SofaBuffers

Structured Objects For Anyone
... so optimized, feels amazing.

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SofaBuffers C/C++ library

GitHub repository

Source documentation

Documentation

Supported languages

• C99 or later
• C++20 or later

Built with following compilers

Target	Status
GCC x86_64 (little endian)
Clang x86_64 (little endian)
GCC MIPS (big endian)
GCC PowerPC (big endian)
GCC RISCV-V 64 (little endian)

Who is this suitable for?

The C core library is very much aimed at small embedded devices, where C is simply essential. The focus here was therefore on minimal resource consumption.

The C++ core library is aimed more at IoT devices. Such devices do not necessarily run Linux directly, but they are powerful enough to deal with C++/Heap etc. However, the focus here was also on supporting IoT devices that do not support everything specified by C++ - for example, no exceptions are used, as these are often prohibited or not supported. Similarly, std::iostream is not used, as this is often not supported or simply too heavy.

Features

Since the focus was on embedded devices, special attention was paid to the following features during implementation:

• Keep it simple and don't use anything too fancy.
• Fully streaming-capable to serialize messages larger than the available memory.
• The start of the message in the destination buffer can be defined by an offset value to reserve space for protocol headers of underlying protocols, thus reducing the amount of copy operations.
• Data can be serialized and deserialized without heap to avoid heap fragmentation.
• The corelib API should remain clearly structured so that it can be used without a code generator.
• No dependencies on other libraries to be embeddable.

Is this C/C++ implementation zero-copy?

No. SofaBuffers focuses on generating as little protocol overhead as possible, which is why the words in the payload of a message are not always aligned. To be compatible with all architectures, the data from the message is copied to user-provided memory.

Footprint

This table shows the memory requirements of the C corelib for different bare metal architectures.

The lib was always built with -Os (optimized for minimal size).

Full configuration

Architecture	.text	.data	.bss
ARMv6-m	~2.6KB	0.0KB	0.0KB
ARMv7-m+fp.dp	~2.7KB	0.0KB	0.0KB
ARMv8-m.main+fp	~2.7KB	0.0KB	0.0KB
ARMv8.1-m.main+mve	~2.7KB	0.0KB	0.0KB
atmega8	~6.3KB	0.0KB	0.0KB

Minimal configuration

Architecture	.text	.data	.bss
ARMv6-m	~1.0KB	0.0KB	0.0KB
ARMv7-m+fp.dp	~1.1KB	0.0KB	0.0KB
ARMv8-m.main+fp	~1.1KB	0.0KB	0.0KB
ARMv8.1-m.main+mve	~1.1KB	0.0KB	0.0KB
atmega8	~2.6KB	0.0KB	0.0KB

corelib API without object.c:

Architecture	.text	.data	.bss
ARMv6-m	~0.8KB	0.0KB	0.0KB
ARMv7-m+fp.dp	~0.9KB	0.0KB	0.0KB
ARMv8-m.main+fp	~0.9KB	0.0KB	0.0KB
ARMv8.1-m.main+mve	~0.9KB	0.0KB	0.0KB
atmega8	~1.9KB	0.0KB	0.0KB