Test plasma manager.

lib/python/plasma.py

@@ -16,6 +16,8 @@ PLASMA_SEAL = 2
 PLASMA_TRANSFER = 3
 PLASMA_DATA = 4
 PLASMA_REGISTER = 5
+PLASMA_GET_MANAGER_PORT = 6
+PLASMA_RETURN_MANAGER_PORT = 7
 
 class PlasmaRequest(ctypes.Structure):
   _fields_ = [("type", ctypes.c_int),
@@ -38,24 +40,43 @@ def make_plasma_id(string):
   return PlasmaID(plasma_id=ID(*object_id))
 
 class PlasmaManager(object):
+  """The PlasmaManager is used to manage a PlasmaStore.
+
+  There should be one PlasmaManager per PlasmaStore. The PlasmaManager is
+  responsible for interfacing with other PlasmaManagers in order to transfer
+  objects between PlasmaStores. This class sends commands to the C
+  implementation of the PlasmaManager using sockets.
+
+  Attributes:
+    sock: The socket used to communicate with the C implementation of the
+      PlasmaManager.
+  """
 
   def __init__(self, addr, port):
+    """Initialize the PlasmaManager."""
     self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     self.sock.connect((addr, port))
 
   def register(self, manager_id, addr, port):
-    "Register another object manager."
+    """Register another object manager."""
     req = PlasmaRequest(type=PLASMA_REGISTER, manager_id=manager_id,
                         addr=Addr(*map(int, addr.split("."))), port=port)
     self.sock.send(buffer(req)[:])
 
   def transfer(self, manager_id, object_id):
-    "Transfer local object with id object_id to manager with id manager_id."
+    """Transfer local object with id object_id to manager with id manager_id."""
     req = PlasmaRequest(type=PLASMA_TRANSFER, manager_id=manager_id,
                         object_id=make_plasma_id(object_id))
     self.sock.send(buffer(req)[:])
 
 class PlasmaClient(object):
+  """The PlasmaClient is used to interface with a PlasmaStore.
+
+  The PlasmaClient can ask the PlasmaStore to allocate a new buffer, seal a
+  buffer, and get a buffer. Buffers are referred to by object IDs, which are
+  strings.
+  """
+
   def __init__(self, socket_name):
     plasma_client_library = os.path.join(os.path.abspath(os.path.dirname(__file__)), "../../build/plasma_client.so")
     self.client = ctypes.cdll.LoadLibrary(plasma_client_library)
@@ -82,12 +103,36 @@ class PlasmaClient(object):
     self.sock = self.client.plasma_store_connect(socket_name)
 
   def create(self, object_id, size):
+    """Create a new buffer in the PlasmaStore for a particular object ID.
+
+    The returned buffer is mutable until seal is called.
+
+    Args:
+      object_id (str): A string used to identify an object.
+      size (int): The size in bytes of the created buffer.
+    """
     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):
+    """Create a buffer from the PlasmaStore based on object ID.
+
+    This method can only be called after the buffer has been sealed. The
+    retrieved buffer is immutable.
+
+    Args:
+      object_id (str): A string used to identify an object.
+    """
     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):
+    """Seal the buffer in the PlasmaStore for a particular object ID.
+
+    Once a buffer has been sealed, the buffer is immutable and can only be
+    accessed through get.
+
+    Args:
+      object_id (str): A string used to identify an object.
+    """
     self.client.plasma_seal(self.sock, make_plasma_id(object_id))