OLD | NEW |
(Empty) | |
| 1 import sys |
| 2 import imp |
| 3 import marshal |
| 4 from distutils.version import StrictVersion |
| 5 from imp import PKG_DIRECTORY, PY_COMPILED, PY_SOURCE, PY_FROZEN |
| 6 |
| 7 from .py33compat import Bytecode |
| 8 |
| 9 |
| 10 __all__ = [ |
| 11 'Require', 'find_module', 'get_module_constant', 'extract_constant' |
| 12 ] |
| 13 |
| 14 |
| 15 class Require: |
| 16 """A prerequisite to building or installing a distribution""" |
| 17 |
| 18 def __init__(self, name, requested_version, module, homepage='', |
| 19 attribute=None, format=None): |
| 20 |
| 21 if format is None and requested_version is not None: |
| 22 format = StrictVersion |
| 23 |
| 24 if format is not None: |
| 25 requested_version = format(requested_version) |
| 26 if attribute is None: |
| 27 attribute = '__version__' |
| 28 |
| 29 self.__dict__.update(locals()) |
| 30 del self.self |
| 31 |
| 32 def full_name(self): |
| 33 """Return full package/distribution name, w/version""" |
| 34 if self.requested_version is not None: |
| 35 return '%s-%s' % (self.name, self.requested_version) |
| 36 return self.name |
| 37 |
| 38 def version_ok(self, version): |
| 39 """Is 'version' sufficiently up-to-date?""" |
| 40 return self.attribute is None or self.format is None or \ |
| 41 str(version) != "unknown" and version >= self.requested_version |
| 42 |
| 43 def get_version(self, paths=None, default="unknown"): |
| 44 """Get version number of installed module, 'None', or 'default' |
| 45 |
| 46 Search 'paths' for module. If not found, return 'None'. If found, |
| 47 return the extracted version attribute, or 'default' if no version |
| 48 attribute was specified, or the value cannot be determined without |
| 49 importing the module. The version is formatted according to the |
| 50 requirement's version format (if any), unless it is 'None' or the |
| 51 supplied 'default'. |
| 52 """ |
| 53 |
| 54 if self.attribute is None: |
| 55 try: |
| 56 f, p, i = find_module(self.module, paths) |
| 57 if f: |
| 58 f.close() |
| 59 return default |
| 60 except ImportError: |
| 61 return None |
| 62 |
| 63 v = get_module_constant(self.module, self.attribute, default, paths) |
| 64 |
| 65 if v is not None and v is not default and self.format is not None: |
| 66 return self.format(v) |
| 67 |
| 68 return v |
| 69 |
| 70 def is_present(self, paths=None): |
| 71 """Return true if dependency is present on 'paths'""" |
| 72 return self.get_version(paths) is not None |
| 73 |
| 74 def is_current(self, paths=None): |
| 75 """Return true if dependency is present and up-to-date on 'paths'""" |
| 76 version = self.get_version(paths) |
| 77 if version is None: |
| 78 return False |
| 79 return self.version_ok(version) |
| 80 |
| 81 |
| 82 def find_module(module, paths=None): |
| 83 """Just like 'imp.find_module()', but with package support""" |
| 84 |
| 85 parts = module.split('.') |
| 86 |
| 87 while parts: |
| 88 part = parts.pop(0) |
| 89 f, path, (suffix, mode, kind) = info = imp.find_module(part, paths) |
| 90 |
| 91 if kind == PKG_DIRECTORY: |
| 92 parts = parts or ['__init__'] |
| 93 paths = [path] |
| 94 |
| 95 elif parts: |
| 96 raise ImportError("Can't find %r in %s" % (parts, module)) |
| 97 |
| 98 return info |
| 99 |
| 100 |
| 101 def get_module_constant(module, symbol, default=-1, paths=None): |
| 102 """Find 'module' by searching 'paths', and extract 'symbol' |
| 103 |
| 104 Return 'None' if 'module' does not exist on 'paths', or it does not define |
| 105 'symbol'. If the module defines 'symbol' as a constant, return the |
| 106 constant. Otherwise, return 'default'.""" |
| 107 |
| 108 try: |
| 109 f, path, (suffix, mode, kind) = find_module(module, paths) |
| 110 except ImportError: |
| 111 # Module doesn't exist |
| 112 return None |
| 113 |
| 114 try: |
| 115 if kind == PY_COMPILED: |
| 116 f.read(8) # skip magic & date |
| 117 code = marshal.load(f) |
| 118 elif kind == PY_FROZEN: |
| 119 code = imp.get_frozen_object(module) |
| 120 elif kind == PY_SOURCE: |
| 121 code = compile(f.read(), path, 'exec') |
| 122 else: |
| 123 # Not something we can parse; we'll have to import it. :( |
| 124 if module not in sys.modules: |
| 125 imp.load_module(module, f, path, (suffix, mode, kind)) |
| 126 return getattr(sys.modules[module], symbol, None) |
| 127 |
| 128 finally: |
| 129 if f: |
| 130 f.close() |
| 131 |
| 132 return extract_constant(code, symbol, default) |
| 133 |
| 134 |
| 135 def extract_constant(code, symbol, default=-1): |
| 136 """Extract the constant value of 'symbol' from 'code' |
| 137 |
| 138 If the name 'symbol' is bound to a constant value by the Python code |
| 139 object 'code', return that value. If 'symbol' is bound to an expression, |
| 140 return 'default'. Otherwise, return 'None'. |
| 141 |
| 142 Return value is based on the first assignment to 'symbol'. 'symbol' must |
| 143 be a global, or at least a non-"fast" local in the code block. That is, |
| 144 only 'STORE_NAME' and 'STORE_GLOBAL' opcodes are checked, and 'symbol' |
| 145 must be present in 'code.co_names'. |
| 146 """ |
| 147 if symbol not in code.co_names: |
| 148 # name's not there, can't possibly be an assignment |
| 149 return None |
| 150 |
| 151 name_idx = list(code.co_names).index(symbol) |
| 152 |
| 153 STORE_NAME = 90 |
| 154 STORE_GLOBAL = 97 |
| 155 LOAD_CONST = 100 |
| 156 |
| 157 const = default |
| 158 |
| 159 for byte_code in Bytecode(code): |
| 160 op = byte_code.opcode |
| 161 arg = byte_code.arg |
| 162 |
| 163 if op == LOAD_CONST: |
| 164 const = code.co_consts[arg] |
| 165 elif arg == name_idx and (op == STORE_NAME or op == STORE_GLOBAL): |
| 166 return const |
| 167 else: |
| 168 const = default |
| 169 |
| 170 |
| 171 def _update_globals(): |
| 172 """ |
| 173 Patch the globals to remove the objects not available on some platforms. |
| 174 |
| 175 XXX it'd be better to test assertions about bytecode instead. |
| 176 """ |
| 177 |
| 178 if not sys.platform.startswith('java') and sys.platform != 'cli': |
| 179 return |
| 180 incompatible = 'extract_constant', 'get_module_constant' |
| 181 for name in incompatible: |
| 182 del globals()[name] |
| 183 __all__.remove(name) |
| 184 |
| 185 |
| 186 _update_globals() |
OLD | NEW |