.. contents ::
+
+
+
Compilation options
===================
-The following options can be specified using -D switch given to the C compiler:
-
-============================ ================================================================================================
-__BIG_ENDIAN__ Set this if your platform stores integers and floats in big-endian format.
- Mixed-endian systems (different layout for ints and floats) are currently not supported.
-NANOPB_INTERNALS Set this to expose the field encoder functions that are hidden since nanopb-0.1.3.
-PB_MAX_REQUIRED_FIELDS Maximum number of required fields to check for presence. Default value is 64. Increases stack
- usage 1 byte per every 8 fields. Compiler warning will tell if you need this.
-PB_FIELD_16BIT Add support for tag numbers > 255 and fields larger than 255 bytes or 255 array entries.
- 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.
-============================ ================================================================================================
-
-The PB_MAX_REQUIRED_FIELDS, PB_FIELD_16BIT and PB_FIELD_32BIT settings allow raising some datatype limits to suit larger messages.
-Their need is recognized automatically by C-preprocessor #if-directives in the generated .pb.h files. The default setting is to use
-the smallest datatypes (least resources used).
+The following options can be specified in one of two ways:
+
+1. Using the -D switch on the C compiler command line.
+2. By #defining them at the top of pb.h.
+
+You must have the same settings for the nanopb library and all code that
+includes pb.h.
+
+============================ ================================================
+PB_NO_PACKED_STRUCTS Disable packed structs. Increases RAM usage but
+ is necessary on some platforms that do not
+ support unaligned memory access.
+PB_ENABLE_MALLOC Set this to enable dynamic allocation support
+ in the decoder.
+PB_MAX_REQUIRED_FIELDS Maximum number of required fields to check for
+ presence. Default value is 64. Increases stack
+ usage 1 byte per every 8 fields. Compiler
+ warning will tell if you need this.
+PB_FIELD_16BIT Add support for tag numbers > 255 and fields
+ larger than 255 bytes or 255 array entries.
+ 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 and decoding with 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.
+PB_SYSTEM_HEADER Replace the standard header files with a single
+ header file. It should define all the required
+ functions and typedefs listed on the
+ `overview page`_. Value must include quotes,
+ for example *#define PB_SYSTEM_HEADER "foo.h"*.
+============================ ================================================
+
+The PB_MAX_REQUIRED_FIELDS, PB_FIELD_16BIT and PB_FIELD_32BIT settings allow
+raising some datatype limits to suit larger messages. Their need is recognized
+automatically by C-preprocessor #if-directives in the generated .pb.h files.
+The default setting is to use the smallest datatypes (least resources used).
+
+.. _`overview page`: index.html#compiler-requirements
+
+
+Proto file options
+==================
+The generator behaviour can be adjusted using these options, defined in the
+'nanopb.proto' file in the generator folder:
+
+============================ ================================================
+max_size Allocated size for *bytes* and *string* fields.
+max_count Allocated number of entries in arrays
+ (*repeated* fields).
+int_size Override the integer type of a field.
+ (To use e.g. uint8_t to save RAM.)
+type Type of the generated field. Default value
+ is *FT_DEFAULT*, which selects automatically.
+ You can use *FT_CALLBACK*, *FT_POINTER*,
+ *FT_STATIC*, *FT_IGNORE*, or *FT_INLINE* to
+ force a callback field, a dynamically
+ allocated field, a static field, to
+ completely ignore the field or to
+ generate an inline bytes field.
+long_names Prefix the enum name to the enum value in
+ definitions, i.e. *EnumName_EnumValue*. Enabled
+ by default.
+packed_struct Make the generated structures packed.
+ NOTE: This cannot be used on CPUs that break
+ on unaligned accesses to variables.
+skip_message Skip the whole message from generation.
+no_unions Generate 'oneof' fields as optional fields
+ instead of C unions.
+msgid Specifies a unique id for this message type.
+ Can be used by user code as an identifier.
+anonymous_oneof Generate 'oneof' fields as anonymous unions.
+============================ ================================================
+
+These options can be defined for the .proto files before they are converted
+using the nanopb-generatory.py. There are three ways to define the options:
+
+1. Using a separate .options file.
+ This is the preferred way as of nanopb-0.2.1, because it has the best
+ compatibility with other protobuf libraries.
+2. Defining the options on the command line of nanopb_generator.py.
+ This only makes sense for settings that apply to a whole file.
+3. Defining the options in the .proto file using the nanopb extensions.
+ This is the way used in nanopb-0.1, and will remain supported in the
+ future. It however sometimes causes trouble when using the .proto file
+ with other protobuf libraries.
+
+The effect of the options is the same no matter how they are given. The most
+common purpose is to define maximum size for string fields in order to
+statically allocate them.
+
+Defining the options in a .options file
+---------------------------------------
+The preferred way to define options is to have a separate file
+'myproto.options' in the same directory as the 'myproto.proto'. ::
+
+ # myproto.proto
+ message MyMessage {
+ required string name = 1;
+ repeated int32 ids = 4;
+ }
+
+::
+
+ # myproto.options
+ MyMessage.name max_size:40
+ MyMessage.ids max_count:5
+
+The generator will automatically search for this file and read the
+options from it. The file format is as follows:
+
+* Lines starting with '#' or '//' are regarded as comments.
+* Blank lines are ignored.
+* All other lines should start with a field name pattern, followed by one or
+ more options. For example: *"MyMessage.myfield max_size:5 max_count:10"*.
+* The field name pattern is matched against a string of form *'Message.field'*.
+ For nested messages, the string is *'Message.SubMessage.field'*.
+* The field name pattern may use the notation recognized by Python fnmatch():
+
+ - *\** matches any part of string, like 'Message.\*' for all fields
+ - *\?* matches any single character
+ - *[seq]* matches any of characters 's', 'e' and 'q'
+ - *[!seq]* matches any other character
+
+* The options are written as *'option_name:option_value'* and several options
+ can be defined on same line, separated by whitespace.
+* Options defined later in the file override the ones specified earlier, so
+ it makes sense to define wildcard options first in the file and more specific
+ ones later.
+
+If preferred, the name of the options file can be set using the command line
+switch *-f* to nanopb_generator.py.
+
+Defining the options on command line
+------------------------------------
+The nanopb_generator.py has a simple command line option *-s OPTION:VALUE*.
+The setting applies to the whole file that is being processed.
+
+Defining the options in the .proto file
+---------------------------------------
+The .proto file format allows defining custom options for the fields.
+The nanopb library comes with *nanopb.proto* which does exactly that, allowing
+you do define the options directly in the .proto file::
+
+ import "nanopb.proto";
+
+ message MyMessage {
+ required string name = 1 [(nanopb).max_size = 40];
+ repeated int32 ids = 4 [(nanopb).max_count = 5];
+ }
+
+A small complication is that you have to set the include path of protoc so that
+nanopb.proto can be found. This file, in turn, requires the file
+*google/protobuf/descriptor.proto*. This is usually installed under
+*/usr/include*. Therefore, to compile a .proto file which uses options, use a
+protoc command similar to::
+
+ protoc -I/usr/include -Inanopb/generator -I. -omessage.pb message.proto
+
+The options can be defined in file, message and field scopes::
+
+ option (nanopb_fileopt).max_size = 20; // File scope
+ message Message
+ {
+ option (nanopb_msgopt).max_size = 30; // Message scope
+ required string fieldsize = 1 [(nanopb).max_size = 40]; // Field scope
+ }
+
+
+
+
+
+
+
+
pb.h
====
+pb_byte_t
+---------
+Type used for storing byte-sized data, such as raw binary input and bytes-type fields. ::
+
+ typedef uint_least8_t pb_byte_t;
+
+For most platforms this is equivalent to `uint8_t`. Some platforms however do not support
+8-bit variables, and on those platforms 16 or 32 bits need to be used for each byte.
+
pb_type_t
---------
-Defines the encoder/decoder behaviour that should be used for a field. ::
+Type used to store the type of each field, to control the encoder/decoder behaviour. ::
- typedef enum { ... } pb_type_t;
+ typedef uint_least8_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.
-==================== ===== ================================================
+=========================== ===== ================================================
+LTYPE identifier Value Storage format
+=========================== ===== ================================================
+PB_LTYPE_VARINT 0x00 Integer.
+PB_LTYPE_UVARINT 0x01 Unsigned integer.
+PB_LTYPE_SVARINT 0x02 Integer, zigzag encoded.
+PB_LTYPE_FIXED32 0x03 32-bit integer or floating point.
+PB_LTYPE_FIXED64 0x04 64-bit integer or floating point.
+PB_LTYPE_BYTES 0x05 Structure with *size_t* field and byte array.
+PB_LTYPE_STRING 0x06 Null-terminated string.
+PB_LTYPE_SUBMESSAGE 0x07 Submessage structure.
+PB_LTYPE_EXTENSION 0x08 Point to *pb_extension_t*.
+PB_LTYPE_FIXED_LENGTH_BYTES 0x09 Inline *pb_byte_t* array of fixed size.
+=========================== ===== ================================================
-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. ::
- typedef struct _pb_field_t pb_field_t;
- struct _pb_field_t {
- uint8_t tag;
+ typedef struct pb_field_s pb_field_t;
+ struct pb_field_s {
+ pb_size_t tag;
pb_type_t type;
- uint8_t data_offset;
- int8_t size_offset;
- uint8_t data_size;
- uint8_t array_size;
+ pb_size_t data_offset;
+ pb_ssize_t size_offset;
+ pb_size_t data_size;
+ pb_size_t array_size;
const void *ptr;
} 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.
An byte array with a field for storing the length::
typedef struct {
- size_t size;
- uint8_t bytes[1];
+ pb_size_t size;
+ pb_byte_t bytes[1];
} pb_bytes_array_t;
In an actual array, the length of *bytes* may be different.
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.
PB_WT_32BIT = 5
} pb_wire_type_t;
+pb_extension_type_t
+-------------------
+Defines the handler functions and auxiliary data for a field that extends
+another message. Usually autogenerated by *nanopb_generator.py*::
+
+ typedef struct {
+ bool (*decode)(pb_istream_t *stream, pb_extension_t *extension,
+ uint32_t tag, pb_wire_type_t wire_type);
+ bool (*encode)(pb_ostream_t *stream, const pb_extension_t *extension);
+ const void *arg;
+ } pb_extension_type_t;
+
+In the normal case, the function pointers are *NULL* and the decoder and
+encoder use their internal implementations. The internal implementations
+assume that *arg* points to a *pb_field_t* that describes the field in question.
+
+To implement custom processing of unknown fields, you can provide pointers
+to your own functions. Their functionality is mostly the same as for normal
+callback fields, except that they get called for any unknown field when decoding.
+
+pb_extension_t
+--------------
+Ties together the extension field type and the storage for the field value::
+
+ typedef struct {
+ const pb_extension_type_t *type;
+ void *dest;
+ pb_extension_t *next;
+ bool found;
+ } pb_extension_t;
+
+:type: Pointer to the structure that defines the callback functions.
+:dest: Pointer to the variable that stores the field value
+ (as used by the default extension callback functions.)
+:next: Pointer to the next extension handler, or *NULL*.
+:found: Decoder sets this to true if the extension was found.
+
+PB_GET_ERROR
+------------
+Get the current error message from a stream, or a placeholder string if
+there is no error message::
+
+ #define PB_GET_ERROR(stream) (string expression)
+
+This should be used for printing errors, for example::
+
+ if (!pb_decode(...))
+ {
+ printf("Decode failed: %s\n", PB_GET_ERROR(stream));
+ }
+
+The macro only returns pointers to constant strings (in code memory),
+so that there is no need to release the returned pointer.
+
+PB_RETURN_ERROR
+---------------
+Set the error message and return false::
+
+ #define PB_RETURN_ERROR(stream,msg) (sets error and returns false)
+
+This should be used to handle error conditions inside nanopb functions
+and user callback functions::
+
+ if (error_condition)
+ {
+ PB_RETURN_ERROR(stream, "something went wrong");
+ }
+
+The *msg* parameter must be a constant string.
+
+
+
pb_encode.h
===========
----------------------
Constructs an output stream for writing into a memory buffer. This is just a helper function, it doesn't do anything you couldn't do yourself in a callback function. It uses an internal callback that stores the pointer in stream *state* field. ::
- pb_ostream_t pb_ostream_from_buffer(uint8_t *buf, size_t bufsize);
+ pb_ostream_t pb_ostream_from_buffer(pb_byte_t *buf, size_t bufsize);
:buf: Memory buffer to write into.
:bufsize: Maximum number of bytes to write.
--------
Writes data to an output stream. Always use this function, instead of trying to call stream callback manually. ::
- bool pb_write(pb_ostream_t *stream, const uint8_t *buf, size_t count);
+ bool pb_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count);
:stream: Output stream to write to.
:buf: Pointer to buffer with the data to be written.
Normally pb_encode simply walks through the fields description array and serializes each field in turn. However, submessages must be serialized twice: first to calculate their size and then to actually write them to output. This causes some constraints for callback fields, which must return the same data on every call.
+pb_encode_delimited
+-------------------
+Calculates the length of the message, encodes it as varint and then encodes the message. ::
+
+ bool pb_encode_delimited(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct);
+
+(parameters are the same as for `pb_encode`_.)
+
+A common way to indicate the message length in Protocol Buffers is to prefix it with a varint.
+This function does this, and it is compatible with *parseDelimitedFrom* in Google's protobuf library.
+
.. sidebar:: Encoding fields manually
The functions with names *pb_encode_\** are used when dealing with callback fields. The typical reason for using callbacks is to have an array of unlimited size. In that case, `pb_encode`_ will call your callback function, which in turn will call *pb_encode_\** functions repeatedly to write out values.
Writing packed arrays is a little bit more involved: you need to use `pb_encode_tag` and specify `PB_WT_STRING` as the wire type. Then you need to know exactly how much data you are going to write, and use `pb_encode_varint`_ to write out the number of bytes before writing the actual data. Substreams can be used to determine the number of bytes beforehand; see `pb_encode_submessage`_ source code for an example.
+pb_get_encoded_size
+-------------------
+Calculates the length of the encoded message. ::
+
+ bool pb_get_encoded_size(size_t *size, const pb_field_t fields[], const void *src_struct);
+
+:size: Calculated size of the encoded message.
+:fields: A field description array, usually autogenerated.
+:src_struct: Pointer to the data that will be serialized.
+:returns: True on success, false on detectable errors in field description or if a field encoder returns false.
+
pb_encode_tag
-------------
Starts a field in the Protocol Buffers binary format: encodes the field number and the wire type of the data. ::
- bool pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, int field_number);
+ bool pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, uint32_t field_number);
:stream: Output stream to write to. 1-5 bytes will be written.
:wiretype: PB_WT_VARINT, PB_WT_64BIT, PB_WT_STRING or PB_WT_32BIT
Wire type mapping is as follows:
-========================= ============
-LTYPEs Wire type
-========================= ============
-VARINT, SVARINT PB_WT_VARINT
-FIXED64 PB_WT_64BIT
-STRING, BYTES, SUBMESSAGE PB_WT_STRING
-FIXED32 PB_WT_32BIT
-========================= ============
+============================================= ============
+LTYPEs Wire type
+============================================= ============
+VARINT, UVARINT, SVARINT PB_WT_VARINT
+FIXED64 PB_WT_64BIT
+STRING, BYTES, SUBMESSAGE, FIXED_LENGTH_BYTES PB_WT_STRING
+FIXED32 PB_WT_32BIT
+============================================= ============
pb_encode_varint
----------------
----------------
Writes the length of a string as varint and then contents of the string. Works for fields of type `bytes` and `string`::
- bool pb_encode_string(pb_ostream_t *stream, const uint8_t *buffer, size_t size);
+ bool pb_encode_string(pb_ostream_t *stream, const pb_byte_t *buffer, size_t size);
:stream: Output stream to write to.
:buffer: Pointer to string data.
If the submessage contains callback fields, the callback function might misbehave and write out a different amount of data on the second call. This situation is recognized and *false* is returned, but garbage will be written to the output before the problem is detected.
+
+
+
+
+
+
+
+
+
+
+
pb_decode.h
===========
----------------------
Helper function for creating an input stream that reads data from a memory buffer. ::
- pb_istream_t pb_istream_from_buffer(uint8_t *buf, size_t bufsize);
+ pb_istream_t pb_istream_from_buffer(const pb_byte_t *buf, size_t bufsize);
:buf: Pointer to byte array to read from.
:bufsize: Size of the byte array.
-------
Read data from input stream. Always use this function, don't try to call the stream callback directly. ::
- bool pb_read(pb_istream_t *stream, uint8_t *buf, size_t count);
+ bool pb_read(pb_istream_t *stream, pb_byte_t *buf, size_t count);
:stream: Input stream to read from.
:buf: Buffer to store the data to, or NULL to just read data without storing it anywhere.
For optional fields, this function applies the default value and sets *has_<field>* to false if the field is not present.
+If *PB_ENABLE_MALLOC* is defined, this function may allocate storage for any pointer type fields.
+In this case, you have to call `pb_release`_ to release the memory after you are done with the message.
+On error return `pb_decode` will release the memory itself.
+
pb_decode_noinit
----------------
Same as `pb_decode`_, except does not apply the default values to fields. ::
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. ::
+In addition to decoding a single message, this function can be used to merge two messages, so that
+values from previous message will remain if the new message does not contain a field.
- bool pb_skip_varint(pb_istream_t *stream);
+This function *will not* release the message even on error return. If you use *PB_ENABLE_MALLOC*,
+you will need to call `pb_release`_ yourself.
-:stream: Input stream to read from. Will read 1 byte at a time until the MSB is clear.
-:returns: True on success, false on IO error.
+pb_decode_delimited
+-------------------
+Same as `pb_decode`_, except that it first reads a varint with the length of the message. ::
-pb_skip_string
---------------
-Skip a varint-length-prefixed string. This means skipping a value with wire type PB_WT_STRING. ::
+ bool pb_decode_delimited(pb_istream_t *stream, const pb_field_t fields[], void *dest_struct);
- bool pb_skip_string(pb_istream_t *stream);
+(parameters are the same as for `pb_decode`_.)
-:stream: Input stream to read from.
-:returns: True on success, false on IO error or length exceeding uint32_t.
+A common method to indicate message size in Protocol Buffers is to prefix it with a varint.
+This function is compatible with *writeDelimitedTo* in the Google's Protocol Buffers library.
+
+pb_release
+----------
+Releases any dynamically allocated fields::
+
+ void pb_release(const pb_field_t fields[], void *dest_struct);
+
+:fields: A field description array. Usually autogenerated.
+:dest_struct: Pointer to structure where data is stored. If NULL, function does nothing.
+
+This function is only available if *PB_ENABLE_MALLOC* is defined. It will release any
+pointer type fields in the structure and set the pointers to NULL.
pb_decode_tag
-------------
Decode the tag that comes before field in the protobuf encoding::
- bool pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, int *tag, bool *eof);
+ bool pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, uint32_t *tag, bool *eof);
:stream: Input stream to read from.
:wire_type: Pointer to variable where to store the wire type of the field.
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.
-----------------
Decode a *fixed64*, *sfixed64* or *double* value. ::
- bool pb_dec_fixed(pb_istream_t *stream, const pb_field_t *field, void *dest);
+ bool pb_decode_fixed64(pb_istream_t *stream, void *dest);
:stream: Input stream to read from. 8 bytes will be read.
-:field: Not used.
:dest: Pointer to destination *int64_t*, *uint64_t* or *double*.
:returns: True on success, false on IO errors.
Code Review / apps / agl-service-can-low-level.git / blobdiff