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Avoid memory allocation when searching index summary 

patch by benedict; reviewed by ariel for CASSANDRA-8793
This commit is contained in:
Benedict Elliott Smith 2015-03-10 13:54:36 +00:00
parent 6d266253a5
commit bf9c503130
6 changed files with 54 additions and 13 deletions
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1
CHANGES.txt
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@ -1,4 +1,5 @@
3.0
* Avoid memory allocation when searching index summary (CASSANDRA-8793)
* Optimise (Time)?UUIDType Comparisons (CASSANDRA-8730)
* Make CRC32Ex into a separate maven dependency (CASSANDRA-8836)
* Use preloaded jemalloc w/ Unsafe (CASSANDRA-8714)

12
src/java/org/apache/cassandra/io/sstable/IndexSummary.java
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@ -30,6 +30,7 @@ import org.apache.cassandra.io.util.Memory;
import org.apache.cassandra.io.util.MemoryOutputStream;
import org.apache.cassandra.utils.FBUtilities;
import org.apache.cassandra.utils.concurrent.WrappedSharedCloseable;
import org.apache.cassandra.utils.memory.MemoryUtil;
import static org.apache.cassandra.io.sstable.Downsampling.BASE_SAMPLING_LEVEL;
@ -105,11 +106,13 @@ public class IndexSummary extends WrappedSharedCloseable
// Harmony's Collections implementation
public int binarySearch(RowPosition key)
{
ByteBuffer hollow = MemoryUtil.getHollowDirectByteBuffer();
int low = 0, mid = offsetCount, high = mid - 1, result = -1;
while (low <= high)
{
mid = (low + high) >> 1;
result = -DecoratedKey.compareTo(partitioner, ByteBuffer.wrap(getKey(mid)), key);
fillTemporaryKey(mid, hollow);
result = -DecoratedKey.compareTo(partitioner, hollow, key);
if (result > 0)
{
low = mid + 1;
@ -147,6 +150,13 @@ public class IndexSummary extends WrappedSharedCloseable
return key;
}
private void fillTemporaryKey(int index, ByteBuffer buffer)
{
long start = getPositionInSummary(index);
int keySize = (int) (calculateEnd(index) - start - 8L);
entries.setByteBuffer(buffer, start, keySize);
}
public long getPosition(int index)
{
return entries.getLong(calculateEnd(index) - 8);

4
src/java/org/apache/cassandra/io/sstable/IndexSummaryBuilder.java
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@ -107,8 +107,8 @@ public class IndexSummaryBuilder implements AutoCloseable
// for initializing data structures, adjust our estimates based on the sampling level
maxExpectedEntries = Math.max(1, (maxExpectedEntries * samplingLevel) / BASE_SAMPLING_LEVEL);
offsets = new SafeMemoryWriter(4 * maxExpectedEntries).withByteOrder(ByteOrder.nativeOrder());
entries = new SafeMemoryWriter(40 * maxExpectedEntries).withByteOrder(ByteOrder.nativeOrder());
offsets = new SafeMemoryWriter(4 * maxExpectedEntries).order(ByteOrder.nativeOrder());
entries = new SafeMemoryWriter(40 * maxExpectedEntries).order(ByteOrder.nativeOrder());
setNextSamplePosition(-minIndexInterval);
}

21
src/java/org/apache/cassandra/io/util/Memory.java
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@ -182,7 +182,7 @@ public class Memory implements AutoCloseable
public void setShort(long offset, short l)
{
checkBounds(offset, offset + 4);
checkBounds(offset, offset + 2);
if (unaligned)
{
unsafe.putShort(peer + offset, l);
@ -245,9 +245,7 @@ public class Memory implements AutoCloseable
else if (count == 0)
return;
long end = memoryOffset + count;
checkBounds(memoryOffset, end);
checkBounds(memoryOffset, memoryOffset + count);
unsafe.copyMemory(buffer, BYTE_ARRAY_BASE_OFFSET + bufferOffset, null, peer + memoryOffset, count);
}
@ -343,6 +341,8 @@ public class Memory implements AutoCloseable
public void put(long trgOffset, Memory memory, long srcOffset, long size)
{
checkBounds(trgOffset, trgOffset + size);
memory.checkBounds(srcOffset, srcOffset + size);
unsafe.copyMemory(memory.peer + srcOffset, peer + trgOffset, size);
}
@ -401,6 +401,19 @@ public class Memory implements AutoCloseable
return result;
}
public ByteBuffer asByteBuffer(long offset, int length)
{
checkBounds(offset, offset + length);
return MemoryUtil.getByteBuffer(peer + offset, length);
}
// MUST provide a buffer created via MemoryUtil.getHollowDirectByteBuffer()
public void setByteBuffer(ByteBuffer buffer, long offset, int length)
{
checkBounds(offset, offset + length);
MemoryUtil.setByteBuffer(buffer, peer + offset, length);
}
public String toString()
{
return toString(peer, size);

15
src/java/org/apache/cassandra/io/util/SafeMemoryWriter.java
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@ -33,6 +33,7 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
buffer = new SafeMemory(initialCapacity);
}
@Override
public void write(byte[] buffer, int offset, int count)
{
long newLength = ensureCapacity(count);
@ -40,6 +41,7 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
this.length = newLength;
}
@Override
public void write(int oneByte)
{
long newLength = ensureCapacity(1);
@ -47,6 +49,7 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
length = newLength;
}
@Override
public void writeShort(int val) throws IOException
{
if (order != ByteOrder.nativeOrder())
@ -56,6 +59,7 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
length = newLength;
}
@Override
public void writeInt(int val)
{
if (order != ByteOrder.nativeOrder())
@ -65,6 +69,7 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
length = newLength;
}
@Override
public void writeLong(long val)
{
if (order != ByteOrder.nativeOrder())
@ -74,6 +79,7 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
length = newLength;
}
@Override
public void write(ByteBuffer buffer)
{
long newLength = ensureCapacity(buffer.remaining());
@ -81,10 +87,11 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
length = newLength;
}
public void write(Memory memory)
@Override
public void write(Memory memory, long offset, long size)
{
long newLength = ensureCapacity(memory.size());
buffer.put(length, memory, 0, memory.size());
long newLength = ensureCapacity(size);
buffer.put(length, memory, offset, size);
length = newLength;
}
@ -128,7 +135,7 @@ public class SafeMemoryWriter extends AbstractDataOutput implements DataOutputPl
// TODO: consider hoisting this into DataOutputPlus, since most implementations can copy with this gracefully
// this would simplify IndexSummary.IndexSummarySerializer.serialize()
public SafeMemoryWriter withByteOrder(ByteOrder order)
public SafeMemoryWriter order(ByteOrder order)
{
this.order = order;
return this;

14
src/java/org/apache/cassandra/utils/memory/MemoryUtil.java
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@ -123,6 +123,13 @@ public abstract class MemoryUtil
}
public static ByteBuffer getByteBuffer(long address, int length)
{
ByteBuffer instance = getHollowDirectByteBuffer();
setByteBuffer(instance, address, length);
return instance;
}
public static ByteBuffer getHollowDirectByteBuffer()
{
ByteBuffer instance;
try
@ -133,12 +140,15 @@ public abstract class MemoryUtil
{
throw new AssertionError(e);
}
instance.order(ByteOrder.nativeOrder());
return instance;
}
public static void setByteBuffer(ByteBuffer instance, long address, int length)
{
unsafe.putLong(instance, DIRECT_BYTE_BUFFER_ADDRESS_OFFSET, address);
unsafe.putInt(instance, DIRECT_BYTE_BUFFER_CAPACITY_OFFSET, length);
unsafe.putInt(instance, DIRECT_BYTE_BUFFER_LIMIT_OFFSET, length);
instance.order(ByteOrder.nativeOrder());
return instance;
}
public static long getLongByByte(long address)