Added proxy nodes, optimized node management policy

Now, when 'file,,x' is requested, nsmux will create a proxy
node and will set the translator 'x' on this node, not on
the real filesystem node. Also, nsmux will not create nodes
for simple file looks, instead it will simply return the
port to the required file, thus avoiding the necessity
to handle IO operations inside itself.

1 files changed, 57 insertions, 14 deletions

diff --git a/node.h b/node.h
index 72c244e8c..6cec6ddfe 100644
--- a/node.h
+++ b/node.h
@@ -5,7 +5,7 @@
 /*----------------------------------------------------------------------------*/
 /*Based on the code of unionfs translator.*/
 /*----------------------------------------------------------------------------*/
-/*Copyright (C) 2001, 2002, 2005 Free Software Foundation, Inc.
+/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc.
   Written by Sergiu Ivanov <unlimitedscolobb@gmail.com>.
 
   This program is free software; you can redistribute it and/or
@@ -51,24 +51,47 @@
 #	define OFFSET_T __off_t
 #endif /*__USE_FILE_OFFSET64*/
 /*----------------------------------------------------------------------------*/
-/*The size of a chunk of a string (for a small optimization in checking
-	the property)*/
-#define STRING_CHUNK 256
-/*----------------------------------------------------------------------------*/
 
 /*----------------------------------------------------------------------------*/
+/*--------Types---------------------------------------------------------------*/
+/*A list element containing a port*/
+struct port_el
+	{
+	/*the port*/
+	mach_port_t p;
+	
+	/*the next element in the list*/
+	struct port_el * next;
+	};/*struct port_el*/
+/*----------------------------------------------------------------------------*/
+typedef struct port_el port_el_t;
+/*----------------------------------------------------------------------------*/
 /*The user-defined node for libnetfs*/
 struct netnode
 	{
 	/*the reference to the corresponding light node*/
 	lnode_t * lnode;
 	
-	/*the flags associated with this node (might be not required)*/
+	/*the flags associated with this node*/
 	int flags;
 
 	/*a port to the underlying filesystem*/
 	file_t port;
 	
+	/*the malloced set of translators which have to be stacked upon this node
+	  and upon its children; the corresponding translators will have to decide
+	  on their own whether to accept directories or not*/
+	char * trans;
+	
+	/*the number of translators listed in `translators`*/
+	size_t ntrans;
+	
+	/*the length of the list of translators (in bytes)*/
+	size_t translen;
+	
+	/*the list of control ports to the translators being set on this node*/
+	port_el_t * cntl_ports;
+
 	/*the neighbouring entries in the cache*/
 	node_t * ncache_prev, * ncache_next;
 	};/*struct netnode*/
@@ -104,6 +127,14 @@ node_create
 	node_t ** node	/*store the result here*/
 	);
 /*----------------------------------------------------------------------------*/
+/*Derives a new proxy from `lnode`*/
+error_t
+node_create_proxy
+	(
+	lnode_t * lnode,
+	node_t ** node	/*store the result here*/
+	);
+/*----------------------------------------------------------------------------*/
 /*Destroys the specified node and removes a light reference from the
 	associated light node*/
 void
@@ -165,15 +196,17 @@ node_unlink_file
 	char * name
 	);
 /*----------------------------------------------------------------------------*/
-/*Sets the given translator on the supplied node*/
-/*This function will normally be called from netfs_attempt_lookup, therefore
-	it's better that the caller should provide the parent node for `node`.*/
+/*Sets the given translators on the specified node and returns the port to
+	the topmost one opened as `flags` require*/
 error_t
-node_set_translator
+node_set_translators
 	(
-	node_t * dir,
-	node_t * node,
-	const char * trans	/*set this on `name`*/
+	struct protid * diruser,
+	node_t * np,
+	char * trans,	/*set these on `node`*/
+	size_t ntrans,
+	int flags,
+	mach_port_t * port
 	);
 /*----------------------------------------------------------------------------*/
 /*Kill the topmost translator for this node*/
@@ -189,9 +222,19 @@ node_kill_translator
 /*Kills all translators on the current node or on all underlying nodes it the
 	current node is a directory*/
 void
-node_kill_all_translators
+node_kill_translators
 	(
 	node_t * node
 	);
 /*----------------------------------------------------------------------------*/
+/*Constructs a list of translators that were set on the ancestors of `node`*/
+/*TODO: Remove node_list_translators.*/
+error_t
+node_list_translators
+	(
+	node_t * node,
+	char ** trans,	/*the malloced list of 0-separated strings*/
+	size_t * ntrans	/*the number of elements in `trans`*/
+	);
+/*----------------------------------------------------------------------------*/
 #endif /*__NODE_H__*/