tools/powermodel/src/com/android/powermodel/PowerProfile.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2018 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.powermodel;

 import java.io.InputStream;
 import java.io.IOException;
 import java.util.regex.Pattern;
 import java.util.regex.Matcher;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;
 import org.xml.sax.Attributes;
 import org.xml.sax.Locator;
 import org.xml.sax.SAXException;
 import org.xml.sax.SAXParseException;
 import org.xml.sax.helpers.DefaultHandler;

 import com.android.powermodel.component.AudioProfile;
 import com.android.powermodel.component.BluetoothProfile;
 import com.android.powermodel.component.CameraProfile;
 import com.android.powermodel.component.CpuProfile;
 import com.android.powermodel.component.FlashlightProfile;
 import com.android.powermodel.component.GpsProfile;
 import com.android.powermodel.component.ModemProfile;
 import com.android.powermodel.component.ScreenProfile;
 import com.android.powermodel.component.VideoProfile;
 import com.android.powermodel.component.WifiProfile;
 import com.android.powermodel.util.Conversion;

 public class PowerProfile {

     // Remaining fields from the android code for which the actual usage is unclear.
     //   battery.capacity
     //   bluetooth.controller.voltage
     //   modem.controller.voltage
     //   gps.voltage
     //   wifi.controller.voltage
     //   radio.on
     //   radio.scanning
     //   radio.active
     //   memory.bandwidths
     //   wifi.batchedscan
     //   wifi.scan
     //   wifi.on
     //   wifi.active
     //   wifi.controller.tx_levels

     private static Pattern RE_CLUSTER_POWER = Pattern.compile("cpu.cluster_power.cluster([0-9]*)");
     private static Pattern RE_CORE_SPEEDS = Pattern.compile("cpu.core_speeds.cluster([0-9]*)");
     private static Pattern RE_CORE_POWER = Pattern.compile("cpu.core_power.cluster([0-9]*)");

     private HashMap<Component, ComponentProfile> mComponents = new HashMap();

     /**
      * Which element we are currently parsing.
      */
     enum ElementState {
         BEGIN,
         TOP,
         ITEM,
         ARRAY,
         VALUE
     }

     /**
      * Implements the reading and power model logic.
      */
     private static class Parser {
         private final InputStream mStream;
         private final PowerProfile mResult;

         // Builders for the ComponentProfiles.
         private final AudioProfile mAudio = new AudioProfile();
         private final BluetoothProfile mBluetooth = new BluetoothProfile();
         private final CameraProfile mCamera = new CameraProfile();
         private final CpuProfile.Builder mCpuBuilder = new CpuProfile.Builder();
         private final FlashlightProfile mFlashlight = new FlashlightProfile();
         private final GpsProfile.Builder mGpsBuilder = new GpsProfile.Builder();
         private final ModemProfile.Builder mModemBuilder = new ModemProfile.Builder();
         private final ScreenProfile mScreen = new ScreenProfile();
         private final VideoProfile mVideo = new VideoProfile();
         private final WifiProfile mWifi = new WifiProfile();

         /**
          * Constructor to capture the parameters to read.
          */
         Parser(InputStream stream) {
             mStream = stream;
             mResult = new PowerProfile();
         }

         /**
          * Read the stream, parse it, and apply the power model.
          * Do not call this more than once.
          */
         PowerProfile parse() throws ParseException {
             final SAXParserFactory factory = SAXParserFactory.newInstance();
             AndroidResourceHandler handler = null;
             try {
                 final SAXParser saxParser = factory.newSAXParser();

                 handler = new AndroidResourceHandler() {
                     @Override
                     public void onItem(Locator locator, String name, float value)
                             throws SAXParseException {
                         Parser.this.onItem(locator, name, value);
                     }

                     @Override
                     public void onArray(Locator locator, String name, float[] value)
                             throws SAXParseException {
                         Parser.this.onArray(locator, name, value);
                     }
                 };

                 saxParser.parse(mStream, handler);
             } catch (ParserConfigurationException ex) {
                 // Coding error, not runtime error.
                 throw new RuntimeException(ex);
             } catch (SAXParseException ex) {
                 throw new ParseException(ex.getLineNumber(), ex.getMessage(), ex);
             } catch (SAXException | IOException ex) {
                 // Make a guess about the line number.
                 throw new ParseException(handler.getLineNumber(), ex.getMessage(), ex);
             }

             // TODO: This doesn't cover the multiple algorithms. Some refactoring will
             // be necessary.
             mResult.mComponents.put(Component.AUDIO, mAudio);
             mResult.mComponents.put(Component.BLUETOOTH, mBluetooth);
             mResult.mComponents.put(Component.CAMERA, mCamera);
             mResult.mComponents.put(Component.CPU, mCpuBuilder.build());
             mResult.mComponents.put(Component.FLASHLIGHT, mFlashlight);
             mResult.mComponents.put(Component.GPS, mGpsBuilder.build());
             mResult.mComponents.put(Component.MODEM, mModemBuilder.build());
             mResult.mComponents.put(Component.SCREEN, mScreen);
             mResult.mComponents.put(Component.VIDEO, mVideo);
             mResult.mComponents.put(Component.WIFI, mWifi);

             return mResult;
         }

         /**
          * Handles an item tag in the power_profile.xml.
          */
         public void onItem(Locator locator, String name, float value) throws SAXParseException {
             Integer index;
             try {
                 if ("ambient.on".equals(name)) {
                     mScreen.ambientMa = value;
                 } else if ("audio".equals(name)) {
                     mAudio.onMa = value;
                 } else if ("bluetooth.controller.idle".equals(name)) {
                     mBluetooth.idleMa = value;
                 } else if ("bluetooth.controller.rx".equals(name)) {
                     mBluetooth.rxMa = value;
                 } else if ("bluetooth.controller.tx".equals(name)) {
                     mBluetooth.txMa = value;
                 } else if ("camera.avg".equals(name)) {
                     mCamera.onMa = value;
                 } else if ("camera.flashlight".equals(name)) {
                     mFlashlight.onMa = value;
                 } else if ("cpu.suspend".equals(name)) {
                     mCpuBuilder.setSuspendMa(value);
                 } else if ("cpu.idle".equals(name)) {
                     mCpuBuilder.setIdleMa(value);
                 } else if ("cpu.active".equals(name)) {
                     mCpuBuilder.setActiveMa(value);
                 } else if ((index = matchIndexedRegex(locator, RE_CLUSTER_POWER, name)) != null) {
                     mCpuBuilder.setClusterPower(index, value);
                 } else if ("gps.on".equals(name)) {
                     mGpsBuilder.setOnMa(value);
                 } else if ("modem.controller.sleep".equals(name)) {
                     mModemBuilder.setSleepMa(value);
                 } else if ("modem.controller.idle".equals(name)) {
                     mModemBuilder.setIdleMa(value);
                 } else if ("modem.controller.rx".equals(name)) {
                     mModemBuilder.setRxMa(value);
                 } else if ("radio.scanning".equals(name)) {
                     mModemBuilder.setScanningMa(value);
                 } else if ("screen.on".equals(name)) {
                     mScreen.onMa = value;
                 } else if ("screen.full".equals(name)) {
                     mScreen.fullMa = value;
                 } else if ("video".equals(name)) {
                     mVideo.onMa = value;
                 } else if ("wifi.controller.idle".equals(name)) {
                     mWifi.idleMa = value;
                 } else if ("wifi.controller.rx".equals(name)) {
                     mWifi.rxMa = value;
                 } else if ("wifi.controller.tx".equals(name)) {
                     mWifi.txMa = value;
                 } else {
                     // TODO: Uncomment this when we have all of the items parsed.
                     // throw new SAXParseException("Unhandled <item name=\"" + name + "\"> element",
                     //        locator, ex);

                 }
             } catch (ParseException ex) {
                 throw new SAXParseException(ex.getMessage(), locator, ex);
             }
         }

         /**
          * Handles an array tag in the power_profile.xml.
          */
         public void onArray(Locator locator, String name, float[] value) throws SAXParseException {
             Integer index;
             try {
                 if ("cpu.clusters.cores".equals(name)) {
                     mCpuBuilder.setCoreCount(Conversion.toIntArray(value));
                 } else if ((index = matchIndexedRegex(locator, RE_CORE_SPEEDS, name)) != null) {
                     mCpuBuilder.setCoreSpeeds(index, Conversion.toIntArray(value));
                 } else if ((index = matchIndexedRegex(locator, RE_CORE_POWER, name)) != null) {
                     mCpuBuilder.setCorePower(index, value);
                 } else if ("gps.signalqualitybased".equals(name)) {
                     mGpsBuilder.setSignalMa(value);
                 } else if ("modem.controller.tx".equals(name)) {
                     mModemBuilder.setTxMa(value);
                 } else {
                     // TODO: Uncomment this when we have all of the items parsed.
                     // throw new SAXParseException("Unhandled <item name=\"" + name + "\"> element",
                     //        locator, ex);
                 }
             } catch (ParseException ex) {
                 throw new SAXParseException(ex.getMessage(), locator, ex);
             }
         }
     }

     /**
      * SAX XML handler that can parse the android resource files.
      * In our case, all elements are floats.
      */
     abstract static class AndroidResourceHandler extends DefaultHandler {
         /**
          * The set of names already processed. Map of name to line number.
          */
         private HashMap<String,Integer> mAlreadySeen = new HashMap<String,Integer>();

         /**
          * Where in the document we are parsing.
          */
         private Locator mLocator;

         /**
          * Which element we are currently parsing.
          */
         private ElementState mState = ElementState.BEGIN;

         /**
          * Saved name from item and array elements.
          */
         private String mName;

         /**
          * The text that is currently being captured, or null if {@link #startCapturingText()}
          * has not been called.
          */
         private StringBuilder mText;

         /**
          * The array values that have been parsed so for for this array. Null if we are
          * not inside an array tag.
          */
         private ArrayList<Float> mArray;

         /**
          * Called when an item tag is encountered.
          */
         public abstract void onItem(Locator locator, String name, float value)
                 throws SAXParseException;

         /**
          * Called when an array is encountered.
          */
         public abstract void onArray(Locator locator, String name, float[] value)
                 throws SAXParseException;

         /**
          * If we have a Locator set, return the line number, otherwise return 0.
          */
         public int getLineNumber() {
             return mLocator != null ? mLocator.getLineNumber() : 0;
         }

         /**
          * Handle setting the parse location object.
          */
         public void setDocumentLocator(Locator locator) {
             mLocator = locator;
         }

         /**
          * Handle beginning of an element.
          *
          * @param ns Namespace uri
          * @param ln Local name (inside namespace)
          * @param element Tag name
          */
         @Override
         public void startElement(String ns, String ln, String element,
                 Attributes attr) throws SAXException {
             switch (mState) {
                 case BEGIN:
                     // Outer element, we don't care the tag name.
                     mState = ElementState.TOP;
                     return;
                 case TOP:
                     if ("item".equals(element)) {
                         mState = ElementState.ITEM;
                         saveNameAttribute(attr);
                         startCapturingText();
                         return;
                     } else if ("array".equals(element)) {
                         mState = ElementState.ARRAY;
                         mArray = new ArrayList<Float>();
                         saveNameAttribute(attr);
                         return;
                     }
                     break;
                 case ARRAY:
                     if ("value".equals(element)) {
                         mState = ElementState.VALUE;
                         startCapturingText();
                         return;
                     }
                     break;
             }
             throw new SAXParseException("unexpected element: '" + element + "'", mLocator);
         }

         /**
          * Handle end of an element.
          *
          * @param ns Namespace uri
          * @param ln Local name (inside namespace)
          * @param element Tag name
          */
         @Override
         public void endElement(String ns, String ln, String element) throws SAXException {
             switch (mState) {
                 case ITEM: {
                     float value = parseFloat(finishCapturingText());
                     mState = ElementState.TOP;
                     onItem(mLocator, mName, value);
                     break;
                 }
                 case ARRAY: {
                     final int N = mArray.size();
                     float[] values = new float[N];
                     for (int i=0; i<N; i++) {
                         values[i] = mArray.get(i);
                     }
                     mArray = null;
                     mState = ElementState.TOP;
                     onArray(mLocator, mName, values);
                     break;
                 }
                 case VALUE: {
                     mArray.add(parseFloat(finishCapturingText()));
                     mState = ElementState.ARRAY;
                     break;
                 }
             }
         }

         /**
          * Interstitial text received.
          *
          * @throws SAXException if there shouldn't be non-whitespace text here
          */
         @Override
         public void characters(char text[], int start, int length) throws SAXException {
             if (mText == null && length > 0 && !isWhitespace(text, start, length)) {
                 throw new SAXParseException("unexpected text: '"
                         + firstLine(text, start, length).trim() + "'", mLocator);
             }
             if (mText != null) {
                 mText.append(text, start, length);
             }
         }

         /**
          * Begin collecting text from inside an element.
          */
         private void startCapturingText() {
             if (mText != null) {
                 throw new RuntimeException("ASSERTION FAILED: Shouldn't be already capturing"
                         + " text. mState=" + mState.name()
                         + " line=" + mLocator.getLineNumber()
                         + " column=" + mLocator.getColumnNumber());
             }
             mText = new StringBuilder();
         }

         /**
          * Stop capturing text from inside an element.
          *
          * @return the captured text
          */
         private String finishCapturingText() {
             if (mText == null) {
                 throw new RuntimeException("ASSERTION FAILED: Should already be capturing"
                         + " text. mState=" + mState.name()
                         + " line=" + mLocator.getLineNumber()
                         + " column=" + mLocator.getColumnNumber());
             }
             final String result = mText.toString().trim();
             mText = null;
             return result;
         }

         /**
          * Get the "name" attribute.
          *
          * @throws SAXParseException if the name attribute is not present or if
          * the name has already been seen in the file.
          */
         private void saveNameAttribute(Attributes attr) throws SAXParseException {
             final String name = attr.getValue("name");
             if (name == null) {
                 throw new SAXParseException("expected 'name' attribute", mLocator);
             }
             Integer prev = mAlreadySeen.put(name, mLocator.getLineNumber());
             if (prev != null) {
                 throw new SAXParseException("name '" + name + "' already seen on line: " + prev,
                         mLocator);
             }
             mName = name;
         }

         /**
          * Gets the float value of the string.
          *
          * @throws SAXParseException if 'text' can't be parsed as a float.
          */
         private float parseFloat(String text) throws SAXParseException {
             try {
                 return Float.parseFloat(text);
             } catch (NumberFormatException ex) {
                 throw new SAXParseException("not a valid float value: '" + text + "'",
                         mLocator, ex);
             }
         }
     }

     /**
      * Return whether the given substring is all whitespace.
      */
     private static boolean isWhitespace(char[] text, int start, int length) {
         for (int i = start; i < (start + length); i++) {
             if (!Character.isSpace(text[i])) {
                 return false;
             }
         }
         return true;
     }

     /**
      * Return the contents of text up to the first newline.
      */
     private static String firstLine(char[] text, int start, int length) {
         // TODO: The line number will be wrong if we skip preceeding blank lines.
         while (length > 0) {
             if (Character.isSpace(text[start])) {
                 start++;
                 length--;
             }
         }
         int newlen = 0;
         for (; newlen < length; newlen++) {
             final char c = text[newlen];
             if (c == '\n' || c == '\r') {
                 break;
             }
         }
         return new String(text, start, newlen);
     }

     /**
      * If the pattern matches, return the first group of that as an Integer.
      * If not return null.
      */
     private static Integer matchIndexedRegex(Locator locator, Pattern pattern, String text)
             throws SAXParseException {
         final Matcher m = pattern.matcher(text);
         if (m.matches()) {
             try {
                 return Integer.parseInt(m.group(1));
             } catch (NumberFormatException ex) {
                 throw new SAXParseException("Invalid field name: '" + text + "'", locator, ex);
             }
         } else {
             return null;
         }
     }

     public static PowerProfile parse(InputStream stream) throws ParseException {
         return (new Parser(stream)).parse();
     }

     private PowerProfile() {
     }

     public ComponentProfile getComponent(Component component) {
         return mComponents.get(component);
     }

 }
	/*
	* Copyright (C) 2018 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.powermodel;

	import java.io.InputStream;
	import java.io.IOException;
	import java.util.regex.Pattern;
	import java.util.regex.Matcher;
	import java.util.ArrayList;
	import java.util.Arrays;
	import java.util.HashMap;
	import javax.xml.parsers.ParserConfigurationException;
	import javax.xml.parsers.SAXParser;
	import javax.xml.parsers.SAXParserFactory;
	import org.xml.sax.Attributes;
	import org.xml.sax.Locator;
	import org.xml.sax.SAXException;
	import org.xml.sax.SAXParseException;
	import org.xml.sax.helpers.DefaultHandler;

	import com.android.powermodel.component.AudioProfile;
	import com.android.powermodel.component.BluetoothProfile;
	import com.android.powermodel.component.CameraProfile;
	import com.android.powermodel.component.CpuProfile;
	import com.android.powermodel.component.FlashlightProfile;
	import com.android.powermodel.component.GpsProfile;
	import com.android.powermodel.component.ModemProfile;
	import com.android.powermodel.component.ScreenProfile;
	import com.android.powermodel.component.VideoProfile;
	import com.android.powermodel.component.WifiProfile;
	import com.android.powermodel.util.Conversion;

	public class PowerProfile {

	// Remaining fields from the android code for which the actual usage is unclear.
	// battery.capacity
	// bluetooth.controller.voltage
	// modem.controller.voltage
	// gps.voltage
	// wifi.controller.voltage
	// radio.on
	// radio.scanning
	// radio.active
	// memory.bandwidths
	// wifi.batchedscan
	// wifi.scan
	// wifi.on
	// wifi.active
	// wifi.controller.tx_levels

	private static Pattern RE_CLUSTER_POWER = Pattern.compile("cpu.cluster_power.cluster([0-9]*)");
	private static Pattern RE_CORE_SPEEDS = Pattern.compile("cpu.core_speeds.cluster([0-9]*)");
	private static Pattern RE_CORE_POWER = Pattern.compile("cpu.core_power.cluster([0-9]*)");

	private HashMap<Component, ComponentProfile> mComponents = new HashMap();

	/**
	* Which element we are currently parsing.
	*/
	enum ElementState {
	BEGIN,
	TOP,
	ITEM,
	ARRAY,
	VALUE
	}

	/**
	* Implements the reading and power model logic.
	*/
	private static class Parser {
	private final InputStream mStream;
	private final PowerProfile mResult;

	// Builders for the ComponentProfiles.
	private final AudioProfile mAudio = new AudioProfile();
	private final BluetoothProfile mBluetooth = new BluetoothProfile();
	private final CameraProfile mCamera = new CameraProfile();
	private final CpuProfile.Builder mCpuBuilder = new CpuProfile.Builder();
	private final FlashlightProfile mFlashlight = new FlashlightProfile();
	private final GpsProfile.Builder mGpsBuilder = new GpsProfile.Builder();
	private final ModemProfile.Builder mModemBuilder = new ModemProfile.Builder();
	private final ScreenProfile mScreen = new ScreenProfile();
	private final VideoProfile mVideo = new VideoProfile();
	private final WifiProfile mWifi = new WifiProfile();

	/**
	* Constructor to capture the parameters to read.
	*/
	Parser(InputStream stream) {
	mStream = stream;
	mResult = new PowerProfile();
	}

	/**
	* Read the stream, parse it, and apply the power model.
	* Do not call this more than once.
	*/
	PowerProfile parse() throws ParseException {
	final SAXParserFactory factory = SAXParserFactory.newInstance();
	AndroidResourceHandler handler = null;
	try {
	final SAXParser saxParser = factory.newSAXParser();

	handler = new AndroidResourceHandler() {
	@Override
	public void onItem(Locator locator, String name, float value)
	throws SAXParseException {
	Parser.this.onItem(locator, name, value);
	}

	@Override
	public void onArray(Locator locator, String name, float[] value)
	throws SAXParseException {
	Parser.this.onArray(locator, name, value);
	}
	};

	saxParser.parse(mStream, handler);
	} catch (ParserConfigurationException ex) {
	// Coding error, not runtime error.
	throw new RuntimeException(ex);
	} catch (SAXParseException ex) {
	throw new ParseException(ex.getLineNumber(), ex.getMessage(), ex);
	} catch (SAXException \| IOException ex) {
	// Make a guess about the line number.
	throw new ParseException(handler.getLineNumber(), ex.getMessage(), ex);
	}

	// TODO: This doesn't cover the multiple algorithms. Some refactoring will
	// be necessary.
	mResult.mComponents.put(Component.AUDIO, mAudio);
	mResult.mComponents.put(Component.BLUETOOTH, mBluetooth);
	mResult.mComponents.put(Component.CAMERA, mCamera);
	mResult.mComponents.put(Component.CPU, mCpuBuilder.build());
	mResult.mComponents.put(Component.FLASHLIGHT, mFlashlight);
	mResult.mComponents.put(Component.GPS, mGpsBuilder.build());
	mResult.mComponents.put(Component.MODEM, mModemBuilder.build());
	mResult.mComponents.put(Component.SCREEN, mScreen);
	mResult.mComponents.put(Component.VIDEO, mVideo);
	mResult.mComponents.put(Component.WIFI, mWifi);

	return mResult;
	}

	/**
	* Handles an item tag in the power_profile.xml.
	*/
	public void onItem(Locator locator, String name, float value) throws SAXParseException {
	Integer index;
	try {
	if ("ambient.on".equals(name)) {
	mScreen.ambientMa = value;
	} else if ("audio".equals(name)) {
	mAudio.onMa = value;
	} else if ("bluetooth.controller.idle".equals(name)) {
	mBluetooth.idleMa = value;
	} else if ("bluetooth.controller.rx".equals(name)) {
	mBluetooth.rxMa = value;
	} else if ("bluetooth.controller.tx".equals(name)) {
	mBluetooth.txMa = value;
	} else if ("camera.avg".equals(name)) {
	mCamera.onMa = value;
	} else if ("camera.flashlight".equals(name)) {
	mFlashlight.onMa = value;
	} else if ("cpu.suspend".equals(name)) {
	mCpuBuilder.setSuspendMa(value);
	} else if ("cpu.idle".equals(name)) {
	mCpuBuilder.setIdleMa(value);
	} else if ("cpu.active".equals(name)) {
	mCpuBuilder.setActiveMa(value);
	} else if ((index = matchIndexedRegex(locator, RE_CLUSTER_POWER, name)) != null) {
	mCpuBuilder.setClusterPower(index, value);
	} else if ("gps.on".equals(name)) {
	mGpsBuilder.setOnMa(value);
	} else if ("modem.controller.sleep".equals(name)) {
	mModemBuilder.setSleepMa(value);
	} else if ("modem.controller.idle".equals(name)) {
	mModemBuilder.setIdleMa(value);
	} else if ("modem.controller.rx".equals(name)) {
	mModemBuilder.setRxMa(value);
	} else if ("radio.scanning".equals(name)) {
	mModemBuilder.setScanningMa(value);
	} else if ("screen.on".equals(name)) {
	mScreen.onMa = value;
	} else if ("screen.full".equals(name)) {
	mScreen.fullMa = value;
	} else if ("video".equals(name)) {
	mVideo.onMa = value;
	} else if ("wifi.controller.idle".equals(name)) {
	mWifi.idleMa = value;
	} else if ("wifi.controller.rx".equals(name)) {
	mWifi.rxMa = value;
	} else if ("wifi.controller.tx".equals(name)) {
	mWifi.txMa = value;
	} else {
	// TODO: Uncomment this when we have all of the items parsed.
	// throw new SAXParseException("Unhandled <item name=\"" + name + "\"> element",
	// locator, ex);

	}
	} catch (ParseException ex) {
	throw new SAXParseException(ex.getMessage(), locator, ex);
	}
	}

	/**
	* Handles an array tag in the power_profile.xml.
	*/
	public void onArray(Locator locator, String name, float[] value) throws SAXParseException {
	Integer index;
	try {
	if ("cpu.clusters.cores".equals(name)) {
	mCpuBuilder.setCoreCount(Conversion.toIntArray(value));
	} else if ((index = matchIndexedRegex(locator, RE_CORE_SPEEDS, name)) != null) {
	mCpuBuilder.setCoreSpeeds(index, Conversion.toIntArray(value));
	} else if ((index = matchIndexedRegex(locator, RE_CORE_POWER, name)) != null) {
	mCpuBuilder.setCorePower(index, value);
	} else if ("gps.signalqualitybased".equals(name)) {
	mGpsBuilder.setSignalMa(value);
	} else if ("modem.controller.tx".equals(name)) {
	mModemBuilder.setTxMa(value);
	} else {
	// TODO: Uncomment this when we have all of the items parsed.
	// throw new SAXParseException("Unhandled <item name=\"" + name + "\"> element",
	// locator, ex);
	}
	} catch (ParseException ex) {
	throw new SAXParseException(ex.getMessage(), locator, ex);
	}
	}
	}

	/**
	* SAX XML handler that can parse the android resource files.
	* In our case, all elements are floats.
	*/
	abstract static class AndroidResourceHandler extends DefaultHandler {
	/**
	* The set of names already processed. Map of name to line number.
	*/
	private HashMap<String,Integer> mAlreadySeen = new HashMap<String,Integer>();

	/**
	* Where in the document we are parsing.
	*/
	private Locator mLocator;

	/**
	* Which element we are currently parsing.
	*/
	private ElementState mState = ElementState.BEGIN;

	/**
	* Saved name from item and array elements.
	*/
	private String mName;

	/**
	* The text that is currently being captured, or null if {@link #startCapturingText()}
	* has not been called.
	*/
	private StringBuilder mText;

	/**
	* The array values that have been parsed so for for this array. Null if we are
	* not inside an array tag.
	*/
	private ArrayList<Float> mArray;

	/**
	* Called when an item tag is encountered.
	*/
	public abstract void onItem(Locator locator, String name, float value)
	throws SAXParseException;

	/**
	* Called when an array is encountered.
	*/
	public abstract void onArray(Locator locator, String name, float[] value)
	throws SAXParseException;

	/**
	* If we have a Locator set, return the line number, otherwise return 0.
	*/
	public int getLineNumber() {
	return mLocator != null ? mLocator.getLineNumber() : 0;
	}

	/**
	* Handle setting the parse location object.
	*/
	public void setDocumentLocator(Locator locator) {
	mLocator = locator;
	}

	/**
	* Handle beginning of an element.
	*
	* @param ns Namespace uri
	* @param ln Local name (inside namespace)
	* @param element Tag name
	*/
	@Override
	public void startElement(String ns, String ln, String element,
	Attributes attr) throws SAXException {
	switch (mState) {
	case BEGIN:
	// Outer element, we don't care the tag name.
	mState = ElementState.TOP;
	return;
	case TOP:
	if ("item".equals(element)) {
	mState = ElementState.ITEM;
	saveNameAttribute(attr);
	startCapturingText();
	return;
	} else if ("array".equals(element)) {
	mState = ElementState.ARRAY;
	mArray = new ArrayList<Float>();
	saveNameAttribute(attr);
	return;
	}
	break;
	case ARRAY:
	if ("value".equals(element)) {
	mState = ElementState.VALUE;
	startCapturingText();
	return;
	}
	break;
	}
	throw new SAXParseException("unexpected element: '" + element + "'", mLocator);
	}

	/**
	* Handle end of an element.
	*
	* @param ns Namespace uri
	* @param ln Local name (inside namespace)
	* @param element Tag name
	*/
	@Override
	public void endElement(String ns, String ln, String element) throws SAXException {
	switch (mState) {
	case ITEM: {
	float value = parseFloat(finishCapturingText());
	mState = ElementState.TOP;
	onItem(mLocator, mName, value);
	break;
	}
	case ARRAY: {
	final int N = mArray.size();
	float[] values = new float[N];
	for (int i=0; i<N; i++) {
	values[i] = mArray.get(i);
	}
	mArray = null;
	mState = ElementState.TOP;
	onArray(mLocator, mName, values);
	break;
	}
	case VALUE: {
	mArray.add(parseFloat(finishCapturingText()));
	mState = ElementState.ARRAY;
	break;
	}
	}
	}

	/**
	* Interstitial text received.
	*
	* @throws SAXException if there shouldn't be non-whitespace text here
	*/
	@Override
	public void characters(char text[], int start, int length) throws SAXException {
	if (mText == null && length > 0 && !isWhitespace(text, start, length)) {
	throw new SAXParseException("unexpected text: '"
	+ firstLine(text, start, length).trim() + "'", mLocator);
	}
	if (mText != null) {
	mText.append(text, start, length);
	}
	}

	/**
	* Begin collecting text from inside an element.
	*/
	private void startCapturingText() {
	if (mText != null) {
	throw new RuntimeException("ASSERTION FAILED: Shouldn't be already capturing"
	+ " text. mState=" + mState.name()
	+ " line=" + mLocator.getLineNumber()
	+ " column=" + mLocator.getColumnNumber());
	}
	mText = new StringBuilder();
	}

	/**
	* Stop capturing text from inside an element.
	*
	* @return the captured text
	*/
	private String finishCapturingText() {
	if (mText == null) {
	throw new RuntimeException("ASSERTION FAILED: Should already be capturing"
	+ " text. mState=" + mState.name()
	+ " line=" + mLocator.getLineNumber()
	+ " column=" + mLocator.getColumnNumber());
	}
	final String result = mText.toString().trim();
	mText = null;
	return result;
	}

	/**
	* Get the "name" attribute.
	*
	* @throws SAXParseException if the name attribute is not present or if
	* the name has already been seen in the file.
	*/
	private void saveNameAttribute(Attributes attr) throws SAXParseException {
	final String name = attr.getValue("name");
	if (name == null) {
	throw new SAXParseException("expected 'name' attribute", mLocator);
	}
	Integer prev = mAlreadySeen.put(name, mLocator.getLineNumber());
	if (prev != null) {
	throw new SAXParseException("name '" + name + "' already seen on line: " + prev,
	mLocator);
	}
	mName = name;
	}

	/**
	* Gets the float value of the string.
	*
	* @throws SAXParseException if 'text' can't be parsed as a float.
	*/
	private float parseFloat(String text) throws SAXParseException {
	try {
	return Float.parseFloat(text);
	} catch (NumberFormatException ex) {
	throw new SAXParseException("not a valid float value: '" + text + "'",
	mLocator, ex);
	}
	}
	}

	/**
	* Return whether the given substring is all whitespace.
	*/
	private static boolean isWhitespace(char[] text, int start, int length) {
	for (int i = start; i < (start + length); i++) {
	if (!Character.isSpace(text[i])) {
	return false;
	}
	}
	return true;
	}

	/**
	* Return the contents of text up to the first newline.
	*/
	private static String firstLine(char[] text, int start, int length) {
	// TODO: The line number will be wrong if we skip preceeding blank lines.
	while (length > 0) {
	if (Character.isSpace(text[start])) {
	start++;
	length--;
	}
	}
	int newlen = 0;
	for (; newlen < length; newlen++) {
	final char c = text[newlen];
	if (c == '\n' \|\| c == '\r') {
	break;
	}
	}
	return new String(text, start, newlen);
	}

	/**
	* If the pattern matches, return the first group of that as an Integer.
	* If not return null.
	*/
	private static Integer matchIndexedRegex(Locator locator, Pattern pattern, String text)
	throws SAXParseException {
	final Matcher m = pattern.matcher(text);
	if (m.matches()) {
	try {
	return Integer.parseInt(m.group(1));
	} catch (NumberFormatException ex) {
	throw new SAXParseException("Invalid field name: '" + text + "'", locator, ex);
	}
	} else {
	return null;
	}
	}

	public static PowerProfile parse(InputStream stream) throws ParseException {
	return (new Parser(stream)).parse();
	}

	private PowerProfile() {
	}

	public ComponentProfile getComponent(Component component) {
	return mComponents.get(component);
	}

	}