80 lines
2.3 KiB
Lua
80 lines
2.3 KiB
Lua
--
|
|
-- bencode.lua: BitTorrent data encoding
|
|
--
|
|
-- Copyright (c) 2017, Přemysl Janouch <p@janouch.name>
|
|
--
|
|
-- Permission to use, copy, modify, and/or distribute this software for any
|
|
-- purpose with or without fee is hereby granted.
|
|
--
|
|
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
|
|
-- SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
|
|
-- OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
|
|
-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
--
|
|
|
|
local detect = function (c)
|
|
-- There is no magic to go by
|
|
return false
|
|
end
|
|
|
|
-- We're not making it exactly readable but at least we're trying
|
|
local function one_value (c, level)
|
|
local p, type = c.position, c:read (1)
|
|
if type == "e" then
|
|
c (p, c.position - 1):mark ("%d: container end", level - 1)
|
|
return false
|
|
elseif type == "i" then
|
|
local n = ""
|
|
type = c:read (1)
|
|
while type ~= "e" do
|
|
n = n .. type
|
|
type = c:read (1)
|
|
end
|
|
c (p, c.position - 1):mark ("%d: integer: %s", level, n)
|
|
elseif type == "l" then
|
|
c (p, p):mark ("%d: list begin", level)
|
|
local i = 0
|
|
while true do
|
|
local p = c.position
|
|
if not one_value (c, level + 1) then break end
|
|
c (p, c.position - 1):mark ("%d: list value %d", level, i)
|
|
i = i + 1
|
|
end
|
|
elseif type == "d" then
|
|
c (p, p):mark ("%d: dictionary begin", level)
|
|
while true do
|
|
local p = c.position
|
|
if not one_value (c, level + 1) then break end
|
|
c (p, c.position - 1):mark ("%d: dictionary key", level)
|
|
|
|
local p = c.position
|
|
if not one_value (c, level + 1) then break end
|
|
c (p, c.position - 1):mark ("%d: dictionary value", level)
|
|
end
|
|
else
|
|
local n = type
|
|
type = c:read (1)
|
|
while type ~= ":" do
|
|
n = n .. type
|
|
type = c:read (1)
|
|
end
|
|
c (p, c.position - 1):mark ("%d: string length: %s", level, n)
|
|
|
|
p = c.position
|
|
c:read (tonumber (n))
|
|
c (p, c.position - 1):mark ("%d: string value", level)
|
|
end
|
|
return true
|
|
end
|
|
|
|
local decode = function (c)
|
|
while not c.eof do
|
|
one_value (c, 0)
|
|
end
|
|
end
|
|
|
|
hex.register { type="bencode", detect=detect, decode=decode }
|