Decoding

The following diagram illustrates the relationship among different parts of libcbor from the decoding standpoint.

┌──────────────────────────────────────────────────────────────────────────────────────────────┐
│                                                                                              │
│                                      Client application                                      │
│                                                                                              │
│                                                 ┌────────────────────────────────────────────┘
│                                                 │                     ↕
│                                                 │ ┌──────────────────────────────────────────┐
│                                                 │ │                                          │
│                                                 │ │          Manipulation routines           │
│                                                 │ │                                          │
│           ┌─────────────────────────────────────┘ └──────────────────────────────────────────┘
│           │     ↑    ↑                  ↑                              ↑
│           │     │    │    ┌─────────────╫──────────┬───────────────────┴─┐
│           │     │   CDS   │             ║          │                     │
│           │     │    │   PDS            ║         PDS                   PDS
│           │     ↓    ↓    ↓             ↓          ↓                     ↓
│           │ ┌─────────────────┐   ┌────────────────────┐   ┌────────────────────────────┐
│           │ │                 │   │                    │   │                            │
│           │ │  Custom driver  │ ↔ │  Streaming driver  │ ↔ │       Default driver       │ ↔ CD
│           │ │                 │   │                    │   │                            │
└───────────┘ └─────────────────┘   └────────────────────┘   └────────────────────────────┘
      ↕                ↕                        ↕                           ↕
┌──────────────────────────────────────────────────────────────────────────────────────────────┐
│                                                                                              │
│                            Stateless event─driven decoder                                    │
│                                                                                              │
└──────────────────────────────────────────────────────────────────────────────────────────────┘

              (PSD = Provided Data Structures, CDS = Custom Data Structures)

This section will deal with the API that is labeled as the “Default driver” in the diagram. That is, routines that decode complete libcbor data items

cbor_item_t *cbor_load(cbor_data source, size_t source_size, struct cbor_load_result *result)

Loads data item from a buffer.

Return

new CBOR item or NULL on failure. In that case, result contains location and description of the error.

Parameters

• source: The buffer

• source_size:

• result[out]: Result indicator. CBOR_ERR_NONE on success

Associated data structures

enum cbor_error_code

Possible decoding errors.

Values:

CBOR_ERR_NONE

CBOR_ERR_NOTENOUGHDATA

CBOR_ERR_NODATA

CBOR_ERR_MALFORMATED

CBOR_ERR_MEMERROR

Memory error - item allocation failed.

Is it too big for your allocator?

CBOR_ERR_SYNTAXERROR

Stack parsing algorithm failed.

struct cbor_load_result

High-level decoding result.

Public Members

struct cbor_error error

Error indicator.

size_t read

Number of bytes read.

struct cbor_error

High-level decoding error.

Public Members

size_t position

Approximate position.

cbor_error_code code

Description.