Adding Util class for FIrebaseInstallations APIs.

firebase-installations-interop/src/main/java/com/google/firebase/installations/InstallationTokenResult.java

@@ -21,12 +21,12 @@
 @AutoValue
 public abstract class InstallationTokenResult {
 
-  /** A new FIS Auth-Token, created for this firebase installation. */
+  /** A new FIS Auth-Token, created for this Firebase Installation. */
   @NonNull
-  public abstract String getAuthToken();
+  public abstract String getToken();
   /**
-   * The amount of time, in milliseconds, before the auth-token expires for this firebase
-   * installation.
+   * The amount of time, in milliseconds, before the auth-token expires for this Firebase
+   * Installation.
    */
   @NonNull
   public abstract long getTokenExpirationTimestampMillis();
@@ -43,7 +43,7 @@ public static InstallationTokenResult.Builder builder() {
   @AutoValue.Builder
   public abstract static class Builder {
     @NonNull
-    public abstract Builder setAuthToken(@NonNull String value);
+    public abstract Builder setToken(@NonNull String value);
 
     @NonNull
     public abstract Builder setTokenExpirationTimestampMillis(@NonNull long value);

firebase-installations/src/androidTest/AndroidManifest.xml

@@ -14,7 +14,7 @@
 <!-- limitations under the License. -->
 
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="com.google.firebase.installation">
+    package="com.google.firebase.installations">
 
     <application>
         <uses-library android:name="android.test.runner"/>

firebase-installations/src/androidTest/java/com/google/firebase/installations/FirebaseInstallationsInstrumentedTest.java

@@ -0,0 +1,29 @@
+// Copyright 2019 Google LLC
+//
+// 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.google.firebase.installations;
+
+import androidx.test.runner.AndroidJUnit4;
+import org.junit.FixMethodOrder;
+import org.junit.runner.RunWith;
+import org.junit.runners.MethodSorters;
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * @see <a href="http://d.android.com/tools/testing">Testing documentation</a>
+ */
+@RunWith(AndroidJUnit4.class)
+@FixMethodOrder(MethodSorters.NAME_ASCENDING)
+public class FirebaseInstallationsInstrumentedTest {}

firebase-installations/src/androidTest/java/com/google/firebase/installation/local/FiidCacheTest.java → firebase-installations/src/androidTest/java/com/google/firebase/installations/local/FiidCacheTest.java

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package com.google.firebase.installation.local;
+package com.google.firebase.installations.local;
 
 import static com.google.common.truth.Truth.assertThat;
 import static org.junit.Assert.assertNull;
@@ -22,8 +22,6 @@
 import androidx.test.runner.AndroidJUnit4;
 import com.google.firebase.FirebaseApp;
 import com.google.firebase.FirebaseOptions;
-import com.google.firebase.installations.local.FiidCache;
-import com.google.firebase.installations.local.FiidCacheEntryValue;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

firebase-installations/src/main/AndroidManifest.xml

@@ -11,4 +11,7 @@
                 android:value="com.google.firebase.components.ComponentRegistrar" />
         </service>
     </application>
+
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+    <uses-permission android:name="android.permission.INTERNET" />
 </manifest>

firebase-installations/src/main/java/com/google/firebase/installations/FirebaseInstallationsException.java

@@ -0,0 +1,56 @@
+// Copyright 2019 Google LLC
+//
+// 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.google.firebase.installations;
+
+import androidx.annotation.NonNull;
+import com.google.firebase.FirebaseException;
+
+/** The class for all Exceptions thrown by {@link FirebaseInstallations}. */
+public class FirebaseInstallationsException extends FirebaseException {
+
+  // TODO(ankitagj): Improve clear exception handling.
+  public enum Status {
+    SDK_INTERNAL_ERROR,
+
+    CLIENT_ERROR
+  }
+
+  @NonNull private final Status status;
+
+  public FirebaseInstallationsException(@NonNull Status status) {
+    this.status = status;
+  }
+
+  public FirebaseInstallationsException(@NonNull String message, @NonNull Status status) {
+    super(message);
+    this.status = status;
+  }
+
+  public FirebaseInstallationsException(
+      @NonNull String message, @NonNull Status status, @NonNull Throwable cause) {
+    super(message, cause);
+    this.status = status;
+  }
+
+  /**
+   * Gets the status for the operation that failed.
+   *
+   * @return the status for the FirebaseInstallationsException
+   */
+  @NonNull
+  public Status getStatus() {
+    return status;
+  }
+}

firebase-installations/src/main/java/com/google/firebase/installations/Utils.java

@@ -0,0 +1,95 @@
+// Copyright 2019 Google LLC
+//
+// 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.google.firebase.installations;
+
+import androidx.annotation.NonNull;
+import java.nio.ByteBuffer;
+import java.nio.charset.Charset;
+import java.util.UUID;
+
+/** Util methods used for {@link FirebaseInstallations} */
+class Utils {
+
+  /**
+   * 1 Byte with the first 4 header-bits set to the identifying FID prefix 0111 (0x7). Use this
+   * constant to create FIDs or check the first byte of FIDs. This prefix is also used in legacy
+   * Instance-IDs
+   */
+  public static final byte FID_4BIT_PREFIX = Byte.parseByte("01110000", 2);
+
+  /**
+   * Byte mask to remove the 4 header-bits of a given Byte. Use this constant with Java's Binary AND
+   * Operator in order to remove the first 4 bits of a Byte and replacing it with the FID prefix.
+   */
+  public static final byte REMOVE_PREFIX_MASK = Byte.parseByte("00001111", 2);
+
+  /** Length of new-format FIDs as introduced in 2019. */
+  public static final int FID_LENGTH = 22;
+
+  /**
+   * Creates a random FID of valid format without checking if the FID is already in use by any
+   * Firebase Installation.
+   *
+   * <p>Note: Even though this method does not check with the FIS database if the returned FID is
+   * already in use, the probability of collision is extremely and negligibly small!
+   *
+   * @return random FID value
+   */
+  @NonNull
+  public static String createRandomFid() {
+    // A valid FID has exactly 22 base64 characters, which is 132 bits, or 16.5 bytes.
+    byte[] uuidBytes = getBytesFromUUID(UUID.randomUUID());
+    return encodeFidBase64UrlSafe(uuidBytes);
+  }
+
+  /**
+   * Converts a given byte-array (assumed to be an FID value) to base64-url-safe encoded
+   * String-representation.
+   *
+   * <p>Note: The returned String has at most 22 characters, the length of FIDs. Thus, it is
+   * recommended to deliver a byte-array containing at least 16.5 bytes.
+   *
+   * @param rawValue FID value to be encoded
+   * @return (22-character or shorter) String containing the base64-encoded value
+   */
+  private static String encodeFidBase64UrlSafe(byte[] rawValue) {
+    return new String(
+            android.util.Base64.encode(
+                rawValue,
+                android.util.Base64.URL_SAFE
+                    | android.util.Base64.NO_PADDING
+                    | android.util.Base64.NO_WRAP),
+            Charset.defaultCharset())
+        .substring(0, FID_LENGTH);
+  }
+
+  private static byte[] getBytesFromUUID(UUID uuid) {
+    ByteBuffer bb = ByteBuffer.wrap(new byte[17]);
+
+    // The first 4 bits with the constant FID header of 0x7 (0b0111) followed by the last 4 random
+    // bits of the UUID.
+    byte fidPrefixWithLast4bitsOfUUID =
+        (byte)
+            (FID_4BIT_PREFIX
+                | (ByteBuffer.allocate(8).putLong(uuid.getLeastSignificantBits()).array()[7]
+                    & REMOVE_PREFIX_MASK));
+
+    bb.put(fidPrefixWithLast4bitsOfUUID);
+    bb.putLong(uuid.getMostSignificantBits());
+    bb.putLong(uuid.getLeastSignificantBits());
+
+    return bb.array();
+  }
+}