diff --git a/.gitignore b/.gitignore index 8ca254de..f035f5c9 100644 --- a/.gitignore +++ b/.gitignore @@ -11,3 +11,6 @@ __pycache__/ # Claude .claude + +# local repo dumps +repo_dump*.txt diff --git a/src/part1/constants.py b/src/part1/constants.py index 9abfbba2..1eb7dbde 100644 --- a/src/part1/constants.py +++ b/src/part1/constants.py @@ -19,20 +19,22 @@ # 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] = (1 << TIMESTAMP_BITS) - 1 +NODE_ID_MAX: Final[int] = (1 << NODE_ID_BITS) - 1 +SEQUENCE_ID_MAX: Final[int] = (1 << SEQUENCE_ID_BITS) - 1 # Здесь можно добавить собственные вспомогательные константы # (например, сдвиги полей при сборке идентификатора). +NODE_ID_SHIFT = SEQUENCE_ID_BITS +TIMESTAMP_SHIFT = NODE_ID_SHIFT + NODE_ID_BITS diff --git a/src/part1/snowflake.py b/src/part1/snowflake.py index d3abf050..6c261615 100644 --- a/src/part1/snowflake.py +++ b/src/part1/snowflake.py @@ -4,23 +4,25 @@ coordination between nodes. Each identifier packs the milliseconds elapsed since a custom epoch, a node identifier and a per-millisecond sequence counter into a single 63-bit positive integer (see ``constants`` for the layout). - +gfvhjn The public entry point is :func:`generate_snowflake_id`. It is stateless: the -caller passes the sequence counter on every call and is responsible for +caller passes the sequence counter on every call and is responsible forderftgvhj advancing it within a millisecond and resetting it when the clock ticks over. Each packed field can be read back on its own with :func:`decode_timestamp_ms`, :func:`decode_node_id` and :func:`decode_sequence_id`. """ -import time # noqa: F401 +import time -from .constants import ( # noqa: F401 +from .constants import ( EPOCH_MS_DEFAULT, NODE_ID_DEFAULT, NODE_ID_MAX, + NODE_ID_SHIFT, SEQUENCE_ID_MAX, TIMESTAMP_MS_MAX, + TIMESTAMP_SHIFT, ) @@ -35,7 +37,8 @@ def read_current_millis(epoch_ms: int) -> int: negative if ``epoch_ms`` lies in the future. """ # TODO: реализуйте функцию - return 0 + current_ms = int(time.time() * 1000) + return current_ms - epoch_ms def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: @@ -50,8 +53,8 @@ def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> The absolute Unix time in milliseconds at which the identifier was generated. """ - # TODO: реализуйте функцию - return 0 + timestamp = snowflake_id >> TIMESTAMP_SHIFT + return timestamp + epoch_ms def decode_node_id(snowflake_id: int) -> int: @@ -64,8 +67,7 @@ def decode_node_id(snowflake_id: int) -> int: The node identifier packed into ``snowflake_id``, in the range ``[0, NODE_ID_MAX]``. """ - # TODO: реализуйте функцию - return 0 + return (snowflake_id >> NODE_ID_SHIFT) & NODE_ID_MAX def decode_sequence_id(snowflake_id: int) -> int: @@ -78,8 +80,7 @@ def decode_sequence_id(snowflake_id: int) -> int: The per-millisecond sequence counter packed into ``snowflake_id``, in the range ``[0, SEQUENCE_ID_MAX]``. """ - # TODO: реализуйте функцию - return 0 + return snowflake_id & SEQUENCE_ID_MAX def generate_snowflake_id( @@ -110,5 +111,16 @@ def generate_snowflake_id( timestamp field (roughly 69 years after ``epoch_ms``). In each of those 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 + + if not (0 <= sequence_id <= SEQUENCE_ID_MAX): + print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], got {sequence_id}") + return None + + current_ms = read_current_millis(epoch_ms) + if current_ms > TIMESTAMP_MS_MAX: + print("timestamp overflows") + return None + return (current_ms << TIMESTAMP_SHIFT) | (node_id << NODE_ID_SHIFT) | sequence_id diff --git a/src/part2/cart.py b/src/part2/cart.py index 063f9aea..7344cff4 100644 --- a/src/part2/cart.py +++ b/src/part2/cart.py @@ -11,7 +11,7 @@ from typing import Final -from .crud import read_product, update_product # noqa: F401 +from .crud import read_product, update_product # noqa: F401 from .storage import ( # noqa: F401 NAME_INDEX, PRICE_INDEX, @@ -22,11 +22,16 @@ type CartLine = tuple[int, int] -# TODO: задайте позиции полей внутри кортежа CartLine LINE_PRODUCT_ID_INDEX: Final = 0 -LINE_QUANTITY_INDEX: Final = 0 +LINE_QUANTITY_INDEX: Final = 1 +def find_cart_line(cart: list[CartLine], product_id: int) -> int | None: + for cart_ in cart: + if cart_[LINE_PRODUCT_ID_INDEX] == product_id: + return cart.index(cart_) + return None + def add_to_cart( storage: list[Product], cart: list[CartLine], @@ -53,9 +58,26 @@ def add_to_cart( The cart line for ``product_id`` after the addition, or ``None`` when the product is unknown or the store cannot cover the request. """ - # TODO: реализуйте функцию - return (0, 0) - + product_person = read_product(storage, product_id) + if not product_person: + return None + storage_quantity = product_person[QUANTITY_INDEX] + if storage_quantity < quantity: + print(f"not enough stock for product {product_id} : {product_person[QUANTITY_INDEX]} available, {quantity} requested") + return None + + fields_ = (product_person[NAME_INDEX], product_person[PRICE_INDEX], product_person[QUANTITY_INDEX] - quantity) + update_product(storage, product_id, fields_) + + line_index = find_cart_line(cart, product_id) + if line_index is None: + cartLine = (product_id, quantity) + cart.append(cartLine) + return cartLine + old_quantity = cart[line_index][LINE_QUANTITY_INDEX] + cartLine = (product_id, old_quantity + quantity) + cart[line_index] = cartLine + return cartLine def remove_from_cart( storage: list[Product], @@ -85,5 +107,27 @@ def remove_from_cart( zero means the line was dropped), or ``None`` when the cart has no line for the product or holds too few units. """ - # TODO: реализуйте функцию - return (0, 0) + line_index = find_cart_line(cart, product_id) + if line_index is None: + print(f"product {product_id} is not in the cart") + return None + + cart_quantity = cart[line_index][LINE_QUANTITY_INDEX] + if cart_quantity < quantity: + print(f"cart holds only {cart_quantity} unit(s) of product") + print(f"{product_id}, cannot remove {quantity}") + return None + + product_person = read_product(storage, product_id) + if not product_person: + return None + + fields_ = (product_person[NAME_INDEX],product_person[PRICE_INDEX],product_person[QUANTITY_INDEX] + quantity) + update_product(storage, product_id, fields_) + + new_cart_quantity = cart_quantity - quantity + if new_cart_quantity == 0: + del cart[line_index] + else: + cart[line_index] = (product_id, new_cart_quantity) + return (product_id, new_cart_quantity) \ No newline at end of file diff --git a/src/part2/crud.py b/src/part2/crud.py index d026cbcb..1430fa05 100644 --- a/src/part2/crud.py +++ b/src/part2/crud.py @@ -34,9 +34,9 @@ def generate_product_id(storage: list[Product]) -> int: :data:`~src.part2.storage.PRODUCT_ID_MIN` when ``storage`` is empty. """ - # TODO: реализуйте функцию - return 0 - + if not storage: + return PRODUCT_ID_MIN + return max(product[PRODUCT_ID_INDEX] for product in storage) + 1 def create_product( storage: list[Product], fields: tuple[str, Decimal, int] @@ -56,8 +56,16 @@ def create_product( ``storage`` is left unchanged and a message naming the clashing name is printed. """ - # TODO: реализуйте функцию - return 0 + name, price, quantity = fields + for product in storage: + if product[NAME_INDEX] == name: + print(f"product name{name} is already taken.") + return None + product_id = generate_product_id(storage) + product_price = normalize_price(price) + new_product = (product_id, name, product_price, quantity) + storage.append(new_product) + return product_id def read_product(storage: list[Product], product_id: int) -> Product | None: @@ -72,8 +80,12 @@ def read_product(storage: list[Product], product_id: int) -> Product | None: ``None`` when no product carries that identifier (a message is printed in that case). """ - # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + for product in storage: + if product[PRODUCT_ID_INDEX] == product_id: + return product + + print (f"no product with id {product_id}") + return None def update_product( @@ -99,8 +111,16 @@ def update_product( ``None`` when no product carries that identifier (``storage`` is left unchanged and a message is printed). """ - # TODO: реализуйте функцию - return (0, "", Decimal(0), 0) + name, price, quantity = fields + + for product in storage: + if product[PRODUCT_ID_INDEX] == product_id: + new_product = (product_id, name, normalize_price(price), quantity) + storage[storage.index(product)] = new_product + return new_product + + print (f"no product with id {product_id}") + return None def delete_product(storage: list[Product], product_id: int) -> int | None: @@ -116,5 +136,10 @@ def delete_product(storage: list[Product], product_id: int) -> int | None: product carried that identifier (``storage`` is left unchanged and a message is printed). """ - # TODO: реализуйте функцию - return 0 + for product_index in storage: + if product_index[PRODUCT_ID_INDEX] == product_id: + storage.remove(product_index) + return product_id + + print (f"no product with id {product_id}") + return None \ No newline at end of file diff --git a/src/part2/storage.py b/src/part2/storage.py index b63d5fc7..e4bceff1 100644 --- a/src/part2/storage.py +++ b/src/part2/storage.py @@ -24,11 +24,9 @@ type Product = tuple[int, str, Decimal, int] -# TODO: задайте позиции полей внутри кортежа Product PRODUCT_ID_INDEX: Final = 0 -NAME_INDEX: Final = 0 -PRICE_INDEX: Final = 0 -QUANTITY_INDEX: Final = 0 +NAME_INDEX: Final = 1 +PRICE_INDEX: Final = 2 +QUANTITY_INDEX: Final = 3 -# TODO: задайте идентификатор первого товара в пустом хранилище -PRODUCT_ID_MIN: Final[int] = 0 +PRODUCT_ID_MIN: Final[int] = 1 diff --git a/src/part2/utils.py b/src/part2/utils.py index ec0348d3..5e51a050 100644 --- a/src/part2/utils.py +++ b/src/part2/utils.py @@ -11,8 +11,8 @@ # TODO: задайте число знаков после запятой и шаг квантования -PRICE_PRECISION: Final[int] = 0 -PRICE_STEP: Final = Decimal(0) +PRICE_PRECISION: Final[int] = 2 +PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION) def normalize_price(price: Decimal) -> Decimal: @@ -26,4 +26,5 @@ def normalize_price(price: Decimal) -> Decimal: with halves rounded up. """ # TODO: реализуйте функцию - return Decimal(0) + # + return price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP)