Tweak the definition of CamelProvider. Among other things, a provider may

	* camel-provider.h: Tweak the definition of CamelProvider. Among
	other things, a provider may now be both a store and a transport.

	* camel-provider.c: Remove a lot of code we had no intention of
	using. This now only contains two functions: camel_provider_init
	to read the installed .urls files, and camel_provider_load to
	load and register a new provider.

	* camel-session.c: Remove more unused code and simplify some of
	the remaining code. The list of available provider modules is now
	stored in the session, and it handles calling camel_provider_load
	to load them as needed. Provider registration is now done by
	calling back from the module init routine, which allows a single
	module to register providers for multiple URL types.

	* providers/*: Update provider structures and init routines for
	the new stuff. Add a .urls file to each provider specifying what
	urls it handles, and install that with the library.

	* providers/nntp/camel-nntp-provider.c: Add hints towards
	supporting both news: and nntp: URLs, and using nntp as both a
	store and a transport.

svn path=/trunk/; revision=2691

20 files changed, 329 insertions, 499 deletions

diff --git a/camel/ChangeLog b/camel/ChangeLog
index 9a2deae312..6c28e6371c 100644
--- a/camel/ChangeLog
+++ b/camel/ChangeLog
@@ -1,3 +1,28 @@
+2000-04-30  Dan Winship  <danw@helixcode.com>
+
+	* camel-provider.h: Tweak the definition of CamelProvider. Among
+	other things, a provider may now be both a store and a transport.
+
+	* camel-provider.c: Remove a lot of code we had no intention of
+	using. This now only contains two functions: camel_provider_init
+	to read the installed .urls files, and camel_provider_load to
+	load and register a new provider.
+
+	* camel-session.c: Remove more unused code and simplify some of
+	the remaining code. The list of available provider modules is now
+	stored in the session, and it handles calling camel_provider_load
+	to load them as needed. Provider registration is now done by
+	calling back from the module init routine, which allows a single
+	module to register providers for multiple URL types.
+
+	* providers/*: Update provider structures and init routines for
+	the new stuff. Add a .urls file to each provider specifying what
+	urls it handles, and install that with the library.
+
+	* providers/nntp/camel-nntp-provider.c: Add hints towards
+	supporting both news: and nntp: URLs, and using nntp as both a
+	store and a transport.
+
 2000-04-29  Dan Winship  <danw@helixcode.com>
 
 	* camel-internet-address.c (camel_internet_address_get): const
diff --git a/camel/camel-provider.c b/camel/camel-provider.c
index 52cfea60a1..83a51c3579 100644
--- a/camel/camel-provider.c
+++ b/camel/camel-provider.c
@@ -1,15 +1,16 @@
 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
-/* camel-provider.c :  provider framework   */
+/* camel-provider.c: provider framework */
 
-/* 
+/*
  *
- * Author : 
+ * Authors:
  *  Bertrand Guiheneuf <bertrand@helixcode.com>
+ *  Dan Winship <danw@helixcode.com>
  *
  * Copyright 1999, 2000 Helix Code, Inc. (http://www.helixcode.com)
  *
- * This program is free software; you can redistribute it and/or 
- * modify it under the terms of the GNU General Public License as 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or (at your option) any later version.
  *
@@ -25,177 +26,128 @@
  */
 
 
-/* 
-   A provider can be added "by hand" or by loading a module. 
-
-
-   Adding providers with modules. 
-   ------------------------------
-
-   The modules are shared libraries which must contain the 
-   function
-
-   CamelProvider *camel_provider_module_init ();
-  
-   returning the provider object defined in the module 
-
-   
-*/
-
 /* FIXME: Shouldn't we add a version number to providers ? */
 
 #include "config.h"
 #include "camel-provider.h"
+#include "camel-exception.h"
+#include "hash-table-utils.h"
 
 #include <dirent.h>
+#include <errno.h>
+#include <stdio.h>
 #include <string.h>
 
-static GList *_provider_list = NULL;
+#include <gmodule.h>
 
-static gint        
-_provider_name_cmp (gconstpointer a, gconstpointer b)
-{
-	CamelProvider *provider_a = CAMEL_PROVIDER (a);
-	CamelProvider *provider_b = CAMEL_PROVIDER (b);
+char *camel_provider_type_name[CAMEL_NUM_PROVIDER_TYPES] = {
+	"store",
+	"transport"
+};
 
-	return strcmp ( provider_a->name,  provider_b->name);
-}
-
-void
-camel_provider_register (CamelProvider *provider)
+/**
+ * camel_provider_init:
+ *
+ * Initialize the Camel provider system by reading in the .urls
+ * files in the provider directory and creating a hash table mapping
+ * URLs to module names.
+ *
+ * A .urls file has the same initial prefix as the shared library it
+ * correspond to, and consists of a series of lines containing the URL
+ * protocols that that library handles.
+ *
+ * Return value: a hash table mapping URLs to module names
+ **/
+GHashTable *
+camel_provider_init (void)
 {
-	GList *old_provider_node = NULL;
-
-	g_assert (provider);
+	GHashTable *providers;
+	DIR *dir;
+	struct dirent *d;
+	char *p, *name, buf[80];
+	FILE *f;
 
-	if (_provider_list)
-		old_provider_node = g_list_find_custom (_provider_list, provider, _provider_name_cmp);
+	providers = g_hash_table_new (g_strcase_hash, g_strcase_equal);
 
-	if (old_provider_node != NULL) {
-		/* camel_provider_unref (CAMEL_PROVIDER (old_provider_node->data)); */
-		old_provider_node->data = provider;
-	} else {
-		/* be careful, we use prepend here, so that last registered
-		   providers come first */
-		_provider_list = g_list_prepend (_provider_list, provider);
+	dir = opendir (CAMEL_PROVIDERDIR);
+	if (!dir) {
+		g_error ("Could not open camel provider directory: %s",
+			 g_strerror (errno));
+		return NULL;
 	}
-	/* camel_provider_ref (provider); */
-}
 
+	while ((d = readdir (dir))) {
+		p = strchr (d->d_name, '.');
+		if (!p || strcmp (p, ".urls") != 0)
+			continue;
 
-const CamelProvider *
-camel_provider_register_as_module (const gchar *module_path)
-{
-	
-	CamelProvider *new_provider = NULL;
-	GModule *new_module = NULL;
-	CamelProvider * (*camel_provider_module_init) ();
-	gboolean has_module_init;
-	
-	g_return_val_if_fail (module_path, NULL);
+		name = g_strdup_printf ("%s/%s", CAMEL_PROVIDERDIR, d->d_name);
+		f = fopen (name, "r");
+		if (!f) {
+			g_warning ("Could not read provider info file %s: %s",
+				   name, g_strerror (errno));
+			g_free (name);
+			continue;
+		}
 
-	if (!g_module_supported ()) {
-		g_warning ("CamelProvider::register_as_module: module "
-			   "loading not supported on this system\n");
-		return NULL;
-	}
-	
+		p = strrchr (name, '.');
+		strcpy (p, ".so");
+		while ((fgets (buf, sizeof (buf), f))) {
+			buf[sizeof (buf) - 1] = '\0';
+			p = strchr (buf, '\n');
+			if (p)
+				*p = '\0';
 
-	new_module = g_module_open (module_path, 0);
-	if (!new_module) {
-		printf ("g_module_open reports: %s\n", g_module_error ());
-		g_warning ("CamelProvider::register_as_module: Unable to "
-			   "load module %s\n", module_path);
-		return NULL;
-	}
-		
-	has_module_init = g_module_symbol (new_module, "camel_provider_module_init", (gpointer *)&camel_provider_module_init);
-	if (!has_module_init){
-		g_warning ("CamelProvider::register_as_module loading "
-			   "of module %s failed,\n\tSymbol "
-			   "camel_provider_module_init not defined in it\n",
-			   module_path);
-		return NULL;
+			g_hash_table_insert (providers, g_strdup (buf), name);
+		}
+		fclose (f);
 	}
 
-	new_provider = camel_provider_module_init();
-	new_provider->gmodule = new_module;
-	camel_provider_register (new_provider);
-
-	return new_provider;
-} 
+	closedir (dir);
+	return providers;
+}
 
 /**
- * camel_provider_scan: Scan for available providers and return a list.
- *
- * Note that this function will cause all providers in the providerdir
- * to be loaded into memory.
+ * camel_provider_load:
+ * @session: the current session
+ * @path: the path to a shared library
+ * @ex: a CamelException
  *
- * Return value: the list of CamelProviders. The caller must free this
- * list when it is done with it.
- **/
-GList *
-camel_provider_scan (void)
+ * Loads the provider at @path, and calls its initialization function,
+ * passing @session as an argument. The provider should then register
+ * itself with @session.
+ **/ 
+void
+camel_provider_load (CamelSession *session, const char *path,
+		     CamelException *ex)
 {
-	DIR *dir;
-	struct dirent *dent;
-	char *p, *name;
+	GModule *module;
+	CamelProvider *(*camel_provider_module_init) ();
 
-	dir = opendir (CAMEL_PROVIDERDIR);
-	if (!dir)
-		return NULL;
-	while ((dent = readdir (dir))) {
-		p = strstr (dent->d_name, ".so");
-		if (!p || strcmp (p, ".so") != 0)
-			continue;
-
-		name = g_module_build_path (CAMEL_PROVIDERDIR, dent->d_name);
-		camel_provider_register_as_module (name);
-		g_free (name);
+	if (!g_module_supported ()) {
+		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+				      "Could not load %s: Module loading "
+				      "not supported on this system.",
+				      path);
+		return;
 	}
-	closedir (dir);
 
-	return g_list_copy (_provider_list);
-}
-	
+	module = g_module_open (path, 0);
+	if (!module) {
+		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+				      "Could not load %s: %s",
+				      path, g_module_error ());
+		return;
+	}
 
-/**
- * camel_provider_get_for_protocol: get a registered provider for a protocol
- * @protocol: protocol name (case insensitive)
- * @type: provider type (transport, store, ...)
- * 
- * Look into the list of registered provider if 
- * one correspond both to the protocol name 
- * and to the protocol type. When several providers
- * exist for a same protocol, the last registered
- * is returned.
- * 
- * Return value: Matching provider or NULL if none exists. 
- **/
-const CamelProvider *
-camel_provider_get_for_protocol (const gchar *protocol, ProviderType type)
-{
-	CamelProvider *current_provider = NULL;
-	GList *current_provider_node;
-	gboolean protocol_is_found;
-	gboolean provider_is_found;
-
-	g_assert (protocol);
-	g_return_val_if_fail (_provider_list, NULL);
-
-	current_provider_node = _provider_list;
-	provider_is_found = FALSE;
-
-	while ((!provider_is_found) && current_provider_node) {
-		current_provider = (CamelProvider *)current_provider_node->data;
-		
-		protocol_is_found = (g_strcasecmp (protocol, current_provider->protocol) == 0);
-		if (protocol_is_found) 
-			provider_is_found = (current_provider->provider_type == type);
-		
-		current_provider_node = current_provider_node->next;
-		}
+	if (!g_module_symbol (module, "camel_provider_module_init",
+			      (gpointer *)&camel_provider_module_init)) {
+		camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
+				      "Could not load %s: No initialization "
+				      "routine in module.", path);
+		g_module_close (module);
+		return;
+	}
 
-	if (provider_is_found) return current_provider;
-	else return NULL;
+	camel_provider_module_init (session);
 }
diff --git a/camel/camel-provider.h b/camel/camel-provider.h
index d359ca90c8..cac6e9d6cc 100644
--- a/camel/camel-provider.h
+++ b/camel/camel-provider.h
@@ -1,15 +1,15 @@
 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
 /* camel-provider.h :  provider definition  */
 
-/* 
+/*
  *
- * Author : 
+ * Author :
  *  Bertrand Guiheneuf <bertrand@helixcode.com>
  *
  * Copyright 1999, 2000 Helix Code, Inc. (http://www.helixcode.com)
  *
- * This program is free software; you can redistribute it and/or 
- * modify it under the terms of the GNU General Public License as 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or (at your option) any later version.
  *
@@ -35,27 +35,26 @@ extern "C" {
 #endif /* __cplusplus }*/
 
 #include <gtk/gtk.h>
-#include <gmodule.h>
+#include "camel-types.h"
 
 #define CAMEL_PROVIDER(obj) ((CamelProvider *)(obj))
 
 typedef enum {
-	PROVIDER_STORE,
-	PROVIDER_TRANSPORT
-} ProviderType;
+	CAMEL_PROVIDER_STORE,
+	CAMEL_PROVIDER_TRANSPORT,
+	CAMEL_NUM_PROVIDER_TYPES
+} CamelProviderType;
 
-#define PROVIDER_REMOTE		0x01
+extern char *camel_provider_type_name[CAMEL_NUM_PROVIDER_TYPES];
 
-typedef struct {
-	GtkType object_type;        /* used to create instance of the provider */
-	ProviderType provider_type; /* is a store or a transport */ 
-	int flags;                  /* information about the provider */
+#define CAMEL_PROVIDER_IS_REMOTE	(1 << 0)
 
+typedef struct {
 	/* Provider name used in CamelURLs. */
-	gchar *protocol;
+	char *protocol;
 
 	/* Provider name as used by people. (May be the same as protocol) */
-	gchar *name;
+	char *name;
 
 	/* Description of the provider. A novice user should be able
 	 * to read this description, and the information provided by
@@ -63,16 +62,19 @@ typedef struct {
 	 * this provider is relevant to him, and if so, which
 	 * information goes with it.
 	 */
-	gchar *description;
+	char *description;
+
+	int flags;
 
-	GModule *gmodule;
+	GtkType object_types [CAMEL_NUM_PROVIDER_TYPES];
 } CamelProvider;
 
-void camel_provider_register (CamelProvider *provider);
-const CamelProvider *camel_provider_register_as_module (const gchar *module_path);
-const CamelProvider *camel_provider_get_for_protocol (const gchar *protocol, ProviderType type);
-GList *camel_provider_scan (void);
+GHashTable *camel_provider_init (void);
+void camel_provider_load (CamelSession *session, const char *path,
+			  CamelException *ex);
 
+/* This is defined by each module, not by camel-provider.c. */
+void camel_provider_module_init (CamelSession *session);
 
 #ifdef __cplusplus
 }
diff --git a/camel/camel-session.c b/camel/camel-session.c
index 7b672c5c60..06a708b752 100644
--- a/camel/camel-session.c
+++ b/camel/camel-session.c
@@ -1,15 +1,16 @@
 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
 /* camel-session.c : Abstract class for an email session */
 
-/* 
+/*
  *
- * Author : 
+ * Author:
  *  Bertrand Guiheneuf <bertrand@helixcode.com>
+ *  Dan Winship <danw@helixcode.com>
  *
  * Copyright 1999, 2000 Helix Code, Inc. (http://www.helixcode.com)
  *
- * This program is free software; you can redistribute it and/or 
- * modify it under the terms of the GNU General Public License as 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or (at your option) any later version.
  *
@@ -24,9 +25,6 @@
  * USA
  */
 
-
-
-
 #include <config.h>
 #include "camel-session.h"
 #include "camel-store.h"
@@ -36,59 +34,36 @@
 #include "camel-url.h"
 #include "hash-table-utils.h"
 
-
-
-static GtkObjectClass *parent_class=NULL;
-
-
-
-/* Returns the class for a CamelSession */
-#define CSS_CLASS(so) CAMEL_SESSION_CLASS (GTK_OBJECT(so)->klass)
-
-
-static void
-camel_session_class_init (CamelSessionClass *camel_session_class)
-{
-	parent_class = gtk_type_class (gtk_object_get_type ());
-	
-	/* virtual method definition */
-	/* virtual method overload */
-}
-
-
-
-
-
 static void
 camel_session_init (CamelSession *session)
 {
-	session->store_provider_list = g_hash_table_new (g_strcase_hash, g_strcase_equal);
-	session->transport_provider_list = g_hash_table_new (g_strcase_hash, g_strcase_equal);
+	session->modules = camel_provider_init ();
+	session->providers = g_hash_table_new (g_strcase_hash,
+					       g_strcase_equal);
 }
 
-
-
 GtkType
 camel_session_get_type (void)
 {
 	static GtkType camel_session_type = 0;
-	
-	if (!camel_session_type)	{
-		GtkTypeInfo camel_session_info =	
+
+	if (!camel_session_type) {
+		GtkTypeInfo camel_session_info =
 		{
 			"CamelSession",
 			sizeof (CamelSession),
 			sizeof (CamelSessionClass),
-			(GtkClassInitFunc) camel_session_class_init,
+			(GtkClassInitFunc) NULL,
 			(GtkObjectInitFunc) camel_session_init,
 				/* reserved_1 */ NULL,
 				/* reserved_2 */ NULL,
 			(GtkClassInitFunc) NULL,
 		};
-		
-		camel_session_type = gtk_type_unique (gtk_object_get_type (), &camel_session_info);
+
+		camel_session_type = gtk_type_unique (gtk_object_get_type (),
+						      &camel_session_info);
 	}
-	
+
 	return camel_session_type;
 }
 
@@ -103,158 +78,67 @@ camel_session_new (CamelAuthCallback authenticator)
 }
 
 /**
- * camel_session_set_provider: set the default provider for a protocol
- * @session: session object for wich the provider will the default
+ * camel_session_register_provider:
+ * @session: a session object
+ * @protocol: the protocol the provider provides for
  * @provider: provider object
- * 
- * Set the default implementation for a protocol. The protocol
- * is determined by provider->protocol field (See CamelProvider).
- * It overrides the default provider for this protocol.
- * 
+ *
+ * Registers a protocol to provider mapping for the session.
  **/
-void 
-camel_session_set_provider (CamelSession *session, CamelProvider *provider)
+void
+camel_session_register_provider (CamelSession *session,
+				 CamelProvider *provider)
 {
-	GHashTable *table;
+	g_return_if_fail (CAMEL_IS_SESSION (session));
+	g_return_if_fail (provider != NULL);
 
-	g_assert(session);
-	g_assert(provider);
-	
-	if (provider->provider_type == PROVIDER_STORE)
-		table = session->store_provider_list;
-	else
-		table = session->transport_provider_list;
-	
-	g_hash_table_insert (table, (gpointer)(provider->protocol), (gpointer)(provider));
-	
+	g_hash_table_insert (session->providers, provider->protocol, provider);
 }
 
 
-
-
-
-/**
- * camel_session_get_store_from_provider: create a folder instance for a given provider
- * @session: session object the folder will be initialized with
- * @provider: provider folder to instantiate
- * @ex: a CamelException
- * 
- * 
- * Return value: the newly instantiated store
- **/
-CamelStore *
-camel_session_get_store_from_provider (CamelSession *session,
-				       CamelProvider *provider,
-				       CamelException *ex)
+CamelService *
+camel_session_get_service (CamelSession *session, const char *url_string,
+			   CamelProviderType type, CamelException *ex)
 {
-	g_assert(session);
-	g_assert(provider);
-
-	return CAMEL_STORE (camel_service_new (provider->object_type,
-					       session, NULL, ex));
-}
-
-
+	CamelURL *url;
+	const CamelProvider *provider;
 
-/**
- * get_store_for_protocol_with_url: private helper routine
- * @session: CamelSession object
- * @protocol: protocol name
- * @url: a URL, or NULL
- * @ex: a CamelException
- *
- * Used by camel_session_get_store_for_protocol and
- * camel_session_get_store.
- *
- * Return value: initialized store associated with this protocol, or NULL if no provider was found.
- **/
-static CamelStore *
-get_store_for_protocol_with_url (CamelSession *session, const char *protocol,
-				 CamelURL *url, CamelException *ex)
-{
-	const CamelProvider *provider = NULL;
+	url = camel_url_new (url_string, ex);
+	if (!url)
+		return NULL;
 
-	/* See if there is a provider assiciated with this
-	 * protocol in this session.
-	 */
-	provider = CAMEL_PROVIDER (g_hash_table_lookup (session->store_provider_list, protocol));
+	provider = g_hash_table_lookup (session->providers, url->protocol);
 	if (!provider) {
-		/* No provider was found in this session. See
-		 * if there is a registered provider for this 
-		 * protocol.
-		 */
-		provider = camel_provider_get_for_protocol (protocol, PROVIDER_STORE);
+		/* See if there's one we can load. */
+		char *path;
+
+		path = g_hash_table_lookup (session->modules, url->protocol);
+		if (path) {
+			camel_provider_load (session, path, ex);
+			if (camel_exception_get_id (ex) !=
+			    CAMEL_EXCEPTION_NONE) {
+				camel_url_free (url);
+				return NULL;
+			}
+		}
+		provider = g_hash_table_lookup (session->providers,
+						url->protocol);
 	}
-	if (!provider) {
+
+	if (!provider || !provider->object_types[type]) {
 		camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_URL_INVALID,
-				      "No provider available for protocol "
-				      "`%s'", protocol);
+				      "No %s available for protocol `%s'",
+				      camel_provider_type_name[type],
+				      url->protocol);
+		camel_url_free (url);
 		return NULL;
 	}
 
-	return CAMEL_STORE (camel_service_new (provider->object_type,
-					       session, url, ex));
-}
-
-
-/**
- * camel_session_get_store_for_protocol: get the store associated to a protocol
- * @session: CamelSession object
- * @protocol: protocol name 
- * @ex: a CamelException
- * 
- * Return a CamelStore object associated with a given
- * store protocol. If a provider has been set for this
- * protocol in the session @session using 
- * camel_session_set_provider (), then a store 
- * obtained from this provider is returned.
- * Otherwise, if one or more providers corresponding 
- * to this protocol have been registered (See 
- * camel_provider_register_as_module), the last registered
- * one is used. 
- * 
- * Return value: store associated with this protocol, or NULL if no provider was found. 
- **/
-CamelStore *
-camel_session_get_store_for_protocol (CamelSession *session,
-				      const char *protocol,
-				      CamelException *ex)
-{
-	return get_store_for_protocol_with_url (session, protocol, NULL, ex);
-}
-
-
-
-/**
- * camel_session_get_store: get a store object for an URL
- * @session: session object
- * @url_string: url
- * @ex: a CamelException
- * 
- * return a store corresponding to an URL. 
- * 
- * Return value: the store, or NULL if no provider correponds to the protocol
- **/
-CamelStore *
-camel_session_get_store (CamelSession *session, const char *url_string,
-			 CamelException *ex)
-{
-	CamelURL *url;
-	CamelStore *store;
-
-	url = camel_url_new (url_string, ex);
-	if (!url)
-		return NULL;
-	
-	store = get_store_for_protocol_with_url (session, url->protocol,
-						 url, ex);
-	if (store == NULL)
-		camel_url_free (url);
-	return store;
+	return camel_service_new (provider->object_types[type], session,
+				  url, ex);
 }
 
 
-
 /**
  * camel_session_query_authenticator: query the session authenticator
  * @session: session object
@@ -286,45 +170,3 @@ camel_session_query_authenticator (CamelSession *session, char *prompt,
 {
 	return session->authenticator (prompt, secret, service, item, ex);
 }
-
-
-
-/**
- * camel_session_get_transport_for_protocol: get the transport for a protocol
- * @session: the session
- * @protocol: protocol name
- * @ex: a CamelException
- *
- * Return a CamelTransport object associated with a given transport
- * protocol. If a provider has been set for this protocol in the
- * session @session using camel_session_set_provider (), then a transport
- * obtained from this provider is returned. Otherwise, if one or more
- * providers corresponding to this protocol have been registered (See
- * camel_provider_register_as_module), the last registered one is
- * used.
- * 
- * Return value: transport associated with this protocol, or NULL if no provider was found. 
- **/
-CamelTransport *
-camel_session_get_transport_for_protocol (CamelSession *session,
-					  const char *protocol,
-					  CamelException *ex)
-{
-	const CamelProvider *provider = NULL;
-
-	/* See if there is a provider assiciated with this
-	 * protocol in this session.
-	 */
-	provider = CAMEL_PROVIDER (g_hash_table_lookup (session->transport_provider_list, protocol));
-	if (!provider) {
-		/* No provider was found in this session. See
-		 * if there is a registered provider for this 
-		 * protocol.
-		 */
-		provider = camel_provider_get_for_protocol (protocol, PROVIDER_TRANSPORT);
-	}
-	if (!provider)
-		return NULL;
-
-	return CAMEL_TRANSPORT (gtk_object_new (provider->object_type, NULL));
-}
diff --git a/camel/camel-session.h b/camel/camel-session.h
index 4bb51804ac..4eff6c94a3 100644
--- a/camel/camel-session.h
+++ b/camel/camel-session.h
@@ -1,15 +1,15 @@
 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
 /* camel-session.h : Abstract class for an email session */
 
-/* 
+/*
  *
- * Author : 
+ * Author :
  *  Bertrand Guiheneuf <bertrand@helixcode.com>
  *
  * Copyright 1999, 2000 Helix Code, Inc. (http://www.helixcode.com)
  *
- * This program is free software; you can redistribute it and/or 
- * modify it under the terms of the GNU General Public License as 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or (at your option) any later version.
  *
@@ -48,23 +48,17 @@ typedef char *(*CamelAuthCallback) (char *prompt, gboolean secret,
 				    CamelService *service, char *item,
 				    CamelException *ex);
 
-
 struct _CamelSession
 {
 	GtkObject parent_object;
 
 	CamelAuthCallback authenticator;
-	GHashTable *store_provider_list; /* providers are identified by their protocol */
-	GHashTable *transport_provider_list; 
 
+	GHashTable *providers, *modules;
 };
 
-
-
 typedef struct {
 	GtkObjectClass parent_class;
-	
-	/* Virtual methods */	
 
 } CamelSessionClass;
 
@@ -72,24 +66,31 @@ typedef struct {
 /* public methods */
 
 /* Standard Gtk function */
-GtkType            camel_session_get_type                      (void);
-
-
-CamelSession *     camel_session_new                           (CamelAuthCallback authenticator);
-void               camel_session_set_provider                  (CamelSession *session, CamelProvider *provider);
-CamelStore *       camel_session_get_store_for_protocol        (CamelSession *session,
-								const gchar *protocol,
-								CamelException *ex);
-CamelStore *       camel_session_get_store                     (CamelSession *session,
-								const char *url_string,
-								CamelException *ex);
-CamelTransport *   camel_session_get_transport_for_protocol    (CamelSession *session,
-								const char *protocol,
-								CamelException *ex);
-char *             camel_session_query_authenticator           (CamelSession *session, char *prompt,
-								gboolean secret,
-								CamelService *service, char *item,
-								CamelException *ex);
+GtkType camel_session_get_type (void);
+
+
+CamelSession *  camel_session_new                     (CamelAuthCallback
+						       authenticator);
+
+void            camel_session_register_provider       (CamelSession *session,
+						       CamelProvider *provider);
+
+CamelService *  camel_session_get_service             (CamelSession *session,
+						       const char *url_string,
+						       CamelProviderType type,
+						       CamelException *ex);
+#define camel_session_get_store(session, url_string, ex) \
+	((CamelStore *) camel_session_get_service (session, url_string, CAMEL_PROVIDER_STORE, ex))
+#define camel_session_get_transport(session, url_string, ex) \
+	((CamelTransport *) camel_session_get_service (session, url_string, CAMEL_PROVIDER_TRANSPORT, ex))
+
+
+char *          camel_session_query_authenticator     (CamelSession *session,
+						       char *prompt,
+						       gboolean secret,
+						       CamelService *service,
+						       char *item,
+						       CamelException *ex);
 
 #ifdef __cplusplus
 }
diff --git a/camel/providers/mbox/Makefile.am b/camel/providers/mbox/Makefile.am
index 258c01a94e..25a26e25db 100644
--- a/camel/providers/mbox/Makefile.am
+++ b/camel/providers/mbox/Makefile.am
@@ -8,6 +8,7 @@ libcamelmboxincludedir = $(includedir)/camel
 providerdir = $(pkglibdir)/camel-providers/$(VERSION)
 
 provider_LTLIBRARIES = libcamelmbox.la
+provider_DATA = libcamelmbox.urls
 
 INCLUDES = -I.. \
 	-I$(srcdir)/..				\
@@ -37,5 +38,5 @@ libcamelmbox_la_LDFLAGS = -version-info 0:0:0 -rpath $(libdir)
 libcamelmbox_la_LIBADD = $(top_builddir)/e-util/libeutil.la $(top_builddir)/libibex/libibex.la $(UNICODE_LIBS)
 #libcamelmbox_la_LIBADD = $(top_builddir)/libibex/libibex.la $(UNICODE_LIBS)
 
-EXTRA_DIST = 
+EXTRA_DIST = libcamelmbox.urls
 
diff --git a/camel/providers/mbox/camel-mbox-provider.c b/camel/providers/mbox/camel-mbox-provider.c
index 74c4345306..04ce88de12 100644
--- a/camel/providers/mbox/camel-mbox-provider.c
+++ b/camel/providers/mbox/camel-mbox-provider.c
@@ -26,32 +26,25 @@
 #include "config.h"
 #include "camel-mbox-store.h"
 #include "camel-provider.h"
+#include "camel-session.h"
 
-
-static CamelProvider _mbox_provider = {
-	(GtkType) 0,
-	PROVIDER_STORE,
-	0,
-
+static CamelProvider mbox_provider = {
 	"mbox",
 	"UNIX mbox-format mail files",
 
 	"For reading mail delivered by the local system, and for "
 	"storing mail on local disk.",
 
-	(GModule *) NULL
-};
-
-CamelProvider *
-camel_provider_module_init (void);
+	0,
 
+	{ 0, 0 }
+};
 
-CamelProvider *
-camel_provider_module_init (void)
+void
+camel_provider_module_init (CamelSession *session)
 {
-	_mbox_provider.object_type = camel_mbox_store_get_type();
-	return &_mbox_provider;
-}
-
-
+	mbox_provider.object_types[CAMEL_PROVIDER_STORE] =
+		camel_mbox_store_get_type();
 
+	camel_session_register_provider (session, &mbox_provider);
+}
diff --git a/camel/providers/mbox/libcamelmbox.urls b/camel/providers/mbox/libcamelmbox.urls
new file mode 100644
index 0000000000..e021190356
--- /dev/null
+++ b/camel/providers/mbox/libcamelmbox.urls
@@ -0,0 +1 @@
+mbox
diff --git a/camel/providers/nntp/Makefile.am b/camel/providers/nntp/Makefile.am
index 2aabff29ef..ec393ea907 100644
--- a/camel/providers/nntp/Makefile.am
+++ b/camel/providers/nntp/Makefile.am
@@ -7,6 +7,7 @@ libcamelnntpincludedir = $(includedir)/camel
 providerdir = $(pkglibdir)/camel-providers/$(VERSION)
 
 provider_LTLIBRARIES = libcamelnntp.la
+provider_DATA = libcamelnntp.urls
 
 INCLUDES = -I.. -I$(srcdir)/.. -I$(includedir)	\
 	-I$(top_srcdir)/intl			\
@@ -28,4 +29,4 @@ libcamelnntpinclude_HEADERS =			\
 
 libcamelnntp_la_LDFLAGS = -version-info 0:0:0 -rpath $(libdir) 
 
-EXTRA_DIST = 
+EXTRA_DIST = libcamelnntp.urls
diff --git a/camel/providers/nntp/camel-nntp-provider.c b/camel/providers/nntp/camel-nntp-provider.c
index 5ddda3f39d..449de945e6 100644
--- a/camel/providers/nntp/camel-nntp-provider.c
+++ b/camel/providers/nntp/camel-nntp-provider.c
@@ -26,27 +26,45 @@
 #include "config.h"
 #include "camel-nntp-store.h"
 #include "camel-provider.h"
+#include "camel-session.h"
 
-
-static CamelProvider _nntp_provider = {
-	(GtkType) 0,
-	PROVIDER_STORE,
-	PROVIDER_REMOTE,
+static CamelProvider news_provider = {
 	"news",
-	"Camel default NNTP provider",
-	"This is a provider that reads from a NNTP server.",
-	(GModule *) NULL
+	"USENET news",
+
+	"This is a read-only provider for USENET newsgroups.",
+
+	CAMEL_PROVIDER_IS_REMOTE,
+
+	{ 0, 0 }
 };
 
-CamelProvider *
-camel_provider_module_init (void);
+static CamelProvider nntp_provider = {
+	"nntp",
+	"USENET news via NNTP",
 
+	"This is a provider for reading from and posting to"
+	"USENET newsgroups.",
 
-CamelProvider *
-camel_provider_module_init (void)
+	CAMEL_PROVIDER_IS_REMOTE,
+
+	{ 0, 0 }
+};
+
+void
+camel_provider_module_init (CamelSession *session)
 {
-	_nntp_provider.object_type = camel_nntp_store_get_type();
-	return &_nntp_provider;
+	news_provider.object_types[CAMEL_PROVIDER_STORE] =
+		camel_nntp_store_get_type();
+	nntp_provider.object_types[CAMEL_PROVIDER_STORE] =
+		camel_nntp_store_get_type();
+#ifdef NOTYET
+	nntp_provider.object_types[CAMEL_PROVIDER_TRANSPORT] =
+		camel_nntp_transport_get_type();
+#endif
+
+	camel_session_register_provider (session", &news_provider);
+	camel_session_register_provider (session", &nntp_provider);
 }
 
 
diff --git a/camel/providers/nntp/libcamelnntp.urls b/camel/providers/nntp/libcamelnntp.urls
new file mode 100644
index 0000000000..dee2e70f14
--- /dev/null
+++ b/camel/providers/nntp/libcamelnntp.urls
@@ -0,0 +1,2 @@
+news
+nntp
diff --git a/camel/providers/pop3/Makefile.am b/camel/providers/pop3/Makefile.am
index 202320b3f0..4775c866d1 100644
--- a/camel/providers/pop3/Makefile.am
+++ b/camel/providers/pop3/Makefile.am
@@ -7,6 +7,7 @@ libcamelpop3includedir = $(includedir)/camel
 providerdir = $(pkglibdir)/camel-providers/$(VERSION)
 
 provider_LTLIBRARIES = libcamelpop3.la
+provider_DATA = libcamelpop3.urls
 
 INCLUDES =					\
 	-I..					\
@@ -30,4 +31,4 @@ libcamelpop3include_HEADERS =			\
 
 libcamelpop3_la_LDFLAGS = -version-info 0:0:0 -rpath $(libdir) 
 
-EXTRA_DIST = 
+EXTRA_DIST = libcamelpop3.urls
diff --git a/camel/providers/pop3/camel-pop3-provider.c b/camel/providers/pop3/camel-pop3-provider.c
index 8d9d4ac94d..dc6e2b9442 100644
--- a/camel/providers/pop3/camel-pop3-provider.c
+++ b/camel/providers/pop3/camel-pop3-provider.c
@@ -26,13 +26,9 @@
 #include "config.h"
 #include "camel-pop3-store.h"
 #include "camel-provider.h"
+#include "camel-session.h"
 
-
-static CamelProvider _pop3_provider = {
-	(GtkType) 0,
-	PROVIDER_STORE,
-	PROVIDER_REMOTE,
-
+static CamelProvider pop3_provider = {
 	"pop",
 	"POP",
 
@@ -40,19 +36,16 @@ static CamelProvider _pop3_provider = {
 	"to retrieve mail from certain web mail providers and proprietary "
 	"email systems.",
 
-	(GModule *) NULL
-};
-
-CamelProvider *
-camel_provider_module_init (void);
+	CAMEL_PROVIDER_IS_REMOTE,
 
+	{ 0, 0 }
+};
 
-CamelProvider *
-camel_provider_module_init (void)
+void
+camel_provider_module_init (CamelSession *session)
 {
-	_pop3_provider.object_type = camel_pop3_store_get_type();
-	return &_pop3_provider;
-}
-
-
+	pop3_provider.object_types[CAMEL_PROVIDER_STORE] =
+		camel_pop3_store_get_type();
 
+	camel_session_register_provider (session, &pop3_provider);
+}
diff --git a/camel/providers/pop3/libcamelpop3.urls b/camel/providers/pop3/libcamelpop3.urls
new file mode 100644
index 0000000000..7fffa4d861
--- /dev/null
+++ b/camel/providers/pop3/libcamelpop3.urls
@@ -0,0 +1 @@
+pop
diff --git a/camel/providers/sendmail/Makefile.am b/camel/providers/sendmail/Makefile.am
index 9c9c3f356b..0c12a6e23d 100644
--- a/camel/providers/sendmail/Makefile.am
+++ b/camel/providers/sendmail/Makefile.am
@@ -8,6 +8,7 @@ libcamelsendmailincludedir = $(includedir)/camel
 providerdir = $(pkglibdir)/camel-providers/$(VERSION)
 
 provider_LTLIBRARIES = libcamelsendmail.la
+provider_DATA = libcamelsendmail.urls
 
 INCLUDES =					\
 	-I..					\
@@ -26,4 +27,4 @@ libcamelsendmailinclude_HEADERS =		\
 
 libcamelsendmail_la_LDFLAGS = -version-info 0:0:0 -rpath $(libdir) 
 
-EXTRA_DIST = 
+EXTRA_DIST = libcamelsendmail.urls
diff --git a/camel/providers/sendmail/camel-sendmail-provider.c b/camel/providers/sendmail/camel-sendmail-provider.c
index 5d3809b6f0..16ebce8b12 100644
--- a/camel/providers/sendmail/camel-sendmail-provider.c
+++ b/camel/providers/sendmail/camel-sendmail-provider.c
@@ -26,30 +26,27 @@
 #include "config.h"
 #include "camel-provider.h"
 #include "camel-sendmail-transport.h"
+#include "camel-session.h"
 
-static CamelProvider _sendmail_provider = {
-	(GtkType) 0,
-	PROVIDER_TRANSPORT,
-	0,
-
+static CamelProvider sendmail_provider = {
 	"sendmail",
 	"Sendmail",
 
 	"For delivering mail by passing it to the \"sendmail\" program "
 	"on the local system.",
 
-	(GModule *) NULL
-};
-
-CamelProvider *
-camel_provider_module_init (void);
+	0,
 
+	{ 0, 0 }
+};
 
-CamelProvider *
-camel_provider_module_init (void)
+void
+camel_provider_module_init (CamelSession *session)
 {
-	_sendmail_provider.object_type = camel_sendmail_transport_get_type();
-	return &_sendmail_provider;
+	sendmail_provider.object_types[CAMEL_PROVIDER_TRANSPORT] =
+		camel_sendmail_transport_get_type();
+
+	camel_session_register_provider (session, &sendmail_provider);
 }
 
 
diff --git a/camel/providers/sendmail/libcamelsendmail.urls b/camel/providers/sendmail/libcamelsendmail.urls
new file mode 100644
index 0000000000..ccad52828e
--- /dev/null
+++ b/camel/providers/sendmail/libcamelsendmail.urls
@@ -0,0 +1 @@
+sendmail
diff --git a/camel/providers/smtp/Makefile.am b/camel/providers/smtp/Makefile.am
index dee3a50abb..8c49e8778b 100644
--- a/camel/providers/smtp/Makefile.am
+++ b/camel/providers/smtp/Makefile.am
@@ -7,6 +7,7 @@ libcamelsmtpincludedir = $(includedir)/camel
 providerdir = $(pkglibdir)/camel-providers/$(VERSION)
 
 provider_LTLIBRARIES = libcamelsmtp.la
+provider_DATA = libcamelsmtp.urls
 
 INCLUDES =					\
 	-I..					\
@@ -27,4 +28,4 @@ libcamelsmtpinclude_HEADERS =			\
 
 libcamelsmtp_la_LDFLAGS = -version-info 0:0:0 -rpath $(libdir) 
 
-EXTRA_DIST = 
+EXTRA_DIST = libcamelsmtp.urls
diff --git a/camel/providers/smtp/camel-smtp-provider.c b/camel/providers/smtp/camel-smtp-provider.c
index 03ef1a9eb3..44560ce34c 100644
--- a/camel/providers/smtp/camel-smtp-provider.c
+++ b/camel/providers/smtp/camel-smtp-provider.c
@@ -26,30 +26,26 @@
 #include "config.h"
 #include "camel-smtp-transport.h"
 #include "camel-provider.h"
+#include "camel-session.h"
 
-
-static CamelProvider _smtp_provider = {
-	(GtkType) 0,
-	PROVIDER_TRANSPORT,
-	0,
-
+static CamelProvider smtp_provider = {
 	"smtp",
 	"SMTP",
 
 	"For delivering mail by connecting to a remote mailhub using SMTP.",
 
-	(GModule *) NULL
-};
-
-CamelProvider *
-camel_provider_module_init (void);
+	0,
 
+	{ 0, 0 }
+};
 
-CamelProvider *
-camel_provider_module_init (void)
+void
+camel_provider_module_init (CamelSession *session)
 {
-	_smtp_provider.object_type = camel_smtp_transport_get_type();
-	return &_smtp_provider;
+	smtp_provider.object_types[CAMEL_TRANSPORT_TYPE] =
+		camel_smtp_transport_get_type();
+
+	camel_session_register_provider (session, &smtp_provider);
 }
 
 
diff --git a/camel/providers/smtp/libcamelsmtp.urls b/camel/providers/smtp/libcamelsmtp.urls
new file mode 100644
index 0000000000..ec2fc0fc16
--- /dev/null
+++ b/camel/providers/smtp/libcamelsmtp.urls
@@ -0,0 +1 @@
+smtp