Alawn/Chronicle-Map
1
0
Fork 0
mirror of https://github.com/OpenHFT/Chronicle-Map.git synced 2021-09-13 01:26:12 +00:00
Code Releases Activity

Don't account segment filling variance, if there is only one segment

Browse Source
This commit is contained in:
leventov
2015-12-21 17:19:39 +03:00
parent 60de795949
commit 7154278bb1
1 changed files with 18 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/main/java/net/openhft/chronicle/map/ChronicleMapBuilder.java
+18 -9
View File
@@ -52,6 +52,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
import static java.lang.Double.isNaN;
import static java.lang.Math.round;
import static net.openhft.chronicle.bytes.NativeBytesStore.lazyNativeBytesStoreWithFixedCapacity;
import static net.openhft.chronicle.core.Maths.divideRoundUp;
import static net.openhft.chronicle.core.Maths.isPowerOf2;
import static net.openhft.chronicle.core.Maths.nextPower2;
import static net.openhft.chronicle.hash.impl.CompactOffHeapLinearHashTable.*;
@@ -765,8 +766,13 @@ public final class ChronicleMapBuilder<K, V> implements
} else {
int actualSegments = actualSegments();
double averageEntriesPerSegment = entries() * 1.0 / actualSegments;
entriesPerSegment = PoissonDistribution.inverseCumulativeProbability(
averageEntriesPerSegment, nonTieredSegmentsPercentile);
if (actualSegments > 1) {
entriesPerSegment = PoissonDistribution.inverseCumulativeProbability(
averageEntriesPerSegment, nonTieredSegmentsPercentile);
} else {
// if there is only 1 segment, there is no source of variance in segments filling
entriesPerSegment = ((long) averageEntriesPerSegment) + 1;
}
}
boolean actualChunksDefined = actualChunksPerSegmentTier > 0;
if (!actualChunksDefined) {
@@ -962,10 +968,10 @@ public final class ChronicleMapBuilder<K, V> implements
private long segmentsGivenEntriesPerSegmentFixed(long entriesPerSegment) {
double precision = 1.0 / averageChunksPerEntry();
double entriesPerSegmentShouldBe =
PoissonDistribution.meanByCumulativeProbabilityAndValue(
long entriesPerSegmentShouldBe =
(long) PoissonDistribution.meanByCumulativeProbabilityAndValue(
nonTieredSegmentsPercentile, entriesPerSegment, precision);
long segments = ((long) (entries() / entriesPerSegmentShouldBe)) + 1;
long segments = divideRoundUp(entries(), entriesPerSegmentShouldBe);
checkSegments(segments);
if (minSegments > 0)
segments = Math.max(minSegments, segments);
@@ -975,10 +981,13 @@ public final class ChronicleMapBuilder<K, V> implements
long tierHashLookupCapacity() {
long entriesPerSegment = entriesPerSegment();
long capacity = CompactOffHeapLinearHashTable.capacityFor(entriesPerSegment);
long maxEntriesPerTier = PoissonDistribution.inverseCumulativeProbability(
entriesPerSegment, nonTieredSegmentsPercentile);
while (maxEntriesPerTier > MAX_LOAD_FACTOR * capacity) {
capacity *= 2;
if (actualSegments() > 1) {
// if there is only 1 segment, there is no source of variance in segments filling
long maxEntriesPerTier = PoissonDistribution.inverseCumulativeProbability(
entriesPerSegment, nonTieredSegmentsPercentile);
while (maxEntriesPerTier > MAX_LOAD_FACTOR * capacity) {
capacity *= 2;
}
}
return capacity;
}