Join with aliencode

Author: jgg
Date: 2001-02-20 07:03:16 GMT
Join with aliencode

1 files changed, 95 insertions, 0 deletions

diff --git a/apt-pkg/pkgsystem.h b/apt-pkg/pkgsystem.h
new file mode 100644
index 000000000..7d0e42d13
--- /dev/null
+++ b/apt-pkg/pkgsystem.h
@@ -0,0 +1,95 @@
+// -*- mode: cpp; mode: fold -*-
+// Description								/*{{{*/
+// $Id: pkgsystem.h,v 1.2 2001/02/20 07:03:17 jgg 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
+
+#ifdef __GNUG__
+#pragma interface "apt-pkg/pkgsystem.h"
+#endif
+
+#include <apt-pkg/depcache.h>
+#include <vector.h>
+    
+class pkgPackageManager;
+class pkgVersioningSystem;
+class Configuration;
+class pkgIndexFile;
+
+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(vector<pkgIndexFile *> &List) = 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