code: /*
   * Copyright (C) 2006 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.lody.virtual.helper.utils;
  
  import org.xmlpull.v1.XmlSerializer;
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.io.UnsupportedEncodingException;
  import java.io.Writer;
  import java.nio.ByteBuffer;
  import java.nio.CharBuffer;
  import java.nio.charset.Charset;
  import java.nio.charset.CharsetEncoder;
  import java.nio.charset.CoderResult;
  import java.nio.charset.IllegalCharsetNameException;
  import java.nio.charset.UnsupportedCharsetException;
  
  /**
   * This is a quick and dirty implementation of XmlSerializer that isn't horribly
   * painfully slow like the normal one.  It only does what is needed for the
   * specific XML files being written with it.
   */
  public class FastXmlSerializer implements XmlSerializer {
      private static final String ESCAPE_TABLE[] = new String[] {
          null,     null,     null,     null,     null,     null,     null,     null,  // 0-7
          null,     null,     null,     null,     null,     null,     null,     null,  // 8-15
          null,     null,     null,     null,     null,     null,     null,     null,  // 16-23
          null,     null,     null,     null,     null,     null,     null,     null,  // 24-31
          null,     null,     "&quot;", null,     null,     null,     "&amp;",  null,  // 32-39
          null,     null,     null,     null,     null,     null,     null,     null,  // 40-47
          null,     null,     null,     null,     null,     null,     null,     null,  // 48-55
          null,     null,     null,     null,     "&lt;",   null,     "&gt;",   null,  // 56-63
      };
  
      private static final int BUFFER_LEN = 8192;
  
      private static String sSpace = "                                                              ";
  
      private final char[] mText = new char[BUFFER_LEN];
      private int mPos;
  
      private Writer mWriter;
  
      private OutputStream mOutputStream;
      private CharsetEncoder mCharset;
      private ByteBuffer mBytes = ByteBuffer.allocate(BUFFER_LEN);
  
      private boolean mIndent = false;
      private boolean mInTag;
  
      private int mNesting = 0;
      private boolean mLineStart = true;
  
      private void append(char c) throws IOException {
          int pos = mPos;
          if (pos >= (BUFFER_LEN-1)) {
              flush();
              pos = mPos;
          }
          mText[pos] = c;
          mPos = pos+1;
      }
  
      private void append(String str, int i, final int length) throws IOException {
          if (length > BUFFER_LEN) {
              final int end = i + length;
              while (i < end) {
                  int next = i + BUFFER_LEN;
                  append(str, i, next<end ? BUFFER_LEN : (end-i));
                  i = next;
              }
              return;
          }
          int pos = mPos;
          if ((pos+length) > BUFFER_LEN) {
              flush();
              pos = mPos;
          }
          str.getChars(i, i+length, mText, pos);
          mPos = pos + length;
      }
  
      private void append(char[] buf, int i, final int length) throws IOException {
          if (length > BUFFER_LEN) {
              final int end = i + length;
              while (i < end) {
                  int next = i + BUFFER_LEN;
                  append(buf, i, next<end ? BUFFER_LEN : (end-i));
                  i = next;
              }
              return;
          }
          int pos = mPos;
          if ((pos+length) > BUFFER_LEN) {
              flush();
              pos = mPos;
          }
          System.arraycopy(buf, i, mText, pos, length);
          mPos = pos + length;
      }
  
      private void append(String str) throws IOException {
          append(str, 0, str.length());
      }
  
      private void appendIndent(int indent) throws IOException {
          indent *= 4;
          if (indent > sSpace.length()) {
              indent = sSpace.length();
          }
          append(sSpace, 0, indent);
      }
  
      private void escapeAndAppendString(final String string) throws IOException {
          final int N = string.length();
          final char NE = (char)ESCAPE_TABLE.length;
          final String[] escapes = ESCAPE_TABLE;
          int lastPos = 0;
          int pos;
          for (pos=0; pos<N; pos++) {
              char c = string.charAt(pos);
              if (c >= NE) continue;
              String escape = escapes[c];
              if (escape == null) continue;
              if (lastPos < pos) append(string, lastPos, pos-lastPos);
              lastPos = pos + 1;
              append(escape);
          }
          if (lastPos < pos) append(string, lastPos, pos-lastPos);
      }
  
      private void escapeAndAppendString(char[] buf, int start, int len) throws IOException {
          final char NE = (char)ESCAPE_TABLE.length;
          final String[] escapes = ESCAPE_TABLE;
          int end = start+len;
          int lastPos = start;
          int pos;
          for (pos=start; pos<end; pos++) {
              char c = buf[pos];
              if (c >= NE) continue;
              String escape = escapes[c];
              if (escape == null) continue;
              if (lastPos < pos) append(buf, lastPos, pos-lastPos);
              lastPos = pos + 1;
              append(escape);
          }
          if (lastPos < pos) append(buf, lastPos, pos-lastPos);
      }
  
      public XmlSerializer attribute(String namespace, String name, String value) throws IOException,
              IllegalArgumentException, IllegalStateException {
          append(' ');
          if (namespace != null) {
              append(namespace);
              append(':');
          }
          append(name);
          append("=\"");
  
          escapeAndAppendString(value);
          append('"');
          mLineStart = false;
          return this;
      }
  
      public void cdsect(String text) throws IOException, IllegalArgumentException,
              IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      public void comment(String text) throws IOException, IllegalArgumentException,
              IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      public void docdecl(String text) throws IOException, IllegalArgumentException,
              IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      public void endDocument() throws IOException, IllegalArgumentException, IllegalStateException {
          flush();
      }
  
      public XmlSerializer endTag(String namespace, String name) throws IOException,
              IllegalArgumentException, IllegalStateException {
          mNesting--;
          if (mInTag) {
              append(" />\n");
          } else {
              if (mIndent && mLineStart) {
                  appendIndent(mNesting);
              }
              append("</");
              if (namespace != null) {
                  append(namespace);
                  append(':');
              }
              append(name);
              append(">\n");
          }
          mLineStart = true;
          mInTag = false;
          return this;
      }
  
      public void entityRef(String text) throws IOException, IllegalArgumentException,
              IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      private void flushBytes() throws IOException {
          int position;
          if ((position = mBytes.position()) > 0) {
              mBytes.flip();
              mOutputStream.write(mBytes.array(), 0, position);
              mBytes.clear();
          }
      }
  
      public void flush() throws IOException {
          //Log.i("PackageManager", "flush mPos=" + mPos);
          if (mPos > 0) {
              if (mOutputStream != null) {
                  CharBuffer charBuffer = CharBuffer.wrap(mText, 0, mPos);
                  CoderResult result = mCharset.encode(charBuffer, mBytes, true);
                  while (true) {
                      if (result.isError()) {
                          throw new IOException(result.toString());
                      } else if (result.isOverflow()) {
                          flushBytes();
                          result = mCharset.encode(charBuffer, mBytes, true);
                          continue;
                      }
                      break;
                  }
                  flushBytes();
                  mOutputStream.flush();
              } else {
                  mWriter.write(mText, 0, mPos);
                  mWriter.flush();
              }
              mPos = 0;
          }
      }
  
      public int getDepth() {
          throw new UnsupportedOperationException();
      }
  
      public boolean getFeature(String name) {
          throw new UnsupportedOperationException();
      }
  
      public String getName() {
          throw new UnsupportedOperationException();
      }
  
      public String getNamespace() {
          throw new UnsupportedOperationException();
      }
  
      public String getPrefix(String namespace, boolean generatePrefix)
              throws IllegalArgumentException {
          throw new UnsupportedOperationException();
      }
  
      public Object getProperty(String name) {
          throw new UnsupportedOperationException();
      }
  
      public void ignorableWhitespace(String text) throws IOException, IllegalArgumentException,
              IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      public void processingInstruction(String text) throws IOException, IllegalArgumentException,
              IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      public void setFeature(String name, boolean state) throws IllegalArgumentException,
              IllegalStateException {
          if (name.equals("http://xmlpull.org/v1/doc/features.html#indent-output")) {
              mIndent = true;
              return;
          }
          throw new UnsupportedOperationException();
      }
  
      public void setOutput(OutputStream os, String encoding) throws IOException,
              IllegalArgumentException, IllegalStateException {
          if (os == null)
              throw new IllegalArgumentException();
          try {
              mCharset = Charset.forName(encoding).newEncoder();
          } catch (IllegalCharsetNameException e) {
              throw (UnsupportedEncodingException) (new UnsupportedEncodingException(
                      encoding).initCause(e));
          } catch (UnsupportedCharsetException e) {
              throw (UnsupportedEncodingException) (new UnsupportedEncodingException(
                      encoding).initCause(e));
          }
          mOutputStream = os;
      }
  
      public void setOutput(Writer writer) throws IOException, IllegalArgumentException,
              IllegalStateException {
          mWriter = writer;
      }
  
      public void setPrefix(String prefix, String namespace) throws IOException,
              IllegalArgumentException, IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      public void setProperty(String name, Object value) throws IllegalArgumentException,
              IllegalStateException {
          throw new UnsupportedOperationException();
      }
  
      public void startDocument(String encoding, Boolean standalone) throws IOException,
              IllegalArgumentException, IllegalStateException {
          append("<?xml version='1.0' encoding='utf-8' standalone='"
                  + (standalone ? "yes" : "no") + "' ?>\n");
          mLineStart = true;
      }
  
      public XmlSerializer startTag(String namespace, String name) throws IOException,
              IllegalArgumentException, IllegalStateException {
          if (mInTag) {
              append(">\n");
          }
          if (mIndent) {
              appendIndent(mNesting);
          }
          mNesting++;
          append('<');
          if (namespace != null) {
              append(namespace);
              append(':');
          }
          append(name);
          mInTag = true;
          mLineStart = false;
          return this;
      }
  
      public XmlSerializer text(char[] buf, int start, int len) throws IOException,
              IllegalArgumentException, IllegalStateException {
          if (mInTag) {
              append(">");
              mInTag = false;
          }
          escapeAndAppendString(buf, start, len);
          if (mIndent) {
              mLineStart = buf[start+len-1] == '\n';
          }
          return this;
      }
  
      public XmlSerializer text(String text) throws IOException, IllegalArgumentException,
              IllegalStateException {
          if (mInTag) {
              append(">");
              mInTag = false;
          }
          escapeAndAppendString(text);
          if (mIndent) {
              mLineStart = text.length() > 0 && (text.charAt(text.length()-1) == '\n');
          }
          return this;
      }
  
  }
  