com/android/internal/util/BinaryXmlSerializer.java - platform/prebuilts/fullsdk/sources/android-31 - Git at Google

 /*
  * Copyright (C) 2020 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.internal.util;

 import static org.xmlpull.v1.XmlPullParser.CDSECT;
 import static org.xmlpull.v1.XmlPullParser.COMMENT;
 import static org.xmlpull.v1.XmlPullParser.DOCDECL;
 import static org.xmlpull.v1.XmlPullParser.END_DOCUMENT;
 import static org.xmlpull.v1.XmlPullParser.END_TAG;
 import static org.xmlpull.v1.XmlPullParser.ENTITY_REF;
 import static org.xmlpull.v1.XmlPullParser.IGNORABLE_WHITESPACE;
 import static org.xmlpull.v1.XmlPullParser.PROCESSING_INSTRUCTION;
 import static org.xmlpull.v1.XmlPullParser.START_DOCUMENT;
 import static org.xmlpull.v1.XmlPullParser.START_TAG;
 import static org.xmlpull.v1.XmlPullParser.TEXT;

 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.util.TypedXmlSerializer;

 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlSerializer;

 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.Writer;
 import java.nio.charset.StandardCharsets;
 import java.util.Arrays;

 /**
  * Serializer that writes XML documents using a custom binary wire protocol
  * which benchmarking has shown to be 4.3x faster and use 2.4x less disk space
  * than {@code Xml.newFastSerializer()} for a typical {@code packages.xml}.
  * <p>
  * The high-level design of the wire protocol is to directly serialize the event
  * stream, while efficiently and compactly writing strongly-typed primitives
  * delivered through the {@link TypedXmlSerializer} interface.
  * <p>
  * Each serialized event is a single byte where the lower half is a normal
  * {@link XmlPullParser} token and the upper half is an optional data type
  * signal, such as {@link #TYPE_INT}.
  * <p>
  * This serializer has some specific limitations:
  * <ul>
  * <li>Only the UTF-8 encoding is supported.
  * <li>Variable length values, such as {@code byte[]} or {@link String}, are
  * limited to 65,535 bytes in length. Note that {@link String} values are stored
  * as UTF-8 on the wire.
  * <li>Namespaces, prefixes, properties, and options are unsupported.
  * </ul>
  */
 public final class BinaryXmlSerializer implements TypedXmlSerializer {
     /**
      * The wire protocol always begins with a well-known magic value of
      * {@code ABX_}, representing "Android Binary XML." The final byte is a
      * version number which may be incremented as the protocol changes.
      */
     public static final byte[] PROTOCOL_MAGIC_VERSION_0 = new byte[] { 0x41, 0x42, 0x58, 0x00 };

     /**
      * Internal token which represents an attribute associated with the most
      * recent {@link #START_TAG} token.
      */
     static final int ATTRIBUTE = 15;

     static final int TYPE_NULL = 1 << 4;
     static final int TYPE_STRING = 2 << 4;
     static final int TYPE_STRING_INTERNED = 3 << 4;
     static final int TYPE_BYTES_HEX = 4 << 4;
     static final int TYPE_BYTES_BASE64 = 5 << 4;
     static final int TYPE_INT = 6 << 4;
     static final int TYPE_INT_HEX = 7 << 4;
     static final int TYPE_LONG = 8 << 4;
     static final int TYPE_LONG_HEX = 9 << 4;
     static final int TYPE_FLOAT = 10 << 4;
     static final int TYPE_DOUBLE = 11 << 4;
     static final int TYPE_BOOLEAN_TRUE = 12 << 4;
     static final int TYPE_BOOLEAN_FALSE = 13 << 4;

     /**
      * Default buffer size, which matches {@code FastXmlSerializer}. This should
      * be kept in sync with {@link BinaryXmlPullParser}.
      */
     private static final int BUFFER_SIZE = 32_768;

     private FastDataOutput mOut;

     /**
      * Stack of tags which are currently active via {@link #startTag} and which
      * haven't been terminated via {@link #endTag}.
      */
     private int mTagCount = 0;
     private String[] mTagNames;

     /**
      * Write the given token and optional {@link String} into our buffer.
      */
     private void writeToken(int token, @Nullable String text) throws IOException {
         if (text != null) {
             mOut.writeByte(token | TYPE_STRING);
             mOut.writeUTF(text);
         } else {
             mOut.writeByte(token | TYPE_NULL);
         }
     }

     @Override
     public void setOutput(@NonNull OutputStream os, @Nullable String encoding) throws IOException {
         if (encoding != null && !StandardCharsets.UTF_8.name().equalsIgnoreCase(encoding)) {
             throw new UnsupportedOperationException();
         }

         mOut = new FastDataOutput(os, BUFFER_SIZE);
         mOut.write(PROTOCOL_MAGIC_VERSION_0);

         mTagCount = 0;
         mTagNames = new String[8];
     }

     @Override
     public void setOutput(Writer writer) {
         throw new UnsupportedOperationException();
     }

     @Override
     public void flush() throws IOException {
         mOut.flush();
     }

     @Override
     public void startDocument(@Nullable String encoding, @Nullable Boolean standalone)
             throws IOException {
         if (encoding != null && !StandardCharsets.UTF_8.name().equalsIgnoreCase(encoding)) {
             throw new UnsupportedOperationException();
         }
         if (standalone != null && !standalone) {
             throw new UnsupportedOperationException();
         }
         mOut.writeByte(START_DOCUMENT | TYPE_NULL);
     }

     @Override
     public void endDocument() throws IOException {
         mOut.writeByte(END_DOCUMENT | TYPE_NULL);
         flush();
     }

     @Override
     public int getDepth() {
         return mTagCount;
     }

     @Override
     public String getNamespace() {
         // Namespaces are unsupported
         return XmlPullParser.NO_NAMESPACE;
     }

     @Override
     public String getName() {
         return mTagNames[mTagCount - 1];
     }

     @Override
     public XmlSerializer startTag(String namespace, String name) throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         if (mTagCount == mTagNames.length) {
             mTagNames = Arrays.copyOf(mTagNames, mTagCount + (mTagCount >> 1));
         }
         mTagNames[mTagCount++] = name;
         mOut.writeByte(START_TAG | TYPE_STRING_INTERNED);
         mOut.writeInternedUTF(name);
         return this;
     }

     @Override
     public XmlSerializer endTag(String namespace, String name) throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mTagCount--;
         mOut.writeByte(END_TAG | TYPE_STRING_INTERNED);
         mOut.writeInternedUTF(name);
         return this;
     }

     @Override
     public XmlSerializer attribute(String namespace, String name, String value) throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_STRING);
         mOut.writeInternedUTF(name);
         mOut.writeUTF(value);
         return this;
     }

     @Override
     public XmlSerializer attributeInterned(String namespace, String name, String value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_STRING_INTERNED);
         mOut.writeInternedUTF(name);
         mOut.writeInternedUTF(value);
         return this;
     }

     @Override
     public XmlSerializer attributeBytesHex(String namespace, String name, byte[] value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_BYTES_HEX);
         mOut.writeInternedUTF(name);
         mOut.writeShort(value.length);
         mOut.write(value);
         return this;
     }

     @Override
     public XmlSerializer attributeBytesBase64(String namespace, String name, byte[] value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_BYTES_BASE64);
         mOut.writeInternedUTF(name);
         mOut.writeShort(value.length);
         mOut.write(value);
         return this;
     }

     @Override
     public XmlSerializer attributeInt(String namespace, String name, int value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_INT);
         mOut.writeInternedUTF(name);
         mOut.writeInt(value);
         return this;
     }

     @Override
     public XmlSerializer attributeIntHex(String namespace, String name, int value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_INT_HEX);
         mOut.writeInternedUTF(name);
         mOut.writeInt(value);
         return this;
     }

     @Override
     public XmlSerializer attributeLong(String namespace, String name, long value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_LONG);
         mOut.writeInternedUTF(name);
         mOut.writeLong(value);
         return this;
     }

     @Override
     public XmlSerializer attributeLongHex(String namespace, String name, long value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_LONG_HEX);
         mOut.writeInternedUTF(name);
         mOut.writeLong(value);
         return this;
     }

     @Override
     public XmlSerializer attributeFloat(String namespace, String name, float value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_FLOAT);
         mOut.writeInternedUTF(name);
         mOut.writeFloat(value);
         return this;
     }

     @Override
     public XmlSerializer attributeDouble(String namespace, String name, double value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         mOut.writeByte(ATTRIBUTE | TYPE_DOUBLE);
         mOut.writeInternedUTF(name);
         mOut.writeDouble(value);
         return this;
     }

     @Override
     public XmlSerializer attributeBoolean(String namespace, String name, boolean value)
             throws IOException {
         if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
         if (value) {
             mOut.writeByte(ATTRIBUTE | TYPE_BOOLEAN_TRUE);
             mOut.writeInternedUTF(name);
         } else {
             mOut.writeByte(ATTRIBUTE | TYPE_BOOLEAN_FALSE);
             mOut.writeInternedUTF(name);
         }
         return this;
     }

     @Override
     public XmlSerializer text(char[] buf, int start, int len) throws IOException {
         writeToken(TEXT, new String(buf, start, len));
         return this;
     }

     @Override
     public XmlSerializer text(String text) throws IOException {
         writeToken(TEXT, text);
         return this;
     }

     @Override
     public void cdsect(String text) throws IOException {
         writeToken(CDSECT, text);
     }

     @Override
     public void entityRef(String text) throws IOException {
         writeToken(ENTITY_REF, text);
     }

     @Override
     public void processingInstruction(String text) throws IOException {
         writeToken(PROCESSING_INSTRUCTION, text);
     }

     @Override
     public void comment(String text) throws IOException {
         writeToken(COMMENT, text);
     }

     @Override
     public void docdecl(String text) throws IOException {
         writeToken(DOCDECL, text);
     }

     @Override
     public void ignorableWhitespace(String text) throws IOException {
         writeToken(IGNORABLE_WHITESPACE, text);
     }

     @Override
     public void setFeature(String name, boolean state) {
         // Quietly handle no-op features
         if ("http://xmlpull.org/v1/doc/features.html#indent-output".equals(name)) {
             return;
         }
         // Features are not supported
         throw new UnsupportedOperationException();
     }

     @Override
     public boolean getFeature(String name) {
         // Features are not supported
         throw new UnsupportedOperationException();
     }

     @Override
     public void setProperty(String name, Object value) {
         // Properties are not supported
         throw new UnsupportedOperationException();
     }

     @Override
     public Object getProperty(String name) {
         // Properties are not supported
         throw new UnsupportedOperationException();
     }

     @Override
     public void setPrefix(String prefix, String namespace) {
         // Prefixes are not supported
         throw new UnsupportedOperationException();
     }

     @Override
     public String getPrefix(String namespace, boolean generatePrefix) {
         // Prefixes are not supported
         throw new UnsupportedOperationException();
     }

     private static IllegalArgumentException illegalNamespace() {
         throw new IllegalArgumentException("Namespaces are not supported");
     }
 }
	/*
	* Copyright (C) 2020 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.internal.util;

	import static org.xmlpull.v1.XmlPullParser.CDSECT;
	import static org.xmlpull.v1.XmlPullParser.COMMENT;
	import static org.xmlpull.v1.XmlPullParser.DOCDECL;
	import static org.xmlpull.v1.XmlPullParser.END_DOCUMENT;
	import static org.xmlpull.v1.XmlPullParser.END_TAG;
	import static org.xmlpull.v1.XmlPullParser.ENTITY_REF;
	import static org.xmlpull.v1.XmlPullParser.IGNORABLE_WHITESPACE;
	import static org.xmlpull.v1.XmlPullParser.PROCESSING_INSTRUCTION;
	import static org.xmlpull.v1.XmlPullParser.START_DOCUMENT;
	import static org.xmlpull.v1.XmlPullParser.START_TAG;
	import static org.xmlpull.v1.XmlPullParser.TEXT;

	import android.annotation.NonNull;
	import android.annotation.Nullable;
	import android.util.TypedXmlSerializer;

	import org.xmlpull.v1.XmlPullParser;
	import org.xmlpull.v1.XmlSerializer;

	import java.io.IOException;
	import java.io.OutputStream;
	import java.io.Writer;
	import java.nio.charset.StandardCharsets;
	import java.util.Arrays;

	/**
	* Serializer that writes XML documents using a custom binary wire protocol
	* which benchmarking has shown to be 4.3x faster and use 2.4x less disk space
	* than {@code Xml.newFastSerializer()} for a typical {@code packages.xml}.
	* <p>
	* The high-level design of the wire protocol is to directly serialize the event
	* stream, while efficiently and compactly writing strongly-typed primitives
	* delivered through the {@link TypedXmlSerializer} interface.
	* <p>
	* Each serialized event is a single byte where the lower half is a normal
	* {@link XmlPullParser} token and the upper half is an optional data type
	* signal, such as {@link #TYPE_INT}.
	* <p>
	* This serializer has some specific limitations:
	* <ul>
	* <li>Only the UTF-8 encoding is supported.
	* <li>Variable length values, such as {@code byte[]} or {@link String}, are
	* limited to 65,535 bytes in length. Note that {@link String} values are stored
	* as UTF-8 on the wire.
	* <li>Namespaces, prefixes, properties, and options are unsupported.
	* </ul>
	*/
	public final class BinaryXmlSerializer implements TypedXmlSerializer {
	/**
	* The wire protocol always begins with a well-known magic value of
	* {@code ABX_}, representing "Android Binary XML." The final byte is a
	* version number which may be incremented as the protocol changes.
	*/
	public static final byte[] PROTOCOL_MAGIC_VERSION_0 = new byte[] { 0x41, 0x42, 0x58, 0x00 };

	/**
	* Internal token which represents an attribute associated with the most
	* recent {@link #START_TAG} token.
	*/
	static final int ATTRIBUTE = 15;

	static final int TYPE_NULL = 1 << 4;
	static final int TYPE_STRING = 2 << 4;
	static final int TYPE_STRING_INTERNED = 3 << 4;
	static final int TYPE_BYTES_HEX = 4 << 4;
	static final int TYPE_BYTES_BASE64 = 5 << 4;
	static final int TYPE_INT = 6 << 4;
	static final int TYPE_INT_HEX = 7 << 4;
	static final int TYPE_LONG = 8 << 4;
	static final int TYPE_LONG_HEX = 9 << 4;
	static final int TYPE_FLOAT = 10 << 4;
	static final int TYPE_DOUBLE = 11 << 4;
	static final int TYPE_BOOLEAN_TRUE = 12 << 4;
	static final int TYPE_BOOLEAN_FALSE = 13 << 4;

	/**
	* Default buffer size, which matches {@code FastXmlSerializer}. This should
	* be kept in sync with {@link BinaryXmlPullParser}.
	*/
	private static final int BUFFER_SIZE = 32_768;

	private FastDataOutput mOut;

	/**
	* Stack of tags which are currently active via {@link #startTag} and which
	* haven't been terminated via {@link #endTag}.
	*/
	private int mTagCount = 0;
	private String[] mTagNames;

	/**
	* Write the given token and optional {@link String} into our buffer.
	*/
	private void writeToken(int token, @Nullable String text) throws IOException {
	if (text != null) {
	mOut.writeByte(token \| TYPE_STRING);
	mOut.writeUTF(text);
	} else {
	mOut.writeByte(token \| TYPE_NULL);
	}
	}

	@Override
	public void setOutput(@NonNull OutputStream os, @Nullable String encoding) throws IOException {
	if (encoding != null && !StandardCharsets.UTF_8.name().equalsIgnoreCase(encoding)) {
	throw new UnsupportedOperationException();
	}

	mOut = new FastDataOutput(os, BUFFER_SIZE);
	mOut.write(PROTOCOL_MAGIC_VERSION_0);

	mTagCount = 0;
	mTagNames = new String[8];
	}

	@Override
	public void setOutput(Writer writer) {
	throw new UnsupportedOperationException();
	}

	@Override
	public void flush() throws IOException {
	mOut.flush();
	}

	@Override
	public void startDocument(@Nullable String encoding, @Nullable Boolean standalone)
	throws IOException {
	if (encoding != null && !StandardCharsets.UTF_8.name().equalsIgnoreCase(encoding)) {
	throw new UnsupportedOperationException();
	}
	if (standalone != null && !standalone) {
	throw new UnsupportedOperationException();
	}
	mOut.writeByte(START_DOCUMENT \| TYPE_NULL);
	}

	@Override
	public void endDocument() throws IOException {
	mOut.writeByte(END_DOCUMENT \| TYPE_NULL);
	flush();
	}

	@Override
	public int getDepth() {
	return mTagCount;
	}

	@Override
	public String getNamespace() {
	// Namespaces are unsupported
	return XmlPullParser.NO_NAMESPACE;
	}

	@Override
	public String getName() {
	return mTagNames[mTagCount - 1];
	}

	@Override
	public XmlSerializer startTag(String namespace, String name) throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	if (mTagCount == mTagNames.length) {
	mTagNames = Arrays.copyOf(mTagNames, mTagCount + (mTagCount >> 1));
	}
	mTagNames[mTagCount++] = name;
	mOut.writeByte(START_TAG \| TYPE_STRING_INTERNED);
	mOut.writeInternedUTF(name);
	return this;
	}

	@Override
	public XmlSerializer endTag(String namespace, String name) throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mTagCount--;
	mOut.writeByte(END_TAG \| TYPE_STRING_INTERNED);
	mOut.writeInternedUTF(name);
	return this;
	}

	@Override
	public XmlSerializer attribute(String namespace, String name, String value) throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_STRING);
	mOut.writeInternedUTF(name);
	mOut.writeUTF(value);
	return this;
	}

	@Override
	public XmlSerializer attributeInterned(String namespace, String name, String value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_STRING_INTERNED);
	mOut.writeInternedUTF(name);
	mOut.writeInternedUTF(value);
	return this;
	}

	@Override
	public XmlSerializer attributeBytesHex(String namespace, String name, byte[] value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_BYTES_HEX);
	mOut.writeInternedUTF(name);
	mOut.writeShort(value.length);
	mOut.write(value);
	return this;
	}

	@Override
	public XmlSerializer attributeBytesBase64(String namespace, String name, byte[] value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_BYTES_BASE64);
	mOut.writeInternedUTF(name);
	mOut.writeShort(value.length);
	mOut.write(value);
	return this;
	}

	@Override
	public XmlSerializer attributeInt(String namespace, String name, int value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_INT);
	mOut.writeInternedUTF(name);
	mOut.writeInt(value);
	return this;
	}

	@Override
	public XmlSerializer attributeIntHex(String namespace, String name, int value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_INT_HEX);
	mOut.writeInternedUTF(name);
	mOut.writeInt(value);
	return this;
	}

	@Override
	public XmlSerializer attributeLong(String namespace, String name, long value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_LONG);
	mOut.writeInternedUTF(name);
	mOut.writeLong(value);
	return this;
	}

	@Override
	public XmlSerializer attributeLongHex(String namespace, String name, long value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_LONG_HEX);
	mOut.writeInternedUTF(name);
	mOut.writeLong(value);
	return this;
	}

	@Override
	public XmlSerializer attributeFloat(String namespace, String name, float value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_FLOAT);
	mOut.writeInternedUTF(name);
	mOut.writeFloat(value);
	return this;
	}

	@Override
	public XmlSerializer attributeDouble(String namespace, String name, double value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	mOut.writeByte(ATTRIBUTE \| TYPE_DOUBLE);
	mOut.writeInternedUTF(name);
	mOut.writeDouble(value);
	return this;
	}

	@Override
	public XmlSerializer attributeBoolean(String namespace, String name, boolean value)
	throws IOException {
	if (namespace != null && !namespace.isEmpty()) throw illegalNamespace();
	if (value) {
	mOut.writeByte(ATTRIBUTE \| TYPE_BOOLEAN_TRUE);
	mOut.writeInternedUTF(name);
	} else {
	mOut.writeByte(ATTRIBUTE \| TYPE_BOOLEAN_FALSE);
	mOut.writeInternedUTF(name);
	}
	return this;
	}

	@Override
	public XmlSerializer text(char[] buf, int start, int len) throws IOException {
	writeToken(TEXT, new String(buf, start, len));
	return this;
	}

	@Override
	public XmlSerializer text(String text) throws IOException {
	writeToken(TEXT, text);
	return this;
	}

	@Override
	public void cdsect(String text) throws IOException {
	writeToken(CDSECT, text);
	}

	@Override
	public void entityRef(String text) throws IOException {
	writeToken(ENTITY_REF, text);
	}

	@Override
	public void processingInstruction(String text) throws IOException {
	writeToken(PROCESSING_INSTRUCTION, text);
	}

	@Override
	public void comment(String text) throws IOException {
	writeToken(COMMENT, text);
	}

	@Override
	public void docdecl(String text) throws IOException {
	writeToken(DOCDECL, text);
	}

	@Override
	public void ignorableWhitespace(String text) throws IOException {
	writeToken(IGNORABLE_WHITESPACE, text);
	}

	@Override
	public void setFeature(String name, boolean state) {
	// Quietly handle no-op features
	if ("http://xmlpull.org/v1/doc/features.html#indent-output".equals(name)) {
	return;
	}
	// Features are not supported
	throw new UnsupportedOperationException();
	}

	@Override
	public boolean getFeature(String name) {
	// Features are not supported
	throw new UnsupportedOperationException();
	}

	@Override
	public void setProperty(String name, Object value) {
	// Properties are not supported
	throw new UnsupportedOperationException();
	}

	@Override
	public Object getProperty(String name) {
	// Properties are not supported
	throw new UnsupportedOperationException();
	}

	@Override
	public void setPrefix(String prefix, String namespace) {
	// Prefixes are not supported
	throw new UnsupportedOperationException();
	}

	@Override
	public String getPrefix(String namespace, boolean generatePrefix) {
	// Prefixes are not supported
	throw new UnsupportedOperationException();
	}

	private static IllegalArgumentException illegalNamespace() {
	throw new IllegalArgumentException("Namespaces are not supported");
	}
	}