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package org.graalvm.compiler.hotspot.replacements;

import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.nio.ByteBuffer;

import org.graalvm.compiler.core.common.PermanentBailoutException;
import org.graalvm.compiler.core.common.type.DataPointerConstant;

import jdk.vm.ci.hotspot.HotSpotMetaspaceConstant;
import jdk.vm.ci.hotspot.HotSpotObjectConstant;
import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;
import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;
import jdk.vm.ci.meta.Constant;

Represents an encoded representation of a constant.
/** * Represents an encoded representation of a constant. */
public final class EncodedSymbolConstant extends DataPointerConstant { private final Constant constant; private byte[] bytes; public EncodedSymbolConstant(Constant constant) { super(1); this.constant = constant; } @Override public int getSerializedSize() { return getEncodedConstant().length; } @Override public void serialize(ByteBuffer buffer) { buffer.put(getEncodedConstant()); }
Converts a string to a byte array with modified UTF-8 encoding. The first two bytes of the byte array store the length of the string in bytes.
Params:
  • s – a java.lang.String in UTF-16
/** * Converts a string to a byte array with modified UTF-8 encoding. The first two bytes of the * byte array store the length of the string in bytes. * * @param s a java.lang.String in UTF-16 */
private static byte[] toUTF8String(String s) { try (ByteArrayOutputStream bytes = new ByteArrayOutputStream()) { DataOutputStream stream = new DataOutputStream(bytes); stream.writeUTF(s); return bytes.toByteArray(); } catch (Exception e) { throw new PermanentBailoutException(e, "String conversion failed: %s", s); } } private static byte[] encodeConstant(Constant constant) { assert constant != null; if (constant instanceof HotSpotObjectConstant) { return toUTF8String(((HotSpotObjectConstant) constant).asObject(String.class)); } else if (constant instanceof HotSpotMetaspaceConstant) { HotSpotMetaspaceConstant metaspaceConstant = ((HotSpotMetaspaceConstant) constant); HotSpotResolvedObjectType klass = metaspaceConstant.asResolvedJavaType(); if (klass != null) { return toUTF8String(klass.getName()); } HotSpotResolvedJavaMethod method = metaspaceConstant.asResolvedJavaMethod(); if (method != null) { byte[] methodName = toUTF8String(method.getName()); byte[] signature = toUTF8String(method.getSignature().toMethodDescriptor()); byte[] result = new byte[methodName.length + signature.length]; int resultPos = 0; System.arraycopy(methodName, 0, result, resultPos, methodName.length); resultPos += methodName.length; System.arraycopy(signature, 0, result, resultPos, signature.length); resultPos += signature.length; assert resultPos == result.length; return result; } } throw new PermanentBailoutException("Encoding of constant %s failed", constant); } public byte[] getEncodedConstant() { if (bytes == null) { bytes = encodeConstant(constant); } return bytes; } @Override public String toValueString() { return "encoded symbol\"" + constant.toValueString() + "\""; } }