jdk/src/java.httpclient/share/classes/sun/net/httpclient/hpack/IntegerReader.java
--- a/jdk/src/java.httpclient/share/classes/sun/net/httpclient/hpack/IntegerReader.java Thu Dec 08 21:22:02 2016 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,142 +0,0 @@
-/*
- * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation. Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-package sun.net.httpclient.hpack;
-
-import java.nio.ByteBuffer;
-import java.util.Arrays;
-
-import static java.lang.String.format;
-
-final class IntegerReader {
-
- private static final int NEW = 0;
- private static final int CONFIGURED = 1;
- private static final int FIRST_BYTE_READ = 2;
- private static final int DONE = 4;
-
- private int state = NEW;
-
- private int N;
- private int maxValue;
- private int value;
- private long r;
- private long b = 1;
-
- public IntegerReader configure(int N) {
- return configure(N, Integer.MAX_VALUE);
- }
-
- //
- // Why is it important to configure 'maxValue' here. After all we can wait
- // for the integer to be fully read and then check it. Can't we?
- //
- // Two reasons.
- //
- // 1. Value wraps around long won't be unnoticed.
- // 2. It can spit out an exception as soon as it becomes clear there's
- // an overflow. Therefore, no need to wait for the value to be fully read.
- //
- public IntegerReader configure(int N, int maxValue) {
- if (state != NEW) {
- throw new IllegalStateException("Already configured");
- }
- checkPrefix(N);
- if (maxValue < 0) {
- throw new IllegalArgumentException(
- "maxValue >= 0: maxValue=" + maxValue);
- }
- this.maxValue = maxValue;
- this.N = N;
- state = CONFIGURED;
- return this;
- }
-
- public boolean read(ByteBuffer input) {
- if (state == NEW) {
- throw new IllegalStateException("Configure first");
- }
- if (state == DONE) {
- return true;
- }
- if (!input.hasRemaining()) {
- return false;
- }
- if (state == CONFIGURED) {
- int max = (2 << (N - 1)) - 1;
- int n = input.get() & max;
- if (n != max) {
- value = n;
- state = DONE;
- return true;
- } else {
- r = max;
- }
- state = FIRST_BYTE_READ;
- }
- if (state == FIRST_BYTE_READ) {
- // variable-length quantity (VLQ)
- byte i;
- do {
- if (!input.hasRemaining()) {
- return false;
- }
- i = input.get();
- long increment = b * (i & 127);
- if (r + increment > maxValue) {
- throw new IllegalArgumentException(format(
- "Integer overflow: maxValue=%,d, value=%,d",
- maxValue, r + increment));
- }
- r += increment;
- b *= 128;
- } while ((128 & i) == 128);
-
- value = (int) r;
- state = DONE;
- return true;
- }
- throw new InternalError(Arrays.toString(
- new Object[]{state, N, maxValue, value, r, b}));
- }
-
- public int get() throws IllegalStateException {
- if (state != DONE) {
- throw new IllegalStateException("Has not been fully read yet");
- }
- return value;
- }
-
- private static void checkPrefix(int N) {
- if (N < 1 || N > 8) {
- throw new IllegalArgumentException("1 <= N <= 8: N= " + N);
- }
- }
-
- public IntegerReader reset() {
- b = 1;
- state = NEW;
- return this;
- }
-}