1 files changed, 141 insertions, 0 deletions
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/ServiceUtils.java b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/ServiceUtils.java
new file mode 100644
index 0000000000..695c69666b
--- /dev/null
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/gecko/process/ServiceUtils.java
@@ -0,0 +1,141 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.process;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.ServiceInfo;
+import androidx.annotation.NonNull;
+
+/* package */ final class ServiceUtils {
+  private static final String DEFAULT_ISOLATED_CONTENT_SERVICE_NAME_SUFFIX = "0";
+
+  private ServiceUtils() {}
+
+  /**
+   * @return StringBuilder containing the name of a service class but not qualifed with any unique
+   *     identifiers.
+   */
+  private static StringBuilder startSvcName(@NonNull final GeckoProcessType type) {
+    final StringBuilder builder = new StringBuilder(GeckoChildProcessServices.class.getName());
+    builder.append("$").append(type);
+    return builder;
+  }
+
+  /**
+   * Given a service's GeckoProcessType, obtain the name of its class, including any qualifiers that
+   * are needed to uniquely identify its manifest definition.
+   */
+  public static String buildSvcName(
+      @NonNull final GeckoProcessType type, final String... suffixes) {
+    final StringBuilder builder = startSvcName(type);
+
+    for (final String suffix : suffixes) {
+      builder.append(suffix);
+    }
+
+    return builder.toString();
+  }
+
+  /**
+   * Given a service's GeckoProcessType, obtain the name of its class to be used for the purpose of
+   * binding as an isolated service.
+   *
+   * <p>Content services are defined in the manifest as "tab0" through "tabN" for some value of N.
+   * For the purposes of binding to an isolated content service, we simply need to repeatedly re-use
+   * the definition of "tab0", the "0" being stored as the
+   * DEFAULT_ISOLATED_CONTENT_SERVICE_NAME_SUFFIX constant.
+   */
+  public static String buildIsolatedSvcName(@NonNull final GeckoProcessType type) {
+    if (type == GeckoProcessType.CONTENT) {
+      return buildSvcName(type, DEFAULT_ISOLATED_CONTENT_SERVICE_NAME_SUFFIX);
+    }
+
+    // Non-content services do not require any unique IDs
+    return buildSvcName(type);
+  }
+
+  /**
+   * Given a service's GeckoProcessType, obtain the unqualified name of its class.
+   *
+   * @return The name of the class that hosts the implementation of the service corresponding to
+   *     type, but without any unique identifiers that may be required to actually instantiate it.
+   */
+  private static String buildSvcNamePrefix(@NonNull final GeckoProcessType type) {
+    return startSvcName(type).toString();
+  }
+
+  /**
+   * Extracts flags from the manifest definition of a service.
+   *
+   * @param context Context to use for extraction
+   * @param type Service type
+   * @return flags that are specified in the service's definition in our manifest.
+   * @see android.content.pm.ServiceInfo for explanation of the various flags.
+   */
+  public static int getServiceFlags(
+      @NonNull final Context context, @NonNull final GeckoProcessType type) {
+    final ComponentName component = new ComponentName(context, buildIsolatedSvcName(type));
+    final PackageManager pkgMgr = context.getPackageManager();
+
+    try {
+      final ServiceInfo svcInfo = pkgMgr.getServiceInfo(component, 0);
+      // svcInfo is never null
+      return svcInfo.flags;
+    } catch (final PackageManager.NameNotFoundException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  /** Obtain the list of all services defined for |context|. */
+  private static ServiceInfo[] getServiceList(@NonNull final Context context) {
+    final PackageInfo packageInfo;
+    try {
+      packageInfo =
+          context
+              .getPackageManager()
+              .getPackageInfo(context.getPackageName(), PackageManager.GET_SERVICES);
+    } catch (final PackageManager.NameNotFoundException e) {
+      throw new AssertionError("Should not happen: Can't get package info of own package");
+    }
+    return packageInfo.services;
+  }
+
+  /**
+   * Count the number of service definitions in our manifest that satisfy bindings for a particular
+   * service type.
+   *
+   * @param context Context object to use for extracting the service definitions
+   * @param type The type of service to count
+   * @return The number of available service definitions.
+   */
+  public static int getServiceCount(
+      @NonNull final Context context, @NonNull final GeckoProcessType type) {
+    final ServiceInfo[] svcList = getServiceList(context);
+    final String serviceNamePrefix = buildSvcNamePrefix(type);
+
+    int result = 0;
+    for (final ServiceInfo svc : svcList) {
+      final String svcName = svc.name;
+      // If svcName starts with serviceNamePrefix, then both strings must either be equal
+      // or else the first subsequent character in svcName must be a digit.
+      // This guards against any future GeckoProcessType whose string representation shares
+      // a common prefix with another GeckoProcessType value.
+      if (svcName.startsWith(serviceNamePrefix)
+          && (svcName.length() == serviceNamePrefix.length()
+              || Character.isDigit(svcName.codePointAt(serviceNamePrefix.length())))) {
+        ++result;
+      }
+    }
+
+    if (result <= 0) {
+      throw new RuntimeException("Could not count " + serviceNamePrefix + " services in manifest");
+    }
+
+    return result;
+  }
+}