74 lines
2.9 KiB
Java
74 lines
2.9 KiB
Java
/*
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* Copyright 2021 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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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, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.handler.codec.compression;
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import io.netty.util.internal.ObjectUtil;
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/**
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* {@link DeflateOptions} holds {@link #compressionLevel()},
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* {@link #memLevel()} and {@link #windowBits()} for Deflate compression.
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*/
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public class DeflateOptions implements CompressionOptions {
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private final int compressionLevel;
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private final int windowBits;
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private final int memLevel;
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/**
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* Default implementation of {@link DeflateOptions} with
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* {@link #compressionLevel} set to 6, {@link #windowBits} set to 15
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* and {@link #memLevel} set to 8.
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*/
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static final DeflateOptions DEFAULT = new DeflateOptions(
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6, 15, 8
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);
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/**
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* Create a new {@link DeflateOptions} Instance
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*
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* @param compressionLevel {@code 1} yields the fastest compression and {@code 9} yields the
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* best compression. {@code 0} means no compression. The default
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* compression level is {@code 6}.
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*
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* @param windowBits The base two logarithm of the size of the history buffer. The
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* value should be in the range {@code 9} to {@code 15} inclusive.
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* Larger values result in better compression at the expense of
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* memory usage. The default value is {@code 15}.
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*
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* @param memLevel How much memory should be allocated for the internal compression
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* state. {@code 1} uses minimum memory and {@code 9} uses maximum
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* memory. Larger values result in better and faster compression
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* at the expense of memory usage. The default value is {@code 8}
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*/
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DeflateOptions(int compressionLevel, int windowBits, int memLevel) {
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this.compressionLevel = ObjectUtil.checkInRange(compressionLevel, 0, 9, "compressionLevel");
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this.windowBits = ObjectUtil.checkInRange(windowBits, 9, 15, "windowBits");
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this.memLevel = ObjectUtil.checkInRange(memLevel, 1, 9, "memLevel");
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}
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public int compressionLevel() {
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return compressionLevel;
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}
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public int windowBits() {
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return windowBits;
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}
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public int memLevel() {
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return memLevel;
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}
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}
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