Merge pull request #403 from parsingdata/#402_hash_improvements

#402: Hash calculation improvements
parsingdata · Nov 24, 2023 · f90d79f · f90d79f
2 parents 16f7df2 + 4a3e8d8
commit f90d79f
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Showing 55 changed files with 279 additions and 97 deletions.
diff --git a/core/src/main/java/io/parsingdata/metal/ImmutableObject.java b/core/src/main/java/io/parsingdata/metal/ImmutableObject.java
@@ -0,0 +1,26 @@
+package io.parsingdata.metal;
+
+/**
+ * When objects are immutable, that means their hash code will stay the same the moment it is created.
+ * It will improve performance if these objects cache their hash code.
+ * <p>
+ * This is a lazy implementation, instead of calculating the hash once within the constructor, to avoid
+ * performance decrease during parsing. In most implementations the hash code is not actually used/needed.
+ */
+public abstract class ImmutableObject {
+
+    private Integer hashCode;
+
+    public abstract int immutableHashCode();
+
+    @Override
+    public abstract boolean equals(final Object obj);
+
+    @Override
+    public int hashCode() {
+        if (hashCode == null) {
+            hashCode = immutableHashCode();
+        }
+        return hashCode;
+    }
+}
diff --git a/core/src/main/java/io/parsingdata/metal/data/ByteStreamSource.java b/core/src/main/java/io/parsingdata/metal/data/ByteStreamSource.java
@@ -64,7 +64,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), input);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ConcatenatedValueSource.java b/core/src/main/java/io/parsingdata/metal/data/ConcatenatedValueSource.java
@@ -106,7 +106,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), values, length);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ConstantSource.java b/core/src/main/java/io/parsingdata/metal/data/ConstantSource.java
@@ -62,7 +62,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), Arrays.hashCode(data));
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/DataExpressionSource.java b/core/src/main/java/io/parsingdata/metal/data/DataExpressionSource.java
@@ -102,7 +102,7 @@ public boolean equals(Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), dataExpression, index, parseState, encoding);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ImmutableList.java b/core/src/main/java/io/parsingdata/metal/data/ImmutableList.java
@@ -23,10 +23,11 @@
 
 import java.util.Objects;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Trampoline;
 import io.parsingdata.metal.Util;
 
-public class ImmutableList<T> {
+public class ImmutableList<T> extends ImmutableObject {
 
     public final T head;
     public final ImmutableList<T> tail;
@@ -104,7 +105,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), head, tail);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ImmutablePair.java b/core/src/main/java/io/parsingdata/metal/data/ImmutablePair.java
@@ -20,9 +20,10 @@
 
 import java.util.Objects;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 
-public class ImmutablePair<L, R> {
+public class ImmutablePair<L, R> extends ImmutableObject {
 
     public final L left;
     public final R right;
@@ -45,7 +46,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), left, right);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ParseGraph.java b/core/src/main/java/io/parsingdata/metal/data/ParseGraph.java
@@ -23,11 +23,12 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Trampoline;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.token.Token;
 
-public class ParseGraph implements ParseItem {
+public class ParseGraph extends ImmutableObject implements ParseItem {
 
     public final ParseItem head;
     public final ParseGraph tail;
@@ -143,7 +144,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), head, tail, branched, definition);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ParseReference.java b/core/src/main/java/io/parsingdata/metal/data/ParseReference.java
@@ -24,10 +24,11 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.token.Token;
 
-public class ParseReference implements ParseItem {
+public class ParseReference extends ImmutableObject implements ParseItem {
 
     public final BigInteger location;
     public final Source source;
@@ -61,7 +62,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), location, source, definition);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ParseState.java b/core/src/main/java/io/parsingdata/metal/data/ParseState.java
@@ -29,10 +29,11 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.token.Token;
 
-public class ParseState {
+public class ParseState extends ImmutableObject {
 
     public final ParseGraph order;
     public final ParseValueCache cache;
@@ -120,7 +121,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), order, cache, offset, source, iterations, references);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/ParseValue.java b/core/src/main/java/io/parsingdata/metal/data/ParseValue.java
@@ -61,8 +61,8 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
-        return Objects.hash(super.hashCode(), name, definition);
+    public int immutableHashCode() {
+        return Objects.hash(super.immutableHashCode(), name, definition);
     }
 
 }
diff --git a/core/src/main/java/io/parsingdata/metal/data/Slice.java b/core/src/main/java/io/parsingdata/metal/data/Slice.java
@@ -25,9 +25,10 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 
-public class Slice {
+public class Slice extends ImmutableObject {
 
     public final Source source;
     public final BigInteger offset;
@@ -75,7 +76,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), source, offset, length);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/data/Source.java b/core/src/main/java/io/parsingdata/metal/data/Source.java
@@ -18,7 +18,9 @@
 
 import java.math.BigInteger;
 
-public abstract class Source {
+import io.parsingdata.metal.ImmutableObject;
+
+public abstract class Source extends ImmutableObject {
 
     protected abstract byte[] getData(BigInteger offset, BigInteger length);
 

diff --git a/core/src/main/java/io/parsingdata/metal/encoding/Encoding.java b/core/src/main/java/io/parsingdata/metal/encoding/Encoding.java
@@ -22,9 +22,10 @@
 import java.nio.charset.StandardCharsets;
 import java.util.Objects;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 
-public class Encoding {
+public class Encoding extends ImmutableObject {
 
     public static final Sign DEFAULT_SIGN = Sign.UNSIGNED;
     public static final Charset DEFAULT_CHARSET = StandardCharsets.US_ASCII;
@@ -68,7 +69,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), sign, charset, byteOrder);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/expression/True.java b/core/src/main/java/io/parsingdata/metal/expression/True.java
@@ -16,6 +16,7 @@
 
 package io.parsingdata.metal.expression;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.data.ParseState;
 import io.parsingdata.metal.encoding.Encoding;
@@ -24,7 +25,7 @@
  * An {@link Expression} that always evaluates to <code>true</code>. Generally
  * used as default on undefined predicates.
  */
-public class True implements Expression {
+public class True extends ImmutableObject implements Expression {
 
     @Override
     public boolean eval(final ParseState parseState, final Encoding encoding) {
@@ -42,7 +43,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return getClass().hashCode();
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/expression/comparison/ComparisonExpression.java b/core/src/main/java/io/parsingdata/metal/expression/comparison/ComparisonExpression.java
@@ -23,6 +23,7 @@
 
 import java.util.Objects;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Trampoline;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.data.ImmutableList;
@@ -44,7 +45,7 @@
  * not evaluated and the output value is substituted with a list containing
  * only the {@link Value} most recently added to the {@link ParseState}.
  */
-public abstract class ComparisonExpression implements Expression {
+public abstract class ComparisonExpression extends ImmutableObject implements Expression {
 
     public final ValueExpression value;
     public final ValueExpression predicate;
@@ -97,7 +98,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), value, predicate);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/expression/logical/BinaryLogicalExpression.java b/core/src/main/java/io/parsingdata/metal/expression/logical/BinaryLogicalExpression.java
@@ -20,6 +20,7 @@
 
 import java.util.Objects;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.expression.Expression;
 
@@ -31,7 +32,7 @@
  * their results combined using the operator the concrete expression
  * implements and then returned.
  */
-public abstract class BinaryLogicalExpression implements LogicalExpression {
+public abstract class BinaryLogicalExpression extends ImmutableObject implements LogicalExpression {
 
     public final Expression left;
     public final Expression right;
@@ -54,7 +55,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), left, right);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/expression/logical/UnaryLogicalExpression.java b/core/src/main/java/io/parsingdata/metal/expression/logical/UnaryLogicalExpression.java
@@ -20,6 +20,7 @@
 
 import java.util.Objects;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.expression.Expression;
 
@@ -31,7 +32,7 @@
  * {@link Expression}). The <code>operand</code> is evaluated, the concrete
  * implementation's operator is applied to the result and returned.
  */
-public abstract class UnaryLogicalExpression implements LogicalExpression {
+public abstract class UnaryLogicalExpression extends ImmutableObject implements LogicalExpression {
 
     public final Expression operand;
 
@@ -51,7 +52,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), operand);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/expression/value/BinaryValueExpression.java b/core/src/main/java/io/parsingdata/metal/expression/value/BinaryValueExpression.java
@@ -25,6 +25,7 @@
 import java.util.Objects;
 import java.util.Optional;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Trampoline;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.data.ImmutableList;
@@ -52,7 +53,7 @@
  *
  * @see UnaryValueExpression
  */
-public abstract class BinaryValueExpression implements ValueExpression {
+public abstract class BinaryValueExpression extends ImmutableObject implements ValueExpression {
 
     public final ValueExpression left;
     public final ValueExpression right;
@@ -108,7 +109,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), left, right);
     }
 

diff --git a/core/src/main/java/io/parsingdata/metal/expression/value/Bytes.java b/core/src/main/java/io/parsingdata/metal/expression/value/Bytes.java
@@ -27,6 +27,7 @@
 import java.math.BigInteger;
 import java.util.Objects;
 
+import io.parsingdata.metal.ImmutableObject;
 import io.parsingdata.metal.Trampoline;
 import io.parsingdata.metal.Util;
 import io.parsingdata.metal.data.ImmutableList;
@@ -47,7 +48,7 @@
  * 2 and 3 bytes respectively, the Bytes expression turns this into a list of
  * 5 values, representing the individual bytes of the original results.
  */
-public class Bytes implements ValueExpression {
+public class Bytes extends ImmutableObject implements ValueExpression {
 
     public final ValueExpression operand;
 
@@ -89,7 +90,7 @@ public boolean equals(final Object obj) {
     }
 
     @Override
-    public int hashCode() {
+    public int immutableHashCode() {
         return Objects.hash(getClass(), operand);
     }