1 files changed, 178 insertions, 0 deletions
diff --git a/src/arrow/python/pyarrow/util.py b/src/arrow/python/pyarrow/util.py
new file mode 100644
index 000000000..69bde250c
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+++ b/src/arrow/python/pyarrow/util.py
@@ -0,0 +1,178 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+# Miscellaneous utility code
+
+import contextlib
+import functools
+import gc
+import pathlib
+import socket
+import sys
+import types
+import warnings
+
+
+_DEPR_MSG = (
+    "pyarrow.{} is deprecated as of {}, please use pyarrow.{} instead."
+)
+
+
+def implements(f):
+    def decorator(g):
+        g.__doc__ = f.__doc__
+        return g
+    return decorator
+
+
+def _deprecate_api(old_name, new_name, api, next_version):
+    msg = _DEPR_MSG.format(old_name, next_version, new_name)
+
+    def wrapper(*args, **kwargs):
+        warnings.warn(msg, FutureWarning)
+        return api(*args, **kwargs)
+    return wrapper
+
+
+def _deprecate_class(old_name, new_class, next_version,
+                     instancecheck=True):
+    """
+    Raise warning if a deprecated class is used in an isinstance check.
+    """
+    class _DeprecatedMeta(type):
+        def __instancecheck__(self, other):
+            warnings.warn(
+                _DEPR_MSG.format(old_name, next_version, new_class.__name__),
+                FutureWarning,
+                stacklevel=2
+            )
+            return isinstance(other, new_class)
+
+    return _DeprecatedMeta(old_name, (new_class,), {})
+
+
+def _is_iterable(obj):
+    try:
+        iter(obj)
+        return True
+    except TypeError:
+        return False
+
+
+def _is_path_like(path):
+    # PEP519 filesystem path protocol is available from python 3.6, so pathlib
+    # doesn't implement __fspath__ for earlier versions
+    return (isinstance(path, str) or
+            hasattr(path, '__fspath__') or
+            isinstance(path, pathlib.Path))
+
+
+def _stringify_path(path):
+    """
+    Convert *path* to a string or unicode path if possible.
+    """
+    if isinstance(path, str):
+        return path
+
+    # checking whether path implements the filesystem protocol
+    try:
+        return path.__fspath__()  # new in python 3.6
+    except AttributeError:
+        # fallback pathlib ckeck for earlier python versions than 3.6
+        if isinstance(path, pathlib.Path):
+            return str(path)
+
+    raise TypeError("not a path-like object")
+
+
+def product(seq):
+    """
+    Return a product of sequence items.
+    """
+    return functools.reduce(lambda a, b: a*b, seq, 1)
+
+
+def get_contiguous_span(shape, strides, itemsize):
+    """
+    Return a contiguous span of N-D array data.
+
+    Parameters
+    ----------
+    shape : tuple
+    strides : tuple
+    itemsize : int
+      Specify array shape data
+
+    Returns
+    -------
+    start, end : int
+      The span end points.
+    """
+    if not strides:
+        start = 0
+        end = itemsize * product(shape)
+    else:
+        start = 0
+        end = itemsize
+        for i, dim in enumerate(shape):
+            if dim == 0:
+                start = end = 0
+                break
+            stride = strides[i]
+            if stride > 0:
+                end += stride * (dim - 1)
+            elif stride < 0:
+                start += stride * (dim - 1)
+        if end - start != itemsize * product(shape):
+            raise ValueError('array data is non-contiguous')
+    return start, end
+
+
+def find_free_port():
+    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    with contextlib.closing(sock) as sock:
+        sock.bind(('', 0))
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        return sock.getsockname()[1]
+
+
+def guid():
+    from uuid import uuid4
+    return uuid4().hex
+
+
+def _break_traceback_cycle_from_frame(frame):
+    # Clear local variables in all inner frames, so as to break the
+    # reference cycle.
+    this_frame = sys._getframe(0)
+    refs = gc.get_referrers(frame)
+    while refs:
+        for frame in refs:
+            if frame is not this_frame and isinstance(frame, types.FrameType):
+                break
+        else:
+            # No frame found in referrers (finished?)
+            break
+        refs = None
+        # Clear the frame locals, to try and break the cycle (it is
+        # somewhere along the chain of execution frames).
+        frame.clear()
+        # To visit the inner frame, we need to find it among the
+        # referers of this frame (while `frame.f_back` would let
+        # us visit the outer frame).
+        refs = gc.get_referrers(frame)
+    refs = frame = this_frame = None