FB_Hash_Set (Function Block)

A collection that contains no duplicate items. Implemented using hash table with closed addressing.

Extends: FB_Collection

Implements: I_Hash_Set

Properties

_Bucket_Count

Type: T_Capacity

Number of buckets in the hash set.

Methods

Clear

Empties/Clears/Deletes every item in the set.

Contains

Checks if item is contained in set.

Inputs

Name	Type	Description
`Item`	`ANY`	Item to find.

Create_Buckets

Creates buckets and initialises them since user defined types can’t be created as arrays dynamically using __NEW(…).

Inputs

Name	Type	Description
`Count`	T_Capacity

Outputs

Name	Type	Description
`bSuccess`	`BOOL`
`Error`	T_Error

Create_Node

Creates a new node in dynamic memory with a clone of the generic item as it data.

Inputs

Name	Type	Description
`Item`	T_Generic

Outputs

Name	Type	Description
`bSuccess`	`BOOL`
`Error`	T_Error

Delete_Node

Safety deletes node. If the node and/or it’s value/data is in dynamic memory it/they will be deleted.

Inputs

Name	Type	Description
`pNode`	`REFERENCE TO POINTER TO` T_Hashset_Bucket_Node

FB_exit

Inputs

Name	Type	Description
`bInCopyCode`	`BOOL`	if TRUE, the exit method is called for exiting an instance that is copied afterwards (online change).

FB_init

Inputs

Name	Type	Description
`bInitRetains`	`BOOL`	if TRUE, the retain variables are initialized (warm start / cold start)
`bInCopyCode`	`BOOL`	if TRUE, the instance afterwards gets moved into the copy code (online change)
`Initial_Bucket_Count`	T_Capacity	Number of buckets you want to initialise the hash set with. Use 0 if you don’t know.

Get_Values

Gets an immutable list of the values in the set.

Hash

Wrapper for murmur3 hash function that generates a value that fits in the upperage of DINT to avoid negative values due to integer overflow.

Inputs

Name	Type	Description
`Data`	T_Generic

Insert

Insert item into set.

Inputs

Name	Type	Description
`Item`	`ANY`	Data to insert

Outputs

Name	Type	Description
`bSuccess`	`BOOL`	Indicates whether operation was successful. Success = TRUE, Failure = FALSE

Insert_Generic

Adds new generic item at into set. The set will store a copy of the generic item so as to not modify the original value outside it’s scope.

Inputs

Name	Type	Description
`Item`	T_Generic	Item to store

Outputs

Name	Type	Description
`bSuccess`	`BOOL`	Indicates whether operation was successful. Success = TRUE, Failure = FALSE

Remove

Removes item from the set.

Inputs

Name	Type	Description
`Item`	`ANY`	Data to remove

Outputs

Name	Type	Description
`bSuccess`	`BOOL`	Indicates whether operation was successful. Success = TRUE, Failure = FALSE

Remove_Generic

Removes generic item from the set.

Inputs

Name	Type	Description
`Item`	T_Generic	Data to remove

Outputs

Name	Type	Description
`bSuccess`	`BOOL`	Indicates whether operation was successful. Success = TRUE, Failure = FALSE

Resize

Sets the number of buckets in the hash set. Existing items are rehashed and redistributed into the new buckets. Note that of the count is 0 the hashtable is cleared.

Inputs

Name	Type	Description
`Count`	T_Capacity

Outputs

Name	Type	Description
`bSuccess`	`BOOL`