Software /
code /
prosody
File
util/queue.lua @ 13039:9ddb344b9fab
util.human.io: Allow defining per column ellipsis function
As an alternative to doing it in the mapper function. Could be useful in
cases where one may want to put the ellipsis in the middle or beginning
instead of the start.
author | Kim Alvefur <zash@zash.se> |
---|---|
date | Fri, 07 Apr 2023 13:00:58 +0200 |
parent | 12975:d10957394a3c |
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-- Prosody IM -- Copyright (C) 2008-2015 Matthew Wild -- Copyright (C) 2008-2015 Waqas Hussain -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- -- Small ringbuffer library (i.e. an efficient FIFO queue with a size limit) -- (because unbounded dynamically-growing queues are a bad thing...) local have_utable, utable = pcall(require, "prosody.util.table"); -- For pre-allocation of table local function new(size, allow_wrapping) -- Head is next insert, tail is next read local head, tail = 1, 1; local items = 0; -- Number of stored items local t = have_utable and utable.create(size, 0) or {}; -- Table to hold items --luacheck: ignore 212/self return { _items = t; size = size; count = function (self) return items; end; push = function (self, item) if items >= size then if allow_wrapping then tail = (tail%size)+1; -- Advance to next oldest item items = items - 1; else return nil, "queue full"; end end t[head] = item; items = items + 1; head = (head%size)+1; return true; end; pop = function (self) if items == 0 then return nil; end local item; item, t[tail] = t[tail], 0; tail = (tail%size)+1; items = items - 1; return item; end; peek = function (self) if items == 0 then return nil; end return t[tail]; end; replace = function (self, data) if items == 0 then return self:push(data); end t[tail] = data; return true; end; items = function (self) return function (_, pos) if pos >= items then return nil; end local read_pos = tail + pos; if read_pos > self.size then read_pos = (read_pos%size); end return pos+1, t[read_pos]; end, self, 0; end; consume = function (self) return self.pop, self; end; }; end return { new = new; };