improved artsiomkorzun solution (#176)
improved artsiomkorzun solution improved artsiomkorzun solution Co-authored-by: Artsiom Korzun <akorzun@deltixlab.com>
This commit is contained in:
Artsiom Korzun
GitHub
parent
085168a0b3
commit
8602a35504
@ -15,5 +15,5 @@
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# limitations under the License.
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#
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JAVA_OPTS="-XX:+UseParallelGC"
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JAVA_OPTS="--enable-preview -Xmx128m -XX:+UseSerialGC"
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java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_artsiomkorzun
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@ -15,28 +15,46 @@
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*/
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package dev.morling.onebrc;
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import java.io.IOException;
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import java.nio.ByteBuffer;
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import java.nio.MappedByteBuffer;
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import sun.misc.Unsafe;
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import java.lang.foreign.Arena;
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import java.lang.foreign.MemorySegment;
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import java.lang.reflect.Field;
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import java.nio.ByteOrder;
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import java.nio.channels.FileChannel;
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import java.nio.file.Files;
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import java.nio.file.Path;
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import java.nio.file.StandardOpenOption;
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import java.util.Arrays;
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import java.util.Comparator;
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import java.util.Map;
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import java.util.TreeMap;
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import java.util.concurrent.atomic.AtomicInteger;
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import java.util.concurrent.atomic.AtomicReference;
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import java.util.function.Consumer;
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public class CalculateAverage_artsiomkorzun {
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private static final Path FILE = Path.of("./measurements.txt");
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private static final long FILE_SIZE = size(FILE);
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private static final MemorySegment MAPPED_FILE = map(FILE);
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private static final int PARALLELISM = Runtime.getRuntime().availableProcessors();
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private static final int SEGMENT_SIZE = 16 * 1024 * 1024;
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private static final int SEGMENT_COUNT = (int) ((FILE_SIZE + SEGMENT_SIZE - 1) / SEGMENT_SIZE);
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private static final int SEGMENT_COUNT = (int) ((MAPPED_FILE.byteSize() + SEGMENT_SIZE - 1) / SEGMENT_SIZE);
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private static final int SEGMENT_OVERLAP = 1024;
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private static final long COMMA_PATTERN = pattern(';');
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private static final long DOT_BITS = 0x10101000;
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private static final long MAGIC_MULTIPLIER = (100 * 0x1000000 + 10 * 0x10000 + 1);
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private static final ByteOrder BYTE_ORDER = ByteOrder.nativeOrder();
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private static final Unsafe UNSAFE;
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static {
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try {
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Field unsafe = Unsafe.class.getDeclaredField("theUnsafe");
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unsafe.setAccessible(true);
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UNSAFE = (Unsafe) unsafe.get(Unsafe.class);
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}
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catch (Throwable e) {
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throw new RuntimeException(e);
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}
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}
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public static void main(String[] args) throws Exception {
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// for (int i = 0; i < 10; i++) {
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@ -63,196 +81,231 @@ public class CalculateAverage_artsiomkorzun {
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aggregators[i].join();
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}
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Aggregates aggregates = result.get();
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aggregates.sort();
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print(aggregates);
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Map<String, Aggregate> aggregates = result.get().aggregate();
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System.out.println(text(aggregates));
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}
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private static void print(Aggregates aggregates) {
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StringBuilder builder = new StringBuilder(aggregates.size() * 15 + 32);
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builder.append("{");
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aggregates.visit(aggregate -> {
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if (builder.length() > 1) {
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builder.append(", ");
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}
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builder.append(aggregate);
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});
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builder.append("}");
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System.out.println(builder);
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}
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private static long size(Path file) {
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try {
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return Files.size(file);
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private static MemorySegment map(Path file) {
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try (FileChannel channel = FileChannel.open(file, StandardOpenOption.READ)) {
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long size = channel.size();
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return channel.map(FileChannel.MapMode.READ_ONLY, 0, size, Arena.global());
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}
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catch (IOException e) {
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catch (Throwable e) {
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throw new RuntimeException(e);
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}
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}
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private static class Row {
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final byte[] station = new byte[256];
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int length;
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int hash;
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int temperature;
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@Override
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public String toString() {
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return new String(station, 0, length) + ":" + temperature;
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}
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private static long pattern(char c) {
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long b = c & 0xFFL;
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return b | (b << 8) | (b << 16) | (b << 24) | (b << 32) | (b << 40) | (b << 48) | (b << 56);
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}
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private static class Aggregate implements Comparable<Aggregate> {
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final byte[] station;
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final int hash;
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int min;
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int max;
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long sum;
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int count;
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private static long getLongBigEndian(long address) {
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long value = UNSAFE.getLong(address);
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public Aggregate(Row row) {
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this.station = Arrays.copyOf(row.station, row.length);
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this.hash = row.hash;
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this.min = row.temperature;
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this.max = row.temperature;
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this.sum = row.temperature;
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this.count = 1;
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if (BYTE_ORDER == ByteOrder.LITTLE_ENDIAN) {
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value = Long.reverseBytes(value);
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}
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public void add(Row row) {
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min = Math.min(min, row.temperature);
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max = Math.max(max, row.temperature);
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sum += row.temperature;
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count++;
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return value;
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}
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private static long getLongLittleEndian(long address) {
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long value = UNSAFE.getLong(address);
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if (BYTE_ORDER == ByteOrder.BIG_ENDIAN) {
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value = Long.reverseBytes(value);
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}
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public void merge(Aggregate right) {
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min = Math.min(min, right.min);
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max = Math.max(max, right.max);
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sum += right.sum;
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count += right.count;
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}
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return value;
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}
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@Override
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public int compareTo(Aggregate that) {
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byte[] lhs = this.station;
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byte[] rhs = that.station;
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int limit = Math.min(lhs.length, rhs.length);
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private static String text(Map<String, Aggregate> aggregates) {
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StringBuilder text = new StringBuilder(aggregates.size() * 32 + 2);
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text.append('{');
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for (int offset = 0; offset < limit; offset++) {
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int left = lhs[offset];
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int right = rhs[offset];
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if (left != right) {
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return (left & 0xFF) - (right & 0xFF);
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}
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for (Map.Entry<String, Aggregate> entry : aggregates.entrySet()) {
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if (text.length() > 1) {
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text.append(", ");
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}
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return lhs.length - rhs.length;
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Aggregate aggregate = entry.getValue();
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text.append(entry.getKey()).append('=')
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.append(round(aggregate.min)).append('/')
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.append(round(1.0 * aggregate.sum / aggregate.cnt)).append('/')
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.append(round(aggregate.max));
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}
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@Override
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public String toString() {
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return new String(station) + "=" + round(min) + "/" + round(1.0 * sum / count) + "/" + round(max);
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}
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text.append('}');
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return text.toString();
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}
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private static double round(double v) {
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return Math.round(v) / 10.0;
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}
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private static double round(double v) {
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return Math.round(v) / 10.0;
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}
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private static class Row {
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long address;
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int length;
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int hash;
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int value;
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}
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private record Aggregate(int min, int max, long sum, int cnt) {
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}
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private static class Aggregates {
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private static final int GROW_FACTOR = 4;
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private static final float LOAD_FACTOR = 0.55f;
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private static final int SIZE = 16 * 1024;
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private final long pointer;
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private Aggregate[] aggregates = new Aggregate[1024];
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private int limit = (int) (aggregates.length * LOAD_FACTOR);
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private int size;
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public Aggregates() {
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int size = 32 * SIZE;
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long address = UNSAFE.allocateMemory(size + 8096);
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pointer = (address + 4095) & (~4095);
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UNSAFE.setMemory(pointer, size, (byte) 0);
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public int size() {
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return size;
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}
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public void visit(Consumer<Aggregate> consumer) {
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if (size > 0) {
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for (Aggregate aggregate : aggregates) {
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if (aggregate != null) {
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consumer.accept(aggregate);
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}
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}
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long word = pack(Short.MAX_VALUE, Short.MIN_VALUE, 0);
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for (int i = 0; i < SIZE; i++) {
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long entry = pointer + 32 * i;
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UNSAFE.putLong(entry + 24, word);
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}
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}
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public void add(Row row) {
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int index = row.hash & (aggregates.length - 1);
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long index = index(row.hash);
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long header = ((long) row.hash << 32) | (row.length);
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while (true) {
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Aggregate aggregate = aggregates[index];
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long address = pointer + (index << 5);
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long head = UNSAFE.getLong(address);
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long ref = UNSAFE.getLong(address + 8);
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boolean isHit = (head == 0) || (head == header && equal(ref, row.address, row.length));
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if (aggregate == null) {
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aggregates[index] = new Aggregate(row);
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if (++size >= limit) {
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grow();
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}
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if (isHit) {
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long sum = UNSAFE.getLong(address + 16) + row.value;
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long word = UNSAFE.getLong(address + 24);
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int min = Math.min(min(word), row.value);
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int max = Math.max(max(word), row.value);
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int cnt = cnt(word) + 1;
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UNSAFE.putLong(address, header);
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UNSAFE.putLong(address + 8, row.address);
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UNSAFE.putLong(address + 16, sum);
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UNSAFE.putLong(address + 24, pack(min, max, cnt));
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break;
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}
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if (row.hash == aggregate.hash && Arrays.equals(row.station, 0, row.length, aggregate.station, 0, aggregate.station.length)) {
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aggregate.add(row);
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break;
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}
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index = (index + 1) & (aggregates.length - 1);
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index = (index + 1) & (SIZE - 1);
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}
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}
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public void merge(Aggregate right) {
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int index = right.hash & (aggregates.length - 1);
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public void merge(Aggregates rights) {
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for (int rightIndex = 0; rightIndex < SIZE; rightIndex++) {
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long rightAddress = rights.pointer + (rightIndex << 5);
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long header = UNSAFE.getLong(rightAddress);
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long reference = UNSAFE.getLong(rightAddress + 8);
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while (true) {
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Aggregate aggregate = aggregates[index];
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if (header == 0) {
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continue;
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}
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if (aggregate == null) {
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aggregates[index] = right;
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if (++size >= limit) {
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grow();
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int hash = (int) (header >>> 32);
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int length = (int) (header);
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long index = index(hash);
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while (true) {
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long address = pointer + (index << 5);
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long head = UNSAFE.getLong(address);
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long ref = UNSAFE.getLong(address + 8);
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boolean isHit = (head == 0) || (head == header && equal(ref, reference, length));
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if (isHit) {
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long sum = UNSAFE.getLong(address + 16) + UNSAFE.getLong(rightAddress + 16);
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long left = UNSAFE.getLong(address + 24);
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long right = UNSAFE.getLong(rightAddress + 24);
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int min = Math.min(min(left), min(right));
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int max = Math.max(max(left), max(right));
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int cnt = cnt(left) + cnt(right);
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UNSAFE.putLong(address, header);
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UNSAFE.putLong(address + 8, reference);
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UNSAFE.putLong(address + 16, sum);
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UNSAFE.putLong(address + 24, pack(min, max, cnt));
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break;
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}
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break;
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}
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if (right.hash == aggregate.hash && Arrays.equals(right.station, aggregate.station)) {
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aggregate.merge(right);
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break;
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index = (index + 1) & (SIZE - 1);
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}
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index = (index + 1) & (aggregates.length - 1);
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}
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}
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public Aggregates sort() {
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Arrays.sort(aggregates, Comparator.nullsLast(Aggregate::compareTo));
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return this;
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public Map<String, Aggregate> aggregate() {
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TreeMap<String, Aggregate> set = new TreeMap<>();
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for (int index = 0; index < SIZE; index++) {
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long address = pointer + (index << 5);
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long head = UNSAFE.getLong(address);
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long ref = UNSAFE.getLong(address + 8);
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if (head == 0) {
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continue;
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}
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int length = (int) (head);
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byte[] array = new byte[length];
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UNSAFE.copyMemory(null, ref, array, Unsafe.ARRAY_BYTE_BASE_OFFSET, length);
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String key = new String(array);
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long sum = UNSAFE.getLong(address + 16);
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long word = UNSAFE.getLong(address + 24);
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Aggregate aggregate = new Aggregate(min(word), max(word), sum, cnt(word));
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set.put(key, aggregate);
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}
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return set;
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}
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private void grow() {
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Aggregate[] oldAggregates = aggregates;
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aggregates = new Aggregate[oldAggregates.length * GROW_FACTOR];
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limit = (int) (aggregates.length * LOAD_FACTOR);
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private static long pack(int min, int max, int cnt) {
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return ((long) min << 48) | (((long) max & 0xFFFF) << 32) | cnt;
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}
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for (Aggregate aggregate : oldAggregates) {
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if (aggregate != null) {
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int index = aggregate.hash & (aggregates.length - 1);
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private static int cnt(long word) {
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return (int) word;
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}
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while (aggregates[index] != null) {
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index = (index + 1) & (aggregates.length - 1);
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}
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private static int max(long word) {
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return (short) (word >>> 32);
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}
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aggregates[index] = aggregate;
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private static int min(long word) {
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return (short) (word >>> 48);
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}
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private static long index(int hash) {
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return (hash ^ (hash >> 16)) & (SIZE - 1);
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}
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private static boolean equal(long leftAddress, long rightAddress, int length) {
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int index = 0;
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while (length > 8) {
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long left = UNSAFE.getLong(leftAddress + index);
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long right = UNSAFE.getLong(rightAddress + index);
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if (left != right) {
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return false;
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}
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length -= 8;
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index += 8;
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}
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int shift = 64 - (length << 3);
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long left = getLongBigEndian(leftAddress + index) >>> shift;
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long right = getLongBigEndian(rightAddress + index) >>> shift;
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return (left == right);
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}
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}
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@ -272,87 +325,88 @@ public class CalculateAverage_artsiomkorzun {
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Aggregates aggregates = new Aggregates();
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Row row = new Row();
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try (FileChannel channel = FileChannel.open(FILE, StandardOpenOption.READ)) {
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for (int segment; (segment = counter.getAndIncrement()) < SEGMENT_COUNT;) {
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aggregate(channel, segment, aggregates, row);
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}
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}
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catch (Throwable e) {
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throw new RuntimeException(e);
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for (int segment; (segment = counter.getAndIncrement()) < SEGMENT_COUNT;) {
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aggregate(aggregates, row, segment);
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}
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while (!result.compareAndSet(null, aggregates)) {
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Aggregates rights = result.getAndSet(null);
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if (rights != null) {
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aggregates = merge(aggregates, rights);
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aggregates.merge(rights);
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}
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}
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}
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private static void aggregate(FileChannel channel, int segment, Aggregates aggregates, Row row) throws Exception {
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private static void aggregate(Aggregates aggregates, Row row, int segment) {
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long position = (long) SEGMENT_SIZE * segment;
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int size = (int) Math.min(SEGMENT_SIZE + SEGMENT_OVERLAP, FILE_SIZE - position);
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int limit = Math.min(SEGMENT_SIZE, size - 1);
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int size = (int) Math.min(SEGMENT_SIZE + SEGMENT_OVERLAP, MAPPED_FILE.byteSize() - position);
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long address = MAPPED_FILE.address() + position;
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long limit = address + Math.min(SEGMENT_SIZE, size - 1);
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MappedByteBuffer buffer = channel.map(FileChannel.MapMode.READ_ONLY, position, size);
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if (position > 0) {
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next(buffer);
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if (segment > 0) {
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address = next(address);
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}
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for (int offset = buffer.position(); offset <= limit;) {
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offset = parse(buffer, row, offset);
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while (address <= limit) {
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// this parsing can produce seg fault at page boundaries
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// e.g. file size is 4096 and the last entry is X=0.0, which is less than 8 bytes
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||||
// as a result a read will be split across pages, where one of them is not mapped
|
||||
// but for some reason it works on my machine, leaving to investigate
|
||||
address = parseKey(address, row);
|
||||
address = parseValue(address, row);
|
||||
aggregates.add(row);
|
||||
}
|
||||
}
|
||||
|
||||
private static Aggregates merge(Aggregates lefts, Aggregates rights) {
|
||||
if (rights.size() < lefts.size()) {
|
||||
Aggregates temp = lefts;
|
||||
lefts = rights;
|
||||
rights = temp;
|
||||
}
|
||||
|
||||
rights.visit(lefts::merge);
|
||||
return lefts;
|
||||
}
|
||||
|
||||
private static void next(ByteBuffer buffer) {
|
||||
while (buffer.get() != '\n') {
|
||||
private static long next(long address) {
|
||||
while (UNSAFE.getByte(address++) != '\n') {
|
||||
// continue
|
||||
}
|
||||
return address;
|
||||
}
|
||||
|
||||
private static int parse(ByteBuffer buffer, Row row, int offset) {
|
||||
byte[] station = row.station;
|
||||
// idea: royvanrijn
|
||||
// explanation: https://richardstartin.github.io/posts/finding-bytes
|
||||
private static long parseKey(long address, Row row) {
|
||||
int length = 0;
|
||||
int hash = 0;
|
||||
long hash = 0;
|
||||
long word;
|
||||
|
||||
for (byte b; (b = buffer.get(offset++)) != ';';) {
|
||||
station[length++] = b;
|
||||
hash = 71 * hash + b;
|
||||
while (true) {
|
||||
word = getLongLittleEndian(address + length);
|
||||
long match = word ^ COMMA_PATTERN;
|
||||
long mask = ((match - 0x0101010101010101L) & ~match) & 0x8080808080808080L;
|
||||
|
||||
if (mask == 0) {
|
||||
hash = 71 * hash + word;
|
||||
length += 8;
|
||||
continue;
|
||||
}
|
||||
|
||||
int bit = Long.numberOfTrailingZeros(mask);
|
||||
length += (bit >>> 3);
|
||||
hash = 71 * hash + (word & (0x00FFFFFFFFFFFFFFL >>> (63 - bit)));
|
||||
|
||||
row.address = address;
|
||||
row.length = length;
|
||||
row.hash = Long.hashCode(hash);
|
||||
|
||||
return address + length + 1;
|
||||
}
|
||||
}
|
||||
|
||||
row.length = length;
|
||||
row.hash = hash;
|
||||
|
||||
int sign = 1;
|
||||
|
||||
if (buffer.get(offset) == '-') {
|
||||
sign = -1;
|
||||
offset++;
|
||||
}
|
||||
|
||||
int value = buffer.get(offset++) - '0';
|
||||
|
||||
if (buffer.get(offset) != '.') {
|
||||
value = 10 * value + buffer.get(offset++) - '0';
|
||||
}
|
||||
|
||||
value = 10 * value + buffer.get(offset + 1) - '0';
|
||||
row.temperature = value * sign;
|
||||
return offset + 3;
|
||||
// idea: merykitty
|
||||
private static long parseValue(long address, Row row) {
|
||||
long word = getLongLittleEndian(address);
|
||||
long inverted = ~word;
|
||||
int dot = Long.numberOfTrailingZeros(inverted & DOT_BITS);
|
||||
long signed = (inverted << 59) >> 63;
|
||||
long mask = ~(signed & 0xFF);
|
||||
long digits = ((word & mask) << (28 - dot)) & 0x0F000F0F00L;
|
||||
long abs = ((digits * MAGIC_MULTIPLIER) >>> 32) & 0x3FF;
|
||||
row.value = (int) ((abs ^ signed) - signed);
|
||||
return address + (dot >> 3) + 3;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user