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Posted to commits@druid.apache.org by GitBox <gi...@apache.org> on 2020/01/14 03:50:56 UTC
[GitHub] [druid] gianm opened a new pull request #9181: Speed up String
first/last aggregators when folding isn't needed.
gianm opened a new pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181
Examines the value column, and disables fold checking via a needsFoldCheck
flag if that column can't possibly contain SerializableLongStringPairs. This
is helpful because it avoids calling getObject on the value selector when
unnecessary; say, because the time selector didn't yield an earlier or later
value.
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[GitHub] [druid] lgtm-com[bot] commented on issue #9181: Speed up String
first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
lgtm-com[bot] commented on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-575439630
This pull request **fixes 1 alert** when merging de0697cb1834f77a2fafc57e5d56673a558c5e83 into 486c0fd149d9837a64550ecb9e85d9b6cd4beb24 - [view on LGTM.com](https://lgtm.com/projects/g/apache/druid/rev/pr-cbc76f7454ddad92381f9db32c521dcbd504afb8)
**fixed alerts:**
* 1 for Useless null check
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[GitHub] [druid] gianm commented on a change in pull request #9181: Speed up
String first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
gianm commented on a change in pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#discussion_r367656434
##########
File path: processing/src/main/java/org/apache/druid/query/aggregation/first/StringFirstLastUtils.java
##########
@@ -33,23 +36,63 @@
{
private static final int NULL_VALUE = -1;
+ /**
+ * Shorten "s" to "maxBytes" chars. Fast and loose because these are *chars* not *bytes*. Use
+ * {@link #chop(String, int)} for slower, but accurate chopping.
+ */
+ @Nullable
+ public static String fastLooseChop(@Nullable final String s, final int maxBytes)
+ {
+ if (s == null || s.length() <= maxBytes) {
+ return s;
+ } else {
+ return s.substring(0, maxBytes);
+ }
+ }
+
+ /**
+ * Shorten "s" to what could fit in "maxBytes" bytes as UTF-8.
+ */
@Nullable
public static String chop(@Nullable final String s, final int maxBytes)
{
if (s == null) {
return null;
} else {
- // Shorten firstValue to what could fit in maxBytes as UTF-8.
final byte[] bytes = new byte[maxBytes];
final int len = StringUtils.toUtf8WithLimit(s, ByteBuffer.wrap(bytes));
return new String(bytes, 0, len, StandardCharsets.UTF_8);
}
}
+ /**
+ * Returns whether a given value selector *might* contain SerializablePairLongString objects.
+ */
+ public static boolean selectorNeedsFoldCheck(
+ final BaseObjectColumnValueSelector<?> valueSelector,
+ @Nullable final ColumnCapabilities valueSelectorCapabilities
+ )
+ {
+ if (valueSelectorCapabilities != null && valueSelectorCapabilities.getType() != ValueType.COMPLEX) {
+ // Known, non-complex type.
+ return false;
+ }
+
+ if (valueSelector instanceof NilColumnValueSelector) {
+ // Nil column, definitely no SerializablePairLongStrings.
+ return false;
+ }
+
+ // Check if the reported class could possibly be SerializablePairLongString.
+ final Class<?> clazz = valueSelector.classOfObject();
+ return clazz.isAssignableFrom(SerializablePairLongString.class)
Review comment:
I changed it to:
```java
// Check if the selector class could possibly be a SerializablePairLongString (either a superclass or subclass).
```
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[GitHub] [druid] clintropolis commented on a change in pull request #9181:
Speed up String first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
clintropolis commented on a change in pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#discussion_r367736165
##########
File path: core/src/test/java/org/apache/druid/java/util/common/StringUtilsTest.java
##########
@@ -246,4 +246,32 @@ public void testRpad()
Assert.assertEquals(s5, null);
}
+ @Test
+ public void testChop()
+ {
+ Assert.assertEquals("foo", StringUtils.chop("foo", 5));
+ Assert.assertEquals("fo", StringUtils.chop("foo", 2));
+ Assert.assertEquals("", StringUtils.chop("foo", 0));
+ Assert.assertEquals("smile 🙂 for", StringUtils.chop("smile 🙂 for the camera", 14));
Review comment:
🙂
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[GitHub] [druid] gianm commented on a change in pull request #9181: Speed up
String first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
gianm commented on a change in pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#discussion_r367656532
##########
File path: processing/src/test/java/org/apache/druid/query/aggregation/last/StringLastBufferAggregatorTest.java
##########
@@ -81,6 +82,43 @@ public void testBufferAggregate()
}
+ @Test
+ public void testBufferAggregateWithFoldCheck()
+ {
+ final long[] timestamps = {1526724600L, 1526724700L, 1526724800L, 1526725900L, 1526725000L};
+ final String[] strings = {"AAAA", "BBBB", "CCCC", "DDDD", "EEEE"};
+ Integer maxStringBytes = 1024;
+
+ TestLongColumnSelector longColumnSelector = new TestLongColumnSelector(timestamps);
+ TestObjectColumnSelector<String> objectColumnSelector = new TestObjectColumnSelector<>(strings);
+
+ StringLastAggregatorFactory factory = new StringLastAggregatorFactory(
+ "billy", "billy", maxStringBytes
+ );
+
+ StringLastBufferAggregator agg = new StringLastBufferAggregator(
+ longColumnSelector,
+ objectColumnSelector,
+ maxStringBytes,
+ true
+ );
+
+ ByteBuffer buf = ByteBuffer.allocate(factory.getMaxIntermediateSize());
+ int position = 0;
+
+ agg.init(buf, position);
+ //noinspection ForLoopReplaceableByForEach
+ for (int i = 0; i < timestamps.length; i++) {
+ aggregateBuffer(longColumnSelector, objectColumnSelector, agg, buf, position);
+ }
+
+ SerializablePairLongString sp = ((SerializablePairLongString) agg.get(buf, position));
+
+
+ Assert.assertEquals("expectec last string value", "DDDD", sp.rhs);
Review comment:
Updated.
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[GitHub] [druid] clintropolis commented on a change in pull request #9181:
Speed up String first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
clintropolis commented on a change in pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#discussion_r366825374
##########
File path: processing/src/test/java/org/apache/druid/query/aggregation/last/StringLastBufferAggregatorTest.java
##########
@@ -81,6 +82,43 @@ public void testBufferAggregate()
}
+ @Test
+ public void testBufferAggregateWithFoldCheck()
+ {
+ final long[] timestamps = {1526724600L, 1526724700L, 1526724800L, 1526725900L, 1526725000L};
+ final String[] strings = {"AAAA", "BBBB", "CCCC", "DDDD", "EEEE"};
+ Integer maxStringBytes = 1024;
+
+ TestLongColumnSelector longColumnSelector = new TestLongColumnSelector(timestamps);
+ TestObjectColumnSelector<String> objectColumnSelector = new TestObjectColumnSelector<>(strings);
+
+ StringLastAggregatorFactory factory = new StringLastAggregatorFactory(
+ "billy", "billy", maxStringBytes
+ );
+
+ StringLastBufferAggregator agg = new StringLastBufferAggregator(
+ longColumnSelector,
+ objectColumnSelector,
+ maxStringBytes,
+ true
+ );
+
+ ByteBuffer buf = ByteBuffer.allocate(factory.getMaxIntermediateSize());
+ int position = 0;
+
+ agg.init(buf, position);
+ //noinspection ForLoopReplaceableByForEach
+ for (int i = 0; i < timestamps.length; i++) {
+ aggregateBuffer(longColumnSelector, objectColumnSelector, agg, buf, position);
+ }
+
+ SerializablePairLongString sp = ((SerializablePairLongString) agg.get(buf, position));
+
+
+ Assert.assertEquals("expectec last string value", "DDDD", sp.rhs);
Review comment:
nit: typo 'expectec'
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[GitHub] [druid] clintropolis merged pull request #9181: Speed up String
first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
clintropolis merged pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181
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[GitHub] [druid] lgtm-com[bot] commented on issue #9181: Speed up String
first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
lgtm-com[bot] commented on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-573999395
This pull request **fixes 1 alert** when merging ecc43107320489ea1267aed7b2dbd30f440104f9 into ea51bc45bff8b0b5c373d1121fa88b6d507fcabe - [view on LGTM.com](https://lgtm.com/projects/g/apache/druid/rev/pr-ac29c6587c91acbc15305f2cecfde8dc594497ae)
**fixed alerts:**
* 1 for Useless null check
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[GitHub] [druid] jon-wei commented on issue #9181: Speed up String
first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
jon-wei commented on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-575418815
There's a TC error about an resolved reference to the chop method
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[GitHub] [druid] gianm commented on issue #9181: Speed up String first/last
aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
gianm commented on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-575353132
@clintropolis Thanks for reviewing. I updated the patch to reflect your comments.
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[GitHub] [druid] clintropolis commented on a change in pull request #9181:
Speed up String first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
clintropolis commented on a change in pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#discussion_r366814361
##########
File path: processing/src/main/java/org/apache/druid/query/aggregation/first/StringFirstLastUtils.java
##########
@@ -33,23 +36,63 @@
{
private static final int NULL_VALUE = -1;
+ /**
+ * Shorten "s" to "maxBytes" chars. Fast and loose because these are *chars* not *bytes*. Use
+ * {@link #chop(String, int)} for slower, but accurate chopping.
+ */
+ @Nullable
+ public static String fastLooseChop(@Nullable final String s, final int maxBytes)
+ {
+ if (s == null || s.length() <= maxBytes) {
+ return s;
+ } else {
+ return s.substring(0, maxBytes);
+ }
+ }
+
+ /**
+ * Shorten "s" to what could fit in "maxBytes" bytes as UTF-8.
+ */
@Nullable
public static String chop(@Nullable final String s, final int maxBytes)
{
if (s == null) {
return null;
} else {
- // Shorten firstValue to what could fit in maxBytes as UTF-8.
final byte[] bytes = new byte[maxBytes];
final int len = StringUtils.toUtf8WithLimit(s, ByteBuffer.wrap(bytes));
return new String(bytes, 0, len, StandardCharsets.UTF_8);
}
}
+ /**
+ * Returns whether a given value selector *might* contain SerializablePairLongString objects.
+ */
+ public static boolean selectorNeedsFoldCheck(
+ final BaseObjectColumnValueSelector<?> valueSelector,
+ @Nullable final ColumnCapabilities valueSelectorCapabilities
+ )
+ {
+ if (valueSelectorCapabilities != null && valueSelectorCapabilities.getType() != ValueType.COMPLEX) {
+ // Known, non-complex type.
+ return false;
+ }
+
+ if (valueSelector instanceof NilColumnValueSelector) {
+ // Nil column, definitely no SerializablePairLongStrings.
+ return false;
+ }
+
+ // Check if the reported class could possibly be SerializablePairLongString.
+ final Class<?> clazz = valueSelector.classOfObject();
+ return clazz.isAssignableFrom(SerializablePairLongString.class)
Review comment:
Hmm, it looks to me like this method only returns true if a selector definitely is a `SerializablePairLongString `. Should this just be returning true if we made it here?
Alternatively, should `needsFoldCheck` be rebranded as `isFold` and the `aggregate` methods of the first last heap and buffer aggs just be reading a `SerializablePairLongString` from the value selector directly instead of calling `readPairFromSelectors`?
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[GitHub] [druid] gianm commented on issue #9181: Speed up String first/last
aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
gianm commented on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-575427555
> There's a TC error about an unresolved reference to the chop method
That was from a javadoc for `fastLooseChop`. It looks like `chop` was moved to StringUtils, so I moved `fastLooseChop` to the same place. And added unit tests for good measure.
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[GitHub] [druid] lgtm-com[bot] commented on issue #9181: Speed up String
first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
lgtm-com[bot] commented on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-575400116
This pull request **fixes 1 alert** when merging c56d895caf30f0b3171ea5cc09615e551adeeae4 into 42359c93dd53f16e52ed79dcd8b63829f4bf2f7b - [view on LGTM.com](https://lgtm.com/projects/g/apache/druid/rev/pr-60ba177285eee825f576c2665f6a7661b4aff17a)
**fixed alerts:**
* 1 for Useless null check
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[GitHub] [druid] lgtm-com[bot] commented on issue #9181: Speed up String
first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
lgtm-com[bot] commented on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-575378497
This pull request **fixes 1 alert** when merging 92f2218cf771c70b1173264e96621850bead8ea8 into a87db7f353cdee4dfa9b541063f59d67706d1b07 - [view on LGTM.com](https://lgtm.com/projects/g/apache/druid/rev/pr-cd9a4712d6ee17be67a5574f81c981254ad0052b)
**fixed alerts:**
* 1 for Useless null check
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[GitHub] [druid] jon-wei edited a comment on issue #9181: Speed up String
first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
jon-wei edited a comment on issue #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#issuecomment-575418815
There's a TC error about an unresolved reference to the chop method
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[GitHub] [druid] clintropolis commented on a change in pull request #9181:
Speed up String first/last aggregators when folding isn't needed.
Posted by GitBox <gi...@apache.org>.
clintropolis commented on a change in pull request #9181: Speed up String first/last aggregators when folding isn't needed.
URL: https://github.com/apache/druid/pull/9181#discussion_r367234568
##########
File path: processing/src/main/java/org/apache/druid/query/aggregation/first/StringFirstLastUtils.java
##########
@@ -33,23 +36,63 @@
{
private static final int NULL_VALUE = -1;
+ /**
+ * Shorten "s" to "maxBytes" chars. Fast and loose because these are *chars* not *bytes*. Use
+ * {@link #chop(String, int)} for slower, but accurate chopping.
+ */
+ @Nullable
+ public static String fastLooseChop(@Nullable final String s, final int maxBytes)
+ {
+ if (s == null || s.length() <= maxBytes) {
+ return s;
+ } else {
+ return s.substring(0, maxBytes);
+ }
+ }
+
+ /**
+ * Shorten "s" to what could fit in "maxBytes" bytes as UTF-8.
+ */
@Nullable
public static String chop(@Nullable final String s, final int maxBytes)
{
if (s == null) {
return null;
} else {
- // Shorten firstValue to what could fit in maxBytes as UTF-8.
final byte[] bytes = new byte[maxBytes];
final int len = StringUtils.toUtf8WithLimit(s, ByteBuffer.wrap(bytes));
return new String(bytes, 0, len, StandardCharsets.UTF_8);
}
}
+ /**
+ * Returns whether a given value selector *might* contain SerializablePairLongString objects.
+ */
+ public static boolean selectorNeedsFoldCheck(
+ final BaseObjectColumnValueSelector<?> valueSelector,
+ @Nullable final ColumnCapabilities valueSelectorCapabilities
+ )
+ {
+ if (valueSelectorCapabilities != null && valueSelectorCapabilities.getType() != ValueType.COMPLEX) {
+ // Known, non-complex type.
+ return false;
+ }
+
+ if (valueSelector instanceof NilColumnValueSelector) {
+ // Nil column, definitely no SerializablePairLongStrings.
+ return false;
+ }
+
+ // Check if the reported class could possibly be SerializablePairLongString.
+ final Class<?> clazz = valueSelector.classOfObject();
+ return clazz.isAssignableFrom(SerializablePairLongString.class)
Review comment:
Apologies, I was wrong, I think this line + comment just isn't super intuitive on first glance that it is a catch-all that any ‘unknown’ selector types will also be true (since clazz will be Object.class in that case). Maybe expanding on the comment would make it require less thought?
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