1/1/2023 0 Comments Gdbm database as a semaphor![]()
each_pair do | key, value | print "#\n" end gdbm. Reading out a database: require 'gdbm' gdbm = GDBM. Opening/creating a database, and filling it with some entries: require 'gdbm' gdbm = GDBM. A database can be accessed either by any number of readers or by exactly one writer at the same time. Whereas a reader has only read-access to the database, a writer has read- and write-access. A process can open a database as a “reader” or a “writer”. Furthermore, GDBM mixes in the Enumerable module, thus providing convenient methods such as find, collect, map, etc.Ī process is allowed to open several different databases at the same time. As with objects of the Hash class, elements can be accessed with. A gdbm database thus provides the same functionality as a hash. It furthermore allows a non-sorted traversal of all key-value pairs. ![]() Gdbm allows the user to store, retrieve, and delete data by key. A database is a file that stores key-value pairs. GNU dbm is a library for simple databases. #Gdbm database as a semaphor fullSee the SPOPS module for the full author/helper list.Ruby extension for GNU dbm (gdbm) – a simple database engine for storing key-value pairs on disk. #Gdbm database as a semaphor softwareThis library is free software you can redistribute it and/or modify it under the same terms as Perl itself. This is an internal method, so do not use it.Ĭopyright (c) 2001-2004, inc. This data structure is not blessed yet, it is likely just a hashref of data (depending on how you implement your objects, although the default method for SPOPS objects is a tied hashref). Returns the data structure in the GDBM database corresponding to a particular key. ![]() Save (either insert or update) an object in a GDBM database. If you modify the 'object_key' method, you will probably want to modify this as well. ![]() Retrieve all objects from a GDBM database from a particular class. Instead it is a unique identifier for objects within this class. Note that $id corresponds not to the object key, or the value used to store the data. The default is to prepend the class to the value returned by id() to prevent ID collisions between objects in different classes. In the config file just joins the 'name' and 'version' parameters of an object and returns the result.Ĭreates a key to store the object in GDBM. (To be fair, you can also do this with the SPOPS::DBI module, it is just a little more difficult.) For example: # Read objects from one database, save to another Instead of defining one database throughout the operation, you can change in midstream. If the named database does not exist, it will be created. #Gdbm database as a semaphor codeIn this example, the following code would be run from a timer that fires every minute: final String lockKey 'foo' final long. #Gdbm database as a semaphor how toIf not supplied, the default name junk.gdbm is used instead. The following example illustrates how to use the semaphore to gate the run of a worker called 'foo' to ensure there are never more than twenty instance of 'foo' running across the cluster concurrently. The DBFILE argument supplies the name of the database to open. This is also a little different than the SPOPS::DBI module in that you have a little more flexibility as to how you refer to the actual GDBM file required. The gdbmtool utility allows you to view and modify an existing GDBM database or to create a new one. Currently the interface is not as robust or powerful as the SPOPS::DBI implementation, but if you want more robust data storage, retrieval and searching needs you should probably be using a SQL database anyway. Implements SPOPS persistence in a GDBM database. SPOPS::GDBM - Store SPOPS objects in a GDBM database SYNOPSIS my $obj = Object::Class->new ![]()
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