From 46d375e621d1ae286058407fc38d55600fc679eb Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Serkan=20=C3=96ZAL?= Date: Mon, 29 Jan 2024 01:02:01 +0300 Subject: serkan-ozal's 3rd submission with some minor improvements: (#615) - faster merge by ignoring empty entries in the map - enable CDS for faster startup (added `prepare_serkan-ozal.sh` to generate CDS archive in advance) - some tweaks with JVM options - optimized result printing --- .../onebrc/CalculateAverage_serkan_ozal.java | 54 +++++++++++++++------- 1 file changed, 38 insertions(+), 16 deletions(-) (limited to 'src') diff --git a/src/main/java/dev/morling/onebrc/CalculateAverage_serkan_ozal.java b/src/main/java/dev/morling/onebrc/CalculateAverage_serkan_ozal.java index 8087919..0ca1fe7 100644 --- a/src/main/java/dev/morling/onebrc/CalculateAverage_serkan_ozal.java +++ b/src/main/java/dev/morling/onebrc/CalculateAverage_serkan_ozal.java @@ -30,6 +30,7 @@ import java.nio.ByteOrder; import java.nio.channels.FileChannel; import java.nio.charset.StandardCharsets; import java.util.ArrayList; +import java.util.Arrays; import java.util.List; import java.util.Map; import java.util.TreeMap; @@ -47,7 +48,7 @@ import java.util.concurrent.locks.ReentrantLock; */ public class CalculateAverage_serkan_ozal { - private static final String FILE = "./measurements.txt"; + private static final String FILE = System.getProperty("file.path", "./measurements.txt"); private static final VectorSpecies BYTE_SPECIES = ByteVector.SPECIES_PREFERRED.length() >= 16 // Since majority (99%) of the city names <= 16 bytes, according to my experiments, @@ -327,7 +328,7 @@ public class CalculateAverage_serkan_ozal { private void doProcessRegion(MemorySegment region, long regionAddress, long regionStart, long regionEnd) { final int vectorSize = BYTE_SPECIES.vectorByteSize(); - final long regionMainLimit = regionEnd - MAX_LINE_LENGTH; + final long regionMainLimit = regionEnd - BYTE_SPECIES_SIZE; long regionPtr; @@ -515,7 +516,20 @@ public class CalculateAverage_serkan_ozal { } private void print() { - System.out.println(resultMap); + StringBuilder sb = new StringBuilder(1 << 14); + boolean firstEntryAppended = false; + sb.append("{"); + for (Map.Entry e : resultMap.entrySet()) { + if (firstEntryAppended) { + sb.append(", "); + } + String key = e.getKey(); + KeyResult value = e.getValue(); + sb.append(key).append("=").append(value); + firstEntryAppended = true; + } + sb.append('}'); + System.out.println(sb); } } @@ -546,8 +560,12 @@ public class CalculateAverage_serkan_ozal { private static final int ENTRY_HASH_MASK = MAP_CAPACITY - 1; private static final int MAP_SIZE = ENTRY_SIZE * MAP_CAPACITY; private static final int ENTRY_MASK = MAP_SIZE - 1; + private static final int KEY_ARRAY_OFFSET = KEY_OFFSET - Unsafe.ARRAY_BYTE_BASE_OFFSET; private final byte[] data; + // Max number of unique keys are 10K, so 1 << 14 (16384) is long enough to hold offsets for all of them + private final long[] entryOffsets = new long[1 << 14]; + private int entryOffsetIdx = 0; private OpenMap() { this.data = new byte[MAP_SIZE]; @@ -579,7 +597,6 @@ public class CalculateAverage_serkan_ozal { // and continue until find an available slot in case of hash collision // TODO Prevent infinite loop if all the slots are in use for other keys for (long entryOffset = Unsafe.ARRAY_BYTE_BASE_OFFSET + (idx * ENTRY_SIZE);; entryOffset = (entryOffset + ENTRY_SIZE) & ENTRY_MASK) { - int keyStartOffset = (int) entryOffset + KEY_OFFSET; int keySize = U.getInt(data, entryOffset + KEY_SIZE_OFFSET); // Check whether current index is empty (no another key is inserted yet) if (keySize == 0) { @@ -587,26 +604,28 @@ public class CalculateAverage_serkan_ozal { U.putShort(data, entryOffset + MIN_VALUE_OFFSET, Short.MAX_VALUE); U.putShort(data, entryOffset + MAX_VALUE_OFFSET, Short.MIN_VALUE); U.putInt(data, entryOffset + KEY_SIZE_OFFSET, keyLength); - U.copyMemory(null, keyStartAddress, data, keyStartOffset, keyLength); + U.copyMemory(null, keyStartAddress, data, entryOffset + KEY_OFFSET, keyLength); + entryOffsets[entryOffsetIdx++] = entryOffset; return entryOffset; } + int keyStartArrayOffset = (int) entryOffset + KEY_ARRAY_OFFSET; // Check for hash collision (hashes are same, but keys are different). // If there is no collision (both hashes and keys are equals), return current slot's offset. // Otherwise, continue iterating until find an available slot. - if (keySize == keyLength && keysEqual(keyVector, keyStartAddress, keyLength, keyStartOffset)) { + if (keySize == keyLength && keysEqual(keyVector, keyStartAddress, keyLength, keyStartArrayOffset)) { return entryOffset; } } } - private boolean keysEqual(ByteVector keyVector, long keyStartAddress, int keyLength, int keyStartOffset) { + private boolean keysEqual(ByteVector keyVector, long keyStartAddress, int keyLength, int keyStartArrayOffset) { int keyCheckIdx = 0; if (keyVector != null) { // Use vectorized search for the comparison of keys. // Since majority of the city names >= 8 bytes and <= 16 bytes, // this way is more efficient (according to my experiments) than any other comparisons (byte by byte or 2 longs). int keyCheckLength = Math.min(BYTE_SPECIES_SIZE, keyLength); - ByteVector entryKeyVector = ByteVector.fromArray(BYTE_SPECIES, data, keyStartOffset - Unsafe.ARRAY_BYTE_BASE_OFFSET); + ByteVector entryKeyVector = ByteVector.fromArray(BYTE_SPECIES, data, keyStartArrayOffset); long eqMask = keyVector.compare(VectorOperators.EQ, entryKeyVector).toLong(); int eqCount = Long.numberOfTrailingZeros(~eqMask); if (eqCount < keyCheckLength) { @@ -625,6 +644,7 @@ public class CalculateAverage_serkan_ozal { normalizedKeyLength = Integer.reverseBytes(normalizedKeyLength); } + long keyStartOffset = keyStartArrayOffset + Unsafe.ARRAY_BYTE_BASE_OFFSET; int alignedKeyLength = normalizedKeyLength & 0xFFFFFFF8; int i; for (i = keyCheckIdx; i < alignedKeyLength; i += Long.BYTES) { @@ -663,18 +683,20 @@ public class CalculateAverage_serkan_ozal { private void merge(Map resultMap) { // Merge this local map into global result map - for (int i = 0; i < MAP_SIZE; i += ENTRY_SIZE) { - int baseOffset = Unsafe.ARRAY_BYTE_BASE_OFFSET + i; - int keyLength = U.getInt(data, baseOffset + KEY_SIZE_OFFSET); + Arrays.sort(entryOffsets, 0, entryOffsetIdx); + for (int i = 0; i < entryOffsetIdx; i++) { + long entryOffset = entryOffsets[i]; + int keyLength = U.getInt(data, entryOffset + KEY_SIZE_OFFSET); if (keyLength == 0) { // No entry is available for this index, so continue iterating continue; } - String key = new String(data, i + KEY_OFFSET, keyLength, StandardCharsets.UTF_8); - int count = U.getInt(data, baseOffset + COUNT_OFFSET); - short minValue = U.getShort(data, baseOffset + MIN_VALUE_OFFSET); - short maxValue = U.getShort(data, baseOffset + MAX_VALUE_OFFSET); - long sum = U.getLong(data, baseOffset + VALUE_SUM_OFFSET); + int entryArrayIdx = (int) (entryOffset + KEY_OFFSET - Unsafe.ARRAY_BYTE_BASE_OFFSET); + String key = new String(data, entryArrayIdx, keyLength, StandardCharsets.UTF_8); + int count = U.getInt(data, entryOffset + COUNT_OFFSET); + short minValue = U.getShort(data, entryOffset + MIN_VALUE_OFFSET); + short maxValue = U.getShort(data, entryOffset + MAX_VALUE_OFFSET); + long sum = U.getLong(data, entryOffset + VALUE_SUM_OFFSET); KeyResult result = new KeyResult(count, minValue, maxValue, sum); KeyResult existingResult = resultMap.get(key); if (existingResult == null) { -- cgit v1.2.3