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Graal Native for SamuelYvon (#332)

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* Graal Native

* I need a GC :(

* Fix slash lolz

* Fix god damn output lol

I forgot java :D

* Custom hash, custom key

* More optimisations

* I don't need "optimize-build"

I don't care about image size! :D
This commit is contained in:
Samuel Yvon
2024-01-12 11:16:13 -08:00
committed by GitHub
parent a6e4013170
commit 22b960ada2
3 changed files with 144 additions and 21 deletions
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131
src/main/java/dev/morling/onebrc/CalculateAverage_samuelyvon.java → src/main/java/dev/morling/onebrc/CalculateAverage_SamuelYvon.java
View File

@@ -15,6 +15,8 @@
*/
package dev.morling.onebrc;
//import jdk.incubator.vector.ByteVector;
import java.io.IOException;
import java.io.RandomAccessFile;
import java.nio.MappedByteBuffer;
@@ -52,7 +54,7 @@ import java.util.stream.Collectors;
* 2024-01-09: Naive multi-threaded, no floats, manual line parsing
* </p>
*/
public class CalculateAverage_samuelyvon {
public class CalculateAverage_SamuelYvon {
private static final String FILE = "./measurements.txt";
@@ -60,15 +62,21 @@ public class CalculateAverage_samuelyvon {
private static final byte SEMICOL = 0x3B;
private static final byte DOT = '.';
private static final byte MINUS = '-';
private static final byte ZERO = '0';
private static final String SLASH_S = "/";
private static final byte NEWLINE = '\n';
// The minimum line length in bytes (over-egg.)
private static final int MIN_LINE_LENGTH_BYTES = 200;
private static final int DJB2_INIT = 5381;
/**
* Branchless min (unprecise for large numbers, but good enough)
*
@@ -91,25 +99,84 @@ public class CalculateAverage_samuelyvon {
return b + (diff & dsgn);
}
/**
* A magic key that contains references to the String and where it's located in memory
*/
private static final class StationName {
private final int hash;
private final byte[] value;
private StationName(int hash, MappedByteBuffer backing, int pos, int len) {
this.hash = hash;
this.value = new byte[len];
backing.get(pos, this.value);
}
@Override
public int hashCode() {
return hash;
}
@SuppressWarnings("EqualsWhichDoesntCheckParameterClass")
@Override
public boolean equals(Object obj) {
// Should NEVER be true
// if (!(obj instanceof StationName)) {
// return false;
// }
StationName other = (StationName) obj;
if (this.value.length != other.value.length) {
return false;
}
// Byte for byte compare. This actually is a bug! I'm assuming the input
// is UTF-8 normalized, which in real life would probably not be the case.
// TODO: SIMD?
return Arrays.equals(this.value, other.value);
}
@Override
public String toString() {
return new String(this.value, StandardCharsets.UTF_8);
}
}
private static class StationMeasureAgg {
private int min;
private int max;
private long sum;
private long count;
private final String city;
private final StationName station;
public StationMeasureAgg(String city) {
private String memoizedName;
public StationMeasureAgg(StationName name) {
// Actual numbers are between -99.9 and 99.9, but we *10 to avoid float
this.city = city;
this.station = name;
min = 1000;
max = -1000;
sum = 0;
count = 0;
}
@Override
public int hashCode() {
return this.station.hash;
}
/**
* Get the city name, but also memoized it to avoid building it multiple times
*
* @return the city name
*/
public String city() {
return this.city;
if (null == this.memoizedName) {
this.memoizedName = station.toString();
}
return this.memoizedName;
}
public StationMeasureAgg mergeWith(StationMeasureAgg other) {
@@ -135,27 +202,38 @@ public class CalculateAverage_samuelyvon {
double min = Math.round((double) this.min) / 10.0;
double max = Math.round((double) this.max) / 10.0;
double mean = Math.round((((double) this.sum / this.count))) / 10.0;
return min + "/" + mean + "/" + max;
return min + SLASH_S + mean + SLASH_S + max;
}
public StationName station() {
return this.station;
}
}
private static HashMap<String, StationMeasureAgg> parseChunk(MappedByteBuffer chunk) {
HashMap<String, StationMeasureAgg> m = HashMap.newHashMap(MAX_STATIONS);
private static HashMap<StationName, StationMeasureAgg> parseChunk(MappedByteBuffer chunk) {
HashMap<StationName, StationMeasureAgg> m = HashMap.newHashMap(MAX_STATIONS);
int i = 0;
while (i < chunk.limit()) {
int j = i;
int hash = DJB2_INIT;
// Implement a version of djb2 while we read until the semi, we read anyways
for (; j < chunk.limit(); ++j) {
// TODO: Could compute a hash here, store a byte array, and decode UTF-8 at the
// latest moment.
if (chunk.get(j) == SEMICOL) {
byte b = chunk.get(j);
if (b == SEMICOL) {
break;
}
// How will this behave in java? Why do I get no control OF SIGNEDNESS FFS
// Can I assume int is 32 bits? What is this language! In Java 1.7 it could be 16 bits?
// Apparently not anymore??
hash = (((hash << 5) + hash) + b);
}
byte[] backingNameArray = new byte[j - i];
chunk.get(i, backingNameArray);
String name = new String(backingNameArray, StandardCharsets.UTF_8);
StationName name = new StationName(hash, chunk, i, j - i);
// Skip the `;`
j++;
@@ -167,7 +245,7 @@ public class CalculateAverage_samuelyvon {
for (j = j + (neg ? 1 : 0); j < chunk.limit(); ++j) {
temp *= 10;
byte c = chunk.get(j);
if (c != '.') {
if (c != DOT) {
temp += (char) (c - ZERO);
}
else {
@@ -181,7 +259,7 @@ public class CalculateAverage_samuelyvon {
i = j + 1;
while (chunk.get(i++) != '\n')
while (chunk.get(i++) != NEWLINE)
;
if (neg)
@@ -241,9 +319,24 @@ public class CalculateAverage_samuelyvon {
var fileChunks = getFileChunks();
// Map per core, giving the non-overlapping memory slices
final Map<String, StationMeasureAgg> sortedMeasures = fileChunks.parallelStream().map(CalculateAverage_samuelyvon::parseChunk)
.flatMap(x -> x.values().stream()).collect(Collectors.toMap(StationMeasureAgg::city, x -> x, StationMeasureAgg::mergeWith, TreeMap::new));
final Map<StationName, StationMeasureAgg> allMeasures = fileChunks.parallelStream().map(CalculateAverage_SamuelYvon::parseChunk).flatMap(x -> x.values().stream())
.collect(Collectors.toMap(StationMeasureAgg::station, x -> x, StationMeasureAgg::mergeWith, HashMap::new));
System.out.println(sortedMeasures);
// Give a capacity that should never be gone past
StringBuilder sb = new StringBuilder(allMeasures.size() * (100 + 4 + 20));
sb.append('{');
allMeasures.values().stream().sorted(Comparator.comparing(StationMeasureAgg::city)).forEach(x -> {
sb.append(x.city());
sb.append('=');
sb.append(x);
sb.append(", ");
});
sb.delete(sb.length() - 2, sb.length()); // delete trailing comma and space
sb.append('}');
System.out.println(sb);
}
}