);
+ batteryTemperature = (char)((batteryLevelInt>>14)&0x3ff);
+ batteryVoltage = (char)(batteryLevelInt&0x3fff);
+ if (DEBUG) Slog.i(TAG, "READ DELTA: batteryToken=0x"
+ + Integer.toHexString(batteryLevelInt)
+ + " batteryLevel=" + batteryLevel
+ + " batteryTemp=" + (int)batteryTemperature
+ + " batteryVolt=" + (int)batteryVoltage);
+ }
+
+ if ((firstToken&DELTA_STATE_FLAG) != 0) {
+ int stateInt = src.readInt();
+ states = (firstToken&DELTA_STATE_MASK) | (stateInt&(~DELTA_STATE_MASK));
+ batteryStatus = (byte)((stateInt>>28)&0xf);
+ batteryHealth = (byte)((stateInt>>24)&0xf);
+ batteryPlugType = (byte)((stateInt>>22)&0x3);
+ if (DEBUG) Slog.i(TAG, "READ DELTA: stateToken=0x"
+ + Integer.toHexString(stateInt)
+ + " batteryStatus=" + batteryStatus
+ + " batteryHealth=" + batteryHealth
+ + " batteryPlugType=" + batteryPlugType
+ + " states=0x" + Integer.toHexString(states));
+ } else {
+ states = (firstToken&DELTA_STATE_MASK) | (states&(~DELTA_STATE_MASK));
+ }
}
+ public void clear() {
+ time = 0;
+ cmd = CMD_NULL;
+ batteryLevel = 0;
+ batteryStatus = 0;
+ batteryHealth = 0;
+ batteryPlugType = 0;
+ batteryTemperature = 0;
+ batteryVoltage = 0;
+ states = 0;
+ }
+
public void setTo(HistoryItem o) {
time = o.time;
cmd = o.cmd;