From 4fe00bf7a75530bd363b7599b023d63a4eda0ddf Mon Sep 17 00:00:00 2001
From: Yunus Inci <yunusin@amazon.com>
Date: Thu, 4 Jan 2024 13:52:53 +0000
Subject: [PATCH] Improve spullara's solution
---
calculate_average_yemreinci.sh | 20 ++
.../onebrc/CalculateAverage_yemreinci.java | 217 ++++++++++++++++++
2 files changed, 237 insertions(+)
create mode 100755 calculate_average_yemreinci.sh
create mode 100644 src/main/java/dev/morling/onebrc/CalculateAverage_yemreinci.java
diff --git a/calculate_average_yemreinci.sh b/calculate_average_yemreinci.sh
new file mode 100755
index 0000000..83af875
--- /dev/null
+++ b/calculate_average_yemreinci.sh
@@ -0,0 +1,20 @@
+#!/bin/sh
+#
+# 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.
+#
+
+
+JAVA_OPTS=""
+time java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_yemreinci
diff --git a/src/main/java/dev/morling/onebrc/CalculateAverage_yemreinci.java b/src/main/java/dev/morling/onebrc/CalculateAverage_yemreinci.java
new file mode 100644
index 0000000..2ab4272
--- /dev/null
+++ b/src/main/java/dev/morling/onebrc/CalculateAverage_yemreinci.java
@@ -0,0 +1,217 @@
+/*
+ * 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.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.channels.FileChannel;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.TreeMap;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+
+public class CalculateAverage_yemreinci {
+ private static final String FILE = "./measurements.txt";
+
+ public static void main(String[] args) throws IOException, ExecutionException, InterruptedException {
+ var filename = args.length == 0 ? FILE : args[0];
+ var file = new File(filename);
+ long start = System.currentTimeMillis();
+
+ var totalLines = new AtomicInteger();
+ var results = getFileSegments(file).stream().map(segment -> {
+ var resultMap = new ByteArrayToResultMap();
+ long segmentEnd = segment.end();
+ try (var fileChannel = (FileChannel) Files.newByteChannel(Path.of(filename), StandardOpenOption.READ)) {
+ var bb = fileChannel.map(FileChannel.MapMode.READ_ONLY, segment.start(), segmentEnd - segment.start());
+ var buffer = new byte[64];
+ int lines = 0;
+ int startLine;
+ int limit = bb.limit();
+ while ((startLine = bb.position()) < limit) {
+ int currentPosition = startLine;
+ byte b;
+ int offset = 0;
+ int hash = 0;
+ while ((b = bb.get(currentPosition++)) != ';') {
+ buffer[offset++] = b;
+ hash = (hash << 5) - hash + b;
+ }
+
+ boolean negative = false;
+ if ((b = bb.get(currentPosition)) == '-') {
+ negative = true;
+ currentPosition++;
+ }
+
+ double temp;
+ if ((b = bb.get(currentPosition + 1)) == '.') { // temperature is in either XX.X or X.X form
+ temp = (bb.get(currentPosition) - '0') + (bb.get(currentPosition + 2) - '0') / 10.0;
+ currentPosition += 4;
+ }
+ else {
+ temp = (bb.get(currentPosition) - '0') * 10 + (b - '0') + (bb.get(currentPosition + 3) - '0') / 10.0;
+ currentPosition += 5;
+ }
+
+ double finalTemp = (negative ? -temp : temp);
+ resultMap.putOrMerge(hash, buffer, 0, offset,
+ () -> new Result(temp),
+ measurement -> merge(measurement, finalTemp, finalTemp, finalTemp, 1));
+ lines++;
+ bb.position(currentPosition);
+ }
+ totalLines.addAndGet(lines);
+ return resultMap;
+ }
+ catch (IOException e) {
+ throw new RuntimeException(e);
+ }
+ }).parallel().toList();
+
+ var resultMap = results.stream()
+ .flatMap(partition -> partition.getAll().stream())
+ .collect(Collectors.toMap(e -> new String(e.key()), Entry::value, CalculateAverage_yemreinci::merge, TreeMap::new));
+
+ System.out.println("Time: " + (System.currentTimeMillis() - start) + "ms");
+ System.out.println("Lines processed: " + totalLines);
+ System.out.println(resultMap);
+ }
+
+ private static List<FileSegment> getFileSegments(File file) throws IOException {
+ int numberOfSegments = Runtime.getRuntime().availableProcessors();
+ long fileSize = file.length();
+ long segmentSize = fileSize / numberOfSegments;
+ List<FileSegment> segments = new ArrayList<>();
+ try (RandomAccessFile randomAccessFile = new RandomAccessFile(file, "r")) {
+ for (int i = 0; i < numberOfSegments; i++) {
+ long segStart = i * segmentSize;
+ long segEnd = (i == numberOfSegments - 1) ? fileSize : segStart + segmentSize;
+ segStart = findSegment(i, 0, randomAccessFile, segStart, segEnd);
+ segEnd = findSegment(i, numberOfSegments - 1, randomAccessFile, segEnd, fileSize);
+
+ segments.add(new FileSegment(segStart, segEnd));
+ }
+ }
+ return segments;
+ }
+
+ private static Result merge(Result v, Result value) {
+ return merge(v, value.min, value.max, value.sum, value.count);
+ }
+
+ private static Result merge(Result v, double value, double value1, double value2, long value3) {
+ v.min = Math.min(v.min, value);
+ v.max = Math.max(v.max, value1);
+ v.sum += value2;
+ v.count += value3;
+ return v;
+ }
+
+ private static long findSegment(int i, int skipSegment, RandomAccessFile raf, long location, long fileSize) throws IOException {
+ if (i != skipSegment) {
+ raf.seek(location);
+ while (location < fileSize) {
+ location++;
+ if (raf.read() == '\n')
+ break;
+ }
+ }
+ return location;
+ }
+
+ static class Result {
+ double min, max, sum;
+ long count;
+
+ Result(double value) {
+ min = max = sum = value;
+ this.count = 1;
+ }
+
+ @Override
+ public String toString() {
+ return round(min) + "/" + round(sum / count) + "/" + round(max);
+ }
+
+ double round(double v) {
+ return Math.round(v * 10.0) / 10.0;
+ }
+
+ }
+
+ static record Pair(int slot, Result slotValue) {
+ }
+
+ static record Entry(byte[] key, Result value) {
+ }
+
+ static record FileSegment(long start, long end) {
+ }
+
+ static class ByteArrayToResultMap {
+ public static final int MAPSIZE = 1024 * 128;
+ Result[] slots = new Result[MAPSIZE];
+ byte[][] keys = new byte[MAPSIZE][];
+
+ private Pair getPair(int hash, byte[] key, int offset, int size) {
+ int slot = hash & (slots.length - 1);
+ var slotValue = slots[slot];
+ // Linear probe for open slot
+ while (slotValue != null && (keys[slot].length != size || !Arrays.equals(keys[slot], 0, size, key, offset, size))) {
+ slot = (slot + 1) & (slots.length - 1);
+ slotValue = slots[slot];
+ }
+ return new Pair(slot, slotValue);
+ }
+
+ public void putOrMerge(int hash, byte[] key, int offset, int size, Supplier<Result> supplier, Consumer<Result> merge) {
+ Pair result = getPair(hash, key, offset, size);
+ Result value = result.slotValue();
+ if (value == null) {
+ int slot = result.slot();
+ slots[slot] = supplier.get();
+ byte[] bytes = new byte[size];
+ System.arraycopy(key, offset, bytes, 0, size);
+ keys[slot] = bytes;
+ }
+ else {
+ merge.accept(value);
+ }
+ }
+
+ // Get all pairs
+ public List<Entry> getAll() {
+ List<Entry> result = new ArrayList<>();
+ for (int i = 0; i < slots.length; i++) {
+ Result slotValue = slots[i];
+ if (slotValue != null) {
+ result.add(new Entry(keys[i], slotValue));
+ }
+ }
+ return result;
+ }
+ }
+}