Move ConfigurationRegistry into shadowsapi

PiperOrigin-RevId: 239449649

1 files changed, 64 insertions, 0 deletions

diff --git a/shadowapi/src/main/java/org/robolectric/config/ConfigurationRegistry.java b/shadowapi/src/main/java/org/robolectric/config/ConfigurationRegistry.java
new file mode 100644
index 000000000..7291416c4
--- /dev/null
+++ b/shadowapi/src/main/java/org/robolectric/config/ConfigurationRegistry.java
@@ -0,0 +1,64 @@
+package org.robolectric.config;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Holds configuration objects for the current test, computed using
+ * {@link Configurer}.
+ *
+ * Configuration is computed before tests run, outside of their sandboxes. If the configuration
+ * is needed from within a sandbox (when a test is executing), we need to transfer it to a class
+ * that the SandboxClassLoader recognizes. We do this by serializing and deserializing in
+ * {@link #reloadInSandboxClassLoader(Object)}.
+ */
+public class ConfigurationRegistry {
+
+  public static ConfigurationRegistry instance;
+
+  /**
+   * Returns the configuration object of the specified class, computed using
+   * {@link Configurer}.
+   */
+  public static <T> T get(Class<T> configClass) {
+    return instance.getInSandboxClassLoader(configClass);
+  }
+
+  private final Map<String, Object> configurations = new HashMap<>();
+
+  public ConfigurationRegistry(Map<Class<?>, Object> configClassMap) {
+    for (Class<?> classInParentLoader : configClassMap.keySet()) {
+      Object configInParentLoader = configClassMap.get(classInParentLoader);
+      configurations.put(classInParentLoader.getName(), configInParentLoader);
+    }
+  }
+
+  private <T> T getInSandboxClassLoader(Class<T> someConfigClass) {
+    Object configInParentLoader = configurations.get(someConfigClass.getName());
+    Object configInSandboxLoader = reloadInSandboxClassLoader(configInParentLoader);
+    return someConfigClass.cast(configInSandboxLoader);
+  }
+
+  private static Object reloadInSandboxClassLoader(Object configInParentLoader) {
+    ByteArrayOutputStream buf = new ByteArrayOutputStream();
+    try (ObjectOutputStream out = new ObjectOutputStream(buf)) {
+      out.writeObject(configInParentLoader);
+    } catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+
+    byte[] bytes = buf.toByteArray();
+
+    // ObjectInputStream loads classes in the current classloader by magic
+    try (ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(bytes))) {
+      return in.readObject();
+    } catch (IOException | ClassNotFoundException e) {
+      throw new RuntimeException(e);
+    }
+  }
+}