win32_opts.py 文件源码

def cached_hash_file(self):
        try:
            cache = self.ctx.cache_listdir_cache_hash_file
        except AttributeError:
            cache = self.ctx.cache_listdir_cache_hash_file = {}

        if id(self.parent) in cache:
            try:
                t = cache[id(self.parent)][self.name]
            except KeyError:
                raise IOError('Not a file')
        else:
            # an opportunity to list the files and the timestamps at once
            findData = ctypes.wintypes.WIN32_FIND_DATAW()
            find     = FindFirstFile(TP % self.parent.abspath(), ctypes.byref(findData))

            if find == INVALID_HANDLE_VALUE:
                cache[id(self.parent)] = {}
                raise IOError('Not a file')

            cache[id(self.parent)] = lst_files = {}
            try:
                while True:
                    if findData.cFileName not in UPPER_FOLDERS:
                        thatsadir = findData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY
                        if not thatsadir:
                            ts = findData.ftLastWriteTime
                            d = (ts.dwLowDateTime << 32) | ts.dwHighDateTime
                            lst_files[str(findData.cFileName)] = d
                    if not FindNextFile(find, ctypes.byref(findData)):
                        break
            except Exception as e:
                cache[id(self.parent)] = {}
                raise IOError('Not a file')
            finally:
                FindClose(find)
            t = lst_files[self.name]

        fname = self.abspath()
        if fname in Build.hashes_md5_tstamp:
            if Build.hashes_md5_tstamp[fname][0] == t:
                return Build.hashes_md5_tstamp[fname][1]

        try:
            fd = os.open(fname, os.O_BINARY | os.O_RDONLY | os.O_NOINHERIT)
        except OSError:
            raise IOError('Cannot read from %r' % fname)
        f = os.fdopen(fd, 'rb')
        m = Utils.md5()
        rb = 1
        try:
            while rb:
                rb = f.read(200000)
                m.update(rb)
        finally:
            f.close()

        # ensure that the cache is overwritten
        Build.hashes_md5_tstamp[fname] = (t, m.digest())
        return m.digest()