add python client

lib/python/plasma.py

@@ -0,0 +1,70 @@
+import socket
+import ctypes
+
+Addr = ctypes.c_ubyte * 4
+
+ID = ctypes.c_ubyte * 20
+
+class PlasmaID(ctypes.Structure):
+  _fields_ = [("plasma_id", ID)]
+
+# these must be in sync with plasma_request_type in plasma.h
+PLASMA_CREATE = 0
+
+class PlasmaRequest(ctypes.Structure):
+  _fields_ = [("type", ctypes.c_int),
+              ("manager_id", ctypes.c_int),
+              ("object_id", PlasmaID),
+              ("size", ctypes.c_int64),
+              ("addr", Addr),
+              ("port", ctypes.c_int)]
+
+class PlasmaBuffer(ctypes.Structure):
+  _fields_ = [("plasma_id", PlasmaID),
+              ("data", ctypes.c_void_p),
+              ("size", ctypes.c_int64),
+              ("writable", ctypes.c_int)]
+
+def make_plasma_id(string):
+  if len(string) != 20:
+    raise Exception("PlasmaIDs must be 20 characters long")
+  object_id = map(ord, string)
+  return PlasmaID(plasma_id=ID(*object_id))
+
+class PlasmaClient(object):
+  def __init__(self, socket_name):
+    self.client = ctypes.cdll.LoadLibrary("../../build/plasma_client.so")
+
+    self.client.plasma_store_connect.restype = ctypes.c_int
+
+    self.client.plasma_create.argtypes = [ctypes.c_int, PlasmaID, ctypes.c_int64]
+    self.client.plasma_create.restype = PlasmaBuffer
+    
+    self.client.plasma_get.argtypes = [ctypes.c_int, PlasmaID]
+    self.client.plasma_get.restype = PlasmaBuffer
+
+    self.client.plasma_seal.argtypes = [ctypes.c_int, PlasmaID]
+    self.client.plasma_seal.restype = None
+
+    self.buffer_from_memory = ctypes.pythonapi.PyBuffer_FromMemory
+    self.buffer_from_memory.argtypes = [ctypes.c_void_p, ctypes.c_int64]
+    self.buffer_from_memory.restype = ctypes.py_object
+
+    self.buffer_from_read_write_memory = ctypes.pythonapi.PyBuffer_FromReadWriteMemory
+    self.buffer_from_read_write_memory.argtypes = [ctypes.c_void_p, ctypes.c_int64]
+    self.buffer_from_read_write_memory.restype = ctypes.py_object
+
+    self.sock = self.client.plasma_store_connect(socket_name)
+
+  def create(self, object_id, size):
+    buf = self.client.plasma_create(self.sock, make_plasma_id(object_id), size)
+    return self.buffer_from_read_write_memory(buf.data, buf.size)
+
+  def get(self, object_id):
+    buf = self.client.plasma_get(self.sock, make_plasma_id(object_id))
+    return self.buffer_from_memory(buf.data, buf.size)
+    
+  def seal(self, object_id):
+    self.client.plasma_seal(self.sock, make_plasma_id(object_id))
+
+