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**STACK style Slot methods**

Uses the Slot in FILO mode, pushing and pulling objects at the same end of a list.  The STACK API-Namespace is useful for creating a global Application context stack.

===== opensrf.persist.stack.push( slot_name, object ) =====

Adds an object to a Slot in FILO order.

  * **Parameters:**
    * //slot_name//\\ The name of the Persistence Slot to use for storing the object.
    * //object//\\ The object that should be pushed onto the front of the STACK.
  * **Returns:**
    * //Success//\\ The name of the Slot that was used.
    * //Failure//\\ An empty (NULL) result.


===== opensrf.persist.stack.pop( slot_name ) =====

Removes and returns the next value in a STACK type Slot.

  * **Parameters:**
    * //slot_name//\\ The name of the Persistence Slot from which an object should be retrieved.
  * **Returns:**
    * //Success//\\ The next object on the STACK Slot, or an empty (NULL) result if the Slot is empty.
    * //Failure//\\ An empty (NULL) result.


===== opensrf.persist.stack.peek( slot_name ) =====

Returns the next value in a STACK type Slot <u>without</u> removing it.

  * **Parameters:**
    * //slot_name//\\ The name of the Persistence Slot from which an object should be retrieved.
  * **Returns:**
    * //Success//\\ The next object on the STACK Slot, or an empty (NULL) result if the Slot is empty.
    * //Failure//\\ An empty (NULL) result.


===== opensrf.persist.stack.peek.all( slot_name ) =====

Returns all values in a STACK type Slot <u>without</u> removing them.

  * **Parameters:**
    * //slot_name//\\ The name of the Persistence Slot from which the objects should be retrieved.
  * **Returns:**
    * //Success//\\ A stream of all objects on the STACK Slot, or an empty (NULL) result if the Slot is empty.
    * //Failure//\\ An empty (NULL) result.


===== opensrf.persist.stack.peek.all.atomic( slot_name ) =====

Returns all values in a STACK type Slot <u>without</u> removing them.

  * **Parameters:**
    * //slot_name//\\ The name of the Persistence Slot from which the objects should be retrieved.
  * **Returns:**
    * //Success//\\ A single array of all objects on the STACK Slot, or an empty array if the Slot is empty.
    * //Failure//\\ An empty (NULL) result.



===== opensrf.persist.stack.depth( slot_name ) =====

Returns the number of objects in the STACK type Slot.

  * **Parameters:**
    * //slot_name//\\ The name of the Persistence Slot in question.
  * **Returns:**
    * //Success//\\ The number of objects in the Persistence Slot.
    * //Failure//\\ An empty (NULL) result.


===== opensrf.persist.stack.size( slot_name ) =====

Returns the number bytes taken up by the JSON encoded version of the objects in the STACK type Slot.

  * **Parameters:**
    * //slot_name//\\ The name of the Persistence Slot in question.
  * **Returns:**
    * //Success//\\ The space, in bytes, used by the JSON encoded objects in the Persistence Slot.
    * //Failure//\\ An empty (NULL) result.