| commit | a55f3f80fe1b29bea8d4731087ce6137e1470518 | [log] [tgz] |
|---|---|---|
| author | Laurence Lundblade <laurencelundblade@users.noreply.github.com> | Thu Sep 20 20:07:12 2018 -0700 |
| committer | GitHub <noreply@github.com> | Thu Sep 20 20:07:12 2018 -0700 |
| tree | 10a6298fef4e8a842bd33669d7f4326c9325b9f7 | |
| parent | 3d0f6f783e9506b4f5dcd6e4d6150f451b81df51 [diff] | |
| parent | 9e7f474f85127ef37d0178d82d6c127d71ea813e [diff] |
Merge pull request #1 from laurencelundblade/betterusefulbuf Important fix for bug introduced in some minor recent changes from th…
QCBOR encodes and decodes RFC 7049 CBOR.
Implemented in C with minimal dependecy – Only dependencies are C99, stdint.h, stddef.h, stdbool.h and string.h making it highly portable. There are no #ifdefs.
Focused on C / native data representation – Simpler code because there is no support for encoding/decoding to/from JSON, pretty printing, diagnostic notation... Only encoding from native C representations and decoding to native C representations is supported.
Small simple memory model – Malloc is not used. The encode context is 128 bytes, decode context is 168 bytes and the description of decoded data item is 56 bytes. Stack use is very light and there is no recursion. The caller supplies the memory to hold the encoded CBOR and encode/decode contexts so caller has full control of memory usage and it is good for embedded implementations that have to run in small fixed memory.
Supports nearly all of RFC 7049 – Only minor, corner-case parts of RFC 7049 are not directly supported (canonicalization, decimal fractions, big floats) (indefinite length support is planned, but not ready yet).
Extensible and General – Provides a way to handle data types that are not directly supported.
Secure Coding Style – Uses a construct called UsefulBuf as a discipline for very safe coding the handling of binary data.
Small Code Size – When optimized for size using the compiler -Os option, x86 code is less than 5KB (~2KB encode, 2KB decode, 1KB common).
Clear documented public interface – The public interface is separated from the implementation. It can be put to use without reading the source.
QCBOR was originally developed by Qualcomm. It was open sourced through CAF with a permissive Linux license, September 2018 (thanks Qualcomm!).
This code in Laurence's GitHub has diverged some from the CAF source with some small simplifications and tidying up. The full test suite is not up and running and available in GitHub yet, so some caution is advised. This should be remedies soon.
The following modifications are planned:
These changes may result in some interface changes.
There is a simple makefile for the UNIX style command line binary that compiles everything to run the tests.
The actual non-test source files are these five:
For most use cases you should just be able to add them to your project. Hopefully the easy portability of this implementation makes this work straight away, whatever your development environment is.
The test directory includes some tests that are nearly as portable as the main implementation. If your development environment doesn't support UNIX style command line and make, you should be able to make a simple project and add the test files to it.