--- /dev/null
+/*
+ * 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.util;
+
+import java.util.Arrays;
+
+/**
+ * Simple (mostly) fixed-size list of objects, which may be made immutable.
+ */
+public class FixedSizeList
+ extends MutabilityControl implements ToHuman {
+ /** {@code non-null;} array of elements */
+ private Object[] arr;
+
+ /**
+ * Constructs an instance. All indices initially contain {@code null}.
+ *
+ * @param size the size of the list
+ */
+ public FixedSizeList(int size) {
+ super(size != 0);
+
+ try {
+ arr = new Object[size];
+ } catch (NegativeArraySizeException ex) {
+ // Translate the exception.
+ throw new IllegalArgumentException("size < 0");
+ }
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public boolean equals(Object other) {
+ if (this == other) {
+ // Easy out.
+ return true;
+ }
+
+ if ((other == null) || (getClass() != other.getClass())) {
+ // Another easy out.
+ return false;
+ }
+
+ FixedSizeList list = (FixedSizeList) other;
+ return Arrays.equals(arr, list.arr);
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public int hashCode() {
+ return Arrays.hashCode(arr);
+ }
+
+ /** {@inheritDoc} */
+ @Override
+ public String toString() {
+ String name = getClass().getName();
+
+ return toString0(name.substring(name.lastIndexOf('.') + 1) + '{',
+ ", ",
+ "}",
+ false);
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * This method will only work if every element of the list
+ * implements {@link ToHuman}.
+ */
+ public String toHuman() {
+ String name = getClass().getName();
+
+ return toString0(name.substring(name.lastIndexOf('.') + 1) + '{',
+ ", ",
+ "}",
+ true);
+ }
+
+ /**
+ * Gets a customized string form for this instance.
+ *
+ * @param prefix {@code null-ok;} prefix for the start of the result
+ * @param separator {@code null-ok;} separator to insert between each item
+ * @param suffix {@code null-ok;} suffix for the end of the result
+ * @return {@code non-null;} the custom string
+ */
+ public String toString(String prefix, String separator, String suffix) {
+ return toString0(prefix, separator, suffix, false);
+ }
+
+ /**
+ * Gets a customized human string for this instance. This method will
+ * only work if every element of the list implements {@link
+ * ToHuman}.
+ *
+ * @param prefix {@code null-ok;} prefix for the start of the result
+ * @param separator {@code null-ok;} separator to insert between each item
+ * @param suffix {@code null-ok;} suffix for the end of the result
+ * @return {@code non-null;} the custom string
+ */
+ public String toHuman(String prefix, String separator, String suffix) {
+ return toString0(prefix, separator, suffix, true);
+ }
+
+ /**
+ * Gets the number of elements in this list.
+ */
+ public final int size() {
+ return arr.length;
+ }
+
+ /**
+ * Shrinks this instance to fit, by removing any unset
+ * ({@code null}) elements, leaving the remaining elements in
+ * their original order.
+ */
+ public void shrinkToFit() {
+ int sz = arr.length;
+ int newSz = 0;
+
+ for (int i = 0; i < sz; i++) {
+ if (arr[i] != null) {
+ newSz++;
+ }
+ }
+
+ if (sz == newSz) {
+ return;
+ }
+
+ throwIfImmutable();
+
+ Object[] newa = new Object[newSz];
+ int at = 0;
+
+ for (int i = 0; i < sz; i++) {
+ Object one = arr[i];
+ if (one != null) {
+ newa[at] = one;
+ at++;
+ }
+ }
+
+ arr = newa;
+ if (newSz == 0) {
+ setImmutable();
+ }
+ }
+
+ /**
+ * Gets the indicated element. It is an error to call this with the
+ * index for an element which was never set; if you do that, this
+ * will throw {@code NullPointerException}. This method is
+ * protected so that subclasses may offer a safe type-checked
+ * public interface to their clients.
+ *
+ * @param n {@code >= 0, < size();} which element
+ * @return {@code non-null;} the indicated element
+ */
+ protected final Object get0(int n) {
+ try {
+ Object result = arr[n];
+
+ if (result == null) {
+ throw new NullPointerException("unset: " + n);
+ }
+
+ return result;
+ } catch (ArrayIndexOutOfBoundsException ex) {
+ // Translate the exception.
+ return throwIndex(n);
+ }
+ }
+
+ /**
+ * Gets the indicated element, allowing {@code null}s to be
+ * returned. This method is protected so that subclasses may
+ * (optionally) offer a safe type-checked public interface to
+ * their clients.
+ *
+ * @param n {@code >= 0, < size();} which element
+ * @return {@code null-ok;} the indicated element
+ */
+ protected final Object getOrNull0(int n) {
+ return arr[n];
+ }
+
+ /**
+ * Sets the element at the given index, but without doing any type
+ * checks on the element. This method is protected so that
+ * subclasses may offer a safe type-checked public interface to
+ * their clients.
+ *
+ * @param n {@code >= 0, < size();} which element
+ * @param obj {@code null-ok;} the value to store
+ */
+ protected final void set0(int n, Object obj) {
+ throwIfImmutable();
+
+ try {
+ arr[n] = obj;
+ } catch (ArrayIndexOutOfBoundsException ex) {
+ // Translate the exception.
+ throwIndex(n);
+ }
+ }
+
+ /**
+ * Throws the appropriate exception for the given index value.
+ *
+ * @param n the index value
+ * @return never
+ * @throws IndexOutOfBoundsException always thrown
+ */
+ private Object throwIndex(int n) {
+ if (n < 0) {
+ throw new IndexOutOfBoundsException("n < 0");
+ }
+
+ throw new IndexOutOfBoundsException("n >= size()");
+ }
+
+ /**
+ * Helper for {@link #toString} and {@link #toHuman}, which both of
+ * those call to pretty much do everything.
+ *
+ * @param prefix {@code null-ok;} prefix for the start of the result
+ * @param separator {@code null-ok;} separator to insert between each item
+ * @param suffix {@code null-ok;} suffix for the end of the result
+ * @param human whether the output is to be human
+ * @return {@code non-null;} the custom string
+ */
+ private String toString0(String prefix, String separator, String suffix,
+ boolean human) {
+ int len = arr.length;
+ StringBuffer sb = new StringBuffer(len * 10 + 10);
+
+ if (prefix != null) {
+ sb.append(prefix);
+ }
+
+ for (int i = 0; i < len; i++) {
+ if ((i != 0) && (separator != null)) {
+ sb.append(separator);
+ }
+
+ if (human) {
+ sb.append(((ToHuman) arr[i]).toHuman());
+ } else {
+ sb.append(arr[i]);
+ }
+ }
+
+ if (suffix != null) {
+ sb.append(suffix);
+ }
+
+ return sb.toString();
+ }
+
+}
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