Serd

Serd is a lightweight C library for working with RDF data.

Serd can be used by high-performance or resource-limited applications to read or write Turtle, TriG, NTriples, and NQuads. The included serdi tool can be used to efficiently process RDF documents in scripts or on the command-line.

Features

• Free: Serd is Free Software released under the extremely liberal ISC license.

• Portable and Dependency-Free: Serd has no external dependencies other than the C standard library. It is known to compile with Clang, GCC, and MSVC, and is tested on GNU/Linux, FreeBSD, MacOS, and Windows.

• Small: Serd is implemented in a few thousand lines of C. When optimized, it compiles to well under 100 KiB.

• Fast and Lightweight: Serd can stream abbreviated Turtle, unlike many tools which must first build an internal model. This makes it particularly useful for writing very large data sets, since it can do so using only a small amount of memory. Serd is, to the author's knowledge, the fastest Turtle reader/writer by a wide margin (see Performance below).

• Conformant and Well-Tested: Serd passes all tests in the Turtle and TriG test suites, correctly handles all "normal" examples in the URI specification, and includes many additional tests which were written manually or discovered with fuzz testing. The test suite is run continuously on many platforms, has 100% code coverage by line, and runs with zero memory errors or leaks. Code quality is continuously checked statically by clang-tidy, and dynamically by various clang sanitizers.

Performance

The benchmarks below compare serdi, rapper, and riot re-serialising Turtle data generated by sp2b on an AMD 1950x. Of the three, serdi is the fastest by a wide margin, and the only one that uses a constant amount of memory for all input sizes.

Documentation

• Installation instructions
• Single-page API reference
• Paginated API reference
• serdi man page

Versioning

Serd uses strict semantic versioning, which reflects the ABI of the C library. The shared library name, include directory, and pkg-config file are all suffixed with the major version number to allow for parallel installation of several major versions (which distribution packages should preserve). To build against serd, use the pkg-config package serd-0:

pkg-config --cflags --libs serd-0

-- David Robillard d@drobilla.net