NAME

CPANTS::Weight - Graph based weights for CPAN Distributions

DESCRIPTION

CPAN::Weight is a module that consumes the CPANTS database, and generates a variety of graph-based weighting values for the distributions, producing a SQLite database of the weighting data, for use in higher-level applications that work with the CPANTS data.

METHODS

run

CPANTS::Weight->run;

The main run method does a complete generation cycle for the CPANTS weighting database. It will retrieve the CPANTS data (if needed) calculate the weights, and then (re)populate the CPANTS-Weight.sqlite database.

Once completed, the CPANTS::Weight->sqlite method can be used to locate the completed SQLite database file.

dsn

my $string = Foo::Bar->dsn;

The dsn accessor returns the dbi connection string used to connect to the SQLite database as a string.

dbh

my $handle = Foo::Bar->dbh;

To reliably prevent potential SQLite deadlocks resulting from multiple connections in a single process, each ORLite package will only ever maintain a single connection to the database.

During a transaction, this will be the same (cached) database handle.

Although in most situations you should not need a direct DBI connection handle, the dbh method provides a method for getting a direct connection in a way that is compatible with ORLite's connection management.

Please note that these connections should be short-lived, you should never hold onto a connection beyond the immediate scope.

The transaction system in ORLite is specifically designed so that code using the database should never have to know whether or not it is in a transation.

Because of this, you should never call the ->disconnect method on the database handles yourself, as the handle may be that of a currently running transaction.

Further, you should do your own transaction management on a handle provided by the <dbh> method.

In cases where there are extreme needs, and you absolutely have to violate these connection handling rules, you should create your own completely manual DBI->connect call to the database, using the connect string provided by the dsn method.

The dbh method returns a DBI::db object, or throws an exception on error.

begin

Foo::Bar->begin;

The begin method indicates the start of a transaction.

In the same way that ORLite allows only a single connection, likewise it allows only a single application-wide transaction.

No indication is given as to whether you are currently in a transaction or not, all code should be written neutrally so that it works either way or doesn't need to care.

Returns true or throws an exception on error.

commit

Foo::Bar->commit;

The commit method commits the current transaction. If called outside of a current transaction, it is accepted and treated as a null operation.

Once the commit has been completed, the database connection falls back into auto-commit state. If you wish to immediately start another transaction, you will need to issue a separate ->begin call.

Returns true or throws an exception on error.

rollback

The rollback method rolls back the current transaction. If called outside of a current transaction, it is accepted and treated as a null operation.

Once the rollback has been completed, the database connection falls back into auto-commit state. If you wish to immediately start another transaction, you will need to issue a separate ->begin call.

If a transaction exists at END-time as the process exits, it will be automatically rolled back.

Returns true or throws an exception on error.

do

Foo::Bar->do('insert into table (foo, bar) values (?, ?)', {},
    $foo_value,
    $bar_value,
);

The do method is a direct wrapper around the equivalent DBI method, but applied to the appropriate locally-provided connection or transaction.