1 #ifndef PILS_GENERIC_H 2 #define PILS_GENERIC_H 3 /* 4 * Copyright (C) 2000 Alan Robertson <alanr@unix.sh> 5 * This software licensed under the GNU LGPL. 6 * 7 * 8 * This library is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU Lesser General Public 10 * License as published by the Free Software Foundation; either 11 * version 2.1 of the License, or (at your option) any later version. 12 * 13 * This library is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 16 * Lesser General Public License for more details. 17 * 18 * You should have received a copy of the GNU Lesser General Public 19 * License along with this library; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 * 23 * Generic interface (implementation) manager 24 * 25 * This manager will manage any number of types of interfaces. 26 * 27 * This means that when any implementations of our client interfaces register 28 * or unregister, it is us that makes their interfaces show up in the outside 29 * world. 30 * 31 * And, of course, we have to do this in a very generic way, since we have 32 * no idea about the client programs or interface types, or anything else. 33 * 34 * We do that by getting a parameter passed to us which tell us the names 35 * of the interface types we want to manage, and the address of a GHashTable 36 * for each type that we put the implementation in when they register 37 * themselves. 38 * 39 * So, each type of interface that we manage gets its own private 40 * GHashTable of the implementations of that type that are currently 41 * registered. 42 * 43 * For example, if we manage communication modules, their exported 44 * interfaces will be registered in a hash table. If we manage 45 * authentication modules, they'll have their (separate) hash table that 46 * their exported interfaces are registered in. 47 * 48 */ 49 #include <pils/interface.h> 50 51 /* 52 * Header defintions for using the generic interface/implementation 53 * manager plugin. 54 */ 55 56 /* 57 * Notification types for the callback function. 58 */ 59 typedef enum { 60 PIL_REGISTER, /* Someone has registered an implementation */ 61 PIL_UNREGISTER /* Someone has unregistered an implementation */ 62 }GenericPILCallbackType; 63 64 /* A user callback for the generic interface manager */ 65 typedef int (*GenericPILCallback) 66 ( GenericPILCallbackType type /* Event type */ 67 , PILPluginUniv* univ /* pointer to plugin universe */ 68 , const char * iftype /* Interface type */ 69 , const char * ifname /* Implementation (interface) name */ 70 , void * userptr /* Whatever you want it to be ;-) */ 71 ); 72 73 /* 74 * Structures to declare the set of interface types we're managing. 75 */ 76 typedef struct { 77 const char * iftype; /* What type of interface is this? */ 78 GHashTable** ifmap; /* Table with implementation info */ 79 void* importfuns; /* Functions for interface to import */ 80 GenericPILCallback callback; /* Function2call when events occur */ 81 void* userptr; /* Passed to Callback function */ 82 }PILGenericIfMgmtRqst; 83 /* 84 * What does this look like in practice? 85 * 86 * GHashTable* authmodules = NULL; 87 * GHashTable* commmodules = NULL; 88 * PILGenericIfMgmtRqst RegisterRequests[] = 89 * { 90 * {"auth", &authmodules, &authimports, NULL, NULL}, 91 * {"comm", &commmodules, &commimports, NULL, NULL}, 92 * {NULL, NULL, NULL, NULL, NULL} 93 // NULL entry must be here 94 * }; 95 * 96 * PILPlugin* PluginUniverse; 97 * 98 * PluginUniverse = NewPILPlugin("/usr/lib/whatever/plugins"); 99 * 100 * PILLoadPlugin(PluginUniverse, "InterfaceMgr", "generic", &RegisterRequests); 101 * // N. B.: Passing RegisterRequests as an argument is essential 102 * 103 * Then, when you load an auth module, its exported interface gets added 104 * to "authmodules". When you unload an auth module, it gets removed 105 * from authmodules. 106 * 107 * Then, when you load a comm module, its exported interfaces gets added 108 * to "commodules". When you unload a comm module, its exported 109 * interfaces get removed from "commodules" 110 * 111 * If there are simple changes that would be useful for this generic 112 * plugin manager, then "patches are being accepted" :-) 113 * 114 * On the other hand, If you don't like the way this plugin manager works 115 * in a broader way, you're free to write your own - it's just another 116 * plugin ;-) 117 */ 118 #endif 119