// -*- mode: cpp; mode: fold -*- // Description /*{{{*/ // $Id: pkgsystem.h,v 1.6 2002/11/11 06:55:50 doogie Exp $ /* ###################################################################### System - Abstraction for running on different systems. Instances of this class can be thought of as factories or meta-classes for a variety of more specialized classes. Together this class and it's speciallized offspring completely define the environment and how to access resources for a specific system. There are several sub areas that are all orthogonal - each system has a unique combination of these sub areas: - Versioning. Different systems have different ideas on versions. Within a system all sub classes must follow the same versioning rules. - Local tool locking to prevent multiple tools from accessing the same database. - Candidate Version selection policy - this is probably almost always managed using a standard APT class - Actual Package installation * Indication of what kind of binary formats are supported - Selection of local 'status' indexes that make up the pkgCache. It is important to note that the handling of index files is not a function of the system. Index files are handled through a seperate abstraction - the only requirement is that the index files have the same idea of versioning as the target system. Upon startup each supported system instantiates an instance of the pkgSystem class (using a global constructor) which will make itself available to the main APT init routine. That routine will select the proper system and make it the global default. ##################################################################### */ /*}}}*/ #ifndef PKGLIB_PKGSYSTEM_H #define PKGLIB_PKGSYSTEM_H #include <apt-pkg/pkgcache.h> #include <vector> class pkgDepCache; class pkgPackageManager; class pkgVersioningSystem; class Configuration; class pkgIndexFile; class PkgFileIterator; class pkgSystem { public: // Global list of supported systems static pkgSystem **GlobalList; static unsigned long GlobalListLen; static pkgSystem *GetSystem(const char *Label); const char *Label; pkgVersioningSystem *VS; /* Prevent other programs from touching shared data not covered by other locks (cache or state locks) */ virtual bool Lock() = 0; virtual bool UnLock(bool NoErrors = false) = 0; /* Various helper classes to interface with specific bits of this environment */ virtual pkgPackageManager *CreatePM(pkgDepCache *Cache) const = 0; /* Load environment specific configuration and perform any other setup necessary */ virtual bool Initialize(Configuration &/*Cnf*/) {return true;}; /* Type is some kind of Globally Unique way of differentiating archive file types.. */ virtual bool ArchiveSupported(const char *Type) = 0; // Return a list of system index files.. virtual bool AddStatusFiles(std::vector<pkgIndexFile *> &List) = 0; virtual bool FindIndex(pkgCache::PkgFileIterator File, pkgIndexFile *&Found) const = 0; /* Evauluate how 'right' we are for this system based on the filesystem etc.. */ virtual signed Score(Configuration const &/*Cnf*/) {return 0;}; pkgSystem(); virtual ~pkgSystem() {}; }; // The environment we are operating in. extern pkgSystem *_system; #endif