1 files changed, 70 insertions, 0 deletions
diff --git a/dexgen/src/com/android/dexgen/rop/cst/ConstantPool.java b/dexgen/src/com/android/dexgen/rop/cst/ConstantPool.java
new file mode 100644
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--- /dev/null
+++ b/dexgen/src/com/android/dexgen/rop/cst/ConstantPool.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2007 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.dexgen.rop.cst;
+
+/**
+ * Interface for constant pools, which are, more or less, just lists of
+ * {@link Constant} objects.
+ */
+public interface ConstantPool {
+    /**
+     * Get the "size" of the constant pool. This corresponds to the
+     * class file field {@code constant_pool_count}, and is in fact
+     * always at least one more than the actual size of the constant pool,
+     * as element {@code 0} is always invalid.
+     *
+     * @return {@code >= 1;} the size
+     */
+    public int size();
+
+    /**
+     * Get the {@code n}th entry in the constant pool, which must
+     * be valid.
+     *
+     * @param n {@code n >= 0, n < size();} the constant pool index
+     * @return {@code non-null;} the corresponding entry
+     * @throws IllegalArgumentException thrown if {@code n} is
+     * in-range but invalid
+     */
+    public Constant get(int n);
+
+    /**
+     * Get the {@code n}th entry in the constant pool, which must
+     * be valid unless {@code n == 0}, in which case {@code null}
+     * is returned.
+     *
+     * @param n {@code n >= 0, n < size();} the constant pool index
+     * @return {@code null-ok;} the corresponding entry, if {@code n != 0}
+     * @throws IllegalArgumentException thrown if {@code n} is
+     * in-range and non-zero but invalid
+     */
+    public Constant get0Ok(int n);
+
+    /**
+     * Get the {@code n}th entry in the constant pool, or
+     * {@code null} if the index is in-range but invalid. In
+     * particular, {@code null} is returned for index {@code 0}
+     * as well as the index after any entry which is defined to take up
+     * two slots (that is, {@code Long} and {@code Double}
+     * entries).
+     *
+     * @param n {@code n >= 0, n < size();} the constant pool index
+     * @return {@code null-ok;} the corresponding entry, or {@code null} if
+     * the index is in-range but invalid
+     */
+    public Constant getOrNull(int n);
+}