intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 188 insertions, 0 deletions

diff --git a/contrib/python/ipython/py3/IPython/core/compilerop.py b/contrib/python/ipython/py3/IPython/core/compilerop.py
new file mode 100644
index 0000000000..50672a1954
--- /dev/null
+++ b/contrib/python/ipython/py3/IPython/core/compilerop.py
@@ -0,0 +1,188 @@
+"""Compiler tools with improved interactive support.
+
+Provides compilation machinery similar to codeop, but with caching support so
+we can provide interactive tracebacks.
+
+Authors
+-------
+* Robert Kern
+* Fernando Perez
+* Thomas Kluyver
+"""
+
+# Note: though it might be more natural to name this module 'compiler', that
+# name is in the stdlib and name collisions with the stdlib tend to produce
+# weird problems (often with third-party tools).
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2010-2011 The IPython Development Team.
+#
+#  Distributed under the terms of the BSD License.
+#
+#  The full license is in the file COPYING.txt, distributed with this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+# Stdlib imports
+import __future__
+from ast import PyCF_ONLY_AST
+import codeop
+import functools
+import hashlib
+import linecache
+import operator
+import time
+from contextlib import contextmanager
+
+#-----------------------------------------------------------------------------
+# Constants
+#-----------------------------------------------------------------------------
+
+# Roughly equal to PyCF_MASK | PyCF_MASK_OBSOLETE as defined in pythonrun.h,
+# this is used as a bitmask to extract future-related code flags.
+PyCF_MASK = functools.reduce(operator.or_,
+                             (getattr(__future__, fname).compiler_flag
+                              for fname in __future__.all_feature_names))
+
+#-----------------------------------------------------------------------------
+# Local utilities
+#-----------------------------------------------------------------------------
+
+def code_name(code, number=0):
+    """ Compute a (probably) unique name for code for caching.
+
+    This now expects code to be unicode.
+    """
+    hash_digest = hashlib.sha1(code.encode("utf-8")).hexdigest()
+    # Include the number and 12 characters of the hash in the name.  It's
+    # pretty much impossible that in a single session we'll have collisions
+    # even with truncated hashes, and the full one makes tracebacks too long
+    return '<ipython-input-{0}-{1}>'.format(number, hash_digest[:12])
+
+#-----------------------------------------------------------------------------
+# Classes and functions
+#-----------------------------------------------------------------------------
+
+class CachingCompiler(codeop.Compile):
+    """A compiler that caches code compiled from interactive statements.
+    """
+
+    def __init__(self):
+        codeop.Compile.__init__(self)
+
+        # This is ugly, but it must be done this way to allow multiple
+        # simultaneous ipython instances to coexist.  Since Python itself
+        # directly accesses the data structures in the linecache module, and
+        # the cache therein is global, we must work with that data structure.
+        # We must hold a reference to the original checkcache routine and call
+        # that in our own check_cache() below, but the special IPython cache
+        # must also be shared by all IPython instances.  If we were to hold
+        # separate caches (one in each CachingCompiler instance), any call made
+        # by Python itself to linecache.checkcache() would obliterate the
+        # cached data from the other IPython instances.
+        if not hasattr(linecache, '_ipython_cache'):
+            linecache._ipython_cache = {}
+        if not hasattr(linecache, '_checkcache_ori'):
+            linecache._checkcache_ori = linecache.checkcache
+        # Now, we must monkeypatch the linecache directly so that parts of the
+        # stdlib that call it outside our control go through our codepath
+        # (otherwise we'd lose our tracebacks).
+        linecache.checkcache = check_linecache_ipython
+
+
+    def ast_parse(self, source, filename='<unknown>', symbol='exec'):
+        """Parse code to an AST with the current compiler flags active.
+
+        Arguments are exactly the same as ast.parse (in the standard library),
+        and are passed to the built-in compile function."""
+        return compile(source, filename, symbol, self.flags | PyCF_ONLY_AST, 1)
+
+    def reset_compiler_flags(self):
+        """Reset compiler flags to default state."""
+        # This value is copied from codeop.Compile.__init__, so if that ever
+        # changes, it will need to be updated.
+        self.flags = codeop.PyCF_DONT_IMPLY_DEDENT
+
+    @property
+    def compiler_flags(self):
+        """Flags currently active in the compilation process.
+        """
+        return self.flags
+
+    def get_code_name(self, raw_code, transformed_code, number):
+        """Compute filename given the code, and the cell number.
+
+        Parameters
+        ----------
+        raw_code : str
+          The raw cell code.
+        transformed_code : str
+          The executable Python source code to cache and compile.
+        number : int
+          A number which forms part of the code's name. Used for the execution
+          counter.
+
+        Returns
+        -------
+        The computed filename.
+        """
+        return code_name(transformed_code, number)
+
+    def cache(self, transformed_code, number=0, raw_code=None):
+        """Make a name for a block of code, and cache the code.
+
+        Parameters
+        ----------
+        transformed_code : str
+          The executable Python source code to cache and compile.
+        number : int
+          A number which forms part of the code's name. Used for the execution
+          counter.
+        raw_code : str
+          The raw code before transformation, if None, set to `transformed_code`.
+
+        Returns
+        -------
+        The name of the cached code (as a string). Pass this as the filename
+        argument to compilation, so that tracebacks are correctly hooked up.
+        """
+        if raw_code is None:
+            raw_code = transformed_code
+
+        name = self.get_code_name(raw_code, transformed_code, number)
+        entry = (
+            len(transformed_code),
+            time.time(),
+            [line + "\n" for line in transformed_code.splitlines()],
+            name,
+        )
+        linecache.cache[name] = entry
+        linecache._ipython_cache[name] = entry
+        return name
+
+    @contextmanager
+    def extra_flags(self, flags):
+        ## bits that we'll set to 1
+        turn_on_bits = ~self.flags & flags
+
+
+        self.flags = self.flags | flags
+        try:
+            yield
+        finally:
+            # turn off only the bits we turned on so that something like
+            # __future__ that set flags stays.
+            self.flags &= ~turn_on_bits
+
+
+def check_linecache_ipython(*args):
+    """Call linecache.checkcache() safely protecting our cached values.
+    """
+    # First call the original checkcache as intended
+    linecache._checkcache_ori(*args)
+    # Then, update back the cache with our data, so that tracebacks related
+    # to our compiled codes can be produced.
+    linecache.cache.update(linecache._ipython_cache)