Encoding

The easiest way to encode data items is using the cbor_serialize() or cbor_serialize_alloc() functions:

size_t cbor_serialize(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize the given item.

param item:: A data item
param buffer:: Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result. 0 on failure.

size_t cbor_serialize_alloc(const cbor_item_t *item, unsigned char **buffer, size_t *buffer_size)

Serialize the given item, allocating buffers as needed.

Since libcbor v0.10, the return value is always the same as buffer_size (if provided, see https://github.com/PJK/libcbor/pull/251/). New clients should ignore the return value.

Warning

It is the caller’s responsibility to free the buffer using an appropriate free implementation.

param item:: A data item
param buffer:: [out] Buffer containing the result
param buffer_size:: [out] Size of the buffer, or 0 on memory allocation failure.
return:: Length of the result in bytes
return:: 0 on memory allocation failure, in which case buffer is NULL.

To determine the number of bytes needed to serialize an item, use cbor_serialized_size():

size_t cbor_serialized_size(const cbor_item_t *item)

Compute the length (in bytes) of the item when serialized using cbor_serialize.

Time complexity is proportional to the number of nested items.

param item:: A data item
return:: Length (>= 1) of the item when serialized. 0 if the length overflows size_t.

Type-specific serializers

In case you know the type of the item you want to serialize beforehand, you can use one of the type-specific serializers.

Note

Unless compiled in debug mode, these do not verify the type. Passing an incorrect item will result in an undefined behavior.

size_t cbor_serialize_uint(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize an uint.

param item:: A uint
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result

size_t cbor_serialize_negint(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize a negint.

param item:: A negint
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result

size_t cbor_serialize_bytestring(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize a bytestring.

param item:: A bytestring
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result. The buffer may still be modified

size_t cbor_serialize_string(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize a string.

param item:: A string
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result. The buffer may still be modified

size_t cbor_serialize_array(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize an array.

param item:: An array
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result. The buffer may still be modified

size_t cbor_serialize_map(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize a map.

param item:: A map
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result. The buffer may still be modified

size_t cbor_serialize_tag(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize a tag.

param item:: A tag
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result. The buffer may still be modified

size_t cbor_serialize_float_ctrl(const cbor_item_t *item, cbor_mutable_data buffer, size_t buffer_size)

Serialize a.

param item:: A float or ctrl
param buffer:: [out] Buffer to serialize to
param buffer_size:: Size of the buffer
return:: Length of the result
return:: 0 if the buffer_size doesn’t fit the result