mirror of
https://github.com/koreader/koreader
synced 2024-11-11 19:11:14 +00:00
99 lines
3.3 KiB
Lua
99 lines
3.3 KiB
Lua
local ffi = require("ffi")
|
|
local logger = require("logger")
|
|
local MessageQueue = require("ui/message/messagequeue")
|
|
|
|
local _ = require("ffi/zeromq_h")
|
|
local zmq = ffi.load("libs/libzmq.so.5")
|
|
local czmq = ffi.load("libs/libczmq.so.4")
|
|
local C = ffi.C
|
|
|
|
local StreamMessageQueue = MessageQueue:extend{
|
|
host = nil,
|
|
port = nil,
|
|
}
|
|
|
|
function StreamMessageQueue:start()
|
|
local endpoint = string.format("tcp://%s:%d", self.host, self.port)
|
|
self.socket = czmq.zsock_new(C.ZMQ_STREAM)
|
|
if not self.socket then
|
|
error("cannot create socket for endpoint " .. endpoint)
|
|
end
|
|
logger.dbg("connecting to endpoint", endpoint)
|
|
if czmq.zsock_connect(self.socket, endpoint) ~= 0 then
|
|
error("cannot connect to " .. endpoint)
|
|
end
|
|
local id_size = ffi.new("size_t[1]", 255)
|
|
local buffer = ffi.new("uint8_t[?]", id_size[0])
|
|
if zmq.zmq_getsockopt(czmq.zsock_resolve(self.socket), C.ZMQ_IDENTITY, buffer, id_size) ~= 0 then
|
|
error("cannot get socket identity for endpoint " .. endpoint)
|
|
end
|
|
self.id = ffi.string(buffer, id_size[0])
|
|
self.poller = czmq.zpoller_new(self.socket, nil)
|
|
if not self.poller then
|
|
error("cannot create poller for endpoint " .. endpoint)
|
|
end
|
|
end
|
|
|
|
function StreamMessageQueue:stop()
|
|
if self.poller ~= nil then
|
|
czmq.zpoller_destroy(ffi.new('zpoller_t *[1]', self.poller))
|
|
end
|
|
if self.socket ~= nil then
|
|
czmq.zsock_destroy(ffi.new('zsock_t *[1]', self.socket))
|
|
end
|
|
end
|
|
|
|
function StreamMessageQueue:handleZframe(frame)
|
|
local size = czmq.zframe_size(frame)
|
|
local data = nil
|
|
if size > 0 then
|
|
local frame_data = czmq.zframe_data(frame)
|
|
if frame_data ~= nil then
|
|
data = ffi.string(frame_data, size)
|
|
end
|
|
end
|
|
czmq.zframe_destroy(ffi.new('zframe_t *[1]', frame))
|
|
return data
|
|
end
|
|
|
|
function StreamMessageQueue:waitEvent()
|
|
-- Successive zframes may come in batches of tens or hundreds in some cases.
|
|
-- Since we buffer each frame's data in a Lua string,
|
|
-- and then let the caller concatenate those,
|
|
-- it may consume a significant amount of memory.
|
|
-- And it's fairly easy to trigger when receiving file data from Calibre.
|
|
-- So, throttle reception to 256 packages at most in one waitEvent loop,
|
|
-- after which we immediately call receiveCallback.
|
|
local wait_packages = 256
|
|
-- In a similar spirit, much like LuaSocket,
|
|
-- we store the data as ropes of strings in an array,
|
|
-- to be concatenated by the caller.
|
|
local t = {}
|
|
while czmq.zpoller_wait(self.poller, 0) ~= nil and wait_packages > 0 do
|
|
local id_frame = czmq.zframe_recv(self.socket)
|
|
if id_frame ~= nil then
|
|
self:handleZframe(id_frame)
|
|
end
|
|
local frame = czmq.zframe_recv(self.socket)
|
|
if frame ~= nil then
|
|
local data = self:handleZframe(frame)
|
|
if data then
|
|
table.insert(t, data)
|
|
end
|
|
end
|
|
wait_packages = wait_packages - 1
|
|
end
|
|
if self.receiveCallback and #t ~= 0 then
|
|
self.receiveCallback(t)
|
|
end
|
|
end
|
|
|
|
function StreamMessageQueue:send(data)
|
|
local msg = czmq.zmsg_new()
|
|
czmq.zmsg_addmem(msg, self.id, #self.id)
|
|
czmq.zmsg_addmem(msg, data, #data)
|
|
czmq.zmsg_send(ffi.new('zmsg_t *[1]', msg), self.socket)
|
|
end
|
|
|
|
return StreamMessageQueue
|