1 files changed, 99 insertions, 0 deletions
diff --git a/parallelize.py b/parallelize.py
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+++ b/parallelize.py
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+#!/usr/bin/env python3
+
+"""A decorator to help with dead simple parallelization."""
+
+from enum import Enum
+import functools
+import typing
+
+import executors
+import smart_future
+
+ps_count = 0
+thread_count = 0
+remote_count = 0
+
+
+class Method(Enum):
+    THREAD = 1
+    PROCESS = 2
+    REMOTE = 3
+
+
+def parallelize(
+        _funct: typing.Optional[typing.Callable] = None,
+        *,
+        method: Method = Method.THREAD
+) -> typing.Callable:
+    """Usage:
+
+    @parallelize    # defaults to thread-mode
+    def my_function(a, b, c) -> int:
+        ...do some slow / expensive work, e.g., an http request
+
+    @parallelize(method=Method.PROCESS)
+    def my_other_function(d, e, f) -> str:
+        ...do more really expensice work, e.g., a network read
+
+    @parallelize(method=Method.REMOTE)
+    def my_other_other_function(g, h) -> int:
+        ...this work will be distributed to a remote machine pool
+
+    This decorator will invoke the wrapped function on:
+
+        Method.THREAD (default): a background thread
+        Method.PROCESS: a background process
+        Method.REMOTE: a process on a remote host
+
+    The wrapped function returns immediately with a value that is
+    wrapped in a SmartFuture.  This value will block if it is either
+    read directly (via a call to result._resolve) or indirectly (by
+    using the result in an expression, printing it, hashing it,
+    passing it a function argument, etc...).  See comments on the
+    SmartFuture class for details.
+
+    Note: you may stack @parallelized methods and it will "work".
+    That said, having multiple layers of Method.PROCESS or
+    Method.REMOTE may prove to be problematic because each process in
+    the stack will use its own independent pool which may overload
+    your machine with processes or your network with remote processes
+    beyond the control mechanisms built into one instance of the pool.
+    Be careful.
+    """
+    def wrapper(funct: typing.Callable):
+
+        @functools.wraps(funct)
+        def inner_wrapper(*args, **kwargs):
+            # Look for as of yet unresolved arguments in _funct's
+            # argument list and resolve them now.
+            newargs = []
+            for arg in args:
+                newargs.append(smart_future.SmartFuture.resolve(arg))
+            newkwargs = {}
+            for kw in kwargs:
+                newkwargs[kw] = smart_future.SmartFuture.resolve(
+                    kwargs[kw]
+                )
+
+            executor = None
+            if method == Method.PROCESS:
+                executor = executors.DefaultExecutors().process_pool()
+            elif method == Method.THREAD:
+                executor = executors.DefaultExecutors().thread_pool()
+            elif method == Method.REMOTE:
+                executor = executors.DefaultExecutors().remote_pool()
+            assert executor is not None
+
+            future = executor.submit(funct, *newargs, **newkwargs)
+
+            # Wrap the future that's returned in a SmartFuture object
+            # so that callers do not need to call .result(), they can
+            # just use is as normal.
+            return smart_future.SmartFuture(future)
+
+        return inner_wrapper
+
+    if _funct is None:
+        return wrapper
+    else:
+        return wrapper(_funct)