Differential D4006 Diff 19063 java/src/main/java/org/softwareheritage/graph/labels/FixedWidthLongListLabel.java

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java/src/main/java/org/softwareheritage/graph/labels/FixedWidthLongListLabel.java

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				// TODO: should be in webgraph upstream
				// package it.unimi.dsi.big.webgraph.labelling;
				package org.softwareheritage.graph.labels;

				/*
				* Copyright (C) 2020 TODO
				*
				* This program is free software; you can redistribute it and/or modify it
				* under the terms of the GNU General Public License as published by the Free
				* Software Foundation; either version 3 of the License, or (at your option)
				* any later version.
				*
				* This program 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
				* for more details.
				*
				* You should have received a copy of the GNU General Public License
				* along with this program; if not, see <http://www.gnu.org/licenses/>.
				*
				*/


				import it.unimi.dsi.big.webgraph.labelling.Label;
				import it.unimi.dsi.fastutil.longs.LongArrays;
				import it.unimi.dsi.io.InputBitStream;
				import it.unimi.dsi.io.OutputBitStream;

				import java.io.IOException;
				import java.util.Arrays;

				/** A list of longs represented in fixed width. Each list is prefixed by its
				* length written in {@linkplain OutputBitStream#writeGamma(int) γ
				* coding}.
				*/

				public class FixedWidthLongListLabel extends org.softwareheritage.graph.labels.AbstractLongListLabel {
				/** The bit width used to represent the value of this label. */
				private final int width;

				/** Creates a new fixed-width long label.
				*
				* @param key the (only) key of this label.
				* @param width the label width (in bits).
				* @param value the value of this label.
				*/
				public FixedWidthLongListLabel(String key, int width, long[] value) {
				super(key, value);
				for(int i = value.length; i-- != 0;) if (value[i] < 0 \|\| value[i] >= 1L << width) throw new IllegalArgumentException("Value out of range: " + Long.toString(value[i]));
				this.width = width;
				}

				/** Creates a new fixed-width label with an empty list.
				*
				* @param key the (only) key of this label.
				* @param width the label width (in bits).
				*/
				public FixedWidthLongListLabel(String key, int width) {
				this(key, width, LongArrays.EMPTY_ARRAY);
				}

				/** Creates a new fixed-width long label using the given key and width
				* with an empty list.
				*
				* @param arg two strings containing the key and the width of this label.
				*/
				public FixedWidthLongListLabel(String... arg) {
				this(arg[0], Integer.parseInt(arg[1]));
				}

				@Override
				public Label copy() {
				return new FixedWidthLongListLabel(key, width, value.clone());
				}

				@Override
				public int fromBitStream(InputBitStream inputBitStream, final long sourceUnused) throws IOException {
				long readBits = inputBitStream.readBits();
				value = new long[inputBitStream.readGamma()];
				for(int i = 0; i < value.length; i++) value[i] = inputBitStream.readLong(width);
				return (int)(inputBitStream.readBits() - readBits);
				}

				@Override
				public int toBitStream(OutputBitStream outputBitStream, final long sourceUnused) throws IOException {
				int bits = outputBitStream.writeGamma(value.length);
				for(int i = 0; i < value.length; i++) bits += outputBitStream.writeLong(value[i], width);
				return bits;
				}

				/** Returns -1 (the fixed width refers to a single long, not to the entire list).
				* @return -1;
				*/
				@Override
				public int fixedWidth() {
				return -1;
				}

				@Override
				public String toString() {
				return key + ":" + Arrays.toString(value) + " (width:" + width + ")";
				}

				@Override
				public String toSpec() {
				return this.getClass().getName() + "(" + key + "," + width + ")";
				}
				}