fqqdk/igraph (0.1.0)
Installation
{
"repositories": [{
"type": "composer",
"url": "composer require fqqdk/igraph:0.1.0About this package
igraph
The igraph graph-algorithms C library packaged as a PHP extension — a sibling
to planarity, built to the same recipe: a tiny, audited wrapper (igraph.c,
the only code we author) over a vendored C library, with a .phpt suite, a reproducible
Docker build, Forgejo CI, and a Composer php-ext package.
API
igraph_is_dag(int $n, array $edges): bool
// $n — vertex count; vertices are 0 .. n-1.
// $edges — list of [u, v] integer pairs, each a DIRECTED edge u -> v (0-based). Multigraphs are
// accepted: parallel edges are fine; a self-loop (u -> u) or an anti-parallel pair
// (u -> v and v -> u) forms a cycle. Nothing is dropped.
// → bool — true iff the directed graph is acyclic (a DAG: no directed cycle). The empty and any
// edgeless graph are DAGs.
// throws ValueError on malformed input (endpoint out of range, n out of range, bad edge shape).
igraph_version(): string
// → the linked (vendored) libigraph version, e.g. "1.0.1".
The input shape mirrors the sibling planarity($n, $edges). More igraph capabilities will be added
behind the same tiny-surface, single-cleanup-path discipline.
How igraph is vendored
Unlike planarity (a flat set of .c files listed in config.m4), igraph is a large CMake
library with generated headers and bundled dependencies, so we pin it as a git submodule
(vendor/igraph @ tag 1.0.1) and drive its own build: config.m4 runs cmake to produce a
self-contained static libigraph.a (all deps internal), then links it into the extension. See
vendor/VENDOR.md for the full rationale and the licensing note.
License: igraph is GPL-2.0-or-later; because we statically link it, so is this extension.
Build (host)
Requires cmake, flex, bison, libxml2-dev, and a C++ compiler in addition to the usual
phpize toolchain (see vendor/VENDOR.md). Fetch the submodule first:
git submodule update --init vendor/igraph
phpize && ./configure --enable-igraph && make
The first ./configure builds the vendored igraph static library (several minutes); it is cached
by the presence of vendor/igraph-build/src/libigraph.a, so re-make is fast.
Two PHP installs may coexist on a dev host. The extension loads in the distro php
(/usr/bin/php8.5); a static /usr/local/bin/php build can have dynamic loading disabled. Use the
binary that loads it:
/usr/bin/php8.5 -d extension="$(pwd)/modules/igraph.so" --ri igraph
Tests
The behavioural suite is .phpt (PHP's native extension test format) under tests/, run by the
run-tests.php harness that phpize drops in — no phpunit/composer needed.
make test # after phpize && ./configure --enable-igraph && make
On a host without the full build toolchain, the bundled image builds the extension and runs the suite:
docker build -t php-igraph .
docker run --rm php-igraph # runs `make test`
Dependencies
Dependencies
| ID | Version |
|---|---|
| php | >=8.1 |