core/java/android/service/autofill/UserData.java - platform/frameworks/base - Gitiles

 /*
  * Copyright 2017 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 android.service.autofill;

 import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_CATEGORY_COUNT;
 import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_FIELD_CLASSIFICATION_IDS_SIZE;
 import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_USER_DATA_SIZE;
 import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_VALUE_LENGTH;
 import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MIN_VALUE_LENGTH;
 import static android.view.autofill.Helper.sDebug;

 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.app.ActivityThread;
 import android.content.ContentResolver;
 import android.os.Bundle;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.provider.Settings;
 import android.service.autofill.FieldClassification.Match;
 import android.text.TextUtils;
 import android.util.ArraySet;
 import android.util.Log;
 import android.view.autofill.AutofillManager;
 import android.view.autofill.Helper;

 import com.android.internal.util.Preconditions;

 import java.io.PrintWriter;
 import java.util.ArrayList;

 /**
  * Defines the user data used for
  * <a href="AutofillService.html#FieldClassification">field classification</a>.
  */
 public final class UserData implements Parcelable {

     private static final String TAG = "UserData";

     private static final int DEFAULT_MAX_USER_DATA_SIZE = 50;
     private static final int DEFAULT_MAX_CATEGORY_COUNT = 10;
     private static final int DEFAULT_MAX_FIELD_CLASSIFICATION_IDS_SIZE = 10;
     private static final int DEFAULT_MIN_VALUE_LENGTH = 3;
     private static final int DEFAULT_MAX_VALUE_LENGTH = 100;

     private final String mId;
     private final String mAlgorithm;
     private final Bundle mAlgorithmArgs;
     private final String[] mCategoryIds;
     private final String[] mValues;

     private UserData(Builder builder) {
         mId = builder.mId;
         mAlgorithm = builder.mAlgorithm;
         mAlgorithmArgs = builder.mAlgorithmArgs;
         mCategoryIds = new String[builder.mCategoryIds.size()];
         builder.mCategoryIds.toArray(mCategoryIds);
         mValues = new String[builder.mValues.size()];
         builder.mValues.toArray(mValues);
     }

     /**
      * Gets the name of the algorithm that is used to calculate
      * {@link Match#getScore() match scores}.
      */
     @Nullable
     public String getFieldClassificationAlgorithm() {
         return mAlgorithm;
     }

     /**
      * Gets the id.
      */
     public String getId() {
         return mId;
     }

     /** @hide */
     public Bundle getAlgorithmArgs() {
         return mAlgorithmArgs;
     }

     /** @hide */
     public String[] getCategoryIds() {
         return mCategoryIds;
     }

     /** @hide */
     public String[] getValues() {
         return mValues;
     }

     /** @hide */
     public void dump(String prefix, PrintWriter pw) {
         pw.print(prefix); pw.print("id: "); pw.print(mId);
         pw.print(prefix); pw.print("Algorithm: "); pw.print(mAlgorithm);
         pw.print(" Args: "); pw.println(mAlgorithmArgs);

         // Cannot disclose field ids or values because they could contain PII
         pw.print(prefix); pw.print("Field ids size: "); pw.println(mCategoryIds.length);
         for (int i = 0; i < mCategoryIds.length; i++) {
             pw.print(prefix); pw.print(prefix); pw.print(i); pw.print(": ");
             pw.println(Helper.getRedacted(mCategoryIds[i]));
         }
         pw.print(prefix); pw.print("Values size: "); pw.println(mValues.length);
         for (int i = 0; i < mValues.length; i++) {
             pw.print(prefix); pw.print(prefix); pw.print(i); pw.print(": ");
             pw.println(Helper.getRedacted(mValues[i]));
         }
     }

     /** @hide */
     public static void dumpConstraints(String prefix, PrintWriter pw) {
         pw.print(prefix); pw.print("maxUserDataSize: "); pw.println(getMaxUserDataSize());
         pw.print(prefix); pw.print("maxFieldClassificationIdsSize: ");
         pw.println(getMaxFieldClassificationIdsSize());
         pw.print(prefix); pw.print("maxCategoryCount: "); pw.println(getMaxCategoryCount());
         pw.print(prefix); pw.print("minValueLength: "); pw.println(getMinValueLength());
         pw.print(prefix); pw.print("maxValueLength: "); pw.println(getMaxValueLength());
     }

     /**
      * A builder for {@link UserData} objects.
      */
     public static final class Builder {
         private final String mId;
         private final ArrayList<String> mCategoryIds;
         private final ArrayList<String> mValues;
         private String mAlgorithm;
         private Bundle mAlgorithmArgs;
         private boolean mDestroyed;

         // Non-persistent array used to limit the number of unique ids.
         private final ArraySet<String> mUniqueCategoryIds;
         // Non-persistent array used to ignore duplaicated value/category pairs.
         private final ArraySet<String> mUniqueValueCategoryPairs;


         /**
          * Creates a new builder for the user data used for <a href="#FieldClassification">field
          * classification</a>.
          *
          * <p>The user data must contain at least one pair of {@code value} -> {@code categoryId},
          * and more pairs can be added through the {@link #add(String, String)} method. For example:
          *
          * <pre class="prettyprint">
          * new UserData.Builder("v1", "Bart Simpson", "name")
          *   .add("bart.simpson@example.com", "email")
          *   .add("el_barto@example.com", "email")
          *   .build();
          * </pre>
          *
          * @param id id used to identify the whole {@link UserData} object. This id is also returned
          * by {@link AutofillManager#getUserDataId()}, which can be used to check if the
          * {@link UserData} is up-to-date without fetching the whole object (through
          * {@link AutofillManager#getUserData()}).
          *
          * @param value value of the user data.
          * @param categoryId string used to identify the category the value is associated with.
          *
          * @throws IllegalArgumentException if any of the following occurs:
          * <ul>
          *   <li>{@code id} is empty</li>
          *   <li>{@code categoryId} is empty</li>
          *   <li>{@code value} is empty</li>
          *   <li>the length of {@code value} is lower than {@link UserData#getMinValueLength()}</li>
          *   <li>the length of {@code value} is higher than
          *       {@link UserData#getMaxValueLength()}</li>
          * </ul>
          */
         public Builder(@NonNull String id, @NonNull String value, @NonNull String categoryId) {
             mId = checkNotEmpty("id", id);
             checkNotEmpty("categoryId", categoryId);
             checkValidValue(value);
             final int maxUserDataSize = getMaxUserDataSize();
             mCategoryIds = new ArrayList<>(maxUserDataSize);
             mValues = new ArrayList<>(maxUserDataSize);
             mUniqueValueCategoryPairs = new ArraySet<>(maxUserDataSize);
             mUniqueCategoryIds = new ArraySet<>(getMaxCategoryCount());

             addMapping(value, categoryId);
         }

         /**
          * Sets the algorithm used for <a href="#FieldClassification">field classification</a>.
          *
          * <p>The currently available algorithms can be retrieve through
          * {@link AutofillManager#getAvailableFieldClassificationAlgorithms()}.
          *
          * <p>If not set, the
          * {@link AutofillManager#getDefaultFieldClassificationAlgorithm() default algorithm} is
          * used instead.
          *
          * @param name name of the algorithm or {@code null} to used default.
          * @param args optional arguments to the algorithm.
          *
          * @return this builder
          */
         public Builder setFieldClassificationAlgorithm(@Nullable String name,
                 @Nullable Bundle args) {
             throwIfDestroyed();
             mAlgorithm = name;
             mAlgorithmArgs = args;
             return this;
         }

         /**
          * Adds a new value for user data.
          *
          * @param value value of the user data.
          * @param categoryId string used to identify the category the value is associated with.
          *
          * @throws IllegalStateException if:
          * <ul>
          *   <li>{@link #build()} already called</li>
          *   <li>the {@code value} has already been added (<b>Note: </b> this restriction was
          *   lifted on Android {@link android.os.Build.VERSION_CODES#Q} and later)</li>
          *   <li>the number of unique {@code categoryId} values added so far is more than
          *       {@link UserData#getMaxCategoryCount()}</li>
          *   <li>the number of {@code values} added so far is is more than
          *       {@link UserData#getMaxUserDataSize()}</li>
          * </ul>
          *
          * @throws IllegalArgumentException if any of the following occurs:
          * <ul>
          *   <li>{@code id} is empty</li>
          *   <li>{@code categoryId} is empty</li>
          *   <li>{@code value} is empty</li>
          *   <li>the length of {@code value} is lower than {@link UserData#getMinValueLength()}</li>
          *   <li>the length of {@code value} is higher than
          *       {@link UserData#getMaxValueLength()}</li>
          * </ul>
          */
         public Builder add(@NonNull String value, @NonNull String categoryId) {
             throwIfDestroyed();
             checkNotEmpty("categoryId", categoryId);
             checkValidValue(value);

             if (!mUniqueCategoryIds.contains(categoryId)) {
                 // New category - check size
                 Preconditions.checkState(mUniqueCategoryIds.size() < getMaxCategoryCount(),
                         "already added " + mUniqueCategoryIds.size() + " unique category ids");
             }

             Preconditions.checkState(mValues.size() < getMaxUserDataSize(),
                     "already added " + mValues.size() + " elements");
             addMapping(value, categoryId);

             return this;
         }

         private void addMapping(@NonNull String value, @NonNull String categoryId) {
             final String pair = value + ":" + categoryId;
             if (mUniqueValueCategoryPairs.contains(pair)) {
                 // Don't include value on message because it could contain PII
                 Log.w(TAG, "Ignoring entry with same value / category");
                 return;
             }
             mCategoryIds.add(categoryId);
             mValues.add(value);
             mUniqueCategoryIds.add(categoryId);
             mUniqueValueCategoryPairs.add(pair);
         }

         private String checkNotEmpty(@NonNull String name, @Nullable String value) {
             Preconditions.checkNotNull(value);
             Preconditions.checkArgument(!TextUtils.isEmpty(value), "%s cannot be empty", name);
             return value;
         }

         private void checkValidValue(@Nullable String value) {
             Preconditions.checkNotNull(value);
             final int length = value.length();
             Preconditions.checkArgumentInRange(length, getMinValueLength(),
                     getMaxValueLength(), "value length (" + length + ")");
         }

         /**
          * Creates a new {@link UserData} instance.
          *
          * <p>You should not interact with this builder once this method is called.
          *
          * @throws IllegalStateException if {@link #build()} was already called.
          *
          * @return The built dataset.
          */
         public UserData build() {
             throwIfDestroyed();
             mDestroyed = true;
             return new UserData(this);
         }

         private void throwIfDestroyed() {
             if (mDestroyed) {
                 throw new IllegalStateException("Already called #build()");
             }
         }
     }

     /////////////////////////////////////
     // Object "contract" methods. //
     /////////////////////////////////////
     @Override
     public String toString() {
         if (!sDebug) return super.toString();

         final StringBuilder builder = new StringBuilder("UserData: [id=").append(mId)
                 .append(", algorithm=").append(mAlgorithm);
         // Cannot disclose category ids or values because they could contain PII
         builder.append(", categoryIds=");
         Helper.appendRedacted(builder, mCategoryIds);
         builder.append(", values=");
         Helper.appendRedacted(builder, mValues);
         return builder.append("]").toString();
     }

     /////////////////////////////////////
     // Parcelable "contract" methods. //
     /////////////////////////////////////

     @Override
     public int describeContents() {
         return 0;
     }

     @Override
     public void writeToParcel(Parcel parcel, int flags) {
         parcel.writeString(mId);
         parcel.writeStringArray(mCategoryIds);
         parcel.writeStringArray(mValues);
         parcel.writeString(mAlgorithm);
         parcel.writeBundle(mAlgorithmArgs);
     }

     public static final Parcelable.Creator<UserData> CREATOR =
             new Parcelable.Creator<UserData>() {
         @Override
         public UserData createFromParcel(Parcel parcel) {
             // Always go through the builder to ensure the data ingested by
             // the system obeys the contract of the builder to avoid attacks
             // using specially crafted parcels.
             final String id = parcel.readString();
             final String[] categoryIds = parcel.readStringArray();
             final String[] values = parcel.readStringArray();
             final Builder builder = new Builder(id, values[0], categoryIds[0])
                     .setFieldClassificationAlgorithm(parcel.readString(), parcel.readBundle());
             for (int i = 1; i < categoryIds.length; i++) {
                 builder.add(values[i], categoryIds[i]);
             }
             return builder.build();
         }

         @Override
         public UserData[] newArray(int size) {
             return new UserData[size];
         }
     };

     /**
      * Gets the maximum number of values that can be added to a {@link UserData}.
      */
     public static int getMaxUserDataSize() {
         return getInt(AUTOFILL_USER_DATA_MAX_USER_DATA_SIZE, DEFAULT_MAX_USER_DATA_SIZE);
     }

     /**
      * Gets the maximum number of ids that can be passed to {@link
      * FillResponse.Builder#setFieldClassificationIds(android.view.autofill.AutofillId...)}.
      */
     public static int getMaxFieldClassificationIdsSize() {
         return getInt(AUTOFILL_USER_DATA_MAX_FIELD_CLASSIFICATION_IDS_SIZE,
             DEFAULT_MAX_FIELD_CLASSIFICATION_IDS_SIZE);
     }

     /**
      * Gets the maximum number of unique category ids that can be passed to
      * the builder's constructor and {@link Builder#add(String, String)}.
      */
     public static int getMaxCategoryCount() {
         return getInt(AUTOFILL_USER_DATA_MAX_CATEGORY_COUNT, DEFAULT_MAX_CATEGORY_COUNT);
     }

     /**
      * Gets the minimum length of values passed to the builder's constructor or
      * or {@link Builder#add(String, String)}.
      */
     public static int getMinValueLength() {
         return getInt(AUTOFILL_USER_DATA_MIN_VALUE_LENGTH, DEFAULT_MIN_VALUE_LENGTH);
     }

     /**
      * Gets the maximum length of values passed to the builder's constructor or
      * or {@link Builder#add(String, String)}.
      */
     public static int getMaxValueLength() {
         return getInt(AUTOFILL_USER_DATA_MAX_VALUE_LENGTH, DEFAULT_MAX_VALUE_LENGTH);
     }

     private static int getInt(String settings, int defaultValue) {
         ContentResolver cr = null;
         final ActivityThread at = ActivityThread.currentActivityThread();
         if (at != null) {
             cr = at.getApplication().getContentResolver();
         }

         if (cr == null) {
             Log.w(TAG, "Could not read from " + settings + "; hardcoding " + defaultValue);
             return defaultValue;
         }
         return Settings.Secure.getInt(cr, settings, defaultValue);
     }
 }
	/*
	* Copyright 2017 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 android.service.autofill;

	import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_CATEGORY_COUNT;
	import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_FIELD_CLASSIFICATION_IDS_SIZE;
	import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_USER_DATA_SIZE;
	import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MAX_VALUE_LENGTH;
	import static android.provider.Settings.Secure.AUTOFILL_USER_DATA_MIN_VALUE_LENGTH;
	import static android.view.autofill.Helper.sDebug;

	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.app.ActivityThread;
	import android.content.ContentResolver;
	import android.os.Bundle;
	import android.os.Parcel;
	import android.os.Parcelable;
	import android.provider.Settings;
	import android.service.autofill.FieldClassification.Match;
	import android.text.TextUtils;
	import android.util.ArraySet;
	import android.util.Log;
	import android.view.autofill.AutofillManager;
	import android.view.autofill.Helper;

	import com.android.internal.util.Preconditions;

	import java.io.PrintWriter;
	import java.util.ArrayList;

	/**
	* Defines the user data used for
	* <a href="AutofillService.html#FieldClassification">field classification</a>.
	*/
	public final class UserData implements Parcelable {

	private static final String TAG = "UserData";

	private static final int DEFAULT_MAX_USER_DATA_SIZE = 50;
	private static final int DEFAULT_MAX_CATEGORY_COUNT = 10;
	private static final int DEFAULT_MAX_FIELD_CLASSIFICATION_IDS_SIZE = 10;
	private static final int DEFAULT_MIN_VALUE_LENGTH = 3;
	private static final int DEFAULT_MAX_VALUE_LENGTH = 100;

	private final String mId;
	private final String mAlgorithm;
	private final Bundle mAlgorithmArgs;
	private final String[] mCategoryIds;
	private final String[] mValues;

	private UserData(Builder builder) {
	mId = builder.mId;
	mAlgorithm = builder.mAlgorithm;
	mAlgorithmArgs = builder.mAlgorithmArgs;
	mCategoryIds = new String[builder.mCategoryIds.size()];
	builder.mCategoryIds.toArray(mCategoryIds);
	mValues = new String[builder.mValues.size()];
	builder.mValues.toArray(mValues);
	}

	/**
	* Gets the name of the algorithm that is used to calculate
	* {@link Match#getScore() match scores}.
	*/
	@Nullable
	public String getFieldClassificationAlgorithm() {
	return mAlgorithm;
	}

	/**
	* Gets the id.
	*/
	public String getId() {
	return mId;
	}

	/** @hide */
	public Bundle getAlgorithmArgs() {
	return mAlgorithmArgs;
	}

	/** @hide */
	public String[] getCategoryIds() {
	return mCategoryIds;
	}

	/** @hide */
	public String[] getValues() {
	return mValues;
	}

	/** @hide */
	public void dump(String prefix, PrintWriter pw) {
	pw.print(prefix); pw.print("id: "); pw.print(mId);
	pw.print(prefix); pw.print("Algorithm: "); pw.print(mAlgorithm);
	pw.print(" Args: "); pw.println(mAlgorithmArgs);

	// Cannot disclose field ids or values because they could contain PII
	pw.print(prefix); pw.print("Field ids size: "); pw.println(mCategoryIds.length);
	for (int i = 0; i < mCategoryIds.length; i++) {
	pw.print(prefix); pw.print(prefix); pw.print(i); pw.print(": ");
	pw.println(Helper.getRedacted(mCategoryIds[i]));
	}
	pw.print(prefix); pw.print("Values size: "); pw.println(mValues.length);
	for (int i = 0; i < mValues.length; i++) {
	pw.print(prefix); pw.print(prefix); pw.print(i); pw.print(": ");
	pw.println(Helper.getRedacted(mValues[i]));
	}
	}

	/** @hide */
	public static void dumpConstraints(String prefix, PrintWriter pw) {
	pw.print(prefix); pw.print("maxUserDataSize: "); pw.println(getMaxUserDataSize());
	pw.print(prefix); pw.print("maxFieldClassificationIdsSize: ");
	pw.println(getMaxFieldClassificationIdsSize());
	pw.print(prefix); pw.print("maxCategoryCount: "); pw.println(getMaxCategoryCount());
	pw.print(prefix); pw.print("minValueLength: "); pw.println(getMinValueLength());
	pw.print(prefix); pw.print("maxValueLength: "); pw.println(getMaxValueLength());
	}

	/**
	* A builder for {@link UserData} objects.
	*/
	public static final class Builder {
	private final String mId;
	private final ArrayList<String> mCategoryIds;
	private final ArrayList<String> mValues;
	private String mAlgorithm;
	private Bundle mAlgorithmArgs;
	private boolean mDestroyed;

	// Non-persistent array used to limit the number of unique ids.
	private final ArraySet<String> mUniqueCategoryIds;
	// Non-persistent array used to ignore duplaicated value/category pairs.
	private final ArraySet<String> mUniqueValueCategoryPairs;


	/**
	* Creates a new builder for the user data used for <a href="#FieldClassification">field
	* classification</a>.
	*
	* <p>The user data must contain at least one pair of {@code value} -> {@code categoryId},
	* and more pairs can be added through the {@link #add(String, String)} method. For example:
	*
	* <pre class="prettyprint">
	* new UserData.Builder("v1", "Bart Simpson", "name")
	* .add("bart.simpson@example.com", "email")
	* .add("el_barto@example.com", "email")
	* .build();
	* </pre>
	*
	* @param id id used to identify the whole {@link UserData} object. This id is also returned
	* by {@link AutofillManager#getUserDataId()}, which can be used to check if the
	* {@link UserData} is up-to-date without fetching the whole object (through
	* {@link AutofillManager#getUserData()}).
	*
	* @param value value of the user data.
	* @param categoryId string used to identify the category the value is associated with.
	*
	* @throws IllegalArgumentException if any of the following occurs:
	* <ul>
	* <li>{@code id} is empty</li>
	* <li>{@code categoryId} is empty</li>
	* <li>{@code value} is empty</li>
	* <li>the length of {@code value} is lower than {@link UserData#getMinValueLength()}</li>
	* <li>the length of {@code value} is higher than
	* {@link UserData#getMaxValueLength()}</li>
	* </ul>
	*/
	public Builder(@NonNull String id, @NonNull String value, @NonNull String categoryId) {
	mId = checkNotEmpty("id", id);
	checkNotEmpty("categoryId", categoryId);
	checkValidValue(value);
	final int maxUserDataSize = getMaxUserDataSize();
	mCategoryIds = new ArrayList<>(maxUserDataSize);
	mValues = new ArrayList<>(maxUserDataSize);
	mUniqueValueCategoryPairs = new ArraySet<>(maxUserDataSize);
	mUniqueCategoryIds = new ArraySet<>(getMaxCategoryCount());

	addMapping(value, categoryId);
	}

	/**
	* Sets the algorithm used for <a href="#FieldClassification">field classification</a>.
	*
	* <p>The currently available algorithms can be retrieve through
	* {@link AutofillManager#getAvailableFieldClassificationAlgorithms()}.
	*
	* <p>If not set, the
	* {@link AutofillManager#getDefaultFieldClassificationAlgorithm() default algorithm} is
	* used instead.
	*
	* @param name name of the algorithm or {@code null} to used default.
	* @param args optional arguments to the algorithm.
	*
	* @return this builder
	*/
	public Builder setFieldClassificationAlgorithm(@Nullable String name,
	@Nullable Bundle args) {
	throwIfDestroyed();
	mAlgorithm = name;
	mAlgorithmArgs = args;
	return this;
	}

	/**
	* Adds a new value for user data.
	*
	* @param value value of the user data.
	* @param categoryId string used to identify the category the value is associated with.
	*
	* @throws IllegalStateException if:
	* <ul>
	* <li>{@link #build()} already called</li>
	* <li>the {@code value} has already been added (<b>Note: </b> this restriction was
	* lifted on Android {@link android.os.Build.VERSION_CODES#Q} and later)</li>
	* <li>the number of unique {@code categoryId} values added so far is more than
	* {@link UserData#getMaxCategoryCount()}</li>
	* <li>the number of {@code values} added so far is is more than
	* {@link UserData#getMaxUserDataSize()}</li>
	* </ul>
	*
	* @throws IllegalArgumentException if any of the following occurs:
	* <ul>
	* <li>{@code id} is empty</li>
	* <li>{@code categoryId} is empty</li>
	* <li>{@code value} is empty</li>
	* <li>the length of {@code value} is lower than {@link UserData#getMinValueLength()}</li>
	* <li>the length of {@code value} is higher than
	* {@link UserData#getMaxValueLength()}</li>
	* </ul>
	*/
	public Builder add(@NonNull String value, @NonNull String categoryId) {
	throwIfDestroyed();
	checkNotEmpty("categoryId", categoryId);
	checkValidValue(value);

	if (!mUniqueCategoryIds.contains(categoryId)) {
	// New category - check size
	Preconditions.checkState(mUniqueCategoryIds.size() < getMaxCategoryCount(),
	"already added " + mUniqueCategoryIds.size() + " unique category ids");
	}

	Preconditions.checkState(mValues.size() < getMaxUserDataSize(),
	"already added " + mValues.size() + " elements");
	addMapping(value, categoryId);

	return this;
	}

	private void addMapping(@NonNull String value, @NonNull String categoryId) {
	final String pair = value + ":" + categoryId;
	if (mUniqueValueCategoryPairs.contains(pair)) {
	// Don't include value on message because it could contain PII
	Log.w(TAG, "Ignoring entry with same value / category");
	return;
	}
	mCategoryIds.add(categoryId);
	mValues.add(value);
	mUniqueCategoryIds.add(categoryId);
	mUniqueValueCategoryPairs.add(pair);
	}

	private String checkNotEmpty(@NonNull String name, @Nullable String value) {
	Preconditions.checkNotNull(value);
	Preconditions.checkArgument(!TextUtils.isEmpty(value), "%s cannot be empty", name);
	return value;
	}

	private void checkValidValue(@Nullable String value) {
	Preconditions.checkNotNull(value);
	final int length = value.length();
	Preconditions.checkArgumentInRange(length, getMinValueLength(),
	getMaxValueLength(), "value length (" + length + ")");
	}

	/**
	* Creates a new {@link UserData} instance.
	*
	* <p>You should not interact with this builder once this method is called.
	*
	* @throws IllegalStateException if {@link #build()} was already called.
	*
	* @return The built dataset.
	*/
	public UserData build() {
	throwIfDestroyed();
	mDestroyed = true;
	return new UserData(this);
	}

	private void throwIfDestroyed() {
	if (mDestroyed) {
	throw new IllegalStateException("Already called #build()");
	}
	}
	}

	/////////////////////////////////////
	// Object "contract" methods. //
	/////////////////////////////////////
	@Override
	public String toString() {
	if (!sDebug) return super.toString();

	final StringBuilder builder = new StringBuilder("UserData: [id=").append(mId)
	.append(", algorithm=").append(mAlgorithm);
	// Cannot disclose category ids or values because they could contain PII
	builder.append(", categoryIds=");
	Helper.appendRedacted(builder, mCategoryIds);
	builder.append(", values=");
	Helper.appendRedacted(builder, mValues);
	return builder.append("]").toString();
	}

	/////////////////////////////////////
	// Parcelable "contract" methods. //
	/////////////////////////////////////

	@Override
	public int describeContents() {
	return 0;
	}

	@Override
	public void writeToParcel(Parcel parcel, int flags) {
	parcel.writeString(mId);
	parcel.writeStringArray(mCategoryIds);
	parcel.writeStringArray(mValues);
	parcel.writeString(mAlgorithm);
	parcel.writeBundle(mAlgorithmArgs);
	}

	public static final Parcelable.Creator<UserData> CREATOR =
	new Parcelable.Creator<UserData>() {
	@Override
	public UserData createFromParcel(Parcel parcel) {
	// Always go through the builder to ensure the data ingested by
	// the system obeys the contract of the builder to avoid attacks
	// using specially crafted parcels.
	final String id = parcel.readString();
	final String[] categoryIds = parcel.readStringArray();
	final String[] values = parcel.readStringArray();
	final Builder builder = new Builder(id, values[0], categoryIds[0])
	.setFieldClassificationAlgorithm(parcel.readString(), parcel.readBundle());
	for (int i = 1; i < categoryIds.length; i++) {
	builder.add(values[i], categoryIds[i]);
	}
	return builder.build();
	}

	@Override
	public UserData[] newArray(int size) {
	return new UserData[size];
	}
	};

	/**
	* Gets the maximum number of values that can be added to a {@link UserData}.
	*/
	public static int getMaxUserDataSize() {
	return getInt(AUTOFILL_USER_DATA_MAX_USER_DATA_SIZE, DEFAULT_MAX_USER_DATA_SIZE);
	}

	/**
	* Gets the maximum number of ids that can be passed to {@link
	* FillResponse.Builder#setFieldClassificationIds(android.view.autofill.AutofillId...)}.
	*/
	public static int getMaxFieldClassificationIdsSize() {
	return getInt(AUTOFILL_USER_DATA_MAX_FIELD_CLASSIFICATION_IDS_SIZE,
	DEFAULT_MAX_FIELD_CLASSIFICATION_IDS_SIZE);
	}

	/**
	* Gets the maximum number of unique category ids that can be passed to
	* the builder's constructor and {@link Builder#add(String, String)}.
	*/
	public static int getMaxCategoryCount() {
	return getInt(AUTOFILL_USER_DATA_MAX_CATEGORY_COUNT, DEFAULT_MAX_CATEGORY_COUNT);
	}

	/**
	* Gets the minimum length of values passed to the builder's constructor or
	* or {@link Builder#add(String, String)}.
	*/
	public static int getMinValueLength() {
	return getInt(AUTOFILL_USER_DATA_MIN_VALUE_LENGTH, DEFAULT_MIN_VALUE_LENGTH);
	}

	/**
	* Gets the maximum length of values passed to the builder's constructor or
	* or {@link Builder#add(String, String)}.
	*/
	public static int getMaxValueLength() {
	return getInt(AUTOFILL_USER_DATA_MAX_VALUE_LENGTH, DEFAULT_MAX_VALUE_LENGTH);
	}

	private static int getInt(String settings, int defaultValue) {
	ContentResolver cr = null;
	final ActivityThread at = ActivityThread.currentActivityThread();
	if (at != null) {
	cr = at.getApplication().getContentResolver();
	}

	if (cr == null) {
	Log.w(TAG, "Could not read from " + settings + "; hardcoding " + defaultValue);
	return defaultValue;
	}
	return Settings.Secure.getInt(cr, settings, defaultValue);
	}
	}