rik/nanopb
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Replace PB_MANY_FIELDS with PB_FIELD_16BIT and PB_FIELD_32BIT.

Browse Source 
This allows more precise control over the memory use vs. field size.
This commit is contained in:
Petteri Aimonen
2012-07-01 10:15:37 +03:00
parent 78086cc27d
commit 9b1e1b440a
3 changed files with 65 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

17
docs/reference.rst
View File

@@ -10,14 +10,21 @@ 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.
PB_MANY_FIELDS Add support for tag numbers > 255 and fields larger than 255 bytes or 255 array entries.
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.
============================ ==============================================================================================
============================ ================================================================================================
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).
pb.h
====
@@ -79,7 +86,7 @@ Describes a single structure field with memory position in relation to others. T
:array_size: Maximum number of entries in an array, if it is an array type.
:ptr: Pointer to default value for optional fields, or to submessage description for PB_LTYPE_SUBMESSAGE.
The *uint8_t* datatypes limit the maximum size of a single item to 255 bytes and arrays to 255 items. Compiler will give error if the values are too large. The types can be changed to larger ones by defining *PB_MANY_FIELDS*.
The *uint8_t* datatypes limit the maximum size of a single item to 255 bytes and arrays to 255 items. Compiler will give error if the values are too large. The types can be changed to larger ones by defining *PB_FIELD_16BIT*.
pb_bytes_array_t
----------------