HBASE-22504 Optimize the MultiByteBuff#get(ByteBuffer, offset, len)

This commit is contained in:
huzheng 2019-05-30 22:17:05 +08:00
parent f83c919587
commit 97c1158421
3 changed files with 45 additions and 36 deletions

View File

@ -580,7 +580,7 @@ public class MultiByteBuff extends ByteBuff {
while (length > 0) {
int toRead = Math.min(length, this.curItem.remaining());
ByteBufferUtils.copyFromBufferToArray(dst, this.curItem, this.curItem.position(), offset,
toRead);
toRead);
this.curItem.position(this.curItem.position() + toRead);
length -= toRead;
if (length == 0) break;
@ -598,8 +598,7 @@ public class MultiByteBuff extends ByteBuff {
sourceOffset = sourceOffset - this.itemBeginPos[itemIndex];
while (length > 0) {
int toRead = Math.min((item.limit() - sourceOffset), length);
ByteBufferUtils.copyFromBufferToArray(dst, item, sourceOffset, offset,
toRead);
ByteBufferUtils.copyFromBufferToArray(dst, item, sourceOffset, offset, toRead);
length -= toRead;
if (length == 0) break;
itemIndex++;
@ -1020,24 +1019,30 @@ public class MultiByteBuff extends ByteBuff {
}
pair.setFirst(ByteBuffer.wrap(dst));
pair.setSecond(0);
return;
}
/**
* Copies the content from an this MBB to a ByteBuffer
* @param out the ByteBuffer to which the copy has to happen
* @param sourceOffset the offset in the MBB from which the elements has
* to be copied
* @param out the ByteBuffer to which the copy has to happen, its position will be advanced.
* @param sourceOffset the offset in the MBB from which the elements has to be copied
* @param length the length in the MBB upto which the elements has to be copied
*/
@Override
public void get(ByteBuffer out, int sourceOffset,
int length) {
public void get(ByteBuffer out, int sourceOffset, int length) {
checkRefCount();
// Not used from real read path actually. So not going with
// optimization
for (int i = 0; i < length; ++i) {
out.put(this.get(sourceOffset + i));
int itemIndex = getItemIndex(sourceOffset);
ByteBuffer in = this.items[itemIndex];
sourceOffset = sourceOffset - this.itemBeginPos[itemIndex];
while (length > 0) {
int toRead = Math.min(in.limit() - sourceOffset, length);
ByteBufferUtils.copyFromBufferToBuffer(in, out, sourceOffset, toRead);
length -= toRead;
if (length == 0) {
break;
}
itemIndex++;
in = this.items[itemIndex];
sourceOffset = 0;
}
}

View File

@ -719,8 +719,8 @@ public final class ByteBufferUtils {
* @param sourceOffset offset in the source buffer
* @param length how many bytes to copy
*/
public static void copyFromBufferToBuffer(ByteBuffer in,
ByteBuffer out, int sourceOffset, int length) {
public static void copyFromBufferToBuffer(ByteBuffer in, ByteBuffer out, int sourceOffset,
int length) {
if (in.hasArray() && out.hasArray()) {
System.arraycopy(in.array(), sourceOffset + in.arrayOffset(), out.array(), out.position()
+ out.arrayOffset(), length);
@ -735,27 +735,6 @@ public final class ByteBufferUtils {
}
}
/**
* Find length of common prefix of two parts in the buffer
* @param buffer Where parts are located.
* @param offsetLeft Offset of the first part.
* @param offsetRight Offset of the second part.
* @param limit Maximal length of common prefix.
* @return Length of prefix.
*/
public static int findCommonPrefix(ByteBuffer buffer, int offsetLeft,
int offsetRight, int limit) {
int prefix = 0;
for (; prefix < limit; ++prefix) {
if (buffer.get(offsetLeft + prefix) != buffer.get(offsetRight + prefix)) {
break;
}
}
return prefix;
}
/**
* Find length of common prefix in two arrays.
* @param left Array to be compared.

View File

@ -457,4 +457,29 @@ public class TestMultiByteBuff {
assertEquals(i, mbb.getInt());
assertEquals(l, mbb.getLong());
}
@Test
public void testGetByteBufferWithOffsetAndPos() {
byte[] a = Bytes.toBytes("abcd");
byte[] b = Bytes.toBytes("efghijkl");
ByteBuffer aa = ByteBuffer.wrap(a);
ByteBuffer bb = ByteBuffer.wrap(b);
MultiByteBuff mbb = new MultiByteBuff(aa, bb);
ByteBuffer out = ByteBuffer.allocate(12);
mbb.get(out, 0, 1);
assertEquals(out.position(), 1);
assertTrue(Bytes.equals(Bytes.toBytes("a"), 0, 1, out.array(), 0, 1));
mbb.get(out, 1, 4);
assertEquals(out.position(), 5);
assertTrue(Bytes.equals(Bytes.toBytes("abcde"), 0, 5, out.array(), 0, 5));
mbb.get(out, 10, 1);
assertEquals(out.position(), 6);
assertTrue(Bytes.equals(Bytes.toBytes("abcdek"), 0, 6, out.array(), 0, 6));
mbb.get(out, 0, 6);
assertEquals(out.position(), 12);
assertTrue(Bytes.equals(Bytes.toBytes("abcdekabcdef"), 0, 12, out.array(), 0, 12));
}
}