input.py 文件源码

def __generatePackages(self, nameFormatter, env, cacheKey, sandboxEnabled):
        # use separate caches with and without sandbox
        if sandboxEnabled:
            cacheName = ".bob-packages-sb.pickle"
        else:
            cacheName = ".bob-packages.pickle"

        # try to load the persisted packages
        states = { n:s() for (n,s) in self.__states.items() }
        rootPkg = Package()
        rootPkg.construct("<root>", [], nameFormatter, None, [], [], states,
            {}, {}, None, None, [], {}, -1)
        try:
            with open(cacheName, "rb") as f:
                persistedCacheKey = f.read(len(cacheKey))
                if cacheKey == persistedCacheKey:
                    tmp = PackageUnpickler(f, self.getRecipe, self.__plugins,
                                           nameFormatter).load()
                    return tmp.toStep(nameFormatter, rootPkg).getPackage()
        except (EOFError, OSError, pickle.UnpicklingError):
            pass

        # not cached -> calculate packages
        result = self.__rootRecipe.prepare(nameFormatter, env, sandboxEnabled,
                                           states)[0]

        # save package tree for next invocation
        tmp = CoreStepRef(rootPkg, result.getPackageStep())
        try:
            newCacheName = cacheName + ".new"
            with open(newCacheName, "wb") as f:
                f.write(cacheKey)
                PackagePickler(f, nameFormatter).dump(tmp)
            os.replace(newCacheName, cacheName)
        except OSError as e:
            print("Error saving internal state:", str(e), file=sys.stderr)

        return result