OrderedCollectionLib.h File Reference

Typedefs
typedef struct ORDERED_COLLECTION	ORDERED_COLLECTION
typedef struct ORDERED_COLLECTION_ENTRY	ORDERED_COLLECTION_ENTRY
typedef INTN(EFIAPI *	ORDERED_COLLECTION_USER_COMPARE )(IN CONST VOID *UserStruct1, IN CONST VOID *UserStruct2)
typedef INTN(EFIAPI *	ORDERED_COLLECTION_KEY_COMPARE )(IN CONST VOID *StandaloneKey, IN CONST VOID *UserStruct)

Functions
VOID *EFIAPI	OrderedCollectionUserStruct (IN CONST ORDERED_COLLECTION_ENTRY *Entry)
ORDERED_COLLECTION *EFIAPI	OrderedCollectionInit (IN ORDERED_COLLECTION_USER_COMPARE UserStructCompare, IN ORDERED_COLLECTION_KEY_COMPARE KeyCompare)
BOOLEAN EFIAPI	OrderedCollectionIsEmpty (IN CONST ORDERED_COLLECTION *Collection)
VOID EFIAPI	OrderedCollectionUninit (IN ORDERED_COLLECTION *Collection)
ORDERED_COLLECTION_ENTRY *EFIAPI	OrderedCollectionFind (IN CONST ORDERED_COLLECTION *Collection, IN CONST VOID *StandaloneKey)
ORDERED_COLLECTION_ENTRY *EFIAPI	OrderedCollectionMin (IN CONST ORDERED_COLLECTION *Collection)
ORDERED_COLLECTION_ENTRY *EFIAPI	OrderedCollectionMax (IN CONST ORDERED_COLLECTION *Collection)
ORDERED_COLLECTION_ENTRY *EFIAPI	OrderedCollectionNext (IN CONST ORDERED_COLLECTION_ENTRY *Entry)
ORDERED_COLLECTION_ENTRY *EFIAPI	OrderedCollectionPrev (IN CONST ORDERED_COLLECTION_ENTRY *Entry)
RETURN_STATUS EFIAPI	OrderedCollectionInsert (IN OUT ORDERED_COLLECTION *Collection, OUT ORDERED_COLLECTION_ENTRY **Entry, IN VOID *UserStruct)
VOID EFIAPI	OrderedCollectionDelete (IN OUT ORDERED_COLLECTION *Collection, IN ORDERED_COLLECTION_ENTRY *Entry, OUT VOID **UserStruct)

Detailed Description

An ordered collection library interface.

The library class provides a set of APIs to manage an ordered collection of items.

Copyright (C) 2014, Red Hat, Inc.

SPDX-License-Identifier: BSD-2-Clause-Patent

Typedef Documentation

typedef struct ORDERED_COLLECTION ORDERED_COLLECTION

typedef struct ORDERED_COLLECTION_ENTRY ORDERED_COLLECTION_ENTRY

typedef INTN(EFIAPI * ORDERED_COLLECTION_KEY_COMPARE)(IN CONST VOID *StandaloneKey, IN CONST VOID *UserStruct)

Compare a standalone key against a user structure containing an embedded key.

Parameters

[in]	StandaloneKey	Pointer to the bare key.
[in]	UserStruct	Pointer to the user structure with the embedded key.

Return values

<0	If StandaloneKey compares less than UserStruct's key.
0	If StandaloneKey compares equal to UserStruct's key.
>0	If StandaloneKey compares greater than UserStruct's key.

typedef INTN(EFIAPI * ORDERED_COLLECTION_USER_COMPARE)(IN CONST VOID *UserStruct1, IN CONST VOID *UserStruct2)

Comparator function type for two user structures.

Parameters

[in]	UserStruct1	Pointer to the first user structure.
[in]	UserStruct2	Pointer to the second user structure.

Return values

<0	If UserStruct1 compares less than UserStruct2.
0	If UserStruct1 compares equal to UserStruct2.
>0	If UserStruct1 compares greater than UserStruct2.

Function Documentation

VOID EFIAPI OrderedCollectionDelete	(	IN OUT ORDERED_COLLECTION *	Collection,
		IN ORDERED_COLLECTION_ENTRY *	Entry,
		OUT VOID **	UserStruct
	)

Delete an entry from the collection, unlinking the associated user structure.

Read-write operation.

Parameters

[in,out]	Collection	The collection to delete Entry from.
[in]	Entry	The collection entry to delete from Collection. The caller is responsible for ensuring that Entry belongs to Collection, and that Entry is non-NULL and valid. Entry is typically an earlier return value, or output parameter, of:

• OrderedCollectionFind(), for deleting an entry by user structure key,
• OrderedCollectionMin() / OrderedCollectionMax(), for deleting the minimum / maximum entry,
• OrderedCollectionNext() / OrderedCollectionPrev(), for deleting an entry found during an iteration,
• OrderedCollectionInsert() with return value RETURN_ALREADY_STARTED, for deleting an entry whose linked user structure caused collision during insertion.

Existing ORDERED_COLLECTION_ENTRY pointers (ie. iterators) different from Entry remain valid. For example:

• OrderedCollectionNext() / OrderedCollectionPrev() iterations in the caller can be continued from Entry, if OrderedCollectionNext() or OrderedCollectionPrev() is called on Entry before* OrderedCollectionDelete() is. That is, fetch the successor / predecessor entry first, then delete Entry.
• On-going iterations in the caller that would have otherwise returned Entry at some point, as dictated by user structure order, will correctly reflect the absence of Entry after OrderedCollectionDelete() is called mid-iteration.

Parameters

[out]

UserStruct

If the caller provides this optional output-only parameter, then on output it is set to the user structure originally linked by Entry (which is now freed).

This is a convenience that may save the caller a OrderedCollectionUserStruct() invocation before calling OrderedCollectionDelete(), in order to retrieve the user structure being unlinked.

ORDERED_COLLECTION_ENTRY* EFIAPI OrderedCollectionFind	(	IN CONST ORDERED_COLLECTION *	Collection,
		IN CONST VOID *	StandaloneKey
	)

Look up the collection entry that links the user structure that matches the specified standalone key.

Read-only operation.

Parameters

[in]	Collection	The collection to search for StandaloneKey.
[in]	StandaloneKey	The key to locate among the user structures linked into Collection. StandaloneKey will be passed to ORDERED_COLLECTION_KEY_COMPARE.

Return values

NULL	StandaloneKey could not be found.

Returns

The collection entry that links to the user structure matching StandaloneKey, otherwise.

ORDERED_COLLECTION* EFIAPI OrderedCollectionInit	(	IN ORDERED_COLLECTION_USER_COMPARE	UserStructCompare,
		IN ORDERED_COLLECTION_KEY_COMPARE	KeyCompare
	)

Allocate and initialize the ORDERED_COLLECTION structure.

Parameters

[in]	UserStructCompare	This caller-provided function will be used to order two user structures linked into the collection, during the insertion procedure.
[in]	KeyCompare	This caller-provided function will be used to order the standalone search key against user structures linked into the collection, during the lookup procedure.

Return values

NULL	If allocation failed.

Returns

Pointer to the allocated, initialized ORDERED_COLLECTION structure, otherwise.

RETURN_STATUS EFIAPI OrderedCollectionInsert	(	IN OUT ORDERED_COLLECTION *	Collection,
		OUT ORDERED_COLLECTION_ENTRY **	Entry,
		IN VOID *	UserStruct
	)

Insert (link) a user structure into the collection, allocating a new collection entry.

Read-write operation.

Parameters

[in,out]	Collection	The collection to insert UserStruct into.
[out]	Entry	The meaning of this optional, output-only parameter depends on the return value of the function.

When insertion is successful (RETURN_SUCCESS), Entry is set on output to the new collection entry that now links UserStruct.

When insertion fails due to lack of memory (RETURN_OUT_OF_RESOURCES), Entry is not changed.

When insertion fails due to key collision (ie. another user structure is already in the collection that compares equal to UserStruct), with return value RETURN_ALREADY_STARTED, then Entry is set on output to the entry that links the colliding user structure. This enables "find-or-insert" in one function call, or helps with later removal of the colliding element.

Parameters

[in]

UserStruct

The user structure to link into the collection. UserStruct is ordered against in-collection user structures with the ORDERED_COLLECTION_USER_COMPARE function.

Return values

RETURN_SUCCESS

Insertion successful. A new collection entry has been allocated, linking UserStruct. The new collection entry is reported back in Entry (if the caller requested it).

Existing ORDERED_COLLECTION_ENTRY pointers into Collection remain valid. For example, on-going iterations in the caller can continue with OrderedCollectionNext() / OrderedCollectionPrev(), and they will return the new entry at some point if user structure order dictates it.

Return values

RETURN_OUT_OF_RESOURCES	The function failed to allocate memory for the new collection entry. The collection has not been changed. Existing ORDERED_COLLECTION_ENTRY pointers into Collection remain valid.
RETURN_ALREADY_STARTED	A user structure has been found in the collection that compares equal to UserStruct. The entry linking the colliding user structure is reported back in Entry (if the caller requested it). The collection has not been changed. Existing ORDERED_COLLECTION_ENTRY pointers into Collection remain valid.

BOOLEAN EFIAPI OrderedCollectionIsEmpty

(

IN CONST ORDERED_COLLECTION *

Collection

)

Check whether the collection is empty (has no entries).

Read-only operation.

Parameters

[in]

Collection

The collection to check for emptiness.

Return values

TRUE	The collection is empty.
FALSE	The collection is not empty.

ORDERED_COLLECTION_ENTRY* EFIAPI OrderedCollectionMax

(

IN CONST ORDERED_COLLECTION *

Collection

)

Find the collection entry of the maximum user structure stored in the collection.

Read-only operation.

Parameters

[in]

Collection

The collection to return the maximum entry of. The user structure linked by the maximum entry compares greater than all other user structures in the collection.

Return values

NULL	If Collection is empty.

Returns

The collection entry that links the maximum user structure, otherwise.

ORDERED_COLLECTION_ENTRY* EFIAPI OrderedCollectionMin

(

IN CONST ORDERED_COLLECTION *

Collection

)

Find the collection entry of the minimum user structure stored in the collection.

Read-only operation.

Parameters

[in]

Collection

The collection to return the minimum entry of. The user structure linked by the minimum entry compares less than all other user structures in the collection.

Return values

NULL	If Collection is empty.

Returns

The collection entry that links the minimum user structure, otherwise.

ORDERED_COLLECTION_ENTRY* EFIAPI OrderedCollectionNext

(

IN CONST ORDERED_COLLECTION_ENTRY *

Entry

)

Get the collection entry of the least user structure that is greater than the one linked by Entry.

Read-only operation.

Parameters

[in]

Entry

The entry to get the successor entry of.

Return values

NULL	If Entry is NULL, or Entry is the maximum entry of its containing collection (ie. Entry has no successor entry).

Returns

The collection entry linking the least user structure that is greater than the one linked by Entry, otherwise.

ORDERED_COLLECTION_ENTRY* EFIAPI OrderedCollectionPrev

(

IN CONST ORDERED_COLLECTION_ENTRY *

Entry

)

Get the collection entry of the greatest user structure that is less than the one linked by Entry.

Read-only operation.

Parameters

[in]

Entry

The entry to get the predecessor entry of.

Return values

NULL	If Entry is NULL, or Entry is the minimum entry of its containing collection (ie. Entry has no predecessor entry).

Returns

The collection entry linking the greatest user structure that is less than the one linked by Entry, otherwise.

VOID EFIAPI OrderedCollectionUninit

(

IN ORDERED_COLLECTION *

Collection

)

Uninitialize and release an empty ORDERED_COLLECTION structure.

Read-write operation.

It is the caller's responsibility to delete all entries from the collection before calling this function.

Parameters

[in]

Collection

The empty collection to uninitialize and release.

VOID* EFIAPI OrderedCollectionUserStruct

(

IN CONST ORDERED_COLLECTION_ENTRY *

Entry

)

Retrieve the user structure linked by the specified collection entry.

Read-only operation.

Parameters

[in]

Entry

Pointer to the collection entry whose associated user structure we want to retrieve. The caller is responsible for passing a non-NULL argument.

Returns

Pointer to user structure linked by Entry.