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src/java.xml/share/classes/com/sun/org/apache/bcel/internal/classfile/ConstantUtf8.java
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*** 1,7 ****
/*
! * Copyright (c) 2017, 2019, Oracle and/or its affiliates. All rights reserved.
*/
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
--- 1,7 ----
/*
! * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
*/
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
*** 27,213 ****
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
/**
! * This class is derived from the abstract {@link Constant}
! * and represents a reference to a Utf8 encoded string.
*
- * @version $Id$
* @see Constant
! * @LastModified: Jun 2019
*/
public final class ConstantUtf8 extends Constant {
! private final String bytes;
- // TODO these should perhaps be AtomicInt?
- private static volatile int considered = 0;
- private static volatile int hits = 0;
- private static volatile int skipped = 0;
- private static volatile int created = 0;
-
- // Set the size to 0 or below to skip caching entirely
- private static final int MAX_CACHED_SIZE = 200;
private static final boolean BCEL_STATISTICS = false;
- private static class CACHE_HOLDER {
-
- private static final int MAX_CACHE_ENTRIES = 20000;
- private static final int INITIAL_CACHE_CAPACITY = (int)(MAX_CACHE_ENTRIES/0.75);
-
- private static final HashMap<String, ConstantUtf8> CACHE =
- new LinkedHashMap<String, ConstantUtf8>(INITIAL_CACHE_CAPACITY, 0.75f, true) {
private static final long serialVersionUID = -8506975356158971766L;
@Override
protected boolean removeEldestEntry(final Map.Entry<String, ConstantUtf8> eldest) {
! return size() > MAX_CACHE_ENTRIES;
}
};
! }
! // for accesss by test code
! static void printStats() {
! System.err.println("Cache hit " + hits + "/" + considered +", " + skipped + " skipped");
! System.err.println("Total of " + created + " ConstantUtf8 objects created");
}
- // for accesss by test code
- static void clearStats() {
- hits = considered = skipped = created = 0;
}
! static {
! if (BCEL_STATISTICS) {
! Runtime.getRuntime().addShutdownHook(new Thread() {
! @Override
! public void run() {
! printStats();
! }
! });
! }
}
/**
* @since 6.0
*/
! public static ConstantUtf8 getCachedInstance(final String s) {
! if (s.length() > MAX_CACHED_SIZE) {
! skipped++;
! return new ConstantUtf8(s);
}
! considered++;
synchronized (ConstantUtf8.class) { // might be better with a specific lock object
! ConstantUtf8 result = CACHE_HOLDER.CACHE.get(s);
if (result != null) {
- hits++;
return result;
}
! result = new ConstantUtf8(s);
! CACHE_HOLDER.CACHE.put(s, result);
return result;
}
}
/**
* @since 6.0
*/
! public static ConstantUtf8 getInstance(final String s) {
! return new ConstantUtf8(s);
}
/**
* @since 6.0
*/
! public static ConstantUtf8 getInstance (final DataInput input) throws IOException {
! return getInstance(input.readUTF());
}
/**
! * Initialize from another object.
*/
! public ConstantUtf8(final ConstantUtf8 c) {
! this(c.getBytes());
}
-
/**
! * Initialize instance from file data.
*
! * @param file Input stream
* @throws IOException
*/
! ConstantUtf8(final DataInput file) throws IOException {
super(Const.CONSTANT_Utf8);
! bytes = file.readUTF();
! created++;
}
-
/**
! * @param bytes Data
*/
! public ConstantUtf8(final String bytes) {
super(Const.CONSTANT_Utf8);
! if (bytes == null) {
! throw new IllegalArgumentException("bytes must not be null!");
}
! this.bytes = bytes;
! created++;
}
-
/**
! * Called by objects that are traversing the nodes of the tree implicitely
! * defined by the contents of a Java class. I.e., the hierarchy of methods,
! * fields, attributes, etc. spawns a tree of objects.
*
* @param v Visitor object
*/
@Override
! public void accept( final Visitor v ) {
v.visitConstantUtf8(this);
}
-
/**
! * Dump String in Utf8 format to file stream.
*
* @param file Output file stream
* @throws IOException
*/
@Override
! public final void dump( final DataOutputStream file ) throws IOException {
file.writeByte(super.getTag());
! file.writeUTF(bytes);
}
-
/**
* @return Data converted to string.
*/
! public final String getBytes() {
! return bytes;
}
-
/**
! * @param bytes the raw bytes of this Utf-8
* @deprecated (since 6.0)
*/
@java.lang.Deprecated
! public final void setBytes( final String bytes ) {
throw new UnsupportedOperationException();
}
-
/**
* @return String representation
*/
@Override
! public final String toString() {
! return super.toString() + "(\"" + Utility.replace(bytes, "\n", "\\n") + "\")";
}
}
--- 27,208 ----
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
/**
! * Extends the abstract {@link Constant} to represent a reference to a UTF-8 encoded string.
*
* @see Constant
! * @LastModified: Jan 2020
*/
public final class ConstantUtf8 extends Constant {
! private static class Cache {
private static final boolean BCEL_STATISTICS = false;
+ private static final int MAX_ENTRIES = 20000;
+ private static final int INITIAL_CAPACITY = (int) (MAX_ENTRIES / 0.75);
+ private static final HashMap<String, ConstantUtf8> CACHE = new LinkedHashMap<String, ConstantUtf8>(
+ INITIAL_CAPACITY, 0.75f, true) {
private static final long serialVersionUID = -8506975356158971766L;
@Override
protected boolean removeEldestEntry(final Map.Entry<String, ConstantUtf8> eldest) {
! return size() > MAX_ENTRIES;
}
};
! // Set the size to 0 or below to skip caching entirely
! private static final int MAX_ENTRY_SIZE = 200;
! static boolean isEnabled() {
! return Cache.MAX_ENTRIES > 0 && MAX_ENTRY_SIZE > 0;
}
}
! /**
! * Clears the cache.
! *
! * @since 6.4.0
! */
! public static synchronized void clearCache() {
! Cache.CACHE.clear();
}
/**
+ * Gets a new or cached instance of the given value.
+ * <p>
+ * See {@link ConstantUtf8} class Javadoc for details.
+ * </p>
+ *
+ * @param value the value.
+ * @return a new or cached instance of the given value.
* @since 6.0
*/
! public static ConstantUtf8 getCachedInstance(final String value) {
! if (value.length() > Cache.MAX_ENTRY_SIZE) {
! return new ConstantUtf8(value);
}
!
synchronized (ConstantUtf8.class) { // might be better with a specific lock object
! ConstantUtf8 result = Cache.CACHE.get(value);
if (result != null) {
return result;
}
! result = new ConstantUtf8(value);
! Cache.CACHE.put(value, result);
return result;
}
}
/**
+ * Gets a new or cached instance of the given value.
+ * <p>
+ * See {@link ConstantUtf8} class Javadoc for details.
+ * </p>
+ *
+ * @param dataInput the value.
+ * @return a new or cached instance of the given value.
+ * @throws IOException if an I/O error occurs.
* @since 6.0
*/
! public static ConstantUtf8 getInstance(final DataInput dataInput) throws IOException {
! return getInstance(dataInput.readUTF());
}
/**
+ * Gets a new or cached instance of the given value.
+ * <p>
+ * See {@link ConstantUtf8} class Javadoc for details.
+ * </p>
+ *
+ * @param value the value.
+ * @return a new or cached instance of the given value.
* @since 6.0
*/
! public static ConstantUtf8 getInstance(final String value) {
! return Cache.isEnabled() ? getCachedInstance(value) : new ConstantUtf8(value);
}
+ private final String value;
+
/**
! * Initializes from another object.
! *
! * @param constantUtf8 the value.
*/
! public ConstantUtf8(final ConstantUtf8 constantUtf8) {
! this(constantUtf8.getBytes());
}
/**
! * Initializes instance from file data.
*
! * @param dataInput Input stream
* @throws IOException
*/
! ConstantUtf8(final DataInput dataInput) throws IOException {
super(Const.CONSTANT_Utf8);
! value = dataInput.readUTF();
}
/**
! * @param value Data
*/
! public ConstantUtf8(final String value) {
super(Const.CONSTANT_Utf8);
! if (value == null) {
! throw new IllegalArgumentException("Value must not be null.");
}
! this.value = value;
}
/**
! * Called by objects that are traversing the nodes of the tree implicitely defined by the contents of a Java class.
! * I.e., the hierarchy of methods, fields, attributes, etc. spawns a tree of objects.
*
* @param v Visitor object
*/
@Override
! public void accept(final Visitor v) {
v.visitConstantUtf8(this);
}
/**
! * Dumps String in Utf8 format to file stream.
*
* @param file Output file stream
* @throws IOException
*/
@Override
! public void dump(final DataOutputStream file) throws IOException {
file.writeByte(super.getTag());
! file.writeUTF(value);
}
/**
* @return Data converted to string.
*/
! public String getBytes() {
! return value;
}
/**
! * @param bytes the raw bytes of this UTF-8
* @deprecated (since 6.0)
*/
@java.lang.Deprecated
! public void setBytes(final String bytes) {
throw new UnsupportedOperationException();
}
/**
* @return String representation
*/
@Override
! public String toString() {
! return super.toString() + "(\"" + Utility.replace(value, "\n", "\\n") + "\")";
}
}
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