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Avoid re-parsing sql expressions. #3

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45 changes: 42 additions & 3 deletions pinot-common/src/main/java/org/apache/pinot/pql/parsers/Pql2Compiler.java
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Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,9 @@
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import javax.annotation.concurrent.ThreadSafe;

import com.github.benmanes.caffeine.cache.Cache;
import com.github.benmanes.caffeine.cache.Caffeine;
import org.antlr.v4.runtime.ANTLRInputStream;
import org.antlr.v4.runtime.BailErrorStrategy;
import org.antlr.v4.runtime.BaseErrorListener;
Expand Down Expand Up @@ -73,6 +76,13 @@ public class Pql2Compiler implements AbstractCompiler {
public static String ENABLE_DISTINCT_KEY = "pinot.distinct.enabled";
public static boolean ENABLE_DISTINCT = Boolean.valueOf(System.getProperty(ENABLE_DISTINCT_KEY, "true"));

private static final int REQUEST_CACHE_SIZE = 1_000;
private static final int TRANSFORM_CACHE_SIZE = 1_000;

private static final Cache<String, BrokerRequest> _brokerRequestCache = Caffeine.newBuilder().maximumSize(REQUEST_CACHE_SIZE).build();
private static final Cache<String, BrokerRequest> _brokerRequestCacheWithPinotQuery = Caffeine.newBuilder().maximumSize(REQUEST_CACHE_SIZE).build();
private static final Cache<String, TransformExpressionTree> _expressionTreeCache = Caffeine.newBuilder().maximumSize(TRANSFORM_CACHE_SIZE).build();

private static class ErrorListener extends BaseErrorListener {

@Override
Expand All @@ -84,6 +94,14 @@ public void syntaxError(@Nonnull Recognizer<?, ?> recognizer, @Nullable Object o

private static final ErrorListener ERROR_LISTENER = new ErrorListener();

private static Cache<String, BrokerRequest> getBrokerRequestCache() {
if (ENABLE_PINOT_QUERY) {
return _brokerRequestCacheWithPinotQuery;
}

return _brokerRequestCache;
}

/**
* Compile the given expression into {@link BrokerRequest}.
*
Expand All @@ -94,7 +112,13 @@ public void syntaxError(@Nonnull Recognizer<?, ?> recognizer, @Nullable Object o
public BrokerRequest compileToBrokerRequest(String expression)
throws Pql2CompilationException {
try {
//
// Try to load previously cached result
BrokerRequest cached = getBrokerRequestCache().getIfPresent(expression);
if (cached != null) {
return cached.deepCopy();
}

// Initialize
CharStream charStream = new ANTLRInputStream(expression);
PQL2Lexer lexer = new PQL2Lexer(charStream);
lexer.setTokenFactory(new CommonTokenFactory(true));
Expand Down Expand Up @@ -144,7 +168,11 @@ public BrokerRequest compileToBrokerRequest(String expression)
}
}
}
return brokerRequest;

// Cache parsed broker request for reuse
getBrokerRequestCache().put(expression, brokerRequest);

return brokerRequest.deepCopy();
} catch (Pql2CompilationException e) {
throw e;
} catch (Exception e) {
Expand All @@ -153,6 +181,13 @@ public BrokerRequest compileToBrokerRequest(String expression)
}

public TransformExpressionTree compileToExpressionTree(String expression) {
// Check for cached expression tree
TransformExpressionTree transformExpressionTree = _expressionTreeCache.getIfPresent(expression);
if (transformExpressionTree != null) {
return transformExpressionTree;
}

// Initialize
CharStream charStream = new ANTLRInputStream(expression);
PQL2Lexer lexer = new PQL2Lexer(charStream);
lexer.setTokenFactory(new CommonTokenFactory(true));
Expand All @@ -167,7 +202,11 @@ public TransformExpressionTree compileToExpressionTree(String expression) {
Pql2AstListener listener = new Pql2AstListener(expression);
walker.walk(listener, parseTree);

return new TransformExpressionTree(listener.getRootNode());
// Cache result for future reuse
transformExpressionTree = new TransformExpressionTree(listener.getRootNode());
_expressionTreeCache.put(expression, transformExpressionTree);

return transformExpressionTree;
}

private void validateHavingClause(AstNode rootNode) {
Expand Down
32 changes: 32 additions & 0 deletions pinot-common/src/test/java/org/apache/pinot/pql/parsers/Pql2CompilerTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -39,6 +39,8 @@
import org.testng.Assert;
import org.testng.annotations.Test;

import static junit.framework.Assert.*;


/**
* Some tests for the PQL 2 compiler.
Expand Down Expand Up @@ -476,4 +478,34 @@ private void testOrderBy(String pql, List<String> orderBys, List<Boolean> isAscs
Assert.assertEquals(orderBy.isIsAsc(), isAscs.get(i).booleanValue());
}
}

/**
* Test that ensures we are properly caching requests for performance reasons
*/
@Test
public void testQueryCaching() {
final String PQL = "select * from table order by d2 asc, d3 desc";
final String PQL1 = "select * from table order by d2, d3 desc";
final String EXP = "`a.b.c`";
final String EXP1 = "`a.b.d`";

BrokerRequest brokerRequest = COMPILER.compileToBrokerRequest(PQL);
BrokerRequest secondBrokerRequest = COMPILER.compileToBrokerRequest(PQL1);
BrokerRequest redoBrokerRequest = COMPILER.compileToBrokerRequest(PQL);

assertEquals(brokerRequest, redoBrokerRequest);
// This is completely different Broker Request
assertFalse(brokerRequest == secondBrokerRequest);
// Identity equality won't work because we do deepCopy since broker request options are mutable
assertFalse(brokerRequest == redoBrokerRequest);

TransformExpressionTree expTree = COMPILER.compileToExpressionTree(EXP);
TransformExpressionTree secondExpTree = COMPILER.compileToExpressionTree(EXP1);
TransformExpressionTree redoExpTree = COMPILER.compileToExpressionTree(EXP);

// This is completely different Broker Request
assertFalse(expTree == secondExpTree);
// Identity equality should work because we have cached the previous request
assertTrue(expTree == redoExpTree);
}
}