kopia lustrzana https://github.com/onthegomap/planetiler
126 wiersze
3.6 KiB
Java
126 wiersze
3.6 KiB
Java
/*
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Copyright 2014 The Bazel Authors. All rights reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package com.onthegomap.planetiler.util;
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import java.io.IOException;
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import java.io.OutputStream;
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import java.nio.ByteBuffer;
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/**
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* Encode and decode Protocol Buffer-style VarInts.
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* <p>
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* getVarLong and putVarLong are adapted from <a href=
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* "https://github.com/bazelbuild/bazel/blob/master/src/main/java/com/google/devtools/build/lib/util/VarInt.java">Bazel</a>.
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*/
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public class VarInt {
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private VarInt() {}
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public static int varLongSize(long v) {
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int result = 0;
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do {
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result++;
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v >>>= 7;
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} while (v != 0);
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return result;
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}
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/**
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* Reads an up to 64 bit long varint from the current position of the given ByteBuffer and returns the decoded value
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* as long.
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*
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* <p>
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* The position of the buffer is advanced to the first byte after the decoded varint.
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*
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* @param src the ByteBuffer to get the var int from
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* @return The integer value of the decoded long varint
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*/
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public static long getVarLong(ByteBuffer src) {
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long tmp;
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if ((tmp = src.get()) >= 0) {
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return tmp;
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}
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long result = tmp & 0x7f;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 7;
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} else {
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result |= (tmp & 0x7f) << 7;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 14;
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} else {
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result |= (tmp & 0x7f) << 14;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 21;
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} else {
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result |= (tmp & 0x7f) << 21;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 28;
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} else {
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result |= (tmp & 0x7f) << 28;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 35;
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} else {
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result |= (tmp & 0x7f) << 35;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 42;
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} else {
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result |= (tmp & 0x7f) << 42;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 49;
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} else {
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result |= (tmp & 0x7f) << 49;
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if ((tmp = src.get()) >= 0) {
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result |= tmp << 56;
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} else {
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result |= (tmp & 0x7f) << 56;
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result |= ((long) src.get()) << 63;
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}
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}
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}
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}
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}
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}
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}
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}
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return result;
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}
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public static void putVarLong(long v, ByteBuffer sink) {
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while (true) {
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int bits = ((int) v) & 0x7f;
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v >>>= 7;
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if (v == 0) {
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sink.put((byte) bits);
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return;
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}
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sink.put((byte) (bits | 0x80));
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}
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}
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/**
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* Encodes a long integer in a variable-length encoding, 7 bits per byte.
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*
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* @param v the value to encode
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* @param outputStream the OutputStream to add the encoded value
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*/
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public static void putVarLong(long v, OutputStream outputStream) throws IOException {
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byte[] bytes = new byte[varLongSize(v)];
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ByteBuffer sink = ByteBuffer.wrap(bytes);
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putVarLong(v, sink);
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outputStream.write(bytes);
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}
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}
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