cache.py 文件源码

 复制代码def init_cache(self, d, cache_file_name=None):
        cachedir = (d.getVar("PERSISTENT_DIR", True) or
                    d.getVar("CACHE", True))
        if cachedir in [None, '']:
            return
        bb.utils.mkdirhier(cachedir)
        self.cachefile = os.path.join(cachedir,
                                      cache_file_name or self.__class__.cache_file_name)
        logger.debug(1, "Using cache in '%s'", self.cachefile)

        glf = bb.utils.lockfile(self.cachefile + ".lock")

        try:
            with open(self.cachefile, "rb") as f:
                p = pickle.Unpickler(f)
                data, version = p.load()
        except:
            bb.utils.unlockfile(glf)
            return

        bb.utils.unlockfile(glf)

        if version != self.__class__.CACHE_VERSION:
            return

        self.cachedata = data