diff --git a/src/part1/constants.py b/src/part1/constants.py index 9abfbba2..22c27cee 100644 --- a/src/part1/constants.py +++ b/src/part1/constants.py @@ -19,20 +19,20 @@ # Все константы, зависящие от ёмкостей *_BITS, должны вычисляться из них. # Twitter's original Snowflake epoch: 2010-11-04 01:42:54.657 UTC. -EPOCH_MS_DEFAULT: Final[int] = 0 +EPOCH_MS_DEFAULT: Final[int] = 1288834974657 # Node identifier used when the caller does not supply one. -NODE_ID_DEFAULT: Final[int] = 0 +NODE_ID_DEFAULT: Final[int] = 1 # Width of each field, in bits. -TIMESTAMP_BITS: Final[int] = 0 -NODE_ID_BITS: Final[int] = 0 -SEQUENCE_ID_BITS: Final[int] = 0 +TIMESTAMP_BITS: Final[int] = 41 +NODE_ID_BITS: Final[int] = 10 +SEQUENCE_ID_BITS: Final[int] = 12 # Largest value each field can hold. -TIMESTAMP_MS_MAX: Final[int] = 0 -NODE_ID_MAX: Final[int] = 0 -SEQUENCE_ID_MAX: Final[int] = 0 +TIMESTAMP_MS_MAX: Final[int] = 2**41 - 1 +NODE_ID_MAX: Final[int] = 2**10 - 1 +SEQUENCE_ID_MAX: Final[int] = 2**12 - 1 # Здесь можно добавить собственные вспомогательные константы # (например, сдвиги полей при сборке идентификатора). diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index d3abf050..c137f122 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -13,12 +13,17 @@ :func:`decode_node_id` and :func:`decode_sequence_id`. """ -import time # noqa: F401 +import time -from .constants import ( # noqa: F401 +from .constants import ( + # Epoch EPOCH_MS_DEFAULT, + # Node ID + NODE_ID_BITS, NODE_ID_DEFAULT, NODE_ID_MAX, + # Sequence ID + SEQUENCE_ID_BITS, SEQUENCE_ID_MAX, TIMESTAMP_MS_MAX, ) @@ -35,7 +40,8 @@ def read_current_millis(epoch_ms: int) -> int: negative if ``epoch_ms`` lies in the future. """ # TODO: реализуйте функцию - return 0 + a = (time.time_ns() // 1000000) - epoch_ms + return a def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: @@ -51,7 +57,8 @@ def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> generated. """ # TODO: реализуйте функцию - return 0 + epoch_time = snowflake_id >> (SEQUENCE_ID_BITS + NODE_ID_BITS) + return epoch_time + epoch_ms def decode_node_id(snowflake_id: int) -> int: @@ -65,7 +72,8 @@ def decode_node_id(snowflake_id: int) -> int: ``[0, NODE_ID_MAX]``. """ # TODO: реализуйте функцию - return 0 + node_num = (snowflake_id >> SEQUENCE_ID_BITS) & NODE_ID_MAX + return node_num def decode_sequence_id(snowflake_id: int) -> int: @@ -79,7 +87,8 @@ def decode_sequence_id(snowflake_id: int) -> int: the range ``[0, SEQUENCE_ID_MAX]``. """ # TODO: реализуйте функцию - return 0 + seq_id = snowflake_id & SEQUENCE_ID_MAX + return seq_id def generate_snowflake_id( @@ -111,4 +120,15 @@ def generate_snowflake_id( cases an explanatory message is printed to stdout first. """ # TODO: реализуйте функцию - return 0 + if not (0 <= node_id <= NODE_ID_MAX): + print(f"node_id must be in [0, {NODE_ID_MAX}], got {node_id}") + return None + elif not (0 <= sequence_id <= SEQUENCE_ID_MAX): + print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], got {sequence_id}") + return None + a = (time.time_ns() // 1000000) - epoch_ms + if a > TIMESTAMP_MS_MAX: + print("overflows") + return None + else: + return (a << NODE_ID_BITS + SEQUENCE_ID_BITS) | (node_id << SEQUENCE_ID_BITS) | sequence_id