Model Implementation

The model implementations implement the model components using specific technologies and methods.

Auto assignment algorithms

There are two built in auto-assignment algorithms.

• One marker to a student, which evenly distributes students to markers such that each student only has one marker.
• All markers to a student, which naively creates every possible mapping of students to markers.

Database access objects

The current implementation provides database access through MySQL and file storage.

• Creating a new DAO is relatively easy, just subclass IEntityDAO<NewBean> and implement INewBeanDAO and fill in the required methods, then add to the factory.
• Modified files in a transaction are stored in the Factory and passed to special functions in MySQLResourceDAO when a transaction is started, commited or aborted.
• Code is very messy but functional and withstands stress testing.

Mail sending

The JavaMail framework is used.

Session authentication

DAO methods are used to authenticate (internal database authentication) and to update credentials

Testing framework

Default test runner

• Uses the Java concurrency framework and a thread-pooled worker operation to generate Future objects.
• Unpacks the submission and test resource into a temporary directory before executing tests.
• Executes tests under the context of the worker thread.

Built in test executors

• Provides executors for reading a file, running a shell command, or executing a Java class.
• File reader reads a submission file and treats the content as execution output.
• Shell command is run as a sub process, the submission and test resource directories are passed as environment variables.
• Java class is run as a sub process with a heavily restricted execution environment, the submission and test resource directories are placed on the classpath.

Built in test methods

• Provides test methods for generating a random result, marking using diff, or marking using regular expressions.
• Random result is degenerate and used for testing.
• Diff test based on the BOSS1 diff test method, with a few enhancements to handle errors and exit code.
• Regex test based on the BOSS1 regex test method, with a few enhancements to handle errors and exit code.

Administration operations

Currently only a University of Warwick specific one for synchronising with the data provided by the University via its ADS database.