opus/sys/apis/fs/urlfs.lua

local Util = require('util')

local fs = _G.fs

local urlfs = { }

function urlfs.mount(_, url)
	if not url then
		error('URL is required')
	end
	return {
		url = url,
	}
end

function urlfs.delete(_, dir)
	fs.unmount(dir)
end

function urlfs.exists()
	return true
end

function urlfs.getSize(node)
	return node.size or 0
end

function urlfs.isReadOnly()
	return true
end

function urlfs.isDir()
	return false
end

function urlfs.getDrive()
	return 'url'
end

function urlfs.open(node, fn, fl)

	if fl == 'w' or fl == 'wb' then
		fs.delete(fn)
		return fs.open(fn, fl)
	end

	if fl ~= 'r' and fl ~= 'rb' then
		error('Unsupported mode')
	end

	local c = node.cache
	if not c then
		c = Util.httpGet(node.url)
		if c then
			node.cache = c
			node.size = #c
		end
	end

	if not c then
		return
	end

	local ctr = 0
	local lines

	if fl == 'r' then
		return {
			readLine = function()
				if not lines then
					lines = Util.split(c)
				end
				ctr = ctr + 1
				return lines[ctr]
			end,
			readAll = function()
				return c
			end,
			close = function()
				lines = nil
			end,
		}
	end
	return {
		read = function()
			ctr = ctr + 1
			return c:sub(ctr, ctr):byte()
		end,
		close = function()
			ctr = 0
		end,
	}
end

return urlfs