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- // -*- 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 specialized 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 separate
- 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>
- #ifndef APT_8_CLEANER_HEADERS
- #include <apt-pkg/depcache.h>
- #endif
- 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
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