Increases code size 3 bytes per each field. Compiler error will tell if you need this.
PB_FIELD_32BIT Add support for tag numbers > 65535 and fields larger than 65535 bytes or 65535 array entries.
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.
For optional fields, this function applies the default value and sets *has_<field>* to false if the field is not present.
+pb_decode_noinit
+----------------
+Same as `pb_decode`_, except does not apply the default values to fields. ::
+
+ bool pb_decode_noinit(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
+
+(parameters are the same as for `pb_decode`_.)
+
+The destination structure should be filled with zeros before calling this function. Doing a *memset* manually can be slightly faster than using `pb_decode`_ if you don't need any default values.
+
pb_skip_varint
--------------
Skip a varint_ encoded integer without decoding it. ::
For decoding numeric (including enumerated and boolean) values, use `pb_decode_varint`_, `pb_decode_svarint`_, `pb_decode_fixed32`_ and `pb_decode_fixed64`_. They take a pointer to a 32- or 64-bit C variable, which you may then cast to smaller datatype for storage.
- For decoding strings and bytes fields, the length has already been decoded. You can therefore check the total length in *stream->state* and read the data using `pb_read`_.
+ For decoding strings and bytes fields, the length has already been decoded. You can therefore check the total length in *stream->bytes_left* and read the data using `pb_read`_.
Finally, for decoding submessages in a callback, simply use `pb_decode`_ and pass it the *SubMessage_fields* descriptor array.
:substream: New substream that has limited length. Filled in by the function.
:returns: True on success, false if reading the length fails.
-This function uses `pb_decode_varint`_ to read an integer from the stream. This is interpreted as a number of bytes, and the substream is set up so that its `bytes_left` is initially the same as the length. The substream has a wrapper callback that in turn reads from the parent stream.
+This function uses `pb_decode_varint`_ to read an integer from the stream. This is interpreted as a number of bytes, and the substream is set up so that its `bytes_left` is initially the same as the length, and its callback function and state the same as the parent stream.
+
+pb_close_string_substream
+-------------------------
+Close the substream created with `pb_make_string_substream`_. ::
+
+ void pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream);
+
+:stream: Original input stream to read the length and data from.
+:substream: Substream to close
+
+This function copies back the state from the substream to the parent stream.
+It must be called after done with the substream.
Code Review / apps / agl-service-can-low-level.git / blobdiff