Merge pull request #14 from rdeits/lcm-core

Use LCMCore to provide the LCM interface

.travis.yml

@@ -5,7 +5,6 @@ os:
   - linux
   - osx
 julia:
-  - 0.4
   - 0.5
   - nightly
 notifications:

README.md

@@ -3,11 +3,11 @@
 [![Build Status](https://travis-ci.org/rdeits/PyLCM.jl.svg?branch=master)](https://travis-ci.org/rdeits/PyLCM.jl)
 [![codecov.io](https://codecov.io/github/rdeits/PyLCM.jl/coverage.svg?branch=master)](https://codecov.io/github/rdeits/PyLCM.jl?branch=master)
 
-PyLCM provides an interface to the [Lightweight Communications and Marshalling (LCM) library](https://lcm-proj.github.io/) in Julia. It wraps the LCM Python interface using [PyCall](https://github.com/stevengj/PyCall.jl), so it will be slower than calling the LCM C-API directly.
+PyLCM provides an interface to the [Lightweight Communications and Marshalling (LCM) library](https://lcm-proj.github.io/) in Julia. Most of the functionality is provided by [LCMCore.jl](https://github.com/rdeits/LCMCore.jl), which interacts with LCM through its C API. PyLCM builds on LCMCore by allowing you to send and receive Python LCM types from Julia.
 
 # Installation
 
-If you have a systemwide installation of LCM, PyLCM will try to use it. If you don't, then running `Pkg.build("PyLCM")` will download and install a private copy of LCM and the python bindings for you.
+If you have a systemwide installation of LCM, PyLCM will try to use it. If you don't, then running `Pkg.build("LCMCore")` will download and install a private copy of LCM and the python bindings for you.
 
 # Usage
 
@@ -65,3 +65,13 @@ while true
     handle(lc)
 end
 ```
+
+### Asynchronously handling messages
+
+Creating an asynchronous handler just requires the `@async` macro:
+
+```julia
+@async while true
+    handle(lc)
+end
+```

REQUIRE

@@ -1,5 +1,3 @@
-julia 0.4
+julia 0.5
 PyCall 1.4.0
-BinDeps 0.4.0
-Compat 0.8.0
-@osx Homebrew 0.3.0
+LCMCore 0.0.1

src/PyLCM.jl

@@ -2,59 +2,35 @@ __precompile__()
 
 module PyLCM
 
-using Base.Dates: Period, Millisecond
 using PyCall
+using Base.Dates: Period, Millisecond
+using LCMCore
+import LCMCore: encode, subscribe, decode
+
 export LCM, publish, subscribe, handle, @pyimport
 
 const pylcm = PyNULL()
 
-immutable LCM
-	lcm_obj::PyObject
-
-	LCM() = new(pylcm[:LCM]())
-end
-
-function publish(lc::LCM, channel::AbstractString, msg)
-	pycall(lc.lcm_obj[:publish], PyAny, channel, pycall(msg[:encode], PyObject))
-end
-
-function subscribe(lc::LCM, channel::AbstractString, handler::Function)
-	lc.lcm_obj[:subscribe](channel, pyeval("lambda chan, data, handler=h: handler(chan, bytearray(data))", h=handler))
-end
-
-function subscribe(lc::LCM, channel::AbstractString, handler::Function, msg_type::PyObject)
-	lc.lcm_obj[:subscribe](channel, pyeval("lambda chan, data, handler=h, msg_type=t: handler(chan, msg_type.decode(data))", h=handler, t=msg_type))
-end
-
-"Wait for and dispatch the next incoming message"
-function handle(lc::LCM)
-    pycall(lc.lcm_obj[:handle], PyObject)
-    true
-end
-
-"""
-    handle(lc, timeout)
-
-Wait for and dispatch the next incoming message, with a timeout expressed
-as any Base.Dates.Period type. For example:
-
-    handle(lc, Millisecond(10))
-
-or
-
-    handle(lc, Second(1))
-
-Returns true if a message was handled, false if the function timed out.
-"""
-function handle(lc::LCM, timeout::Period)
-    timeout_ms = convert(Int, convert(Millisecond, timeout))
-    convert(Bool, pycall(lc.lcm_obj[:handle_timeout], PyObject, timeout_ms))
+# This is the only method required to enable publishing python
+# LCM messages
+encode(msg::PyObject) = pycall(msg[:encode], Vector{UInt8})
+
+# We override the subscribe() method that takes in a user-supplied
+# message type. That's because the method in LCMCore assumes that
+# the Julia type of the message is enough to determine how to
+# decode the message. That's not the case for PyLCM because all
+# python LCM types are just PyObjects. 
+function subscribe(lcm::LCM, channel::String, handler, msgtype::PyObject)
+    function inner_handler(channel, data)
+        pymsg = pycall(msgtype[:decode], PyObject, data)
+        handler(channel, pymsg)
+    end
+    subscribe(lcm, channel, inner_handler)
 end
 
 function __init__()
-	depsjl = joinpath(dirname(@__FILE__), "..", "deps", "deps.jl")
-	isfile(depsjl) ? include(depsjl) : error("PyLCM not properly ",
-	    "installed. Please run\nPkg.build(\"PyLCM\")")
+    sys = pyimport("sys")
+    unshift!(PyVector(sys["path"]), joinpath(LCMCore.lcm_prefix, "lib", "python" * string(sys[:version_info][1]) * "." * string(sys[:version_info][2]), "site-packages"))
     copy!(pylcm, pyimport("lcm"))
 end