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Diffstat (limited to 'modules/base/luasrc/ltn12.lua')
| -rw-r--r-- | modules/base/luasrc/ltn12.lua | 391 |
1 files changed, 391 insertions, 0 deletions
diff --git a/modules/base/luasrc/ltn12.lua b/modules/base/luasrc/ltn12.lua new file mode 100644 index 0000000000..9371290c61 --- /dev/null +++ b/modules/base/luasrc/ltn12.lua @@ -0,0 +1,391 @@ +--[[ +LuaSocket 2.0.2 license +Copyright � 2004-2007 Diego Nehab + +Permission is hereby granted, free of charge, to any person obtaining a +copy of this software and associated documentation files (the "Software"), +to deal in the Software without restriction, including without limitation +the rights to use, copy, modify, merge, publish, distribute, sublicense, +and/or sell copies of the Software, and to permit persons to whom the +Software is furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER +DEALINGS IN THE SOFTWARE. +]]-- +--[[ + Changes made by LuCI project: + * Renamed to luci.ltn12 to avoid collisions with luasocket + * Added inline documentation +]]-- +----------------------------------------------------------------------------- +-- LTN12 - Filters, sources, sinks and pumps. +-- LuaSocket toolkit. +-- Author: Diego Nehab +-- RCS ID: $Id$ +----------------------------------------------------------------------------- + +----------------------------------------------------------------------------- +-- Declare module +----------------------------------------------------------------------------- +local string = require("string") +local table = require("table") +local base = _G + +--- Diego Nehab's LTN12 - Filters, sources, sinks and pumps. +-- See http://lua-users.org/wiki/FiltersSourcesAndSinks for design concepts +module("luci.ltn12") + +filter = {} +source = {} +sink = {} +pump = {} + +-- 2048 seems to be better in windows... +BLOCKSIZE = 2048 +_VERSION = "LTN12 1.0.1" + +----------------------------------------------------------------------------- +-- Filter stuff +----------------------------------------------------------------------------- + +--- LTN12 Filter constructors +-- @class module +-- @name luci.ltn12.filter + +--- Return a high level filter that cycles a low-level filter +-- by passing it each chunk and updating a context between calls. +-- @param low Low-level filter +-- @param ctx Context +-- @param extra Extra argument passed to the low-level filter +-- @return LTN12 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 + +--- Chain a bunch of filters together. +-- (thanks to Wim Couwenberg) +-- @param ... filters to be chained +-- @return LTN12 filter +function filter.chain(...) + local n = table.getn(arg) + 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 +----------------------------------------------------------------------------- + +--- LTN12 Source constructors +-- @class module +-- @name luci.ltn12.source + +-- create an empty source +local function empty() + return nil +end + +--- Create an empty source. +-- @return LTN12 source +function source.empty() + return empty +end + +--- Return a source that just outputs an error. +-- @param err Error object +-- @return LTN12 source +function source.error(err) + return function() + return nil, err + end +end + +--- Create a file source. +-- @param handle File handle ready for reading +-- @param io_err IO error object +-- @return LTN12 source +function source.file(handle, io_err) + if handle then + return function() + local chunk = handle:read(BLOCKSIZE) + if not chunk then handle:close() end + return chunk + end + else return source.error(io_err or "unable to open file") end +end + +--- Turn a fancy source into a simple source. +-- @param src fancy source +-- @return LTN12 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 + +--- Create a string source. +-- @param s Data +-- @return LTN12 source +function source.string(s) + if s then + local i = 1 + return function() + local chunk = string.sub(s, i, i+BLOCKSIZE-1) + i = i + BLOCKSIZE + if chunk ~= "" then return chunk + else return nil end + end + else return source.empty() end +end + +--- Creates rewindable source. +-- @param src LTN12 source to be made rewindable +-- @return LTN12 source +function source.rewind(src) + base.assert(src) + local t = {} + return function(chunk) + if not chunk then + chunk = table.remove(t) + if not chunk then return src() + else return chunk end + else + t[#t+1] = chunk + end + end +end + +--- Chain a source and a filter together. +-- @param src LTN12 source +-- @param f LTN12 filter +-- @return LTN12 source +function source.chain(src, f) + base.assert(src and f) + local last_in, last_out = "", "" + local state = "feeding" + local err + return function() + if not last_out then + base.error('source is empty!', 2) + end + while true do + if state == "feeding" then + last_in, err = src() + if err then return nil, err end + last_out = f(last_in) + if not last_out then + if last_in then + base.error('filter returned inappropriate nil') + else + return nil + end + elseif last_out ~= "" then + state = "eating" + if last_in then last_in = "" end + return last_out + end + else + last_out = f(last_in) + if last_out == "" then + if last_in == "" then + state = "feeding" + else + base.error('filter returned ""') + end + elseif not last_out then + if last_in then + base.error('filter returned inappropriate nil') + else + return nil + end + else + return last_out + end + end + end + end +end + +--- Create a source that produces contents of several sources. +-- Sources will be used one after the other, as if they were concatenated +-- (thanks to Wim Couwenberg) +-- @param ... LTN12 sources +-- @return LTN12 source +function source.cat(...) + local src = table.remove(arg, 1) + return function() + while src do + local chunk, err = src() + if chunk then return chunk end + if err then return nil, err end + src = table.remove(arg, 1) + end + end +end + +----------------------------------------------------------------------------- +-- Sink stuff +----------------------------------------------------------------------------- + +--- LTN12 sink constructors +-- @class module +-- @name luci.ltn12.sink + +--- Create a sink that stores into a table. +-- @param t output table to store into +-- @return LTN12 sink +function sink.table(t) + t = t or {} + local f = function(chunk, err) + if chunk then t[#t+1] = chunk end + return 1 + end + return f, t +end + +--- Turn a fancy sink into a simple sink. +-- @param snk fancy sink +-- @return LTN12 sink +function sink.simplify(snk) + base.assert(snk) + return function(chunk, err) + local ret, err_or_new = snk(chunk, err) + if not ret then return nil, err_or_new end + snk = err_or_new or snk + return 1 + end +end + +--- Create a file sink. +-- @param handle file handle to write to +-- @param io_err IO error +-- @return LTN12 sink +function sink.file(handle, io_err) + if handle then + return function(chunk, err) + if not chunk then + handle:close() + return 1 + else return handle:write(chunk) end + end + else return sink.error(io_err or "unable to open file") end +end + +-- creates a sink that discards data +local function null() + return 1 +end + +--- Create a sink that discards data. +-- @return LTN12 sink +function sink.null() + return null +end + +--- Create a sink that just returns an error. +-- @param err Error object +-- @return LTN12 sink +function sink.error(err) + return function() + return nil, err + end +end + +--- Chain a sink with a filter. +-- @param f LTN12 filter +-- @param snk LTN12 sink +-- @return LTN12 sink +function sink.chain(f, snk) + base.assert(f and snk) + return function(chunk, err) + if chunk ~= "" then + local filtered = f(chunk) + local done = chunk and "" + while true do + local ret, snkerr = snk(filtered, err) + if not ret then return nil, snkerr end + if filtered == done then return 1 end + filtered = f(done) + end + else return 1 end + end +end + +----------------------------------------------------------------------------- +-- Pump stuff +----------------------------------------------------------------------------- + +--- LTN12 pump functions +-- @class module +-- @name luci.ltn12.pump + +--- Pump one chunk from the source to the sink. +-- @param src LTN12 source +-- @param snk LTN12 sink +-- @return Chunk of data or nil if an error occured +-- @return Error object +function pump.step(src, snk) + local chunk, src_err = src() + local ret, snk_err = snk(chunk, src_err) + if chunk and ret then return 1 + else return nil, src_err or snk_err end +end + +--- Pump all data from a source to a sink, using a step function. +-- @param src LTN12 source +-- @param snk LTN12 sink +-- @param step step function (optional) +-- @return 1 if the operation succeeded otherwise nil +-- @return Error object +function pump.all(src, snk, step) + base.assert(src and snk) + step = step or pump.step + while true do + local ret, err = step(src, snk) + if not ret then + if err then return nil, err + else return 1 end + end + end +end + |