0  h0x0  h6776102141 "lY>e @;pţ y"----------------------------------------------------------------------------- -- LTN12 - Filters, sources, sinks and pumps. -- LuaSocket toolkit. -- Author: Diego Nehab ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- -- Declare module ----------------------------------------------------------------------------- local string = require("string") local table = require("table") local unpack = unpack or table.unpack local base = _G local select = select local _M = {} if module then -- heuristic for exporting a global package table ltn12 = _M -- luacheck: ignore end local filter,source,sink,pump = {},{},{},{} _M.filter = filter _M.source = source _M.sink = sink _M.pump = pump -- 2048 seems to be better in windows... _M.BLOCKSIZE = 2048 _M._VERSION = "LTN12 1.0.3" ----------------------------------------------------------------------------- -- Filter stuff ----------------------------------------------------------------------------- -- returns a high level filter that cycles a low-level filter function filter.cycle(low, ctx, extra) base.assert(low) return function(chunk) local ret ret, ctx = low(ctx, chunk, extra) return ret end end -- chains a bunch of filters together -- (thanks to Wim Couwenberg) function filter.chain(...) local arg = {...} local n = select('#',...) local top, index = 1, 1 local retry = "" return function(chunk) retry = chunk and retry while true do if index == top then chunk = arg[index](chunk) if chunk == "" or top == n then return chunk elseif chunk then index = index + 1 else top = top+1 index = top end else chunk = arg[index](chunk or "") if chunk == "" then index = index - 1 chunk = retry elseif chunk then if index == n then return chunk else index = index + 1 end else base.error("filter returned inappropriate nil") end end end end end ----------------------------------------------------------------------------- -- Source stuff ----------------------------------------------------------------------------- -- create an empty source local function empty() return nil end function source.empty() return empty end -- returns a source that just outputs an error function source.error(err) return function() return nil, err end end -- creates a file source function source.file(handle, io_err) if handle then return function() local chunk = handle:read(_M.BLOCKSIZE) if not chunk then handle:close() end return chunk end else return source.error(io_err or "unable to open file") end end -- turns a fancy source into a simple source function source.simplify(src) base.assert(src) return function() local chunk, err_or_new = src() src = err_or_new or src if not chunk then return nil, err_or_new else return chunk end end end -- creates string source function source.string(s) if s then local i = 1 return function() local chunk = string.sub(s, i, i+_M.BLOCKSIZE-1) i = i + _M.BLOCKSIZE if chunk ~= "" then return chunk else return nil end end else return source.empty() end end -- creates table source function source.table(t) base.assert('table' == type(t)) local i = 0 return function() i = i + 1 return t[i] end end -- creates rewindable source function source.rewind(src) base.assert(src) local t = {} return function(chunk) if not chunk then