428 lines
10 KiB
Lua
428 lines
10 KiB
Lua
-- shamelessly stolen from plan9k
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buffer = {}
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function buffer.new(mode, stream) -- create a new buffer in mode *mode* backed by stream object *stream*
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local result = {
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mode = {},
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stream = stream,
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bufferRead = "",
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bufferWrite = "",
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bufferSize = math.max(512, math.min(8 * 1024, computer.freeMemory() / 8)),
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bufferMode = "full",
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readTimeout = math.huge
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}
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mode = mode or "r"
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for i = 1, unicode.len(mode) do
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result.mode[unicode.sub(mode, i, i)] = true
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end
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local metatable = {
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__index = buffer,
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__metatable = "file"
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}
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return setmetatable(result, metatable)
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end
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local function badFileDescriptor()
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return nil, "bad file descriptor"
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end
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function buffer:close()
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if self.mode.w or self.mode.a then
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self:flush()
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end
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self.closed = true
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return self.stream:close()
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end
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function buffer:flush()
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local result, reason = self.stream:write(self.bufferWrite)
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if result then
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self.bufferWrite = ""
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else
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if reason then
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return nil, reason
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else
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return badFileDescriptor()
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end
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end
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return self
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end
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function buffer:lines(...)
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local args = table.pack(...)
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return function()
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local result = table.pack(self:read(table.unpack(args, 1, args.n)))
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if not result[1] and result[2] then
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error(result[2])
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end
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return table.unpack(result, 1, result.n)
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end
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end
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function buffer:read(...)
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local timeout = computer.uptime() + self.readTimeout
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local function readChunk()
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if computer.uptime() > timeout then
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error("timeout")
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end
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local result, reason = self.stream:read(self.bufferSize)
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if result then
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self.bufferRead = self.bufferRead .. result
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return self
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else -- error or eof
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return nil, reason
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end
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end
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local function readBytesOrChars(n)
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n = math.max(n, 0)
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local len, sub
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if self.mode.b then
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len = rawlen
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sub = string.sub
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else
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len = unicode.len
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sub = unicode.sub
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end
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local buffer = ""
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repeat
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if len(self.bufferRead) == 0 then
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local result, reason = readChunk()
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if not result then
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if reason then
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return nil, reason
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else -- eof
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return #buffer > 0 and buffer or nil
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end
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end
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end
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local left = n - len(buffer)
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buffer = buffer .. sub(self.bufferRead, 1, left)
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self.bufferRead = sub(self.bufferRead, left + 1)
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until len(buffer) == n
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return buffer
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end
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local function readNumber()
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local len, sub
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if self.mode.b then
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len = rawlen
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sub = string.sub
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else
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len = unicode.len
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sub = unicode.sub
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end
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local buffer = ""
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local first = true
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local decimal = false
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local last = false
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local hex = false
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local pat = "^[0-9]+"
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local minbuf = 3 -- "+0x" (sign + hexadecimal tag)
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-- this function is used to read trailing numbers (1e2, 0x1p2, etc)
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local function readnum(checksign)
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local _buffer = ""
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local sign = ""
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while true do
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if len(self.bufferRead) == 0 then
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local result, reason = readChunk()
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if not result then
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if reason then
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return nil, reason
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else -- eof
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return #_buffer > 0 and (sign .. _buffer) or nil
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end
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end
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end
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if checksign then
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local _sign = sub(self.bufferRead, 1, 1)
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if _sign == "+" or _sign == "-" then
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-- "eat" the sign (Rio Lua behaviour)
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sign = sub(self.bufferRead, 1, 1)
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self.bufferRead = sub(self.bufferRead, 2)
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end
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checksign = false
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else
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local x,y = string.find(self.bufferRead, pat)
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if not x then
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break
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else
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_buffer = _buffer .. sub(self.bufferRead, 1, y)
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self.bufferRead = sub(self.bufferRead, y + 1)
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end
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end
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end
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return #_buffer > 0 and (sign .. _buffer) or nil
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end
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while true do
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if len(self.bufferRead) == 0 or len(self.bufferRead) < minbuf then
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local result, reason = readChunk()
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if not result then
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if reason then
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return nil, reason
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else -- eof
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return #buffer > 0 and tonumber(buffer) or nil
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end
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end
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end
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-- these ifs are here so we run the buffer check above
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if first then
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local sign = sub(self.bufferRead, 1, 1)
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if sign == "+" or sign == "-" then
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-- "eat" the sign (Rio Lua behaviour)
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buffer = buffer .. sub(self.bufferRead, 1, 1)
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self.bufferRead = sub(self.bufferRead, 2)
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end
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local hextag = sub(self.bufferRead, 1, 2)
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if hextag == "0x" or hextag == "0X" then
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pat = "^[0-9A-Fa-f]+"
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-- "eat" the 0x, see https://gist.github.com/SoniEx2/570a363d81b743353151
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buffer = buffer .. sub(self.bufferRead, 1, 2)
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self.bufferRead = sub(self.bufferRead, 3)
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hex = true
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end
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minbuf = 0
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first = false
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elseif decimal then
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local sep = sub(self.bufferRead, 1, 1)
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if sep == "." then
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buffer = buffer .. sep
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self.bufferRead = sub(self.bufferRead, 2)
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local temp = readnum(false) -- no sign
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if temp then
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buffer = buffer .. temp
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end
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end
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if not tonumber(buffer) then break end
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decimal = false
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last = true
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minbuf = 1
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elseif last then
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local tag = sub(self.bufferRead, 1, 1)
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if hex and (tag == "p" or tag == "P") then
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local temp = sub(self.bufferRead, 1, 1)
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self.bufferRead = sub(self.bufferRead, 2)
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local temp2 = readnum(true) -- this eats the next sign if any
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if temp2 then
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buffer = buffer .. temp .. temp2
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end
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elseif tag == "e" or tag == "E" then
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local temp = sub(self.bufferRead, 1, 1)
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self.bufferRead = sub(self.bufferRead, 2)
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local temp2 = readnum(true) -- this eats the next sign if any
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if temp2 then
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buffer = buffer .. temp .. temp2
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end
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end
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break
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else
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local x,y = string.find(self.bufferRead, pat)
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if not x then
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minbuf = 1
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decimal = true
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else
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buffer = buffer .. sub(self.bufferRead, 1, y)
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self.bufferRead = sub(self.bufferRead, y + 1)
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end
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end
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end
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return tonumber(buffer)
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end
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local function readLine(chop)
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local start = 1
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while true do
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local l = self.bufferRead:find("\n", start, true)
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if l then
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local result = self.bufferRead:sub(1, l + (chop and -1 or 0))
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self.bufferRead = self.bufferRead:sub(l + 1)
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return result
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else
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start = #self.bufferRead
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local result, reason = readChunk()
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if not result then
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if reason then
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return nil, reason
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else -- eof
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local result = #self.bufferRead > 0 and self.bufferRead or nil
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self.bufferRead = ""
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return result
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end
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end
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end
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end
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end
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local function readAll()
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repeat
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local result, reason = readChunk()
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if not result and reason then
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return nil, reason
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end
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until not result -- eof
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local result = self.bufferRead
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self.bufferRead = ""
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return result
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end
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local function read(n, format)
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if type(format) == "number" then
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return readBytesOrChars(format)
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else
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if type(format) ~= "string" or unicode.sub(format, 1, 1) ~= "*" then
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error("bad argument #" .. n .. " (invalid option)")
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end
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format = unicode.sub(format, 2, 2)
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if format == "n" then
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return readNumber()
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elseif format == "l" then
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return readLine(true)
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elseif format == "L" then
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return readLine(false)
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elseif format == "a" then
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return readAll()
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else
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error("bad argument #" .. n .. " (invalid format)")
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end
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end
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end
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if self.mode.w or self.mode.a then
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self:flush()
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end
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local results = {}
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local formats = table.pack(...)
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if formats.n == 0 then
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return readLine(true)
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end
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for i = 1, formats.n do
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local result, reason = read(i, formats[i])
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if result then
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results[i] = result
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elseif reason then
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return nil, reason
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end
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end
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return table.unpack(results, 1, formats.n)
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end
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function buffer:seek(whence, offset)
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whence = tostring(whence or "cur")
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assert(whence == "set" or whence == "cur" or whence == "end",
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"bad argument #1 (set, cur or end expected, got " .. whence .. ")")
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offset = offset or 0
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checkArg(2, offset, "number")
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assert(math.floor(offset) == offset, "bad argument #2 (not an integer)")
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if self.mode.w or self.mode.a then
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self:flush()
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elseif whence == "cur" then
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offset = offset - #self.bufferRead
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end
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local result, reason = self.stream:seek(whence, offset)
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if result then
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self.bufferRead = ""
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return result
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else
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return nil, reason
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end
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end
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function buffer:setvbuf(mode, size)
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mode = mode or self.bufferMode
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size = size or self.bufferSize
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assert(mode == "no" or mode == "full" or mode == "line",
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"bad argument #1 (no, full or line expected, got " .. tostring(mode) .. ")")
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assert(mode == "no" or type(size) == "number",
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"bad argument #2 (number expected, got " .. type(size) .. ")")
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self.bufferMode = mode
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self.bufferSize = size
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return self.bufferMode, self.bufferSize
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end
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function buffer:getTimeout()
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return self.readTimeout
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end
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function buffer:setTimeout(value)
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self.readTimeout = tonumber(value)
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end
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function buffer:write(...)
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if self.closed then
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return badFileDescriptor()
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end
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local args = table.pack(...)
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for i = 1, args.n do
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if type(args[i]) == "number" then
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args[i] = tostring(args[i])
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end
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checkArg(i, args[i], "string")
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end
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for i = 1, args.n do
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local arg = args[i]
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local result, reason
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if self.bufferMode == "full" then
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if self.bufferSize - #self.bufferWrite < #arg then
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result, reason = self:flush()
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if not result then
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return nil, reason
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end
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end
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if #arg > self.bufferSize then
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result, reason = self.stream:write(arg)
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else
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self.bufferWrite = self.bufferWrite .. arg
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result = self
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end
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elseif self.bufferMode == "line" then
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local l
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repeat
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local idx = arg:find("\n", (l or 0) + 1, true)
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if idx then
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l = idx
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end
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until not idx
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if l or #arg > self.bufferSize then
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result, reason = self:flush()
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if not result then
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return nil, reason
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end
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end
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if l then
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result, reason = self.stream:write(arg:sub(1, l))
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if not result then
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return nil, reason
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end
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arg = arg:sub(l + 1)
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end
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if #arg > self.bufferSize then
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result, reason = self.stream:write(arg)
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else
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self.bufferWrite = self.bufferWrite .. arg
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result = self
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end
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else -- self.bufferMode == "no"
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result, reason = self.stream:write(arg)
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end
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if not result then
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return nil, reason
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end
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end
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return self
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end
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