1: <?php
  2: 
  3: /*
  4:  * This file is part of SwiftMailer.
  5:  * (c) 2004-2009 Chris Corbyn
  6:  *
  7:  * For the full copyright and license information, please view the LICENSE
  8:  * file that was distributed with this source code.
  9:  */
 10: 
 11: /**
 12:  * Provides the base functionality for an InputStream supporting filters.
 13:  * @package Swift
 14:  * @subpackage ByteStream
 15:  * @author Chris Corbyn
 16:  */
 17: abstract class Swift_ByteStream_AbstractFilterableInputStream implements Swift_InputByteStream, Swift_Filterable
 18: {
 19:     /** Write sequence */
 20:     protected $_sequence = 0;
 21: 
 22:     /** StreamFilters */
 23:     private $_filters = array();
 24: 
 25:     /** A buffer for writing */
 26:     private $_writeBuffer = '';
 27: 
 28:     /** Bound streams */
 29:     private $_mirrors = array();
 30: 
 31:     /**
 32:      * Commit the given bytes to the storage medium immediately.
 33:      * @param string $bytes
 34:      * @access protected
 35:      */
 36:     abstract protected function _commit($bytes);
 37: 
 38:     /**
 39:      * Flush any buffers/content with immediate effect.
 40:      * @access protected
 41:      */
 42:     abstract protected function _flush();
 43: 
 44:     /**
 45:      * Add a StreamFilter to this InputByteStream.
 46:      * @param Swift_StreamFilter $filter
 47:      * @param string             $key
 48:      */
 49:     public function addFilter(Swift_StreamFilter $filter, $key)
 50:     {
 51:         $this->_filters[$key] = $filter;
 52:     }
 53: 
 54:     /**
 55:      * Remove an already present StreamFilter based on its $key.
 56:      * @param string $key
 57:      */
 58:     public function removeFilter($key)
 59:     {
 60:         unset($this->_filters[$key]);
 61:     }
 62: 
 63:     /**
 64:      * Writes $bytes to the end of the stream.
 65:      * @param  string            $bytes
 66:      * @throws Swift_IoException
 67:      */
 68:     public function write($bytes)
 69:     {
 70:         $this->_writeBuffer .= $bytes;
 71:         foreach ($this->_filters as $filter) {
 72:             if ($filter->shouldBuffer($this->_writeBuffer)) {
 73:                 return;
 74:             }
 75:         }
 76:         $this->_doWrite($this->_writeBuffer);
 77: 
 78:         return ++$this->_sequence;
 79:     }
 80: 
 81:     /**
 82:      * For any bytes that are currently buffered inside the stream, force them
 83:      * off the buffer.
 84:      *
 85:      * @throws Swift_IoException
 86:      */
 87:     public function commit()
 88:     {
 89:         $this->_doWrite($this->_writeBuffer);
 90:     }
 91: 
 92:     /**
 93:      * Attach $is to this stream.
 94:      * The stream acts as an observer, receiving all data that is written.
 95:      * All {@link write()} and {@link flushBuffers()} operations will be mirrored.
 96:      *
 97:      * @param Swift_InputByteStream $is
 98:      */
 99:     public function bind(Swift_InputByteStream $is)
100:     {
101:         $this->_mirrors[] = $is;
102:     }
103: 
104:     /**
105:      * Remove an already bound stream.
106:      * If $is is not bound, no errors will be raised.
107:      * If the stream currently has any buffered data it will be written to $is
108:      * before unbinding occurs.
109:      *
110:      * @param Swift_InputByteStream $is
111:      */
112:     public function unbind(Swift_InputByteStream $is)
113:     {
114:         foreach ($this->_mirrors as $k => $stream) {
115:             if ($is === $stream) {
116:                 if ($this->_writeBuffer !== '') {
117:                     $stream->write($this->_filter($this->_writeBuffer));
118:                 }
119:                 unset($this->_mirrors[$k]);
120:             }
121:         }
122:     }
123: 
124:     /**
125:      * Flush the contents of the stream (empty it) and set the internal pointer
126:      * to the beginning.
127:      * @throws Swift_IoException
128:      */
129:     public function flushBuffers()
130:     {
131:         if ($this->_writeBuffer !== '') {
132:             $this->_doWrite($this->_writeBuffer);
133:         }
134:         $this->_flush();
135: 
136:         foreach ($this->_mirrors as $stream) {
137:             $stream->flushBuffers();
138:         }
139:     }
140: 
141:     // -- Private methods
142: 
143:     /** Run $bytes through all filters */
144:     private function _filter($bytes)
145:     {
146:         foreach ($this->_filters as $filter) {
147:             $bytes = $filter->filter($bytes);
148:         }
149: 
150:         return $bytes;
151:     }
152: 
153:     /** Just write the bytes to the stream */
154:     private function _doWrite($bytes)
155:     {
156:         $this->_commit($this->_filter($bytes));
157: 
158:         foreach ($this->_mirrors as $stream) {
159:             $stream->write($bytes);
160:         }
161: 
162:         $this->_writeBuffer = '';
163:     }
164: }
165: