Lists and structures

Lists manipulate sets of objects of a particular type, for example:

• ARNameList manipulates any set of names.
• ARDiaryList manages the group of entries in a diary field.
• AREntryListList represents any group of entries in a schema.
• ARFilterActionList defines the set of actions that the server performs when it executes a filter or escalation.

While each type of list has its own data structure, all list structures have the same form:

typedef struct {
	unsigned int     numItems;
	AR xxxStruct      *xxxList;
} ARxxxList;

Each list structure has an integer that identifies the number of items in the list and a pointer to the allocated memory containing those items. If the number of items is zero, the server or client ignores the pointer and the pointer is usually set to NULL. The following figure shows an example that uses the ARFilterActionList structure.

Generic list structure

In general, the BMC Remedy AR System server handles lists as arrays instead of as linked lists. It then stores all items in the structure in a single area of memory with a pointer that identifies the memory address of the first item in the array. If the item structure itself (ARFilterActionStruct) contains a pointer, the server allocates the nested memory separately.