Add OrCodec

Change-Id: I624f82f169564017d5dbbaf3b47d96715917449c

1 files changed, 104 insertions, 0 deletions

diff --git a/sched/src/com/android/sched/util/codec/OrCodec.java b/sched/src/com/android/sched/util/codec/OrCodec.java
new file mode 100644
index 00000000..c1789a1b
--- /dev/null
+++ b/sched/src/com/android/sched/util/codec/OrCodec.java
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2015 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.sched.util.codec;
+
+import com.android.sched.util.config.ConfigurationError;
+
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+
+import javax.annotation.CheckForNull;
+import javax.annotation.Nonnull;
+
+/**
+ * This {@link StringCodec} tries successively several {@link StringCodec}s until one is successful.
+ *
+ * @param <T> Element type
+ */
+public class OrCodec<T> implements StringCodec<T> {
+  @Nonnull
+  private final List<StringCodec<? extends T>> codecList;
+
+  public OrCodec(@Nonnull List<StringCodec<? extends T>> codecList) {
+    assert codecList.size() >= 1;
+    this.codecList = codecList;
+  }
+
+  @Override
+  @Nonnull
+  public T parseString(@Nonnull CodecContext context, @Nonnull String string) {
+    try {
+      return checkString(context, string);
+    } catch (ParsingException e) {
+      throw new ConfigurationError(e);
+    }
+  }
+
+  @Override
+  @CheckForNull
+  public T checkString(@Nonnull CodecContext context, @Nonnull String string)
+      throws ParsingException  {
+    for (StringCodec<? extends T> codec : codecList) {
+      try {
+        return codec.checkString(context, string);
+      } catch (ParsingException e) {
+        // try next codec
+      }
+    }
+    return codecList.get(0).checkString(context, string);
+  }
+
+  @Override
+  public void checkValue(@Nonnull CodecContext context, @Nonnull T data) {
+  }
+
+  @Override
+  @Nonnull
+  public String getUsage() {
+    StringBuffer usage = new StringBuffer();
+    Iterator<StringCodec<? extends T>> codecListIterator = codecList.iterator();
+    while (codecListIterator.hasNext()) {
+      usage.append(codecListIterator.next().getUsage());
+      if (codecListIterator.hasNext()) {
+        usage.append(" or ");
+      }
+    }
+    return usage.toString();
+  }
+
+  @Override
+  @Nonnull
+  public List<ValueDescription> getValueDescriptions() {
+    return Collections.<ValueDescription> emptyList();
+  }
+
+  @SuppressWarnings("unchecked")
+  @Override
+  @Nonnull
+  public String formatValue(@Nonnull T data) {
+    //STOPSHIP: rework?
+    for (StringCodec<? extends T> codec : codecList) {
+      try {
+        return ((StringCodec<T>) codec).formatValue(data);
+      } catch (ClassCastException e) {
+        // try next codec
+      }
+    }
+    throw new AssertionError();
+  }
+}
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