Full Page Cache: Enterprise_PageCache_Model_Container_Placeholder

How to work/flow Enterprise_PageCache_Model_Container_Placeholder class in Magento?
(Magento EE 1.13.0.2)

Object: $this => Enterprise_PageCache_Model_Container_Placeholder

Following constant is used in above class:

const HTML_NAME_PATTERN = ‘//i’

Following variables is used in above class:

$_definitionMap
$_definition
$_name
$_attributes

Some important functions and its purpose used in this class:

getName(): This function is used for to get placeholder name.
getDefinition(): Get defination of placeholder.
getAttribute(): This function is used for get attribute by specific code.
getReplacer(): This function is used for get placeholder content replacer.
getStartTag(): This function return placeholder start tag for block html generation.
getEndTag(): This function return placeholder end tag for block html generation.

Functions in class Enterprise_PageCache_Model_Container_Placeholder
There are 10 functions used in class Enterprise_PageCache_Model_Container_Placeholder

/**Class constructor.
     * Initialize placeholder name and attributes based on definition
     * @param string $definition **/
      public function __construct($definition){}

/**Get placeholder name
     * @return string **/
      public function getName()
    {
        return $this->_name;
    }

/**Get placeholder definition
     * @return string **/
    public function getDefinition()
    {
        return $this->_definition;
    }

/**Get attribute by specific code
     * @param $code string
     * @return string **/
     public function getAttribute($code)
    {
        return isset($this->_attributes[$code]) ? $this->_attributes[$code] : null;
    }

 /**Get regular expression pattern to replace placeholder content
     * @return string **/
    public function getPattern()
    {
        return '/' . preg_quote($this->getStartTag(), '/') . '(.*?)' . preg_quote($this->getEndTag(), '/') . '/ims';
    }

/**Get placeholder content replacer
     * @return string **/
    public function getReplacer(){}

 /**Get class name of container related with placeholder
     * @return string **/
    public function getContainerClass()
    {
        $class = $this->getAttribute('container');
        if (strpos($class, '/') !== false) {
            return Mage::getConfig()->getModelClassName($class);
        }
        return $class;
    }

** Retrieve placeholder definition hash
     * @return string **/ 
     protected function _getDefinitionHash()
    {
        $definition = $this->getDefinition();
        $result = array_search($definition, self::$_definitionMap);
        if ($result === false) {
            $result = $this->getName() . '_' . md5($definition);
            self::$_definitionMap[$result] = $definition;
        }
        return $result;
    }

**Get placeholder start tag for block html generation
     *
     * @return string
     */
    public function getStartTag()
    {
        return '';
    }

/**Get placeholder end tag for block html generation
     * @return string **/ 
     public function getEndTag()
    {
        return '';
    }

Variation of sample data for different pages (Homepage, Product Listing Page, Product Info Page)
Variables: These values for Homepage
URL: http://localhost/oscp-store/mage-ent-test
$_definitionMap = array

  /** Associative array of definition hash to informative definition **/
   WELCOME_8e20186cee9cf7a5a5d1e0bc75ddfec3 = WELCOME
   container = "Enterprise_PageCache_Model_Container_Welcome"
   block = "Mage_Page_Block_Html_Welcome" 
   cache_id = "bf3668918d4f26657cdbfe6550c62f39a86211ba" 
   cache_lifetime = "86400" 
   template =""

 $_definition=/***Original placeholder definition based on HTML_NAME_PATTERN **/
   WELCOME 
   container = "Enterprise_PageCache_Model_Container_Welcome" 
   block = "Mage_Page_Block_Html_Welcome" 
   cache_id = "bf3668918d4f26657cdbfe6550c62f39a86211ba" 
   cache_lifetime = "86400"
   template=""

```
$_name = WELCOME (Placeholder name)
```

$_attributes = /** * Placeholder attributes **/ 
   Array [5]	
   container = Enterprise_PageCache_Model_Container_Welcome	
   block = Mage_Page_Block_Html_Welcome	
   cache_id = bf3668918d4f26657cdbfe6550c62f39a86211ba	
   cache_lifetime = 86400	
   template =

Variables: These values for product listing page
URL: http://localhost/oscp-store/mage-ent-test/furniture/living-room

 $_definitionMap = Array [2]	
  [0]WELCOME_8e20186cee9cf7a5a5d1e0bc75ddfec3 = WELCOME 
    container = "Enterprise_PageCache_Model_Container_Welcome" 
    block = "Mage_Page_Block_Html_Welcome" 
    cache_id = "bf3668918d4f26657cdbfe6550c62f39a86211ba" 
    cache_lifetime = "86400"
    template=""	 

  [1]ACCLINKS_ef551a42665572f16be6f8a990c96b37 = ACCLINKS 
    container ="Enterprise_PageCache_Model_Container_Accountlinks" 
    block = "Mage_Page_Block_Template_Links" 
    cache_id = "b8f9b3383abc7a26a71bfdc86c4a9d5bff6e3693" 
    cache_lifetime = "86400"
    template = "page/template/links.phtml" 
    links =  garbage value
    name="account.links"

$_definition = CART_SIDEBAR 
  container = "Enterprise_PageCache_Model_Container_Sidebar_Cart" 
  block = "Mage_Checkout_Block_Cart_Sidebar" 
  cache_id = "3ee95d5974c12590e902688083b2097637487b5d" cache_lifetime="86400" 
  template = "checkout/cart/cartheader.phtml" item_renders="default|checkout/cart_item_renderer|    
                      checkout/cart/sidebar/default.phtml|simple|checkout/cart_item_renderer|
                      checkout/cart/sidebar/default.phtml|grouped|checkout/cart_item_renderer_grouped|
                      checkout/cart/sidebar/default.phtml|configurable|
                      checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
                      bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml"

```
$_name = CART_SIDEBAR
```

$_attributes = Array [6]	
	 container = Enterprise_PageCache_Model_Container_Sidebar_Cart	
	 block = Mage_Checkout_Block_Cart_Sidebar	
	 cache_id = 3ee95d5974c12590e902688083b2097637487b5d	
	 cache_lifetime = 86400	
	 template = checkout/cart/cartheader.phtml
	 item_renders = default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|    
             checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
             checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
             checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
             bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml

Variables: These values for product Info page
URL: http://localhost/oscp-store/mage-ent-test/furniture/living-room/couch.html

$_definitionMap = Array [3]	
  [0]WELCOME_8e20186cee9cf7a5a5d1e0bc75ddfec3 = WELCOME
	 container = "Enterprise_PageCache_Model_Container_Welcome" 
	 block = "Mage_Page_Block_Html_Welcome" 
	 cache_id = "bf3668918d4f26657cdbfe6550c62f39a86211ba" 
     cache_lifetime = "86400" 
     template=""	
  [1]ACCLINKS_ef551a42665572f16be6f8a990c96b37 = ACCLINKS
	 container ="Enterprise_PageCache_Model_Container_Accountlinks"
	 block ="Mage_Page_Block_Template_Links" 
	 cache_id = "b8f9b3383abc7a26a71bfdc86c4a9d5bff6e3693" 
	 cache_lifetime = "86400" 
	 template = "page/template/links.phtml" 
	 links = garbage value
	 name="account.links"	
[2]CART_SIDEBAR_ccd944c424b10c67d0f564f5cd4534e0 = CART_SIDEBAR 
    container = "Enterprise_PageCache_Model_Container_Sidebar_Cart" 
    block = "Mage_Checkout_Block_Cart_Sidebar"
    cache_id = "3ee95d5974c12590e902688083b2097637487b5d" 
    cache_lifetime = "86400" 
    template = "checkout/cart/cartheader.phtml" 
    item_renders = "default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|
    checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
    checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
    checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
    bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml"

$_definition = CART_SIDEBAR  
   container ="Enterprise_PageCache_Model_Container_Sidebar_Cart" 
   block = "Mage_Checkout_Block_Cart_Sidebar" 
   cache_id = "3ee95d5974c12590e902688083b2097637487b5d" 
   cache_lifetime = "86400"
   template = "checkout/cart/cartheader.phtml" 
   item_renders = "default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|
   checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
   checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
   checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
   bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml"

```
$_name = CART_SIDEBAR
```

$_attributes = Array [6]	
  container = Enterprise_PageCache_Model_Container_Sidebar_Cart	
  block = Mage_Checkout_Block_Cart_Sidebar	
  cache_id = 3ee95d5974c12590e902688083b2097637487b5d	
  cache_lifetime = 86400	
  template = checkout/cart/cartheader.phtml	
  item_renders = 	default|checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|simple|
  checkout/cart_item_renderer|checkout/cart/sidebar/default.phtml|grouped|
  checkout/cart_item_renderer_grouped|checkout/cart/sidebar/default.phtml|configurable|
  checkout/cart_item_renderer_configurable|checkout/cart/sidebar/default.phtml|bundle|
  bundle/checkout_cart_item_renderer|checkout/cart/sidebar/default.phtml