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