Limit HashLookup slot size with 4 or 8 bytes, back

This commit is contained in:
leventov
2015-09-22 23:07:54 +03:00
parent d9c771bedc
commit b113118707
5 changed files with 158 additions and 46 deletions
@@ -16,13 +16,13 @@
package net.openhft.chronicle.hash.impl;
import net.openhft.lang.Maths;
import net.openhft.chronicle.core.Maths;
import static net.openhft.lang.MemoryUnit.BITS;
import static net.openhft.lang.MemoryUnit.BYTES;
import static net.openhft.lang.io.NativeBytes.UNSAFE;
public class CompactOffHeapLinearHashTable {
public abstract class CompactOffHeapLinearHashTable {
// to fit 64 bits per slot.
public static final int MAX_SEGMENT_CHUNKS = 1 << 30;
public static final int MAX_SEGMENT_ENTRIES = 1 << 29;
@@ -45,7 +45,12 @@ public class CompactOffHeapLinearHashTable {
}
public static int entrySize(int keyBits, int valueBits) {
return (int) BYTES.alignAndConvert((long) (keyBits + valueBits), BITS);
int entrySize = (int) BYTES.alignAndConvert((long) (keyBits + valueBits), BITS);
if (entrySize <= 4)
return 4;
if (entrySize <= 8)
return 8;
return entrySize;
}
public static long capacityFor(long entriesPerSegment) {
@@ -68,23 +73,19 @@ public class CompactOffHeapLinearHashTable {
private final long capacityMask;
private final int hashLookupEntrySize;
private final long capacityMask2;
final long capacityMask2;
private final int keyBits;
private final long keyMask;
private final long valueMask;
private final long entryMask;
CompactOffHeapLinearHashTable(long capacity, int entrySize, int keyBits, int valueBits) {
this.capacityMask = capacity - 1L;
this.hashLookupEntrySize = entrySize;
this.capacityMask2 = capacityMask * entrySize;
this.keyBits = keyBits;
this.keyMask = mask(keyBits);
this.valueMask = mask(valueBits);
this.entryMask = mask(keyBits + valueBits);
}
CompactOffHeapLinearHashTable(VanillaChronicleHash h) {
@@ -92,9 +93,7 @@ public class CompactOffHeapLinearHashTable {
h.segmentHashLookupValueBits);
}
long indexToPos(long index) {
return index * hashLookupEntrySize;
}
abstract long indexToPos(long index);
public long maskUnsetKey(long key) {
return (key &= keyMask) != UNSET_KEY ? key : keyMask;
@@ -105,7 +104,7 @@ public class CompactOffHeapLinearHashTable {
}
public boolean empty(long entry) {
return (entry & entryMask) == UNSET_ENTRY;
return entry == UNSET_ENTRY;
}
public long key(long entry) {
@@ -124,22 +123,14 @@ public class CompactOffHeapLinearHashTable {
return indexToPos(key & capacityMask);
}
public long step(long pos) {
return (pos += hashLookupEntrySize) <= capacityMask2 ? pos : 0L;
}
public abstract long step(long pos);
public long stepBack(long pos) {
return (pos -= hashLookupEntrySize) >= 0 ? pos : capacityMask2;
}
public abstract long stepBack(long pos);
public long readEntry(long addr, long pos) {
return UNSAFE.getLong(addr + pos);
}
public abstract long readEntry(long addr, long pos);
public void writeEntryVolatile(long addr, long pos, long prevEntry, long key, long value) {
long entry = (prevEntry & ~entryMask) | entry(key, value);
UNSAFE.putLongVolatile(null, addr + pos, entry);
}
public abstract void writeEntryVolatile(
long addr, long pos, long prevEntry, long key, long value);
public void putValueVolatile(long addr, long pos, long value) {
checkValueForPut(value);
@@ -147,19 +138,9 @@ public class CompactOffHeapLinearHashTable {
writeEntryVolatile(addr, pos, currentEntry, key(currentEntry), value);
}
void writeEntry(long addr, long pos, long prevEntry, long anotherEntry) {
long entry = (prevEntry & ~entryMask) | (anotherEntry & entryMask);
UNSAFE.putLong(addr + pos, entry);
}
abstract void writeEntry(long addr, long pos, long prevEntry, long anotherEntry);
void clearEntry(long addr, long pos, long prevEntry) {
long entry = (prevEntry & ~entryMask);
UNSAFE.putLong(addr + pos, entry);
}
public void clearHashLookup(long addr) {
UNSAFE.setMemory(addr, capacityMask2 + hashLookupEntrySize, (byte) 0);
}
abstract void clearEntry(long addr, long pos, long prevEntry);
/**
* Returns "insert" position in terms of consequent putValue()
@@ -0,0 +1,63 @@
/*
* Copyright (C) 2015 higherfrequencytrading.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package net.openhft.chronicle.hash.impl;
import static net.openhft.lang.io.NativeBytes.UNSAFE;
public final class IntCompactOffHeapLinearHashTable extends CompactOffHeapLinearHashTable {
private static final long SCALE = 4L;
IntCompactOffHeapLinearHashTable(VanillaChronicleHash h) {
super(h);
}
@Override
long indexToPos(long index) {
return index * SCALE;
}
@Override
public long step(long pos) {
return (pos + SCALE) & capacityMask2;
}
@Override
public long stepBack(long pos) {
return (pos - SCALE) & capacityMask2;
}
@Override
public long readEntry(long addr, long pos) {
return UNSAFE.getInt(addr + pos);
}
@Override
public void writeEntryVolatile(long addr, long pos, long prevEntry, long key, long value) {
UNSAFE.putIntVolatile(null, addr + pos, (int) entry(key, value));
}
@Override
void writeEntry(long addr, long pos, long prevEntry, long anotherEntry) {
UNSAFE.putInt(addr + pos, (int) anotherEntry);
}
@Override
void clearEntry(long addr, long pos, long prevEntry) {
UNSAFE.putInt(addr + pos, 0);
}
}
@@ -0,0 +1,63 @@
/*
* Copyright (C) 2015 higherfrequencytrading.com
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package net.openhft.chronicle.hash.impl;
import static net.openhft.lang.io.NativeBytes.UNSAFE;
public final class LongCompactOffHeapLinearHashTable extends CompactOffHeapLinearHashTable {
private static final long SCALE = 8L;
LongCompactOffHeapLinearHashTable(VanillaChronicleHash h) {
super(h);
}
@Override
long indexToPos(long index) {
return index * SCALE;
}
@Override
public long step(long pos) {
return (pos + SCALE) & capacityMask2;
}
@Override
public long stepBack(long pos) {
return (pos - SCALE) & capacityMask2;
}
@Override
public long readEntry(long addr, long pos) {
return UNSAFE.getLong(addr + pos);
}
@Override
public void writeEntryVolatile(long addr, long pos, long prevEntry, long key, long value) {
UNSAFE.putLongVolatile(null, addr + pos, entry(key, value));
}
@Override
void writeEntry(long addr, long pos, long prevEntry, long anotherEntry) {
UNSAFE.putLong(addr + pos, anotherEntry);
}
@Override
void clearEntry(long addr, long pos, long prevEntry) {
UNSAFE.putLong(addr + pos, 0L);
}
}
@@ -255,7 +255,14 @@ public abstract class VanillaChronicleHash<K, KI, MKI extends MetaBytesInterop<K
private void ownInitTransients() {
keyReaderProvider = Provider.of((Class) originalKeyReader.getClass());
keyInteropProvider = Provider.of((Class) originalKeyInterop.getClass());
hashLookup = new CompactOffHeapLinearHashTable(this);
if (segmentHashLookupEntrySize == 4) {
hashLookup = new IntCompactOffHeapLinearHashTable(this);
} else if (segmentHashLookupEntrySize == 8) {
hashLookup = new LongCompactOffHeapLinearHashTable(this);
} else {
throw new AssertionError("hash lookup slot size could be 4 or 8, " +
segmentHashLookupEntrySize + " observed");
}
}
public final void createMappedStoreAndSegments(BytesStore bytesStore) throws IOException {
@@ -877,8 +877,8 @@ public final class ChronicleMapBuilder<K, V> implements
if (entriesPerSegment > 0) {
return (int) segmentsGivenEntriesPerSegmentFixed(entriesPerSegment, replicated);
}
// iteratively try to fit 3..8 bytes per hash lookup slot. Trying to apply small slot
// sizes (=> segment sizes, because slot size depends on segment size) not only because
// Try to fit 4 bytes per hash lookup slot, then 8. Trying to apply small slot
// size (=> segment size, because slot size depends on segment size) not only because
// they take less memory per entry (if entries are of KBs or MBs, it doesn't matter), but
// also because if segment size is small, slot and free list are likely to lie on a single
// memory page, reducing number of memory pages to update, if Chronicle Map is persisted.
@@ -898,11 +898,9 @@ public final class ChronicleMapBuilder<K, V> implements
// each segment. To compensate this at least on linux, don't accept segment sizes that with
// the given entry sizes, lead to too small total segment sizes in native memory pages,
// see comment in tryHashLookupSlotSize()
for (int hashLookupSlotSize = 3; hashLookupSlotSize <= 7; hashLookupSlotSize++) {
long segments = tryHashLookupSlotSize(hashLookupSlotSize, replicated);
if (segments > 0)
return (int) segments;
}
long segments = tryHashLookupSlotSize(4, replicated);
if (segments > 0)
return (int) segments;
long maxEntriesPerSegment = findMaxEntriesPerSegmentToFitHashLookupSlotSize(8, replicated);
long maxSegments = trySegments(maxEntriesPerSegment, MAX_SEGMENTS, replicated);
if (maxSegments > 0L)