File

util/mercurial.lua @ 10571:cfeb0077c9e9

net.server_epoll: Avoid concatenating buffer with single item Saves creating a string that'll be identical to buffer[1] anyways, as well as a C function call. Depending on Lua version and length of the string, this could be reusing an interned string, but a longer one would probably be duplicated for no reason. Having exactly one item in the buffer seems like it would be fairly common, but I have not done an extensive study. If opportunistic writes are enabled then it will be even more likely. This special case could be optimized like this in table.concat but it does not look like it is.
author Kim Alvefur <zash@zash.se>
date Sat, 28 Dec 2019 06:18:58 +0100
parent 10533:a6cc5b844d7b
line wrap: on
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local lfs = require"lfs";

local hg = { };

function hg.check_id(path)
	if lfs.attributes(path, 'mode') ~= "directory" then
		return nil, "not a directory";
	end
	local hg_dirstate = io.open(path.."/.hg/dirstate");
	local hgid, hgrepo
	if hg_dirstate then
		hgid = ("%02x%02x%02x%02x%02x%02x"):format(hg_dirstate:read(6):byte(1, 6));
		hg_dirstate:close();
		local hg_changelog = io.open(path.."/.hg/store/00changelog.i");
		if hg_changelog then
			hg_changelog:seek("set", 0x20);
			hgrepo = ("%02x%02x%02x%02x%02x%02x"):format(hg_changelog:read(6):byte(1, 6));
			hg_changelog:close();
		end
	else
		local hg_archival,e = io.open(path.."/.hg_archival.txt"); -- luacheck: ignore 211/e
		if hg_archival then
			local repo = hg_archival:read("*l");
			local node = hg_archival:read("*l");
			hg_archival:close()
			hgid = node and node:match("^node: (%x%x%x%x%x%x%x%x%x%x%x%x)")
			hgrepo = repo and repo:match("^repo: (%x%x%x%x%x%x%x%x%x%x%x%x)")
		end
	end
	return hgid, hgrepo;
end

return hg;