Windows Performance Improvement & Multi-Item support (#43)

* Initial IFileOperation for Windows

- Try using IFileOperation instead of SHFileOperation
  - Use pywin32 to accomplish this
  - Implement fallback when pywin32 not available
- Handles paths like `C:\` just fine bu the `\\?\` paths in the test
  cause issue
- Add batching for IFileOperation version (performance)
- Minor formatting applied by editor

* Fix issue with paths starting with \\?\

- Strip these characters off if present just like old implementation

* Add windows version check, legacy list support

- Add check for windows version for IFileOperation
- Add list support to legacy version
- Remove some debugging code
- Fix bug in path converson

Not sure if there is a better way to layout this file

* Split plat_win into legacy and modern

* Update other platforms for list support

Formatter also ran on these so some other minor changes.

* Add unit tests for multi-file calls

send2trash/plat_win.py

@@ -5,88 +5,16 @@
 # http://www.hardcoded.net/licenses/bsd_license
 
 from __future__ import unicode_literals
+from platform import version
 
-from ctypes import (windll, Structure, byref, c_uint,
-                    create_unicode_buffer, addressof,
-                    GetLastError, FormatError)
-from ctypes.wintypes import HWND, UINT, LPCWSTR, BOOL
-import os.path as op
-
-from .compat import text_type
-
-kernel32 = windll.kernel32
-GetShortPathNameW = kernel32.GetShortPathNameW
-
-shell32 = windll.shell32
-SHFileOperationW = shell32.SHFileOperationW
-
-
-class SHFILEOPSTRUCTW(Structure):
-    _fields_ = [
-        ("hwnd", HWND),
-        ("wFunc", UINT),
-        ("pFrom", LPCWSTR),
-        ("pTo", LPCWSTR),
-        ("fFlags", c_uint),
-        ("fAnyOperationsAborted", BOOL),
-        ("hNameMappings", c_uint),
-        ("lpszProgressTitle", LPCWSTR),
-        ]
-
-
-FO_MOVE = 1
-FO_COPY = 2
-FO_DELETE = 3
-FO_RENAME = 4
-
-FOF_MULTIDESTFILES = 1
-FOF_SILENT = 4
-FOF_NOCONFIRMATION = 16
-FOF_ALLOWUNDO = 64
-FOF_NOERRORUI = 1024
-
-
-def get_short_path_name(long_name):
-    if not long_name.startswith('\\\\?\\'):
-        long_name = '\\\\?\\' + long_name
-    buf_size = GetShortPathNameW(long_name, None, 0)
-    # FIX: https://github.com/hsoft/send2trash/issues/31
-    # If buffer size is zero, an error has occurred.
-    if not buf_size:
-        err_no = GetLastError()
-        raise WindowsError(err_no, FormatError(err_no), long_name[4:])
-    output = create_unicode_buffer(buf_size)
-    GetShortPathNameW(long_name, output, buf_size)
-    return output.value[4:]  # Remove '\\?\' for SHFileOperationW
-
-
-def send2trash(path):
-    if not isinstance(path, text_type):
-        path = text_type(path, 'mbcs')
-    if not op.isabs(path):
-        path = op.abspath(path)
-    path = get_short_path_name(path)
-    fileop = SHFILEOPSTRUCTW()
-    fileop.hwnd = 0
-    fileop.wFunc = FO_DELETE
-    # FIX: https://github.com/hsoft/send2trash/issues/17
-    # Starting in python 3.6.3 it is no longer possible to use:
-    # LPCWSTR(path + '\0') directly as embedded null characters are no longer
-    # allowed in strings
-    # Workaround
-    #  - create buffer of c_wchar[] (LPCWSTR is based on this type)
-    #  - buffer is two c_wchar characters longer (double null terminator)
-    #  - cast the address of the buffer to a LPCWSTR
-    # NOTE: based on how python allocates memory for these types they should
-    # always be zero, if this is ever not true we can go back to explicitly
-    # setting the last two characters to null using buffer[index] = '\0'.
-    buffer = create_unicode_buffer(path, len(path)+2)
-    fileop.pFrom = LPCWSTR(addressof(buffer))
-    fileop.pTo = None
-    fileop.fFlags = FOF_ALLOWUNDO | FOF_NOCONFIRMATION | FOF_NOERRORUI | FOF_SILENT
-    fileop.fAnyOperationsAborted = 0
-    fileop.hNameMappings = 0
-    fileop.lpszProgressTitle = None
-    result = SHFileOperationW(byref(fileop))
-    if result:
-        raise WindowsError(result, FormatError(result), path)
+# if windows is vista or newer and pywin32 is available use IFileOperation
+if int(version().split(".", 1)[0]) >= 6:
+    try:
+        # Attempt to use pywin32 to use IFileOperation
+        from .plat_win_modern import send2trash
+    except ImportError:
+        # use SHFileOperation as fallback
+        from .plat_win_legacy import send2trash
+else:
+    # use SHFileOperation as fallback
+    from .plat_win_legacy import send2trash