Scheduler

PHP script providing basic scheduling functionality.

Installation

Install the latest version using composer require riesenia/scheduler

Or add to your composer.json file as a requirement:

{
    "require": {
        "riesenia/scheduler": "~1.0"
    }
}

Usage

Constructor takes two parameters:

• items - array of integers - item IDs
• terms - array of TermInterface

use Riesenia\Scheduler\Scheduler;

$items = [1, 2];
$terms = [$term1, $term2, $term3, $term4];

$scheduler = new Scheduler($items, $terms);

Adding terms and Items

Items and Terms can be also added separately. All added terms have to implement TermInterface.

$scheduler->addItem(3);
$scheduler->addTerm($term5);

TermInterface

Term is defined by its starting and ending date (getFrom() and getTo() methods). Moreover it can be locked to specific item by providing its ID in getLockedId() method.

Scheduling

Calling schedule() method distributes terms to items correctly. If this is not possible, scheduler throws SchedulerException with the information which terms overlap.

use Riesenia\Scheduler\SchedulerException;

try {
    $scheduler->schedule();

    // get all the terms with reassigned item IDs
    $scheduler->getTerms();
} catch (SchedulerException $e) {
    \var_dump($e->getConflictingTerms());
}

External solver binary

For large inputs, the built-in PHP backtracking solver may be too slow. The package includes an optional Rust-based solver in the solver/ directory that uses parallel search for significantly better performance.

Build the binary:

cd solver
cargo build --release
# binary will be at solver/target/release/scheduler-solver

Then point the scheduler to it:

$scheduler->setSolverBinary('/path/to/scheduler-solver');

The solver communicates via JSON over stdin/stdout and is fully compatible with the PHP solver — same input, same results.

Timeout

Both the PHP and external solver support a timeout (in seconds). If the scheduler does not find a solution within the given time, it throws SchedulerException.

$scheduler->setTimeout(10);

When using the external solver, the timeout is passed in the JSON input and handled natively by the Rust binary — the process exits cleanly with a timeout status.