vendor/zendframework/zend-memory/src/Value.php

   1 <?php
   2 /**
   3  * @see       https://github.com/zendframework/zend-memory for the canonical source repository
   4  * @copyright Copyright (c) 2005-2018 Zend Technologies USA Inc. (https://www.zend.com)
   5  * @license   https://github.com/zendframework/zend-memory/blob/master/LICENSE.md New BSD License
   6  */
   7
   8 namespace Zend\Memory;
   9
  10 use ArrayAccess;
  11 use Countable;
  12
  13 /**
  14  * String value object
  15  *
  16  * It's an OO string wrapper.
  17  * Used to intercept string updates.
  18  */
  19 class Value implements ArrayAccess, Countable
  20 {
  21     /**
  22      * Value
  23      *
  24      * @var string
  25      */
  26     private $value;
  27
  28     /**
  29      * Container
  30      *
  31      * @var Container\Movable
  32      */
  33     private $container;
  34
  35     /**
  36      * Boolean flag which signals to trace value modifications
  37      *
  38      * @var bool
  39      */
  40     private $trace;
  41
  42
  43     /**
  44      * Object constructor
  45      *
  46      * @param string $value
  47      * @param \Zend\Memory\Container\Movable $container
  48      */
  49     public function __construct($value, Container\Movable $container)
  50     {
  51         $this->container = $container;
  52
  53         $this->value = (string) $value;
  54
  55         /**
  56          * Object is marked as just modified by memory manager
  57          * So we don't need to trace followed object modifications and
  58          * object is processed (and marked as traced) when another
  59          * memory object is modified.
  60          *
  61          * It reduces overall number of calls necessary to modification trace
  62          */
  63         $this->trace = false;
  64     }
  65
  66     /**
  67      * Countable
  68      *
  69      * @return int
  70      */
  71     public function count()
  72     {
  73         return strlen($this->value);
  74     }
  75
  76     /**
  77      * ArrayAccess interface method
  78      * returns true if string offset exists
  79      *
  80      * @param int $offset
  81      * @return bool
  82      */
  83     public function offsetExists($offset)
  84     {
  85         return $offset >= 0 && $offset < strlen($this->value);
  86     }
  87
  88     /**
  89      * ArrayAccess interface method
  90      * Get character at $offset position
  91      *
  92      * @param int $offset
  93      * @return string
  94      */
  95     public function offsetGet($offset)
  96     {
  97         return $this->value[$offset];
  98     }
  99
 100     /**
 101      * ArrayAccess interface method
 102      * Set character at $offset position
 103      *
 104      * @param int $offset
 105      * @param string $char
 106      */
 107     public function offsetSet($offset, $char)
 108     {
 109         $this->value[$offset] = $char;
 110
 111         if ($this->trace) {
 112             $this->trace = false;
 113             $this->container->processUpdate();
 114         }
 115     }
 116
 117     /**
 118      * ArrayAccess interface method
 119      * Unset character at $offset position
 120      *
 121      * @param int $offset
 122      */
 123     public function offsetUnset($offset)
 124     {
 125         unset($this->value[$offset]);
 126
 127         if ($this->trace) {
 128             $this->trace = false;
 129             $this->container->processUpdate();
 130         }
 131     }
 132
 133     /**
 134      * To string conversion
 135      *
 136      * @return string
 137      */
 138     public function __toString()
 139     {
 140         return $this->value;
 141     }
 142
 143     /**
 144      * Get string value reference
 145      *
 146      * _Must_ be used for value access before PHP v 5.2
 147      * or _may_ be used for performance considerations
 148      *
 149      * @internal
 150      * @return string
 151      */
 152     public function &getRef()
 153     {
 154         return $this->value;
 155     }
 156
 157     /**
 158      * Start modifications trace
 159      *
 160      * _Must_ be used for value access before PHP v 5.2
 161      * or _may_ be used for performance considerations
 162      *
 163      * @internal
 164      */
 165     public function startTrace()
 166     {
 167         $this->trace = true;
 168     }
 169 }