telephony/java/com/android/internal/telephony/RetryManager.java - platform/frameworks/base - Git at Google

 /**
  * Copyright (C) 2009 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.internal.telephony;

 import android.util.Log;
 import android.util.Pair;
 import android.text.TextUtils;

 import java.util.Random;
 import java.util.ArrayList;

 /**
  * Retry manager allows a simple way to declare a series of
  * retires timeouts. After creating a RetryManager the configure
  * method is used to define the sequence. A simple linear series
  * may be initialized using configure with three integer parameters
  * The other configure method allows a series to be declared using
  * a string.
  *<p>
  * The format of the configuration string is a series of parameters
  * separated by a comma. There are two name value pair parameters plus a series
  * of delay times. The units of of these delay times is unspecified.
  * The name value pairs which may be specified are:
  *<ul>
  *<li>max_retries=<value>
  *<li>default_randomizationTime=<value>
  *</ul>
  *<p>
  * max_retries is the number of times that incrementRetryCount
  * maybe called before isRetryNeeded will return false. if value
  * is infinite then isRetryNeeded will always return true.
  *
  * default_randomizationTime will be used as the randomizationTime
  * for delay times which have no supplied randomizationTime. If
  * default_randomizationTime is not defined it defaults to 0.
  *<p>
  * The other parameters define The series of delay times and each
  * may have an optional randomization value separated from the
  * delay time by a colon.
  *<p>
  * Examples:
  * <ul>
  * <li>3 retires with no randomization value which means its 0:
  * <ul><li><code>"1000, 2000, 3000"</code></ul>
  *
  * <li>10 retires with a 500 default randomization value for each and
  * the 4..10 retries all using 3000 as the delay:
  * <ul><li><code>"max_retries=10, default_randomization=500, 1000, 2000, 3000"</code></ul>
  *
  * <li>4 retires with a 100 as the default randomization value for the first 2 values and
  * the other two having specified values of 500:
  * <ul><li><code>"default_randomization=100, 1000, 2000, 4000:500, 5000:500"</code></ul>
  *
  * <li>Infinite number of retires with the first one at 1000, the second at 2000 all
  * others will be at 3000.
  * <ul><li><code>"max_retries=infinite,1000,2000,3000</code></ul>
  * </ul>
  *
  * {@hide}
  */
 public class RetryManager {
     static public final String LOG_TAG = "RetryManager";
     static public final boolean DBG = false;
     static public final int RETRYIES_NOT_STARTED = 0;
     static public final int RETRYIES_ON_GOING = 1;
     static public final int RETRYIES_COMPLETED = 2;

     /**
      * Retry record with times in milli-seconds
      */
     private static class RetryRec {
         RetryRec(int delayTime, int randomizationTime) {
             mDelayTime = delayTime;
             mRandomizationTime = randomizationTime;
         }

         int mDelayTime;
         int mRandomizationTime;
     }

     /** The array of retry records */
     private ArrayList<RetryRec> mRetryArray = new ArrayList<RetryRec>();

     /** When true isRetryNeeded() will always return true */
     private boolean mRetryForever;

     /**
      * The maximum number of retries to attempt before
      * isRetryNeeded returns false
      */
     private int mMaxRetryCount;

     /** The current number of retires */
     private int mRetryCount;

     /** Random number generator */
     private Random rng = new Random();

     /** Constructor */
     public RetryManager() {
         if (DBG) log("constructor");
     }

     /**
      * Configure for a simple linear sequence of times plus
      * a random value.
      *
      * @param maxRetryCount is the maximum number of retries
      *        before isRetryNeeded returns false.
      * @param retryTime is a time that will be returned by getRetryTime.
      * @param randomizationTime a random value between 0 and
      *        randomizationTime will be added to retryTime. this
      *        parameter may be 0.
      * @return true if successfull
      */
     public boolean configure(int maxRetryCount, int retryTime, int randomizationTime) {
         Pair<Boolean, Integer> value;

         if (DBG) log("configure: " + maxRetryCount + ", " + retryTime + "," + randomizationTime);

         if (!validateNonNegativeInt("maxRetryCount", maxRetryCount)) {
             return false;
         }

         if (!validateNonNegativeInt("retryTime", retryTime)) {
             return false;
         }

         if (!validateNonNegativeInt("randomizationTime", randomizationTime)) {
             return false;
         }

         mMaxRetryCount = maxRetryCount;
         resetRetryCount();
         mRetryArray.clear();
         mRetryArray.add(new RetryRec(retryTime, randomizationTime));

         return true;
     }

     /**
      * Configure for using string which allow arbitrary
      * sequences of times. See class comments for the
      * string format.
      *
      * @return true if successful
      */
     public boolean configure(String configStr) {
         // Strip quotes if present.
         if ((configStr.startsWith("\"") && configStr.endsWith("\""))) {
             configStr = configStr.substring(1, configStr.length()-1);
         }
         if (DBG) log("configure: '" + configStr + "'");

         if (!TextUtils.isEmpty(configStr)) {
             int defaultRandomization = 0;

             if (DBG) log("configure: not empty");

             mMaxRetryCount = 0;
             resetRetryCount();
             mRetryArray.clear();

             String strArray[] = configStr.split(",");
             for (int i = 0; i < strArray.length; i++) {
                 if (DBG) log("configure: strArray[" + i + "]='" + strArray[i] + "'");
                 Pair<Boolean, Integer> value;
                 String splitStr[] = strArray[i].split("=", 2);
                 splitStr[0] = splitStr[0].trim();
                 if (DBG) log("configure: splitStr[0]='" + splitStr[0] + "'");
                 if (splitStr.length > 1) {
                     splitStr[1] = splitStr[1].trim();
                     if (DBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
                     if (TextUtils.equals(splitStr[0], "default_randomization")) {
                         value = parseNonNegativeInt(splitStr[0], splitStr[1]);
                         if (!value.first) return false;
                         defaultRandomization = value.second;
                     } else if (TextUtils.equals(splitStr[0], "max_retries")) {
                         if (TextUtils.equals("infinite",splitStr[1])) {
                             mRetryForever = true;
                         } else {
                             value = parseNonNegativeInt(splitStr[0], splitStr[1]);
                             if (!value.first) return false;
                             mMaxRetryCount = value.second;
                         }
                     } else {
                         Log.e(LOG_TAG, "Unrecognized configuration name value pair: "
                                         + strArray[i]);
                         return false;
                     }
                 } else {
                     /**
                      * Assume a retry time with an optional randomization value
                      * following a ":"
                      */
                     splitStr = strArray[i].split(":", 2);
                     splitStr[0] = splitStr[0].trim();
                     RetryRec rr = new RetryRec(0, 0);
                     value = parseNonNegativeInt("delayTime", splitStr[0]);
                     if (!value.first) return false;
                     rr.mDelayTime = value.second;

                     // Check if optional randomization value present
                     if (splitStr.length > 1) {
                         splitStr[1] = splitStr[1].trim();
                         if (DBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
                         value = parseNonNegativeInt("randomizationTime", splitStr[1]);
                         if (!value.first) return false;
                         rr.mRandomizationTime = value.second;
                     } else {
                         rr.mRandomizationTime = defaultRandomization;
                     }
                     mRetryArray.add(rr);
                 }
             }
             if (mRetryArray.size() > mMaxRetryCount) {
                 mMaxRetryCount = mRetryArray.size();
                 if (DBG) log("configure: setting mMaxRetryCount=" + mMaxRetryCount);
             }
             if (DBG) log("configure: true");
             return true;
         } else {
             if (DBG) log("configure: false it's empty");
             return false;
         }
     }

     /**
      * Report whether data reconnection should be retried
      *
      * @return {@code true} if the max retires has not been reached. {@code
      *         false} otherwise.
      */
     public boolean isRetryNeeded() {
         boolean retVal = mRetryForever || (mRetryCount < mMaxRetryCount);
         if (DBG) log("isRetryNeeded: " + retVal);
         return retVal;
     }

     /**
      * Return the timer that should be used to trigger the data reconnection
      */
     public int getRetryTimer() {
         int index;
         if (mRetryCount < mRetryArray.size()) {
             index = mRetryCount;
         } else {
             index = mRetryArray.size() - 1;
         }

         int retVal;
         if ((index >= 0) && (index < mRetryArray.size())) {
             retVal = mRetryArray.get(index).mDelayTime + nextRandomizationTime(index);
         } else {
             retVal = 0;
         }

         if (DBG) log("getRetryTimer: " + retVal);
         return retVal;
     }

     /**
      * @return retry count
      */
     public int getRetryCount() {
         if (DBG) log("getRetryCount: " + mRetryCount);
         return mRetryCount;
     }

     /**
      * Increase the retry counter, does not change retry forever.
      */
     public void increaseRetryCount() {
         mRetryCount++;
         if (mRetryCount > mMaxRetryCount) {
             mRetryCount = mMaxRetryCount;
         }
         if (DBG) log("increseRetryCount: " + mRetryCount);
     }

     /**
      * Set retry count to the specified value
      * and turns off retrying forever.
      */
     public void setRetryCount(int count) {
         mRetryCount = count;
         if (mRetryCount > mMaxRetryCount) {
             mRetryCount = mMaxRetryCount;
         }

         if (mRetryCount < 0) {
             mRetryCount = 0;
         }

         mRetryForever = false;
         if (DBG) log("setRetryCount: " + mRetryCount);
     }

     /**
      * Reset network re-registration indicator and clear the data-retry counter
      * and turns off retrying forever.
      */
     public void resetRetryCount() {
         mRetryCount = 0;
         mRetryForever = false;
         if (DBG) log("resetRetryCount: " + mRetryCount);
     }

     /**
      * Retry forever using last timeout time.
      */
     public void retryForeverUsingLastTimeout() {
         mRetryCount = mMaxRetryCount;
         mRetryForever = true;
         if (DBG) log("retryForeverUsingLastTimeout: " + mRetryForever + ", " + mRetryCount);
     }

     /**
      * @return true if retrying forever
      */
     public boolean isRetryForever() {
         if (DBG) log("isRetryForever: " + mRetryForever);
         return mRetryForever;
     }

     /**
      * Parse an integer validating the value is not negative.
      *
      * @param name
      * @param stringValue
      * @return Pair.first == true if stringValue an integer >= 0
      */
     private Pair<Boolean, Integer> parseNonNegativeInt(String name, String stringValue) {
         int value;
         Pair<Boolean, Integer> retVal;
         try {
             value = Integer.parseInt(stringValue);
             retVal = new Pair<Boolean, Integer>(validateNonNegativeInt(name, value), value);
         } catch (NumberFormatException e) {
             Log.e(LOG_TAG, name + " bad value: " + stringValue, e);
             retVal = new Pair<Boolean, Integer>(false, 0);
         }
         if (DBG) log("parseNonNetativeInt: " + name + ", " + stringValue + ", "
                     + retVal.first + ", " + retVal.second);
         return retVal;
     }

     /**
      * Validate an integer is >= 0 and logs an error if not
      *
      * @param name
      * @param value
      * @return Pair.first
      */
     private boolean validateNonNegativeInt(String name, int value) {
         boolean retVal;
         if (value < 0) {
             Log.e(LOG_TAG, name + " bad value: is < 0");
             retVal = false;
         } else {
             retVal = true;
         }
         if (DBG) log("validateNonNegative: " + name + ", " + value + ", " + retVal);
         return retVal;
     }

     /**
      * Return next random number for the index
      */
     private int nextRandomizationTime(int index) {
         int randomTime = mRetryArray.get(index).mRandomizationTime;
         if (randomTime == 0) {
             return 0;
         } else {
             return rng.nextInt(randomTime);
         }
     }

     private void log(String s) {
         Log.d(LOG_TAG, s);
     }
 }
	/**
	* Copyright (C) 2009 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.internal.telephony;

	import android.util.Log;
	import android.util.Pair;
	import android.text.TextUtils;

	import java.util.Random;
	import java.util.ArrayList;

	/**
	* Retry manager allows a simple way to declare a series of
	* retires timeouts. After creating a RetryManager the configure
	* method is used to define the sequence. A simple linear series
	* may be initialized using configure with three integer parameters
	* The other configure method allows a series to be declared using
	* a string.
	*<p>
	* The format of the configuration string is a series of parameters
	* separated by a comma. There are two name value pair parameters plus a series
	* of delay times. The units of of these delay times is unspecified.
	* The name value pairs which may be specified are:
	*<ul>
	*<li>max_retries=<value>
	*<li>default_randomizationTime=<value>
	*</ul>
	*<p>
	* max_retries is the number of times that incrementRetryCount
	* maybe called before isRetryNeeded will return false. if value
	* is infinite then isRetryNeeded will always return true.
	*
	* default_randomizationTime will be used as the randomizationTime
	* for delay times which have no supplied randomizationTime. If
	* default_randomizationTime is not defined it defaults to 0.
	*<p>
	* The other parameters define The series of delay times and each
	* may have an optional randomization value separated from the
	* delay time by a colon.
	*<p>
	* Examples:
	* <ul>
	* <li>3 retires with no randomization value which means its 0:
	* <ul><li><code>"1000, 2000, 3000"</code></ul>
	*
	* <li>10 retires with a 500 default randomization value for each and
	* the 4..10 retries all using 3000 as the delay:
	* <ul><li><code>"max_retries=10, default_randomization=500, 1000, 2000, 3000"</code></ul>
	*
	* <li>4 retires with a 100 as the default randomization value for the first 2 values and
	* the other two having specified values of 500:
	* <ul><li><code>"default_randomization=100, 1000, 2000, 4000:500, 5000:500"</code></ul>
	*
	* <li>Infinite number of retires with the first one at 1000, the second at 2000 all
	* others will be at 3000.
	* <ul><li><code>"max_retries=infinite,1000,2000,3000</code></ul>
	* </ul>
	*
	* {@hide}
	*/
	public class RetryManager {
	static public final String LOG_TAG = "RetryManager";
	static public final boolean DBG = false;
	static public final int RETRYIES_NOT_STARTED = 0;
	static public final int RETRYIES_ON_GOING = 1;
	static public final int RETRYIES_COMPLETED = 2;

	/**
	* Retry record with times in milli-seconds
	*/
	private static class RetryRec {
	RetryRec(int delayTime, int randomizationTime) {
	mDelayTime = delayTime;
	mRandomizationTime = randomizationTime;
	}

	int mDelayTime;
	int mRandomizationTime;
	}

	/** The array of retry records */
	private ArrayList<RetryRec> mRetryArray = new ArrayList<RetryRec>();

	/** When true isRetryNeeded() will always return true */
	private boolean mRetryForever;

	/**
	* The maximum number of retries to attempt before
	* isRetryNeeded returns false
	*/
	private int mMaxRetryCount;

	/** The current number of retires */
	private int mRetryCount;

	/** Random number generator */
	private Random rng = new Random();

	/** Constructor */
	public RetryManager() {
	if (DBG) log("constructor");
	}

	/**
	* Configure for a simple linear sequence of times plus
	* a random value.
	*
	* @param maxRetryCount is the maximum number of retries
	* before isRetryNeeded returns false.
	* @param retryTime is a time that will be returned by getRetryTime.
	* @param randomizationTime a random value between 0 and
	* randomizationTime will be added to retryTime. this
	* parameter may be 0.
	* @return true if successfull
	*/
	public boolean configure(int maxRetryCount, int retryTime, int randomizationTime) {
	Pair<Boolean, Integer> value;

	if (DBG) log("configure: " + maxRetryCount + ", " + retryTime + "," + randomizationTime);

	if (!validateNonNegativeInt("maxRetryCount", maxRetryCount)) {
	return false;
	}

	if (!validateNonNegativeInt("retryTime", retryTime)) {
	return false;
	}

	if (!validateNonNegativeInt("randomizationTime", randomizationTime)) {
	return false;
	}

	mMaxRetryCount = maxRetryCount;
	resetRetryCount();
	mRetryArray.clear();
	mRetryArray.add(new RetryRec(retryTime, randomizationTime));

	return true;
	}

	/**
	* Configure for using string which allow arbitrary
	* sequences of times. See class comments for the
	* string format.
	*
	* @return true if successful
	*/
	public boolean configure(String configStr) {
	// Strip quotes if present.
	if ((configStr.startsWith("\"") && configStr.endsWith("\""))) {
	configStr = configStr.substring(1, configStr.length()-1);
	}
	if (DBG) log("configure: '" + configStr + "'");

	if (!TextUtils.isEmpty(configStr)) {
	int defaultRandomization = 0;

	if (DBG) log("configure: not empty");

	mMaxRetryCount = 0;
	resetRetryCount();
	mRetryArray.clear();

	String strArray[] = configStr.split(",");
	for (int i = 0; i < strArray.length; i++) {
	if (DBG) log("configure: strArray[" + i + "]='" + strArray[i] + "'");
	Pair<Boolean, Integer> value;
	String splitStr[] = strArray[i].split("=", 2);
	splitStr[0] = splitStr[0].trim();
	if (DBG) log("configure: splitStr[0]='" + splitStr[0] + "'");
	if (splitStr.length > 1) {
	splitStr[1] = splitStr[1].trim();
	if (DBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
	if (TextUtils.equals(splitStr[0], "default_randomization")) {
	value = parseNonNegativeInt(splitStr[0], splitStr[1]);
	if (!value.first) return false;
	defaultRandomization = value.second;
	} else if (TextUtils.equals(splitStr[0], "max_retries")) {
	if (TextUtils.equals("infinite",splitStr[1])) {
	mRetryForever = true;
	} else {
	value = parseNonNegativeInt(splitStr[0], splitStr[1]);
	if (!value.first) return false;
	mMaxRetryCount = value.second;
	}
	} else {
	Log.e(LOG_TAG, "Unrecognized configuration name value pair: "
	+ strArray[i]);
	return false;
	}
	} else {
	/**
	* Assume a retry time with an optional randomization value
	* following a ":"
	*/
	splitStr = strArray[i].split(":", 2);
	splitStr[0] = splitStr[0].trim();
	RetryRec rr = new RetryRec(0, 0);
	value = parseNonNegativeInt("delayTime", splitStr[0]);
	if (!value.first) return false;
	rr.mDelayTime = value.second;

	// Check if optional randomization value present
	if (splitStr.length > 1) {
	splitStr[1] = splitStr[1].trim();
	if (DBG) log("configure: splitStr[1]='" + splitStr[1] + "'");
	value = parseNonNegativeInt("randomizationTime", splitStr[1]);
	if (!value.first) return false;
	rr.mRandomizationTime = value.second;
	} else {
	rr.mRandomizationTime = defaultRandomization;
	}
	mRetryArray.add(rr);
	}
	}
	if (mRetryArray.size() > mMaxRetryCount) {
	mMaxRetryCount = mRetryArray.size();
	if (DBG) log("configure: setting mMaxRetryCount=" + mMaxRetryCount);
	}
	if (DBG) log("configure: true");
	return true;
	} else {
	if (DBG) log("configure: false it's empty");
	return false;
	}
	}

	/**
	* Report whether data reconnection should be retried
	*
	* @return {@code true} if the max retires has not been reached. {@code
	* false} otherwise.
	*/
	public boolean isRetryNeeded() {
	boolean retVal = mRetryForever \|\| (mRetryCount < mMaxRetryCount);
	if (DBG) log("isRetryNeeded: " + retVal);
	return retVal;
	}

	/**
	* Return the timer that should be used to trigger the data reconnection
	*/
	public int getRetryTimer() {
	int index;
	if (mRetryCount < mRetryArray.size()) {
	index = mRetryCount;
	} else {
	index = mRetryArray.size() - 1;
	}

	int retVal;
	if ((index >= 0) && (index < mRetryArray.size())) {
	retVal = mRetryArray.get(index).mDelayTime + nextRandomizationTime(index);
	} else {
	retVal = 0;
	}

	if (DBG) log("getRetryTimer: " + retVal);
	return retVal;
	}

	/**
	* @return retry count
	*/
	public int getRetryCount() {
	if (DBG) log("getRetryCount: " + mRetryCount);
	return mRetryCount;
	}

	/**
	* Increase the retry counter, does not change retry forever.
	*/
	public void increaseRetryCount() {
	mRetryCount++;
	if (mRetryCount > mMaxRetryCount) {
	mRetryCount = mMaxRetryCount;
	}
	if (DBG) log("increseRetryCount: " + mRetryCount);
	}

	/**
	* Set retry count to the specified value
	* and turns off retrying forever.
	*/
	public void setRetryCount(int count) {
	mRetryCount = count;
	if (mRetryCount > mMaxRetryCount) {
	mRetryCount = mMaxRetryCount;
	}

	if (mRetryCount < 0) {
	mRetryCount = 0;
	}

	mRetryForever = false;
	if (DBG) log("setRetryCount: " + mRetryCount);
	}

	/**
	* Reset network re-registration indicator and clear the data-retry counter
	* and turns off retrying forever.
	*/
	public void resetRetryCount() {
	mRetryCount = 0;
	mRetryForever = false;
	if (DBG) log("resetRetryCount: " + mRetryCount);
	}

	/**
	* Retry forever using last timeout time.
	*/
	public void retryForeverUsingLastTimeout() {
	mRetryCount = mMaxRetryCount;
	mRetryForever = true;
	if (DBG) log("retryForeverUsingLastTimeout: " + mRetryForever + ", " + mRetryCount);
	}

	/**
	* @return true if retrying forever
	*/
	public boolean isRetryForever() {
	if (DBG) log("isRetryForever: " + mRetryForever);
	return mRetryForever;
	}

	/**
	* Parse an integer validating the value is not negative.
	*
	* @param name
	* @param stringValue
	* @return Pair.first == true if stringValue an integer >= 0
	*/
	private Pair<Boolean, Integer> parseNonNegativeInt(String name, String stringValue) {
	int value;
	Pair<Boolean, Integer> retVal;
	try {
	value = Integer.parseInt(stringValue);
	retVal = new Pair<Boolean, Integer>(validateNonNegativeInt(name, value), value);
	} catch (NumberFormatException e) {
	Log.e(LOG_TAG, name + " bad value: " + stringValue, e);
	retVal = new Pair<Boolean, Integer>(false, 0);
	}
	if (DBG) log("parseNonNetativeInt: " + name + ", " + stringValue + ", "
	+ retVal.first + ", " + retVal.second);
	return retVal;
	}

	/**
	* Validate an integer is >= 0 and logs an error if not
	*
	* @param name
	* @param value
	* @return Pair.first
	*/
	private boolean validateNonNegativeInt(String name, int value) {
	boolean retVal;
	if (value < 0) {
	Log.e(LOG_TAG, name + " bad value: is < 0");
	retVal = false;
	} else {
	retVal = true;
	}
	if (DBG) log("validateNonNegative: " + name + ", " + value + ", " + retVal);
	return retVal;
	}

	/**
	* Return next random number for the index
	*/
	private int nextRandomizationTime(int index) {
	int randomTime = mRetryArray.get(index).mRandomizationTime;
	if (randomTime == 0) {
	return 0;
	} else {
	return rng.nextInt(randomTime);
	}
	}

	private void log(String s) {
	Log.d(LOG_TAG, s);
	}
	}