Increases code size 9 bytes per each field. Compiler error will tell if you need this.
PB_NO_ERRMSG Disables the support for error messages; only error information is the true/false return value.
Decreases the code size by a few hundred bytes.
+PB_BUFFER_ONLY Disables the support for custom streams. Only supports encoding to memory buffers.
+ Speeds up execution and decreases code size slightly.
+PB_OLD_CALLBACK_STYLE Use the old function signature (void\* instead of void\*\*) for callback fields. This was the
+ default until nanopb-0.2.1.
============================ ================================================================================================
The PB_MAX_REQUIRED_FIELDS, PB_FIELD_16BIT and PB_FIELD_32BIT settings allow raising some datatype limits to suit larger messages.
---------
Defines the encoder/decoder behaviour that should be used for a field. ::
- typedef enum { ... } pb_type_t;
+ typedef uint8_t pb_type_t;
-The low-order byte of the enumeration values defines the function that can be used for encoding and decoding the field data:
+The low-order nibble of the enumeration values defines the function that can be used for encoding and decoding the field data:
==================== ===== ================================================
LTYPE identifier Value Storage format
==================== ===== ================================================
PB_LTYPE_VARINT 0x00 Integer.
PB_LTYPE_SVARINT 0x01 Integer, zigzag encoded.
-PB_LTYPE_FIXED 0x02 Integer or floating point.
-PB_LTYPE_BYTES 0x03 Structure with *size_t* field and byte array.
-PB_LTYPE_STRING 0x04 Null-terminated string.
-PB_LTYPE_SUBMESSAGE 0x05 Submessage structure.
+PB_LTYPE_FIXED32 0x02 32-bit integer or floating point.
+PB_LTYPE_FIXED64 0x03 64-bit integer or floating point.
+PB_LTYPE_BYTES 0x04 Structure with *size_t* field and byte array.
+PB_LTYPE_STRING 0x05 Null-terminated string.
+PB_LTYPE_SUBMESSAGE 0x06 Submessage structure.
==================== ===== ================================================
-The high-order byte defines whether the field is required, optional, repeated or callback:
+The bits 4-5 define whether the field is required, optional or repeated:
==================== ===== ================================================
HTYPE identifier Value Field handling
PB_HTYPE_REQUIRED 0x00 Verify that field exists in decoded message.
PB_HTYPE_OPTIONAL 0x10 Use separate *has_<field>* boolean to specify
whether the field is present.
-PB_HTYPE_ARRAY 0x20 A repeated field with preallocated array.
+ (Unless it is a callback)
+PB_HTYPE_REPEATED 0x20 A repeated field with preallocated array.
Separate *<field>_count* for number of items.
-PB_HTYPE_CALLBACK 0x30 A field with dynamic storage size, data is
- actually a pointer to a structure containing a
- callback function.
+ (Unless it is a callback)
==================== ===== ================================================
+The bits 6-7 define the how the storage for the field is allocated:
+
+==================== ===== ================================================
+ATYPE identifier Value Allocation method
+==================== ===== ================================================
+PB_ATYPE_STATIC 0x00 Statically allocated storage in the structure.
+PB_ATYPE_CALLBACK 0x40 A field with dynamic storage size. Struct field
+ actually contains a pointer to a callback
+ function.
+==================== ===== ================================================
+
+
pb_field_t
----------
Describes a single structure field with memory position in relation to others. The descriptions are usually autogenerated. ::
} pb_packed;
:tag: Tag number of the field or 0 to terminate a list of fields.
-:type: LTYPE and HTYPE of the field.
+:type: LTYPE, HTYPE and ATYPE of the field.
:data_offset: Offset of field data, relative to the end of the previous field.
:size_offset: Offset of *bool* flag for optional fields or *size_t* count for arrays, relative to field data.
:data_size: Size of a single data entry, in bytes. For PB_LTYPE_BYTES, the size of the byte array inside the containing structure. For PB_HTYPE_CALLBACK, size of the C data type if known.
typedef struct _pb_callback_t pb_callback_t;
struct _pb_callback_t {
union {
- bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void *arg);
- bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, const void *arg);
+ bool (*decode)(pb_istream_t *stream, const pb_field_t *field, void **arg);
+ bool (*encode)(pb_ostream_t *stream, const pb_field_t *field, void * const *arg);
} funcs;
void *arg;
};
-The *arg* is passed to the callback when calling. It can be used to store any information that the callback might need.
+A pointer to the *arg* is passed to the callback when calling. It can be used to store any information that the callback might need.
+
+Previously the function received just the value of *arg* instead of a pointer to it. This old behaviour can be enabled by defining *PB_OLD_CALLBACK_STYLE*.
When calling `pb_encode`_, *funcs.encode* is used, and similarly when calling `pb_decode`_, *funcs.decode* is used. The function pointers are stored in the same memory location but are of incompatible types. You can set the function pointer to NULL to skip the field.
Code Review / apps / agl-service-can-low-level.git / blobdiff