FB_Hash_Map (Function Block)

A collection of key value pairs items. Implemented using hash table with closed addressing.

Extends: FB_Collection

Implements: I_Hash_Map

Properties

_Bucket_Count

Type: T_Capacity

Number of buckets in the hash map.

Methods

Clear

Empties/Clears/Deletes every item in the map.

Contains

Checks if key is contained in the map.

Inputs

Name	Type	Description
`Key`	`ANY`	Key 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
`Key, Value`	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_Hashmap_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 map with. Use 0 if you don’t know.

Get

Gets the value associated with the specified key without removing it from the map.

Inputs

Name	Type	Description
`Key`	`ANY`	Key used to identify stored value
`Value`	`ANY`	Variable to store requested data

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Get_As_String

Returns value as a string, if type to string conversion is supported.

Inputs

Name	Type	Description
`Key`	`ANY`	Key used to identify stored value
`sValue`	`REFERENCE TO` `STRING`	Variable to store returned item.

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Get_Generic

Gets the value in its generic form associated with the specified key in its generic form without removing it from the map. Use carefully as this contains the pointer of the actual value in the collection. If you wish to use this it is recommeded you create a copy of the returned value using MEMCPY

Inputs

Name	Type	Description
`Key`	T_Generic	Key used to identify stored value

Outputs

Name	Type	Description
`Value`	T_Generic	Variable to store requested data
`bSuccess`	`BOOL`

Get_Keys

Gets an immutable list of the keys.

Get_Values

Gets an immutable list of the values.

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 an element with the provided key and value to the map.

Inputs

Name	Type	Description
`Key`	`ANY`	Key used to identify stored value
`Value`	`ANY`	Value to store in map with key

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Insert_Generic

Insert an element with the provided key and value in their generic forms to the map.

Inputs

Name	Type	Description
`Key`	T_Generic	Key used to identify stored value
`Value`	T_Generic	Value to store in map with key
`bUpdate`	`BOOL`	If this is true the value will be updated if the key already exists.

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Remove

Removes value with the specified key from the map.

Inputs

Name	Type	Description
`Key`	`ANY`	Key used to identify stored value

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Remove_Generic

Removes value with the specified key in its generic form from the map.

Inputs

Name	Type	Description
`Key`	T_Generic	Key used to identify stored value

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Resize

Sets the number of buckets in the hash map. 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`

Update

Updates the value at the provided key with the new value in the map.

Inputs

Name	Type	Description
`Key`	`ANY`	Key used to identify stored value
`Value`	`ANY`	Value to store in map with key

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Update_Generic

Updates the value at the provided key with the new value in their generic forms in the map.

Inputs

Name	Type	Description
`Key`	T_Generic	Key used to identify stored value
`Value`	T_Generic	Value to store in map with key

Outputs

Name	Type	Description
`bSuccess`	`BOOL`

Upsert

Updates a value in the map for a given key. If the key doesnt exist, it will be inserted.

Inputs

Name	Type	Description
`Key`	`ANY`	Key used to identify stored value
`Value`	`ANY`	Value to store in map with key

Outputs

Name	Type	Description
`bSuccess`	`BOOL`