Recipe package system.

recipe_engine/third_party/setuptools/depends.py

+import sys
+import imp
+import marshal
+from imp import PKG_DIRECTORY, PY_COMPILED, PY_SOURCE, PY_FROZEN
+from distutils.version import StrictVersion
+from setuptools import compat
+
+__all__ = [
+    'Require', 'find_module', 'get_module_constant', 'extract_constant'
+]
+
+class Require:
+    """A prerequisite to building or installing a distribution"""
+
+    def __init__(self, name, requested_version, module, homepage='',
+            attribute=None, format=None):
+
+        if format is None and requested_version is not None:
+            format = StrictVersion
+
+        if format is not None:
+            requested_version = format(requested_version)
+            if attribute is None:
+                attribute = '__version__'
+
+        self.__dict__.update(locals())
+        del self.self
+
+    def full_name(self):
+        """Return full package/distribution name, w/version"""
+        if self.requested_version is not None:
+            return '%s-%s' % (self.name,self.requested_version)
+        return self.name
+
+    def version_ok(self, version):
+        """Is 'version' sufficiently up-to-date?"""
+        return self.attribute is None or self.format is None or \
+            str(version) != "unknown" and version >= self.requested_version
+
+    def get_version(self, paths=None, default="unknown"):
+
+        """Get version number of installed module, 'None', or 'default'
+
+        Search 'paths' for module.  If not found, return 'None'.  If found,
+        return the extracted version attribute, or 'default' if no version
+        attribute was specified, or the value cannot be determined without
+        importing the module.  The version is formatted according to the
+        requirement's version format (if any), unless it is 'None' or the
+        supplied 'default'.
+        """
+
+        if self.attribute is None:
+            try:
+                f,p,i = find_module(self.module,paths)
+                if f: f.close()
+                return default
+            except ImportError:
+                return None
+
+        v = get_module_constant(self.module, self.attribute, default, paths)
+
+        if v is not None and v is not default and self.format is not None:
+            return self.format(v)
+
+        return v
+
+    def is_present(self, paths=None):
+        """Return true if dependency is present on 'paths'"""
+        return self.get_version(paths) is not None
+
+    def is_current(self, paths=None):
+        """Return true if dependency is present and up-to-date on 'paths'"""
+        version = self.get_version(paths)
+        if version is None:
+            return False
+        return self.version_ok(version)
+
+
+def _iter_code(code):
+
+    """Yield '(op,arg)' pair for each operation in code object 'code'"""
+
+    from array import array
+    from dis import HAVE_ARGUMENT, EXTENDED_ARG
+
+    bytes = array('b',code.co_code)
+    eof = len(code.co_code)
+
+    ptr = 0
+    extended_arg = 0
+
+    while ptr<eof:
+
+        op = bytes[ptr]
+
+        if op>=HAVE_ARGUMENT:
+
+            arg = bytes[ptr+1] + bytes[ptr+2]*256 + extended_arg
+            ptr += 3
+
+            if op==EXTENDED_ARG:
+                extended_arg = arg * compat.long_type(65536)
+                continue
+
+        else:
+            arg = None
+            ptr += 1
+
+        yield op,arg
+
+
+def find_module(module, paths=None):
+    """Just like 'imp.find_module()', but with package support"""
+
+    parts = module.split('.')
+
+    while parts:
+        part = parts.pop(0)
+        f, path, (suffix,mode,kind) = info = imp.find_module(part, paths)
+
+        if kind==PKG_DIRECTORY:
+            parts = parts or ['__init__']
+            paths = [path]
+
+        elif parts:
+            raise ImportError("Can't find %r in %s" % (parts,module))
+
+    return info
+
+
+def get_module_constant(module, symbol, default=-1, paths=None):
+
+    """Find 'module' by searching 'paths', and extract 'symbol'
+
+    Return 'None' if 'module' does not exist on 'paths', or it does not define
+    'symbol'.  If the module defines 'symbol' as a constant, return the
+    constant.  Otherwise, return 'default'."""
+
+    try:
+        f, path, (suffix, mode, kind) = find_module(module, paths)
+    except ImportError:
+        # Module doesn't exist
+        return None
+
+    try:
+        if kind==PY_COMPILED:
+            f.read(8)   # skip magic & date
+            code = marshal.load(f)
+        elif kind==PY_FROZEN:
+            code = imp.get_frozen_object(module)
+        elif kind==PY_SOURCE:
+            code = compile(f.read(), path, 'exec')
+        else:
+            # Not something we can parse; we'll have to import it.  :(
+            if module not in sys.modules:
+                imp.load_module(module, f, path, (suffix, mode, kind))
+            return getattr(sys.modules[module], symbol, None)
+
+    finally:
+        if f:
+            f.close()
+
+    return extract_constant(code, symbol, default)
+
+
+def extract_constant(code, symbol, default=-1):
+    """Extract the constant value of 'symbol' from 'code'
+
+    If the name 'symbol' is bound to a constant value by the Python code
+    object 'code', return that value.  If 'symbol' is bound to an expression,
+    return 'default'.  Otherwise, return 'None'.
+
+    Return value is based on the first assignment to 'symbol'.  'symbol' must
+    be a global, or at least a non-"fast" local in the code block.  That is,
+    only 'STORE_NAME' and 'STORE_GLOBAL' opcodes are checked, and 'symbol'
+    must be present in 'code.co_names'.
+    """
+
+    if symbol not in code.co_names:
+        # name's not there, can't possibly be an assigment
+        return None
+
+    name_idx = list(code.co_names).index(symbol)
+
+    STORE_NAME = 90
+    STORE_GLOBAL = 97
+    LOAD_CONST = 100
+
+    const = default
+
+    for op, arg in _iter_code(code):
+
+        if op==LOAD_CONST:
+            const = code.co_consts[arg]
+        elif arg==name_idx and (op==STORE_NAME or op==STORE_GLOBAL):
+            return const
+        else:
+            const = default
+
+
+def _update_globals():
+    """
+    Patch the globals to remove the objects not available on some platforms.
+
+    XXX it'd be better to test assertions about bytecode instead.
+    """
+
+    if not sys.platform.startswith('java') and sys.platform != 'cli':
+        return
+    incompatible = 'extract_constant', 'get_module_constant'
+    for name in incompatible:
+        del globals()[name]
+        __all__.remove(name)
+
+_update_globals()