LwM2M data types

Macros
#define	ANJ_DATA_TYPE_NULL   ((anj_data_type_t) 0)
#define	ANJ_DATA_TYPE_BYTES   ((anj_data_type_t) (1 << 0))
#define	ANJ_DATA_TYPE_STRING   ((anj_data_type_t) (1 << 1))
#define	ANJ_DATA_TYPE_INT   ((anj_data_type_t) (1 << 2))
#define	ANJ_DATA_TYPE_DOUBLE   ((anj_data_type_t) (1 << 3))
#define	ANJ_DATA_TYPE_BOOL   ((anj_data_type_t) (1 << 4))
#define	ANJ_DATA_TYPE_OBJLNK   ((anj_data_type_t) (1 << 5))
#define	ANJ_DATA_TYPE_UINT   ((anj_data_type_t) (1 << 6))
#define	ANJ_DATA_TYPE_TIME   ((anj_data_type_t) (1 << 7))
#define	ANJ_DATA_TYPE_ANY
#define	ANJ_DATA_TYPE_FLAG_EXTERNAL   ((anj_data_type_t) (1 << 15))
#define	ANJ_DATA_TYPE_EXTERNAL_BYTES
#define	ANJ_DATA_TYPE_EXTERNAL_STRING

Typedefs
typedef uint16_t	anj_data_type_t

Detailed Description

Data type identifiers used in the Anjay Lite data model.

These values correspond to the types defined in OMA LwM2M Core Specification v1.2.2 [OMA-TS-LightweightM2M_Core-V1_2_2-20240613-A] §C. They are primarily used when parsing or encoding request/response payloads.

Each constant indicates which field of anj_res_value_t is used to hold the value.

Macro Definition Documentation

ANJ_DATA_TYPE_ANY

#define ANJ_DATA_TYPE_ANY

Value:

        ((anj_data_type_t) (ANJ_DATA_TYPE_BYTES | ANJ_DATA_TYPE_STRING  \
                            | ANJ_DATA_TYPE_INT | ANJ_DATA_TYPE_DOUBLE  \
                            | ANJ_DATA_TYPE_BOOL | ANJ_DATA_TYPE_OBJLNK \
                            | ANJ_DATA_TYPE_UINT | ANJ_DATA_TYPE_TIME))

Bitmask representing all supported data types.

Note

Does not include ANJ_DATA_TYPE_FLAG_EXTERNAL.

ANJ_DATA_TYPE_NULL is not a part of the bitmask.

ANJ_DATA_TYPE_BOOL

#define ANJ_DATA_TYPE_BOOL   ((anj_data_type_t) (1 << 4))

Boolean data type.

The anj_res_value_t::bool_value field holds the value.

ANJ_DATA_TYPE_BYTES

#define ANJ_DATA_TYPE_BYTES   ((anj_data_type_t) (1 << 0))

Opaque data type.

The anj_res_value_t::bytes_or_string field holds the raw bytes.

ANJ_DATA_TYPE_DOUBLE

#define ANJ_DATA_TYPE_DOUBLE   ((anj_data_type_t) (1 << 3))

Floating-point data type.

The anj_res_value_t::double_value field holds the number.

ANJ_DATA_TYPE_EXTERNAL_BYTES

#define ANJ_DATA_TYPE_EXTERNAL_BYTES

Value:

            ((anj_data_type_t) (ANJ_DATA_TYPE_BYTES \
                                | ANJ_DATA_TYPE_FLAG_EXTERNAL))

Opaque data type supplied via external callback.

The anj_res_value_t::external_data field provides the data. Valid only for output contexts.

ANJ_DATA_TYPE_EXTERNAL_STRING

#define ANJ_DATA_TYPE_EXTERNAL_STRING

Value:

            ((anj_data_type_t) (ANJ_DATA_TYPE_STRING \
                                | ANJ_DATA_TYPE_FLAG_EXTERNAL))

String data type supplied via external callback.

The anj_res_value_t::external_data field provides the data. Valid only for output contexts.

ANJ_DATA_TYPE_FLAG_EXTERNAL

#define ANJ_DATA_TYPE_FLAG_EXTERNAL   ((anj_data_type_t) (1 << 15))

Flag indicating that data is supplied via an external callback.

May be OR-ed with ANJ_DATA_TYPE_BYTES or ANJ_DATA_TYPE_STRING. Valid only for output contexts.

When this flag is set, the anj_res_value_t::external_data field must be used to provide the data.

Typical use cases:

• Data is not directly available in memory and must be streamed (e.g., from external storage).
• Data size is unknown in advance; the external data callback interface does not require providing the total length beforehand.

Note

When encoding CBOR-based formats (LwM2M CBOR, SenML CBOR), data is encoded as an Indefinite-Length String, split into chunks of up to 23 bytes.

ANJ_DATA_TYPE_INT

#define ANJ_DATA_TYPE_INT   ((anj_data_type_t) (1 << 2))

Integer data type.

The anj_res_value_t::int_value field holds the number.

ANJ_DATA_TYPE_NULL

#define ANJ_DATA_TYPE_NULL   ((anj_data_type_t) 0)

Null data type.

Indicates absence of a value. It is reported in the following cases:

• Parsing a Composite-Read request payload.
• Parsing a SenML-ETCH JSON/CBOR Write-Composite payload that contains an entry without a value (removal of a Resource Instance).
• Parsing a LwM2M CBOR or SenML-ETCH JSON/CBOR Write-Composite payload that contains an explicit NULL value (removal of a Resource Instance).
• Parsing a TLV or LwM2M CBOR payload where an aggregate (Object Instance or Multiple Instance Resource) contains zero nested elements.

Note

For this type, anj_res_value_t is not used.

ANJ_DATA_TYPE_OBJLNK

#define ANJ_DATA_TYPE_OBJLNK   ((anj_data_type_t) (1 << 5))

Object Link (Objlnk) data type.

The anj_res_value_t::objlnk field holds the value.

ANJ_DATA_TYPE_STRING

#define ANJ_DATA_TYPE_STRING   ((anj_data_type_t) (1 << 1))

String data type.

The anj_res_value_t::bytes_or_string field holds the string.

Note

May also be used to represent the "Corelnk" type, as both appear identical on the wire.

ANJ_DATA_TYPE_TIME

#define ANJ_DATA_TYPE_TIME   ((anj_data_type_t) (1 << 7))

Time data type.

The anj_res_value_t::time_value field holds the value.

ANJ_DATA_TYPE_UINT

#define ANJ_DATA_TYPE_UINT   ((anj_data_type_t) (1 << 6))

Unsigned Integer data type.

The anj_res_value_t::uint_value field holds the number.

Typedef Documentation

anj_data_type_t

typedef uint16_t anj_data_type_t

LwM2M data type identifier. As this type is a bitmask, see LwM2M data types for possible combinations.