hadoop-mapreduce/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/webapp/hamlet/HamletImpl.java - hadoop - Git at Google

 /**
 * 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.  The ASF licenses this file
 * to you 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 org.apache.hadoop.yarn.webapp.hamlet;

 import com.google.common.base.Joiner;
 import static com.google.common.base.Preconditions.*;
 import com.google.common.base.Splitter;
 import com.google.common.collect.Iterables;

 import java.io.PrintWriter;
 import java.util.EnumSet;
 import static java.util.EnumSet.*;
 import java.util.Iterator;

 import static org.apache.commons.lang.StringEscapeUtils.*;
 import static org.apache.hadoop.yarn.webapp.hamlet.HamletImpl.EOpt.*;

 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.yarn.webapp.SubView;
 import org.apache.hadoop.yarn.webapp.WebAppException;


 /**
  * A simple unbuffered generic hamlet implementation.
  *
  * Zero copy but allocation on every element, which could be
  * optimized to use a thread-local element pool.
  *
  * Prints HTML as it builds. So the order is important.
  */
 @InterfaceAudience.Private
 public class HamletImpl extends HamletSpec {
   private static final String INDENT_CHARS = "  ";
   private static final Splitter SS = Splitter.on('.').
       omitEmptyStrings().trimResults();
   private static final Joiner SJ = Joiner.on(' ');
   private static final Joiner CJ = Joiner.on(", ");
   static final int S_ID = 0;
   static final int S_CLASS = 1;

   int nestLevel;
   int indents; // number of indent() called. mostly for testing.
   private final PrintWriter out;
   private final StringBuilder sb = new StringBuilder(); // not shared
   private boolean wasInline = false;

   /**
    * Element options. (whether it needs end tag, is inline etc.)
    */
   public enum EOpt {
     /** needs end(close) tag */
     ENDTAG,
     /** The content is inline */
     INLINE,
     /** The content is preformatted */
     PRE
   };

   /**
    * The base class for elements
    * @param <T> type of the parent (containing) element for the element
    */
   public class EImp<T extends _> implements _Child {
     private final String name;
     private final T parent; // short cut for parent element
     private final EnumSet<EOpt> opts; // element options

     private boolean started = false;
     private boolean attrsClosed = false;

     EImp(String name, T parent, EnumSet<EOpt> opts) {
       this.name = name;
       this.parent = parent;
       this.opts = opts;
     }

     @Override
     public T _() {
       closeAttrs();
       --nestLevel;
       printEndTag(name, opts);
       return parent;
     }

     protected void _p(boolean quote, Object... args) {
       closeAttrs();
       for (Object s : args) {
         if (!opts.contains(PRE)) {
           indent(opts);
         }
         out.print(quote ? escapeHtml(String.valueOf(s))
                         : String.valueOf(s));
         if (!opts.contains(INLINE) && !opts.contains(PRE)) {
           out.println();
         }
       }
     }

     protected void _v(Class<? extends SubView> cls) {
       closeAttrs();
       subView(cls);
     }

     protected void closeAttrs() {
       if (!attrsClosed) {
         startIfNeeded();
         ++nestLevel;
         out.print('>');
         if (!opts.contains(INLINE) && !opts.contains(PRE)) {
           out.println();
         }
         attrsClosed = true;
       }
     }

     protected void addAttr(String name, String value) {
       checkState(!attrsClosed, "attribute added after content");
       startIfNeeded();
       printAttr(name, value);
     }

     protected void addAttr(String name, Object value) {
       addAttr(name, String.valueOf(value));
     }

     protected void addMediaAttr(String name, EnumSet<Media> media) {
       // 6.13 comma-separated list
       addAttr(name, CJ.join(media));
     }

     protected void addRelAttr(String name, EnumSet<LinkType> types) {
       // 6.12 space-separated list
       addAttr(name, SJ.join(types));
     }

     private void startIfNeeded() {
       if (!started) {
         printStartTag(name, opts);
         started = true;
       }
     }

     protected void _inline(boolean choice) {
       if (choice) {
         opts.add(INLINE);
       } else {
         opts.remove(INLINE);
       }
     }

     protected void _endTag(boolean choice) {
       if (choice) {
         opts.add(ENDTAG);
       } else {
         opts.remove(ENDTAG);
       }
     }

     protected void _pre(boolean choice) {
       if (choice) {
         opts.add(PRE);
       } else {
         opts.remove(PRE);
       }
     }
   }

   public class Generic<T extends _> extends EImp<T> implements PCData {
     Generic(String name, T parent, EnumSet<EOpt> opts) {
       super(name, parent, opts);
     }

     public Generic<T> _inline() {
       super._inline(true);
       return this;
     }

     public Generic<T> _noEndTag() {
       super._endTag(false);
       return this;
     }

     public Generic<T> _pre() {
       super._pre(true);
       return this;
     }

     public Generic<T> _attr(String name, String value) {
       addAttr(name, value);
       return this;
     }

     public Generic<Generic<T>> _elem(String name, EnumSet<EOpt> opts) {
       closeAttrs();
       return new Generic<Generic<T>>(name, this, opts);
     }

     public Generic<Generic<T>> elem(String name) {
       return _elem(name, of(ENDTAG));
     }

     @Override
     public Generic<T> _(Object... lines) {
       _p(true, lines);
       return this;
     }

     @Override
     public Generic<T> _r(Object... lines) {
       _p(false, lines);
       return this;
     }
   }

   public HamletImpl(PrintWriter out, int nestLevel, boolean wasInline) {
     this.out = out;
     this.nestLevel = nestLevel;
     this.wasInline = wasInline;
   }

   public int nestLevel() {
     return nestLevel;
   }

   public boolean wasInline() {
     return wasInline;
   }

   public void setWasInline(boolean state) {
     wasInline = state;
   }

   public PrintWriter getWriter() {
     return out;
   }

   /**
    * Create a root-level generic element.
    * Mostly for testing purpose.
    * @param <T> type of the parent element
    * @param name of the element
    * @param opts {@link EOpt element options}
    * @return the element
    */
   public <T extends _>
   Generic<T> root(String name, EnumSet<EOpt> opts) {
     return new Generic<T>(name, null, opts);
   }

   public <T extends _> Generic<T> root(String name) {
     return root(name, of(ENDTAG));
   }

   protected void printStartTag(String name, EnumSet<EOpt> opts) {
     indent(opts);
     sb.setLength(0);
     out.print(sb.append('<').append(name).toString()); // for easier mock test
   }

   protected void indent(EnumSet<EOpt> opts) {
     if (opts.contains(INLINE) && wasInline) {
       return;
     }
     if (wasInline) {
       out.println();
     }
     wasInline = opts.contains(INLINE) || opts.contains(PRE);
     for (int i = 0; i < nestLevel; ++i) {
       out.print(INDENT_CHARS);
     }
     ++indents;
   }

   protected void printEndTag(String name, EnumSet<EOpt> opts) {
     if (!opts.contains(ENDTAG)) {
       return;
     }
     if (!opts.contains(PRE)) {
       indent(opts);
     } else {
       wasInline = opts.contains(INLINE);
     }
     sb.setLength(0);
     out.print(sb.append("</").append(name).append('>').toString()); // ditto
     if (!opts.contains(INLINE)) {
       out.println();
     }
   }

   protected void printAttr(String name, String value) {
     sb.setLength(0);
     sb.append(' ').append(name);
     if (value != null) {
       sb.append("=\"").append(value).append("\"");
     }
     out.print(sb.toString());
   }

   /**
    * Sub-classes should override this to do something interesting.
    * @param cls the sub-view class
    */
   protected void subView(Class<? extends SubView> cls) {
     indent(of(ENDTAG)); // not an inline view
     sb.setLength(0);
     out.print(sb.append('[').append(cls.getName()).append(']').toString());
     out.println();
   }

   /**
    * Parse selector into id and classes
    * @param selector in the form of (#id)?(.class)*
    * @return an two element array [id, "space-separated classes"].
    *         Either element could be null.
    * @throws WebAppException when both are null or syntax error.
    */
   public static String[] parseSelector(String selector) {
     String[] result = new String[]{null, null};
     Iterable<String> rs = SS.split(selector);
     Iterator<String> it = rs.iterator();
     if (it.hasNext()) {
       String maybeId = it.next();
       if (maybeId.charAt(0) == '#') {
         result[S_ID] = maybeId.substring(1);
         if (it.hasNext()) {
           result[S_CLASS] = SJ.join(Iterables.skip(rs, 1));
         }
       } else {
         result[S_CLASS] = SJ.join(rs);
       }
       return result;
     }
     throw new WebAppException("Error parsing selector: "+ selector);
   }

   /**
    * Set id and/or class attributes for an element.
    * @param <E> type of the element
    * @param e the element
    * @param selector Haml form of "(#id)?(.class)*"
    * @return the element
    */
   public static <E extends CoreAttrs> E setSelector(E e, String selector) {
     String[] res = parseSelector(selector);
     if (res[S_ID] != null) {
       e.$id(res[S_ID]);
     }
     if (res[S_CLASS] != null) {
       e.$class(res[S_CLASS]);
     }
     return e;
   }

   public static <E extends LINK> E setLinkHref(E e, String href) {
     if (href.endsWith(".css")) {
       e.$rel("stylesheet"); // required in html5
     }
     e.$href(href);
     return e;
   }

   public static <E extends SCRIPT> E setScriptSrc(E e, String src) {
     if (src.endsWith(".js")) {
       e.$type("text/javascript"); // required in html4
     }
     e.$src(src);
     return e;
   }
 }
	/**
	* 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. The ASF licenses this file
	* to you 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 org.apache.hadoop.yarn.webapp.hamlet;

	import com.google.common.base.Joiner;
	import static com.google.common.base.Preconditions.*;
	import com.google.common.base.Splitter;
	import com.google.common.collect.Iterables;

	import java.io.PrintWriter;
	import java.util.EnumSet;
	import static java.util.EnumSet.*;
	import java.util.Iterator;

	import static org.apache.commons.lang.StringEscapeUtils.*;
	import static org.apache.hadoop.yarn.webapp.hamlet.HamletImpl.EOpt.*;

	import org.apache.hadoop.classification.InterfaceAudience;
	import org.apache.hadoop.yarn.webapp.SubView;
	import org.apache.hadoop.yarn.webapp.WebAppException;


	/**
	* A simple unbuffered generic hamlet implementation.
	*
	* Zero copy but allocation on every element, which could be
	* optimized to use a thread-local element pool.
	*
	* Prints HTML as it builds. So the order is important.
	*/
	@InterfaceAudience.Private
	public class HamletImpl extends HamletSpec {
	private static final String INDENT_CHARS = " ";
	private static final Splitter SS = Splitter.on('.').
	omitEmptyStrings().trimResults();
	private static final Joiner SJ = Joiner.on(' ');
	private static final Joiner CJ = Joiner.on(", ");
	static final int S_ID = 0;
	static final int S_CLASS = 1;

	int nestLevel;
	int indents; // number of indent() called. mostly for testing.
	private final PrintWriter out;
	private final StringBuilder sb = new StringBuilder(); // not shared
	private boolean wasInline = false;

	/**
	* Element options. (whether it needs end tag, is inline etc.)
	*/
	public enum EOpt {
	/** needs end(close) tag */
	ENDTAG,
	/** The content is inline */
	INLINE,
	/** The content is preformatted */
	PRE
	};

	/**
	* The base class for elements
	* @param <T> type of the parent (containing) element for the element
	*/
	public class EImp<T extends _> implements _Child {
	private final String name;
	private final T parent; // short cut for parent element
	private final EnumSet<EOpt> opts; // element options

	private boolean started = false;
	private boolean attrsClosed = false;

	EImp(String name, T parent, EnumSet<EOpt> opts) {
	this.name = name;
	this.parent = parent;
	this.opts = opts;
	}

	@Override
	public T _() {
	closeAttrs();
	--nestLevel;
	printEndTag(name, opts);
	return parent;
	}

	protected void _p(boolean quote, Object... args) {
	closeAttrs();
	for (Object s : args) {
	if (!opts.contains(PRE)) {
	indent(opts);
	}
	out.print(quote ? escapeHtml(String.valueOf(s))
	: String.valueOf(s));
	if (!opts.contains(INLINE) && !opts.contains(PRE)) {
	out.println();
	}
	}
	}

	protected void _v(Class<? extends SubView> cls) {
	closeAttrs();
	subView(cls);
	}

	protected void closeAttrs() {
	if (!attrsClosed) {
	startIfNeeded();
	++nestLevel;
	out.print('>');
	if (!opts.contains(INLINE) && !opts.contains(PRE)) {
	out.println();
	}
	attrsClosed = true;
	}
	}

	protected void addAttr(String name, String value) {
	checkState(!attrsClosed, "attribute added after content");
	startIfNeeded();
	printAttr(name, value);
	}

	protected void addAttr(String name, Object value) {
	addAttr(name, String.valueOf(value));
	}

	protected void addMediaAttr(String name, EnumSet<Media> media) {
	// 6.13 comma-separated list
	addAttr(name, CJ.join(media));
	}

	protected void addRelAttr(String name, EnumSet<LinkType> types) {
	// 6.12 space-separated list
	addAttr(name, SJ.join(types));
	}

	private void startIfNeeded() {
	if (!started) {
	printStartTag(name, opts);
	started = true;
	}
	}

	protected void _inline(boolean choice) {
	if (choice) {
	opts.add(INLINE);
	} else {
	opts.remove(INLINE);
	}
	}

	protected void _endTag(boolean choice) {
	if (choice) {
	opts.add(ENDTAG);
	} else {
	opts.remove(ENDTAG);
	}
	}

	protected void _pre(boolean choice) {
	if (choice) {
	opts.add(PRE);
	} else {
	opts.remove(PRE);
	}
	}
	}

	public class Generic<T extends _> extends EImp<T> implements PCData {
	Generic(String name, T parent, EnumSet<EOpt> opts) {
	super(name, parent, opts);
	}

	public Generic<T> _inline() {
	super._inline(true);
	return this;
	}

	public Generic<T> _noEndTag() {
	super._endTag(false);
	return this;
	}

	public Generic<T> _pre() {
	super._pre(true);
	return this;
	}

	public Generic<T> _attr(String name, String value) {
	addAttr(name, value);
	return this;
	}

	public Generic<Generic<T>> _elem(String name, EnumSet<EOpt> opts) {
	closeAttrs();
	return new Generic<Generic<T>>(name, this, opts);
	}

	public Generic<Generic<T>> elem(String name) {
	return _elem(name, of(ENDTAG));
	}

	@Override
	public Generic<T> _(Object... lines) {
	_p(true, lines);
	return this;
	}

	@Override
	public Generic<T> _r(Object... lines) {
	_p(false, lines);
	return this;
	}
	}

	public HamletImpl(PrintWriter out, int nestLevel, boolean wasInline) {
	this.out = out;
	this.nestLevel = nestLevel;
	this.wasInline = wasInline;
	}

	public int nestLevel() {
	return nestLevel;
	}

	public boolean wasInline() {
	return wasInline;
	}

	public void setWasInline(boolean state) {
	wasInline = state;
	}

	public PrintWriter getWriter() {
	return out;
	}

	/**
	* Create a root-level generic element.
	* Mostly for testing purpose.
	* @param <T> type of the parent element
	* @param name of the element
	* @param opts {@link EOpt element options}
	* @return the element
	*/
	public <T extends _>
	Generic<T> root(String name, EnumSet<EOpt> opts) {
	return new Generic<T>(name, null, opts);
	}

	public <T extends _> Generic<T> root(String name) {
	return root(name, of(ENDTAG));
	}

	protected void printStartTag(String name, EnumSet<EOpt> opts) {
	indent(opts);
	sb.setLength(0);
	out.print(sb.append('<').append(name).toString()); // for easier mock test
	}

	protected void indent(EnumSet<EOpt> opts) {
	if (opts.contains(INLINE) && wasInline) {
	return;
	}
	if (wasInline) {
	out.println();
	}
	wasInline = opts.contains(INLINE) \|\| opts.contains(PRE);
	for (int i = 0; i < nestLevel; ++i) {
	out.print(INDENT_CHARS);
	}
	++indents;
	}

	protected void printEndTag(String name, EnumSet<EOpt> opts) {
	if (!opts.contains(ENDTAG)) {
	return;
	}
	if (!opts.contains(PRE)) {
	indent(opts);
	} else {
	wasInline = opts.contains(INLINE);
	}
	sb.setLength(0);
	out.print(sb.append("</").append(name).append('>').toString()); // ditto
	if (!opts.contains(INLINE)) {
	out.println();
	}
	}

	protected void printAttr(String name, String value) {
	sb.setLength(0);
	sb.append(' ').append(name);
	if (value != null) {
	sb.append("=\"").append(value).append("\"");
	}
	out.print(sb.toString());
	}

	/**
	* Sub-classes should override this to do something interesting.
	* @param cls the sub-view class
	*/
	protected void subView(Class<? extends SubView> cls) {
	indent(of(ENDTAG)); // not an inline view
	sb.setLength(0);
	out.print(sb.append('[').append(cls.getName()).append(']').toString());
	out.println();
	}

	/**
	* Parse selector into id and classes
	* @param selector in the form of (#id)?(.class)*
	* @return an two element array [id, "space-separated classes"].
	* Either element could be null.
	* @throws WebAppException when both are null or syntax error.
	*/
	public static String[] parseSelector(String selector) {
	String[] result = new String[]{null, null};
	Iterable<String> rs = SS.split(selector);
	Iterator<String> it = rs.iterator();
	if (it.hasNext()) {
	String maybeId = it.next();
	if (maybeId.charAt(0) == '#') {
	result[S_ID] = maybeId.substring(1);
	if (it.hasNext()) {
	result[S_CLASS] = SJ.join(Iterables.skip(rs, 1));
	}
	} else {
	result[S_CLASS] = SJ.join(rs);
	}
	return result;
	}
	throw new WebAppException("Error parsing selector: "+ selector);
	}

	/**
	* Set id and/or class attributes for an element.
	* @param <E> type of the element
	* @param e the element
	* @param selector Haml form of "(#id)?(.class)*"
	* @return the element
	*/
	public static <E extends CoreAttrs> E setSelector(E e, String selector) {
	String[] res = parseSelector(selector);
	if (res[S_ID] != null) {
	e.$id(res[S_ID]);
	}
	if (res[S_CLASS] != null) {
	e.$class(res[S_CLASS]);
	}
	return e;
	}

	public static <E extends LINK> E setLinkHref(E e, String href) {
	if (href.endsWith(".css")) {
	e.$rel("stylesheet"); // required in html5
	}
	e.$href(href);
	return e;
	}

	public static <E extends SCRIPT> E setScriptSrc(E e, String src) {
	if (src.endsWith(".js")) {
	e.$type("text/javascript"); // required in html4
	}
	e.$src(src);
	return e;
	}
	}