1brc/src/main/java/dev/morling/onebrc/CalculateAverage_jparera.java

383 lines
13 KiB
Java

//COMPILE_OPTIONS -source 21 --enable-preview --add-modules jdk.incubator.vector
//RUNTIME_OPTIONS --enable-preview --add-modules jdk.incubator.vector
/*
* Copyright 2023 The original authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package dev.morling.onebrc;
import java.io.IOException;
import java.lang.foreign.Arena;
import java.lang.foreign.MemorySegment;
import java.lang.foreign.ValueLayout;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.VarHandle;
import java.nio.ByteOrder;
import java.nio.channels.FileChannel;
import java.nio.channels.FileChannel.MapMode;
import java.nio.charset.StandardCharsets;
import java.nio.file.Path;
import java.nio.file.StandardOpenOption;
import java.util.ArrayList;
import java.util.List;
import java.util.TreeMap;
import java.util.function.Function;
import java.util.stream.Collectors;
import jdk.incubator.vector.ByteVector;
import jdk.incubator.vector.VectorSpecies;
import jdk.incubator.vector.VectorOperators;
public class CalculateAverage_jparera {
private static final String FILE = "./measurements.txt";
private static final VarHandle BYTE_HANDLE = MethodHandles
.memorySegmentViewVarHandle(ValueLayout.JAVA_BYTE);
private static final VarHandle INT_HANDLE = MethodHandles
.memorySegmentViewVarHandle(ValueLayout.JAVA_INT_UNALIGNED);
private static final VarHandle LONG_LE_HANDLE = MethodHandles
.memorySegmentViewVarHandle(ValueLayout.JAVA_LONG_UNALIGNED.withOrder(ByteOrder.LITTLE_ENDIAN));
private static final VectorSpecies<Byte> BYTE_SPECIES = ByteVector.SPECIES_PREFERRED;
private static final int BYTE_SPECIES_LANES = BYTE_SPECIES.length();
private static final ByteOrder NATIVE_ORDER = ByteOrder.nativeOrder();
private static final byte LF = '\n';
private static final byte SEPARATOR = ';';
private static final byte DECIMAL_SEPARATOR = '.';
private static final byte NEG = '-';
public static void main(String[] args) throws IOException, InterruptedException {
try (var fc = FileChannel.open(Path.of(FILE), StandardOpenOption.READ)) {
try (var arena = Arena.ofShared()) {
var fs = fc.map(MapMode.READ_ONLY, 0, fc.size(), arena);
var cpus = Runtime.getRuntime().availableProcessors();
var output = chunks(fs, cpus).stream()
.parallel()
.map(Chunk::parse)
.flatMap(List::stream)
.collect(Collectors.toMap(
Entry::key,
Function.identity(),
Entry::merge,
TreeMap::new));
System.out.println(output);
}
}
}
private static List<Chunk> chunks(MemorySegment ms, int splits) {
long fileSize = ms.byteSize();
long expectedChunkSize = Math.ceilDiv(fileSize, splits);
var chunks = new ArrayList<Chunk>();
long offset = 0;
while (offset < fileSize) {
var end = Math.min(offset + expectedChunkSize, fileSize);
while (end < fileSize && (byte) BYTE_HANDLE.get(ms, end++) != LF) {
}
long len = end - offset;
chunks.add(new Chunk(ms.asSlice(offset, len)));
offset = end;
}
return chunks;
}
private static final class Chunk {
private static final int KEY_LOG2_BYTES = 7;
private static final int KEY_BYTES = 1 << KEY_LOG2_BYTES;
private static final int ENTRIES_LOG2_CAPACITY = 16;
private static final int ENTRIES_CAPACITY = 1 << ENTRIES_LOG2_CAPACITY;
private static final int ENTRIES_MASK = ENTRIES_CAPACITY - 1;
private final MemorySegment segment;
private final long size;
private final Entry[] entries = new Entry[ENTRIES_CAPACITY];
private final byte[] keys = new byte[ENTRIES_CAPACITY * KEY_BYTES];
private final MemorySegment kms = MemorySegment.ofArray(this.keys);
private static final int KEYS_MASK = (ENTRIES_CAPACITY * KEY_BYTES) - 1;
private long offset;
private byte current;
private boolean hasCurrent = true;
Chunk(MemorySegment segment) {
this.segment = segment;
this.size = segment.byteSize();
}
public List<Entry> parse() {
long safe = size - KEY_BYTES;
while (offset < safe) {
vectorizedEntry().add(vectorizedValue());
}
next();
while (hasCurrent()) {
entry().add(value());
}
var output = new ArrayList<Entry>(entries.length);
for (int i = 0, o = 0; i < entries.length; i++, o += KEY_BYTES) {
var e = entries[i];
if (e != null) {
e.setkey(keys, o);
output.add(e);
}
}
return output;
}
private Entry vectorizedEntry() {
var separators = ByteVector.broadcast(BYTE_SPECIES, SEPARATOR);
int len = 0;
for (int i = 0;; i += BYTE_SPECIES_LANES) {
var block = ByteVector.fromMemorySegment(BYTE_SPECIES, this.segment, offset + i, NATIVE_ORDER);
int equals = block.compare(VectorOperators.EQ, separators).firstTrue();
len += equals;
if (equals != BYTE_SPECIES_LANES) {
break;
}
}
var start = this.offset;
this.offset = start + len + 1;
int hash = hash(segment, start, len);
int index = (hash - (hash >>> -ENTRIES_LOG2_CAPACITY)) & ENTRIES_MASK;
int keyOffset = index << KEY_LOG2_BYTES;
int count = 0;
while (count < ENTRIES_MASK) {
index = index & ENTRIES_MASK;
keyOffset = keyOffset & KEYS_MASK;
var e = this.entries[index];
if (e == null) {
MemorySegment.copy(this.segment, start, kms, keyOffset, len);
return this.entries[index] = new Entry(len, hash);
}
else if (e.hash == hash && e.keyLength == len) {
int total = 0;
for (int i = 0; i < KEY_BYTES; i += BYTE_SPECIES_LANES) {
var ekey = ByteVector.fromArray(BYTE_SPECIES, keys, keyOffset + i);
var okey = ByteVector.fromMemorySegment(BYTE_SPECIES, this.segment, start + i, NATIVE_ORDER);
int equals = ekey.compare(VectorOperators.NE, okey).firstTrue();
total += equals;
if (equals != BYTE_SPECIES_LANES) {
break;
}
}
if (total >= len) {
return e;
}
}
count++;
index++;
keyOffset += KEY_BYTES;
}
throw new IllegalStateException("Map is full!");
}
private Entry entry() {
long start = this.offset - 1;
int len = 0;
while (hasCurrent() && current != SEPARATOR) {
len++;
next();
}
expect(SEPARATOR);
int hash = hash(segment, start, len);
int index = (hash - (hash >>> -ENTRIES_LOG2_CAPACITY)) & ENTRIES_MASK;
int keyOffset = index << KEY_LOG2_BYTES;
int count = 0;
while (count < ENTRIES_MASK) {
index = index & ENTRIES_MASK;
keyOffset = keyOffset & KEYS_MASK;
var e = this.entries[index];
if (e == null) {
MemorySegment.copy(this.segment, start, kms, keyOffset, len);
return this.entries[index] = new Entry(len, hash);
}
else if (e.hash == hash && e.keyLength == len) {
int total = 0;
for (int i = 0; i < len; i++) {
if (((byte) BYTE_HANDLE.get(this.segment, start + i)) != this.keys[keyOffset + i]) {
break;
}
total++;
}
if (total >= len) {
return e;
}
}
count++;
index++;
keyOffset += KEY_BYTES;
}
throw new IllegalStateException("Map is full!");
}
private static final long MULTIPLY_ADD_DIGITS = 100 * (1L << 24) + 10 * (1L << 16) + 1;
private int vectorizedValue() {
long dw = (long) LONG_LE_HANDLE.get(this.segment, this.offset);
int zeros = Long.numberOfTrailingZeros(~dw & 0x10101000L);
boolean negative = ((dw & 0xFF) ^ NEG) == 0;
dw = ((negative ? (dw & ~0xFF) : dw) << (28 - zeros)) & 0x0F000F0F00L;
int value = (int) (((dw * MULTIPLY_ADD_DIGITS) >>> 32) & 0x3FF);
this.offset += (zeros >>> 3) + 3;
return negative ? -value : value;
}
private int value() {
int value = 0;
var negative = false;
if (consume(NEG)) {
negative = true;
}
while (hasCurrent()) {
if ((current & 0xF0) == 0x30) {
value *= 10;
value += current - '0';
}
else if (current != DECIMAL_SEPARATOR) {
break;
}
next();
}
if (hasCurrent()) {
expect(LF);
}
return negative ? -value : value;
}
private static final int GOLDEN_RATIO = 0x9E3779B9;
private static final int HASH_LROTATE = 5;
private static int hash(MemorySegment ms, long start, int len) {
int x, y;
if (len >= Integer.BYTES) {
x = (int) INT_HANDLE.get(ms, start);
y = (int) INT_HANDLE.get(ms, start + len - Integer.BYTES);
}
else {
x = (byte) BYTE_HANDLE.get(ms, start) & 0xFF;
y = (byte) BYTE_HANDLE.get(ms, start + len - Byte.BYTES) & 0xFF;
}
return (Integer.rotateLeft(x * GOLDEN_RATIO, HASH_LROTATE) ^ y) * GOLDEN_RATIO;
}
private void expect(byte b) {
if (!consume(b)) {
throw new IllegalStateException("Unexpected token!");
}
}
private boolean consume(byte b) {
if (current == b) {
next();
return true;
}
return false;
}
private boolean hasCurrent() {
return hasCurrent;
}
private void next() {
if (offset < size) {
this.current = (byte) BYTE_HANDLE.get(segment, offset++);
}
else {
this.hasCurrent = false;
}
}
}
private static final class Entry {
final int keyLength;
final int hash;
private int min = Integer.MAX_VALUE;
private int max = Integer.MIN_VALUE;
private long sum;
private int count;
private String key;
Entry(int keyLength, int hash) {
this.keyLength = keyLength;
this.hash = hash;
}
public String key() {
return key;
}
void setkey(byte[] keys, int offset) {
this.key = new String(keys, offset, keyLength, StandardCharsets.UTF_8);
}
public void add(int value) {
min = Math.min(min, value);
max = Math.max(max, value);
sum += value;
count++;
}
public Entry merge(Entry o) {
min = Math.min(min, o.min);
max = Math.max(max, o.max);
sum += o.sum;
count += o.count;
return this;
}
@Override
public String toString() {
var average = Math.round(((sum / 10.0) / count) * 10.0);
return decimal(min) + '/' + decimal(average) + '/' + decimal(max);
}
private static String decimal(long value) {
var builder = new StringBuilder();
if (value < 0) {
builder.append((char) NEG);
}
value = Math.abs(value);
builder.append(value / 10);
builder.append((char) DECIMAL_SEPARATOR);
builder.append(value % 10);
return builder.toString();
}
}
}