X-Git-Url: https://vcs.maemo.org/git/?a=blobdiff_plain;f=data%2Fluatraverse.lua;fp=data%2Fluatraverse.lua;h=f0a32340fa0925018340cf9d02866a7429501f53;hb=bd8c0fc134e004eebb40d6b0e74c2c860c24fb91;hp=0000000000000000000000000000000000000000;hpb=2d2a163728283108eb78c11d7b02bf5c54d88ea4;p=monky

diff --git a/data/luatraverse.lua b/data/luatraverse.lua
new file mode 100644
index 0000000..f0a3234
--- /dev/null
+++ b/data/luatraverse.lua
@@ -0,0 +1,195 @@
+-------------------------------------------------------------------------------
+-- This module implements a function that traverses all live objects.
+-- You can implement your own function to pass as a parameter of traverse
+-- and give you the information you want. As an example we have implemented
+-- countreferences and findallpaths
+--
+-- Alexandra Barros - 2006.03.15
+-------------------------------------------------------------------------------
+
+module("traverse", package.seeall)
+
+local List = {}
+
+function List.new ()
+	return {first = 0, last = -1}
+end
+
+function List.push (list, value)
+	local last = list.last + 1
+    list.last = last
+    list[last] = value
+end
+
+function List.pop (list)	
+    local first = list.first
+    if first > list.last then error("list is empty") end
+    local value = list[first]
+    list[first] = nil        
+    list.first = first + 1
+    return value
+end
+
+function List.isempty (list)
+	return list.first > list.last
+end
+
+-- Counts all references for a given object
+function countreferences(value)
+	local count = -1 
+	local f = function(from, to, how, v)
+		if to == value then 
+			count = count + 1
+		end 
+	end	
+	traverse({edge=f}, {count, f})
+	return count
+end
+
+-- Main function
+-- 'funcs' is a table that contains a funcation for every lua type and also the
+-- function edge edge (traverseedge).
+function traverse(funcs, ignoreobjs)
+
+	-- The keys of the marked table are the objetcts (for example, table: 00442330).
+	-- The value of each key is true if the object has been found and false
+	-- otherwise.
+	local env = {marked = {}, list=List.new(), funcs=funcs}
+	
+	if ignoreobjs then
+		for i=1, #ignoreobjs do
+			env.marked[ignoreobjs[i]] = true
+		end
+	end
+	
+	env.marked["traverse"] = true
+	env.marked[traverse] = true
+	
+	-- marks and inserts on the list
+	edge(env, nil, "_G", "isname", nil)
+	edge(env, nil, _G, "value", "_G")
+
+	-- traverses the active thread
+	-- inserts the local variables
+	-- interates over the function on the stack, starting from the one that
+	-- called traverse
+	
+	for i=2, math.huge do
+		local info = debug.getinfo(i, "f") 
+		if not info then break end 
+		for j=1, math.huge do
+			local n, v = debug.getlocal(i, j)
+			if not n then break end
+		
+			edge(env, nil, n, "isname", nil)
+			edge(env, nil, v, "local", n)
+		end
+	end
+	
+	while not List.isempty(env.list) do	 		
+	
+		local obj = List.pop(env.list)
+		local t = type(obj)
+		_M["traverse" .. t](env, obj)
+			
+	end			
+	
+end
+
+function traversetable(env, obj)
+	
+	local f = env.funcs.table
+	if f then f(obj) end
+	
+	for key, value in pairs(obj) do	
+		edge(env, obj, key, "key", nil)
+		edge(env, obj, value, "value", key)
+	end
+	
+	local mtable = debug.getmetatable(obj)
+	if mtable then edge(env, obj, mtable, "ismetatable", nil) end
+
+end
+			
+function traversestring(env, obj)
+	local f = env.funcs.string
+	if f then f(obj) end
+	
+end
+
+function traverseuserdata(env, obj)
+	local f = env.funcs.userdata
+	if f then f(obj) end
+	
+	local mtable = debug.getmetatable(obj)
+	if mtable then edge(env, obj, mtable, "ismetatable", nil) end
+	
+	local fenv = debug.getfenv(obj)
+	if fenv then edge(env, obj, fenv, "environment", nil) end
+	
+end
+
+function traversefunction(env, obj)
+	local f = env.funcs.func
+	if f then f(obj) end
+	
+	-- gets the upvalues
+	local i = 1	
+	while true do
+		local n, v = debug.getupvalue(obj, i)
+		if not n then break end -- when there is no upvalues
+		edge(env, obj, n, "isname", nil)
+		edge(env, obj, v, "upvalue", n)
+		i = i + 1
+	end
+		
+	local fenv = debug.getfenv(obj)
+	edge(env, obj, fenv, "environment", nil)
+	
+end
+			
+function traversethread(env, t)
+	local f = env.funcs.thread
+	if f then f(t) end
+	
+	for i=1, math.huge do
+		local info = debug.getinfo(t, i, "f") 
+		if not info then break end 
+		for j=1, math.huge do
+			local n, v = debug.getlocal(t, i , j)
+			if not n then break end
+			print(n, v)
+		
+			edge(env, nil, n, "isname", nil)
+			edge(env, nil, v, "local", n)
+		end
+	end
+	
+	local fenv = debug.getfenv(t)
+	edge(env, t, fenv, "environment", nil)
+	
+end
+
+
+-- 'how' is a string that identifies the content of 'to' and 'value':
+-- 		if 'how' is "key", then 'to' is a key and 'name' is nil.
+-- 		if 'how' is "value", then 'to' is an object and 'name' is the name of the
+--		key.
+function edge(env, from, to, how, name)
+	
+	local t = type(to)	
+	
+	if to and (t~="boolean") and (t~="number") and (t~="new") then
+		-- If the destination object has not been found yet
+		if not env.marked[to] then 
+			env.marked[to] = true
+			List.push(env.list, to) -- puts on the list to be traversed
+		end
+		
+		local f = env.funcs.edge
+		if f then f(from, to, how, name) end
+		
+	end	
+end
+
+return _M;