Data Structures

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Overview

The EspList and EspMap data structures are used to retrieve multiple pieces of information from the SDK atomically. For example, retrieving the number of streams defined in a project.

Entities/Objects
typedef struct EspList	EspList
typedef struct EspMap	EspMap
typedef struct EspSdk	EspSdk

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Enumeration Types

enum ESP_LIST_ITEM_T

Enumeration of types supported by the EspList interface.

Enumerator:

ESP_LIST_MANAGER_T	List to return EspManager references
ESP_LIST_CONTROLLER_T	List to return EspController references
ESP_LIST_WORKSPACE_T	List to return EspWorkspace (string) references
ESP_LIST_APPLICATION_T	List to return EspApplication references
ESP_LIST_STRING_T	List to return strings
ESP_LIST_STREAM_T	List to return EspStream references
ESP_LIST_EVENT_T	List to return references to different events
ESP_LIST_UNDEFINED_T

Functions
ESPAPICALL EspList *	esp_list_create (const ESP_LIST_ITEM_T type, EspError *error)
ESPAPICALL int32_t	esp_list_get_count (const EspList *list, EspError *error)
ESPAPICALL int32_t	esp_list_clear (EspList *list, EspError *error)
ESPAPICALL int32_t	esp_list_free (EspList *list, EspError *error)
ESPAPICALL const EspStream *	esp_list_get_stream (const EspList *list, const int32_t index, EspError *error)
ESPAPICALL const char *	esp_list_get_string (const EspList *list, const int32_t index, EspError *error)
ESPAPICALL const void *	esp_list_get_event (const EspList *list, const int32_t index, EspError *error)
ESPAPICALL EspMap *	esp_map_create (EspError *error)
ESPAPICALL int32_t	esp_map_set (EspMap *map, const char *key, const char *value, EspError *error)
ESPAPICALL const char *	esp_map_get (const EspMap *map, const char *key, EspError *error)
ESPAPICALL int32_t	esp_map_count (const EspMap *map, EspError *error)
ESPAPICALL int32_t	esp_map_item_at (const EspMap *map, const int32_t index, const char **key, const char **value, EspError *error)
ESPAPICALL int32_t	esp_map_free (EspMap *map, EspError *error)

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Function Documentation

ESPAPICALL int32_t esp_list_clear	(	EspList *	list,
		EspError *	error
	)

Clears all items in the list. The EspList can be re used in a fresh query.

ESPAPICALL EspList* esp_list_create	(	const ESP_LIST_ITEM_T	type,
		EspError *	error
	)

Creates an EspList data structure. This must be freed using esp_list_free once done.

Parameters:

type	The type of data this EspList will contain

ESPAPICALL int32_t esp_list_free	(	EspList *	list,
		EspError *	error
	)

Frees an EspList object previously retrieved using esp_list_create.

ESPAPICALL int32_t esp_list_get_count	(	const EspList *	list,
		EspError *	error
	)

Returns number of items held in the EspList.

ESPAPICALL const void* esp_list_get_event	(	const EspList *	list,
		const int32_t	index,
		EspError *	error
	)

Returns a reference to one of the supported event types. The returned void pointer needs to be cast to the appropriate category. Use esp_event_get_category() to determine the category of the event.

Returns:

NULL in case of error.

Parameters:

list	EspList from which to retrieve
index	Index at which to retrieve the item

ESPAPICALL const EspStream* esp_list_get_stream	(	const EspList *	list,
		const int32_t	index,
		EspError *	error
	)

Return the EspStream object as the specified index. Will generate an error if the list is not of the correct type.

Returns:

NULL in case of error.

Parameters:

list	EspList from which to retrieve
index	Index at which to retrieve the item

ESPAPICALL const char* esp_list_get_string	(	const EspList *	list,
		const int32_t	index,
		EspError *	error
	)

Return a string at the specified index in the list. Will generate an error if the list is not of the correct type.

Returns:

NULL in case of error.

Parameters:

list	EspList from which to retrieve
index	Index at which to retrieve the item

ESPAPICALL int32_t esp_map_count	(	const EspMap *	map,
		EspError *	error
	)

Return number of items stored in the map. This function does not correspond to the standard return values scheme used in the SDK.

Returns:

-1 in case of error.

ESPAPICALL EspMap* esp_map_create

(

EspError *

error

)

Creates an EspMap structure that can be used to store key value pairs. The new EspMap must be freed using esp_map_free once done.

Returns:

NULL in case of error.

ESPAPICALL int32_t esp_map_free	(	EspMap *	map,
		EspError *	error
	)

ESPAPICALL const char* esp_map_get	(	const EspMap *	map,
		const char *	key,
		EspError *	error
	)

Retrieve the value for the specified key.

Returns:

NULL in case of error.

ESPAPICALL int32_t esp_map_item_at	(	const EspMap *	map,
		const int32_t	index,
		const char **	key,
		const char **	value,
		EspError *	error
	)

ESPAPICALL int32_t esp_map_set	(	EspMap *	map,
		const char *	key,
		const char *	value,
		EspError *	error
	)

Insert a key value pair into the map.

Returns:

non-zero in case of error.

Parameters:

map	EspMap into which to insert
key	Key of the mapping
value	Value for the mapping