michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.message;
michael@0: 
michael@0: import java.util.NoSuchElementException;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.FormattedHeader;
michael@0: import ch.boye.httpclientandroidlib.Header;
michael@0: import ch.boye.httpclientandroidlib.HeaderElement;
michael@0: import ch.boye.httpclientandroidlib.HeaderElementIterator;
michael@0: import ch.boye.httpclientandroidlib.HeaderIterator;
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: 
michael@0: /**
michael@0:  * Basic implementation of a {@link HeaderElementIterator}.
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public class BasicHeaderElementIterator implements HeaderElementIterator {
michael@0: 
michael@0:     private final HeaderIterator headerIt;
michael@0:     private final HeaderValueParser parser;
michael@0: 
michael@0:     private HeaderElement currentElement = null;
michael@0:     private CharArrayBuffer buffer = null;
michael@0:     private ParserCursor cursor = null;
michael@0: 
michael@0:     /**
michael@0:      * Creates a new instance of BasicHeaderElementIterator
michael@0:      */
michael@0:     public BasicHeaderElementIterator(
michael@0:             final HeaderIterator headerIterator,
michael@0:             final HeaderValueParser parser) {
michael@0:         if (headerIterator == null) {
michael@0:             throw new IllegalArgumentException("Header iterator may not be null");
michael@0:         }
michael@0:         if (parser == null) {
michael@0:             throw new IllegalArgumentException("Parser may not be null");
michael@0:         }
michael@0:         this.headerIt = headerIterator;
michael@0:         this.parser = parser;
michael@0:     }
michael@0: 
michael@0: 
michael@0:     public BasicHeaderElementIterator(final HeaderIterator headerIterator) {
michael@0:         this(headerIterator, BasicHeaderValueParser.DEFAULT);
michael@0:     }
michael@0: 
michael@0: 
michael@0:     private void bufferHeaderValue() {
michael@0:         this.cursor = null;
michael@0:         this.buffer = null;
michael@0:         while (this.headerIt.hasNext()) {
michael@0:             Header h = this.headerIt.nextHeader();
michael@0:             if (h instanceof FormattedHeader) {
michael@0:                 this.buffer = ((FormattedHeader) h).getBuffer();
michael@0:                 this.cursor = new ParserCursor(0, this.buffer.length());
michael@0:                 this.cursor.updatePos(((FormattedHeader) h).getValuePos());
michael@0:                 break;
michael@0:             } else {
michael@0:                 String value = h.getValue();
michael@0:                 if (value != null) {
michael@0:                     this.buffer = new CharArrayBuffer(value.length());
michael@0:                     this.buffer.append(value);
michael@0:                     this.cursor = new ParserCursor(0, this.buffer.length());
michael@0:                     break;
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private void parseNextElement() {
michael@0:         // loop while there are headers left to parse
michael@0:         while (this.headerIt.hasNext() || this.cursor != null) {
michael@0:             if (this.cursor == null || this.cursor.atEnd()) {
michael@0:                 // get next header value
michael@0:                 bufferHeaderValue();
michael@0:             }
michael@0:             // Anything buffered?
michael@0:             if (this.cursor != null) {
michael@0:                 // loop while there is data in the buffer
michael@0:                 while (!this.cursor.atEnd()) {
michael@0:                     HeaderElement e = this.parser.parseHeaderElement(this.buffer, this.cursor);
michael@0:                     if (!(e.getName().length() == 0 && e.getValue() == null)) {
michael@0:                         // Found something
michael@0:                         this.currentElement = e;
michael@0:                         return;
michael@0:                     }
michael@0:                 }
michael@0:                 // if at the end of the buffer
michael@0:                 if (this.cursor.atEnd()) {
michael@0:                     // discard it
michael@0:                     this.cursor = null;
michael@0:                     this.buffer = null;
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public boolean hasNext() {
michael@0:         if (this.currentElement == null) {
michael@0:             parseNextElement();
michael@0:         }
michael@0:         return this.currentElement != null;
michael@0:     }
michael@0: 
michael@0:     public HeaderElement nextElement() throws NoSuchElementException {
michael@0:         if (this.currentElement == null) {
michael@0:             parseNextElement();
michael@0:         }
michael@0: 
michael@0:         if (this.currentElement == null) {
michael@0:             throw new NoSuchElementException("No more header elements available");
michael@0:         }
michael@0: 
michael@0:         HeaderElement element = this.currentElement;
michael@0:         this.currentElement = null;
michael@0:         return element;
michael@0:     }
michael@0: 
michael@0:     public final Object next() throws NoSuchElementException {
michael@0:         return nextElement();
michael@0:     }
michael@0: 
michael@0:     public void remove() throws UnsupportedOperationException {
michael@0:         throw new UnsupportedOperationException("Remove not supported");
michael@0:     }
michael@0: 
michael@0: }