X-Git-Url: https://arthur.barton.de/gitweb/?a=blobdiff_plain;f=lib%2Fbup%2Fcompat.py;h=00575036e27cc46f7fb6b3408e273831526b9daa;hb=4448f184253125e1b8bd0c55d0098a335d15b90b;hp=1ed2d0f70c9fc18f7afc2011a2e55381aa047ca4;hpb=938537c3a9bb76cfa7d62f931ffee0ff3359aa55;p=bup.git

diff --git a/lib/bup/compat.py b/lib/bup/compat.py
index 1ed2d0f..0057503 100644
--- a/lib/bup/compat.py
+++ b/lib/bup/compat.py
@@ -1,6 +1,5 @@
 
 from __future__ import absolute_import, print_function
-from array import array
 from binascii import hexlify
 from traceback import print_exception
 import os, sys
@@ -13,9 +12,14 @@ py3 = py_maj >= 3
 
 if py3:
 
+    # pylint: disable=unused-import
+    from contextlib import ExitStack, nullcontext
     from os import environb as environ
     from os import fsdecode, fsencode
     from shlex import quote
+    # pylint: disable=undefined-variable
+    # (for python2 looking here)
+    ModuleNotFoundError = ModuleNotFoundError
     input = input
     range = range
     str_type = str
@@ -36,6 +40,25 @@ if py3:
         """Do nothing (already handled by Python 3 infrastructure)."""
         return ex
 
+    class pending_raise:
+        """If rethrow is true, rethrow ex (if any), unless the body throws.
+
+        (Supports Python 2 compatibility.)
+
+        """
+        def __init__(self, ex, rethrow=True):
+            self.closed = False
+            self.ex = ex
+            self.rethrow = rethrow
+        def __enter__(self):
+            return None
+        def __exit__(self, exc_type, exc_value, traceback):
+            self.closed = True
+            if not exc_type and self.ex and self.rethrow:
+                raise self.ex
+        def __del__(self):
+            assert self.closed
+
     def items(x):
         return x.items()
 
@@ -64,6 +87,10 @@ if py3:
 
 else:  # Python 2
 
+    from contextlib import contextmanager
+
+    ModuleNotFoundError = ImportError
+
     def fsdecode(x):
         return x
 
@@ -71,13 +98,24 @@ else:  # Python 2
         return x
 
     from pipes import quote
+    # pylint: disable=unused-import
     from os import environ, getcwd
 
+    # pylint: disable=unused-import
     from bup.py2raise import reraise
 
+    @contextmanager
+    def nullcontext(enter_result=None):
+        yield enter_result
+
+    # on py3 this causes errors, obviously
+    # pylint: disable=undefined-variable
     input = raw_input
+    # pylint: disable=undefined-variable
     range = xrange
+    # pylint: disable=undefined-variable
     str_type = basestring
+    # pylint: disable=undefined-variable
     int_types = (int, long)
 
     hexstr = hexlify
@@ -100,6 +138,34 @@ else:  # Python 2
                 ex.__context__ = context_ex
         return ex
 
+    class pending_raise:
+        """If rethrow is true, rethrow ex (if any), unless the body throws.
+
+        If the body does throw, make any provided ex the __context__
+        of the newer exception (assuming there's no existing
+        __context__).  Ensure the exceptions have __tracebacks__.
+        (Supports Python 2 compatibility.)
+
+        """
+        def __init__(self, ex, rethrow=True):
+            self.closed = False
+            self.ex = ex
+            self.rethrow = rethrow
+        def __enter__(self):
+            if self.ex:
+                add_ex_tb(self.ex)
+        def __exit__(self, exc_type, exc_value, traceback):
+            self.closed = True
+            if exc_value:
+                if self.ex:
+                    add_ex_tb(exc_value)
+                    add_ex_ctx(exc_value, self.ex)
+                return
+            if self.rethrow and self.ex:
+                raise self.ex
+        def __del__(self):
+            assert self.closed
+
     def dump_traceback(ex):
         stack = [ex]
         next_ex = getattr(ex, '__context__', None)
@@ -116,6 +182,31 @@ else:  # Python 2
             tb = getattr(ex, '__traceback__', None)
             print_exception(type(ex), ex, tb)
 
+    class ExitStack:
+        def __init__(self):
+            self.contexts = []
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, value_type, value, traceback):
+            init_value = value
+            for ctx in reversed(self.contexts):
+                try:
+                    ctx.__exit__(value_type, value, traceback)
+                except BaseException as ex:
+                    add_ex_tb(ex)
+                    if value:
+                        add_ex_ctx(ex, value)
+                    value_type = type(ex)
+                    value = ex
+                    traceback = ex.__traceback__
+            if value is not init_value:
+                raise value
+
+        def enter_context(self, x):
+            self.contexts.append(x)
+
     def items(x):
         return x.iteritems()
 
@@ -132,41 +223,27 @@ else:  # Python 2
 
     buffer = buffer
 
+try:
+    import bup_main
+except ModuleNotFoundError:
+    bup_main = None
 
-argv = None
-argvb = None
-
-def _configure_argv():
-    global argv, argvb
-    assert not argv
-    assert not argvb
-    if len(sys.argv) > 1:
-        if environ.get(b'BUP_ARGV_0'):
-            print('error: BUP_ARGV* set and sys.argv not empty', file=sys.stderr)
-            sys.exit(2)
-        argv = sys.argv
-        argvb = [argv_bytes(x) for x in argv]
-        return
-    args = []
-    i = 0
-    arg = environ.get(b'BUP_ARGV_%d' % i)
-    while arg is not None:
-        args.append(arg)
-        i += 1
-        arg = environ.get(b'BUP_ARGV_%d' % i)
-    i -= 1
-    while i >= 0:
-        del environ[b'BUP_ARGV_%d' % i]
-        i -= 1
-    argvb = args
-    # System encoding?
+if bup_main:
+    def get_argvb():
+        "Return a new list containing the current process argv bytes."
+        return bup_main.argv()
     if py3:
-        argv = [x.decode(errors='surrogateescape') for x in args]
+        def get_argv():
+            "Return a new list containing the current process argv strings."
+            return [x.decode(errors='surrogateescape') for x in bup_main.argv()]
     else:
-        argv = argvb
-
-_configure_argv()
-
+        def get_argv():
+            return bup_main.argv()
+else:
+    def get_argvb():
+        raise Exception('get_argvb requires the bup_main module');
+    def get_argv():
+        raise Exception('get_argv requires the bup_main module');
 
 def wrap_main(main):
     """Run main() and raise a SystemExit with the return value if it