From 3f36255f98eff2dd1c4c2e9637544d59a61e8d56 Mon Sep 17 00:00:00 2001 From: Egor Vasilev Date: Tue, 10 Nov 2026 19:20:23 +0300 Subject: [PATCH 1/3] hm5 --- src/part5/cart.py | 88 +++++--------- src/part5/constants.py | 21 ++-- src/part5/crud.py | 250 +++++++++++++++------------------------- src/part5/decorators.py | 64 ++++------ src/part5/run_admin.py | 188 +++++++++++++++--------------- src/part5/snowflake.py | 98 +++++++++------- src/part5/storage.py | 6 +- src/part5/utils.py | 193 ++++++++++++++++--------------- 8 files changed, 409 insertions(+), 499 deletions(-) diff --git a/src/part5/cart.py b/src/part5/cart.py index a2363b3a..2880308d 100644 --- a/src/part5/cart.py +++ b/src/part5/cart.py @@ -9,7 +9,7 @@ an explanatory message to stdout and returns ``None``. """ -from .storage import Product +from .storage import QUANTITY_KEY, Product # TODO: при необходимости добавьте свои вспомогательные функции @@ -22,33 +22,19 @@ def add_to_cart( product_id: int, quantity: int, ) -> int | None: - """Move ``quantity`` units of ``product_id`` from the store into ``cart``. - - The product is looked up in ``storage``. If it is missing, a message is - printed (by :func:`~src.part5.crud.read_product`) and nothing - changes. If the store holds fewer units than requested, an explanatory - message is printed and nothing changes. Otherwise the store record is - decremented by ``quantity`` and the cart gains ``quantity`` units of - ``product_id`` -- the product is added when the cart had none of it. - - Args: - storage: The product store to draw stock from; modified in place on - success. - product_names: The normalised names in ``storage``; threaded - through to :func:`~src.part5.crud.update_product`, which - keeps it in sync (a quantity-only update never renames a - product, so it is left unchanged here). - cart: The cart to add the units to; modified in place on success. - product_id: The identifier of the product to add. - quantity: Number of units to move into the cart. - - Returns: - The quantity of ``product_id`` in the cart after the addition, or - ``None`` when the product is unknown or the store cannot cover the - request. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return 0 + if product_id not in storage: + print(f"no product with id {product_id}") + return None + if storage[product_id][QUANTITY_KEY] < quantity: + print( + f"not enough stock for product {product_id}: " + f"{storage[product_id][QUANTITY_KEY]} available, " + f"{quantity} requested" + ) + return None + storage[product_id][QUANTITY_KEY] -= quantity + cart[product_id] = cart.get(product_id, 0) + quantity + return cart[product_id] def remove_from_cart( @@ -58,31 +44,21 @@ def remove_from_cart( product_id: int, quantity: int, ) -> int | None: - """Move ``quantity`` units of ``product_id`` from ``cart`` back to the store. - - If the cart holds no units of ``product_id``, a message is printed and - nothing changes. If it holds fewer units than requested, an explanatory - message is printed and nothing changes. Otherwise the cart loses - ``quantity`` units of the product -- the product is dropped from the - cart when its quantity reaches zero -- and the store record gains - ``quantity`` units back. - - Args: - storage: The product store to return stock to; modified in place on - success. - product_names: The normalised names in ``storage``; threaded - through to :func:`~src.part5.crud.update_product`, which - keeps it in sync (a quantity-only update never renames a - product, so it is left unchanged here). - cart: The cart to take the units from; modified in place on - success. - product_id: The identifier of the product to remove. - quantity: Number of units to move back into the store. - - Returns: - The quantity of ``product_id`` left in the cart after the removal - (zero means the product was dropped from the cart), or ``None`` when - the cart does not hold the product or holds too few units. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return 0 + if product_id not in cart: + print(f"product {product_id} is not in the cart") + return None + if cart[product_id] < quantity: + print( + f"cart holds only {cart[product_id]} unit(s) " + f"of product {product_id}, cannot remove {quantity}" + ) + return None + if product_id not in storage: + print(f"no product with id {product_id}") + return None + storage[product_id][QUANTITY_KEY] += quantity + cart[product_id] -= quantity + if not cart[product_id]: + del cart[product_id] + return 0 + return cart[product_id] diff --git a/src/part5/constants.py b/src/part5/constants.py index 984671bb..7a112a77 100644 --- a/src/part5/constants.py +++ b/src/part5/constants.py @@ -15,23 +15,24 @@ from typing import Final -# TODO: замените заглушки (0) на корректные значения (используйте своё решение -# части 1). +# TODO: замените заглушки (0) на корректные значения, см. TASK.md. +# 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**TIMESTAMP_BITS - 1 +NODE_ID_MAX: Final[int] = 2**NODE_ID_BITS - 1 +SEQUENCE_ID_MAX: Final[int] = 2**SEQUENCE_ID_BITS - 1 # Здесь можно добавить собственные вспомогательные константы +# (например, сдвиги полей при сборке идентификатора). diff --git a/src/part5/crud.py b/src/part5/crud.py index 243b0528..db3f903d 100644 --- a/src/part5/crud.py +++ b/src/part5/crud.py @@ -1,191 +1,127 @@ -"""Create/read/update/delete operations over the in-memory product store. - -Every operation takes the store -- a dictionary mapping product id to its -:data:`~src.part5.storage.Product` record -- as its first argument and -works on it in place. ``create_product``, ``update_product`` and -``delete_product`` additionally take ``product_names``, the ``set[str]`` -of normalised names currently in ``storage`` (see -:mod:`src.part5.storage`), and keep it in sync with ``storage`` on -every successful call. The failure path never raises: the operation -prints an explanatory message to stdout and returns ``None``. - -The identifier of a new product is not chosen by :func:`create_product` -itself: the caller hands in a zero-argument ``generate_id`` function that -returns the next identifier (or ``None`` when it cannot issue one), so the -identifier scheme can be swapped without touching the CRUD code. The module -supplies :func:`generate_snowflake_id`, backed by a Twitter Snowflake -generator (see :mod:`src.part5.snowflake`); the identifiers it issues -grow with creation time, so they are roughly ordered by insertion. - -Every product name that reaches the store is passed through -:func:`~src.part5.utils.normalize_product_name` first. A name that -normalises to an empty string is rejected -- the operation prints a -message and changes nothing. Names are also kept unique -- -:func:`create_product` refuses a normalised name that is already taken, -and :func:`update_product` refuses one that is already taken by another -product -- via an O(1) membership test against ``product_names`` rather -than a scan over ``storage.values()``. - -The four store operations (everything except :func:`generate_snowflake_id`) -should be decorated with :func:`~src.part5.decorators.collect_stats`, which -counts their successful calls and their failed ones (those returning -``None``) in the module-level :data:`STATS_REGISTRY`, filed under -:data:`CREATE_KEY`, :data:`READ_KEY`, :data:`UPDATE_KEY` and -:data:`DELETE_KEY`. The counters live for the lifetime of the process and -are shared by every store. -""" - from collections.abc import Callable from typing import Any, Final -from .decorators import Registry -from .storage import Product +from .decorators import Registry, collect_stats +from .snowflake import get_snowflake_id_generator +from .storage import ( + NAME_KEY, + PRICE_KEY, + QUANTITY_KEY, + Product, +) +from .utils import normalize_price, normalize_product_name STATS_REGISTRY: Final[Registry] = {} -# TODO: задайте ключи операций в реестре, см. TASK.md -CREATE_KEY: Final[str] = "" -READ_KEY: Final[str] = "" -UPDATE_KEY: Final[str] = "" -DELETE_KEY: Final[str] = "" - -# TODO: при необходимости заведите здесь общий генератор Snowflake-идентификаторов -# для generate_snowflake_id (см. TASK.md) +CREATE_KEY: Final[str] = "create" +READ_KEY: Final[str] = "read" +UPDATE_KEY: Final[str] = "update" +DELETE_KEY: Final[str] = "delete" -def generate_snowflake_id() -> int | None: - """Issue the next product identifier from the shared Snowflake generator. +generator = get_snowflake_id_generator() - This is the identifier source callers pass to :func:`create_product`. - Returns: - A positive 63-bit Snowflake integer, or ``None`` (after a message - has been printed) when no identifier can be issued right now -- see - :func:`~src.part5.snowflake.get_snowflake_id_generator` for the - cases. - """ - # TODO: реализуйте функцию - return 0 +def generate_snowflake_id() -> int | None: + if generator is None: + return None + return generator() -# TODO: оберните операцию декоратором collect_stats +@collect_stats(CREATE_KEY, STATS_REGISTRY) def create_product( storage: dict[int, Product], product_names: set[str], fields: dict[str, Any], generate_id: Callable[[], int | None], ) -> int | None: - """Add a new product to ``storage`` and return its new identifier. - - Args: - storage: The product store to add to; modified in place on - success. - product_names: The normalised names already in ``storage``; the - new name is added to it in place on success. - fields: A dictionary with the ``name``, ``price`` and ``quantity`` - keys (see :data:`~src.part5.storage.NAME_KEY`, - :data:`~src.part5.storage.PRICE_KEY` and - :data:`~src.part5.storage.QUANTITY_KEY`) describing the - product. ``name`` is normalised (surrounding whitespace - stripped, lower-cased) before it is stored or compared. - ``price`` is a :class:`~decimal.Decimal` amount and is rounded - to the stored money precision before it is saved. - generate_id: A zero-argument function returning the identifier for - the new product, or ``None`` if it cannot issue one (for - example :func:`generate_snowflake_id`). It is only expected to - return an identifier that is not yet a key of ``storage``. - - Returns: - The identifier returned by ``generate_id`` for the new product, or - ``None`` when ``name`` is blank once normalised, a product with - the same normalised name already exists, or ``generate_id`` - returned ``None``. In the ``None`` case ``storage`` and - ``product_names`` are left unchanged and an explanatory message is - printed (for the last case, by ``generate_id`` itself). - """ - # TODO: реализуйте функцию - return 0 - - -# TODO: оберните операцию декоратором collect_stats -def read_product(storage: dict[int, Product], product_id: int) -> Product | None: - """Return the product stored under ``product_id``. + name_product = normalize_product_name(fields[NAME_KEY]) + + if not name_product: + print("product name must not be blank") + return None - Args: - storage: The product store to search. - product_id: The identifier to look up. + if name_product in product_names: + print(f"product name '{name_product}' is already taken") + return None - Returns: - The matching product record, or ``None`` when no product carries - that identifier (a message is printed in that case). - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return {} + new_id = generate_id() + + if new_id is None: + return None + + price_product = normalize_price(fields[PRICE_KEY]) + quantity_product = fields[QUANTITY_KEY] + + product_names.add(name_product) + storage[new_id] = { + NAME_KEY: name_product, + PRICE_KEY: price_product, + QUANTITY_KEY: quantity_product, + } + return new_id + + +@collect_stats(READ_KEY, STATS_REGISTRY) +def read_product(storage: dict[int, Product], product_id: int) -> Product | None: + reading = storage.get(product_id) + if reading is None: + print(f"no product with id {product_id}") + return reading -# TODO: оберните операцию декоратором collect_stats +@collect_stats(UPDATE_KEY, STATS_REGISTRY) def update_product( storage: dict[int, Product], product_names: set[str], product_id: int, fields: dict[str, Any], ) -> Product | None: - """Overwrite the fields of the product stored under ``product_id``. - - The identifier itself is preserved. ``fields`` may carry any subset of - ``name``, ``price`` and ``quantity``; a key that is missing keeps the - value the product already has, so a caller can update a single field - without repeating the other two. - - Args: - storage: The product store to modify; the matching record is - updated in place on success. - product_names: The normalised names already in ``storage``; on a - successful rename the old name is removed from it and the new - one added. - product_id: The identifier of the product to change. - fields: A dictionary with any of the ``name``, ``price`` and - ``quantity`` keys (see :data:`~src.part5.storage.NAME_KEY`, - :data:`~src.part5.storage.PRICE_KEY` and - :data:`~src.part5.storage.QUANTITY_KEY`) holding the new - values. ``price`` is a :class:`~decimal.Decimal` amount and is - rounded to the stored money precision before it is saved. - Mutated in place: a ``name`` or ``price`` value present in - ``fields`` is overwritten with its normalised form. - - Returns: - The updated product record, or ``None`` when ``name`` is present - and blank once normalised, no product carries that identifier, or - the normalised name is already taken by another product. In every - ``None`` case ``storage`` and ``product_names`` are left unchanged - and an explanatory message is printed. Renaming a product to its - own current name is allowed. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return {} - - -# TODO: оберните операцию декоратором collect_stats + if product_id not in storage: + print(f"no product with id {product_id}") + return None + + if fields.get(NAME_KEY) is not None: + fields[NAME_KEY] = normalize_product_name(fields[NAME_KEY]) + + if not fields[NAME_KEY]: + print("product name must not be blank") + return None + + if (fields[NAME_KEY] != storage[product_id][NAME_KEY]) and ( + fields[NAME_KEY] in product_names + ): + print(f"product name '{fields[NAME_KEY]}' is already taken") + return None + + if fields.get(PRICE_KEY) is not None: + fields[PRICE_KEY] = normalize_price(fields[PRICE_KEY]) + + if fields.get(NAME_KEY) is not None: + product_names.discard(storage[product_id][NAME_KEY]) + product_names.add(fields[NAME_KEY]) + storage[product_id][NAME_KEY] = fields[NAME_KEY] + + if fields.get(PRICE_KEY) is not None: + storage[product_id][PRICE_KEY] = fields[PRICE_KEY] + + if fields.get(QUANTITY_KEY) is not None: + storage[product_id][QUANTITY_KEY] = fields[QUANTITY_KEY] + + return storage[product_id] + + +@collect_stats(DELETE_KEY, STATS_REGISTRY) def delete_product( storage: dict[int, Product], product_names: set[str], product_id: int, ) -> int | None: - """Remove the product stored under ``product_id`` from ``storage``. - - Args: - storage: The product store to remove from; modified in place on - success. - product_names: The normalised names already in ``storage``; the - departing product's name is removed from it in place on - success. - product_id: The identifier of the product to remove. - - Returns: - ``product_id`` when a product was removed, or ``None`` when no - product carried that identifier (``storage`` and ``product_names`` - are left unchanged and a message is printed). - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return 0 + if product_id not in storage: + print(f"no product with id {product_id}") + return None + + product_names.discard(storage[product_id][NAME_KEY]) + del storage[product_id] + return product_id diff --git a/src/part5/decorators.py b/src/part5/decorators.py index 21a9f237..c42b942c 100644 --- a/src/part5/decorators.py +++ b/src/part5/decorators.py @@ -1,25 +1,11 @@ -"""Decorators that add bookkeeping around the part5 CRUD operations. - -The module provides :func:`collect_stats`, a parametric decorator that counts -how often a function succeeds and how often it fails. The counters are kept in -a *registry* shared with the caller -- a plain dictionary mapping a string key -to a :data:`Stats` record -- so that other code (for example the ``stats`` -command of :mod:`src.part5.run_admin`) can read them without knowing -anything about the decorated functions. - -A call counts as a failure when the decorated function returns ``None`` -- the -convention every operation in :mod:`src.part5.crud` uses to report that it -printed an explanation and changed nothing. Any other return value, including -a falsy one such as ``0``, counts as a success. -""" - from collections.abc import Callable +from functools import wraps from typing import Final # TODO: задайте имена двух счётчиков, см. TASK.md -SUCCESS_KEY: Final[str] = "" -FAILS_KEY: Final[str] = "" +SUCCESS_KEY: Final[str] = "success" +FAILS_KEY: Final[str] = "fails" type Stats = dict[str, int] @@ -29,29 +15,21 @@ def collect_stats[**P, R]( key: str, registry: Registry ) -> Callable[[Callable[P, R | None]], Callable[P, R | None]]: - """Build a decorator that counts successful and failed calls of a function. - - Decorating registers a fresh record ``{"success": 0, "fails": 0}`` in - ``registry`` under ``key``. Every call of the decorated function then - updates that record in place: a call that returns ``None`` adds one to the - failure counter, any other result adds one to the success counter. The - result is passed through unchanged, and a call that raises an exception - is not counted at all. - - If ``key`` is already in ``registry``, a message is printed, the existing - record is left untouched and the function is returned undecorated, so its - calls never mix into the counters of whoever registered the key first. - - Args: - key: The registry key to keep this function's counters under, for - example the name of the console command it implements. - registry: The dictionary that receives the counters; modified in - place when the function is decorated and on every later call. - - Returns: - A decorator for a function whose result is either some value or - ``None``. The decorated function has the same signature, name and - docstring as the original (see :func:`functools.wraps`). - """ - # TODO: реализуйте декоратор - return lambda function: function + def decorator(func: Callable[P, R | None]) -> Callable[P, R | None]: + if registry.get(key) is not None: + print(f"stats key {key!r} is already registered") + return func + registry[key] = {SUCCESS_KEY: 0, FAILS_KEY: 0} + + @wraps(func) + def wrapper(*args: P.args, **kwargs: P.kwargs) -> R | None: + result = func(*args, **kwargs) + if result is None: + registry[key][FAILS_KEY] += 1 + else: + registry[key][SUCCESS_KEY] += 1 + return result + + return wrapper + + return decorator diff --git a/src/part5/run_admin.py b/src/part5/run_admin.py index d2e83947..b06c8c37 100644 --- a/src/part5/run_admin.py +++ b/src/part5/run_admin.py @@ -1,112 +1,114 @@ -"""Interactive admin console for the part5 in-memory product store. - -Running this module starts a read-eval-print loop over a single product -store that lives in memory for the lifetime of the process. Every line -typed at the prompt is stripped of surrounding whitespace and matched, -with a ``match`` statement, against the set of known commands: - -* ``help`` -- print the list of commands and what each one does; -* ``exit`` -- leave the loop and end the program; -* ``show`` -- print the whole store as a text table; -* ``create `` -- add a product; -* ``read `` -- print one product; -* ``update `` -- overwrite a product; -* ``delete `` -- remove a product; -* ``stats`` -- print how many times each CRUD command succeeded and failed, - with its success rate, as a text table. - -For ``create`` and ``update`` the price and quantity are always the last -two words of the line; everything between the verb (and, for ``update``, -the id) and those two words is joined with single spaces into the -product name, so a multi-word name such as ``Gibson SG Junior`` needs no -quoting. - -The four CRUD commands forward to :mod:`src.part5.crud`; whatever -that call returns is printed unless it is ``None``. ``create`` hands -:func:`~src.part5.crud.generate_snowflake_id` to the CRUD layer as the -source of the new product's identifier; the ```` typed for ``read``, -``update`` and ``delete`` is converted to an integer before it is looked -up. The counters behind ``stats`` are collected by the CRUD layer itself -(:data:`~src.part5.crud.STATS_REGISTRY`); a command whose arguments do -not parse never reaches it and is not counted. A line whose first -word is not a known verb, or that carries the wrong number of arguments -for its verb, prints an "is not a command" notice. A line that names a -command correctly but whose id, price or quantity argument will not parse -prints a distinct "arguments are invalid" notice. Either way the store -is left untouched and the loop keeps running; only ``exit`` stops it. -""" - -from decimal import InvalidOperation +from decimal import Decimal, InvalidOperation from typing import Final -from .storage import Product - - -# TODO: задайте приглашение и текст справки (используйте своё решение части 4, -# не забудьте добавить команду stats, см. TASK.md) -PROMPT: Final[str] = "" -HELP_TEXT: Final[str] = "" +from .crud import ( + STATS_REGISTRY, + create_product, + delete_product, + generate_snowflake_id, + read_product, + update_product, +) +from .storage import NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product +from .utils import get_stats_str_representation, get_storage_str_representation + + +PROMPT: Final[str] = "admin> " +HELP_TEXT: Final[str] = """Available commands: + help show this message + exit leave the console + show print the whole store as a table + create add a product, print its new id + read print the product with that id + update overwrite that product's fields + delete remove the product with that id + stats print call statistics of the CRUD commands + +For create and update the price and quantity are the last two words of the +line; everything before them is the product name, so it may contain spaces +(for example "Gibson SG Junior") and needs no quoting.""" def show_help() -> None: - """Print the command reference to stdout. - - The text is the module-level :data:`HELP_TEXT` constant, printed as - is: a heading, one line per command with a short description, and a - note on how multi-word names are parsed. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) + print(HELP_TEXT) def print_result(result: object) -> None: - """Print a CRUD result to stdout unless it is ``None``. - - Args: - result: The value returned by a CRUD operation. ``None`` means the - operation already reported its own failure, so nothing is - printed in that case. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) + if result is not None: + print(result) def run_command( storage: dict[int, Product], product_names: set[str], line: str ) -> bool: - """Parse one console line and carry out the command it names. - - Args: - storage: The product store shared across the session; mutated in - place by the ``create``, ``update`` and ``delete`` commands. - product_names: The normalised names already in ``storage``; kept - in sync by the ``create``, ``update`` and ``delete`` commands. - line: One line of console input, already stripped of surrounding - whitespace. - - Returns: - ``True`` to keep the read-eval-print loop running, or ``False`` - once the ``exit`` command has been seen. A line that is not a - known command prints a notice and still returns ``True``. - - Raises: - ValueError: If the id or quantity argument of a CRUD command does - not parse as a base-10 integer. - decimal.InvalidOperation: If the price argument of ``create`` or - ``update`` does not parse as a decimal number. - """ - # TODO: реализуйте функцию - return False + parts = line.split() + + match parts: + case ["exit"]: + return False + + case ["help"]: + show_help() + return True + + case ["show"]: + print(get_storage_str_representation(storage)) + return True + + case ["stats"]: + print(get_stats_str_representation(STATS_REGISTRY)) + return True + + case ["create", *name_parts, price_str, quantity_str] if name_parts: + name = " ".join(name_parts) + price = Decimal(price_str) + quantity = int(quantity_str) + + print_result( + create_product( + storage, + product_names, + {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity}, + generate_snowflake_id, + ) + ) + return True + + case ["read", product_id]: + print_result(read_product(storage, int(product_id))) + return True + + case [ + "update", + product_id, + *name_parts, + price_str, + quantity_str, + ] if name_parts: + name = " ".join(name_parts) + price = Decimal(price_str) + quantity = int(quantity_str) + + print_result( + update_product( + storage, + product_names, + int(product_id), + {NAME_KEY: name, PRICE_KEY: price, QUANTITY_KEY: quantity}, + ) + ) + return True + + case ["delete", product_id]: + print_result(delete_product(storage, product_names, int(product_id))) + return True + + case _: + print(f"'{line}' is not a command") + return True def main() -> None: - """Run the admin console until the ``exit`` command is entered. - - A single product store, and the set of normalised names it holds, are - created empty and kept in memory for the whole session. Each iteration - reads one line from stdin, strips its surrounding whitespace and hands - it to :func:`run_command`. A line that names a command but whose price - or quantity argument does not parse is caught here and reported - without stopping the loop; only ``exit`` ends it. - """ storage: dict[int, Product] = {} product_names: set[str] = set() running = True diff --git a/src/part5/snowflake.py b/src/part5/snowflake.py index 64e28468..3df0bde4 100644 --- a/src/part5/snowflake.py +++ b/src/part5/snowflake.py @@ -14,9 +14,18 @@ :func:`decode_node_id` and :func:`decode_sequence_id`. """ +import time from collections.abc import Callable -from .constants import EPOCH_MS_DEFAULT, NODE_ID_DEFAULT +from .constants import ( + EPOCH_MS_DEFAULT, + NODE_ID_BITS, + NODE_ID_DEFAULT, + NODE_ID_MAX, + SEQUENCE_ID_BITS, + SEQUENCE_ID_MAX, + TIMESTAMP_MS_MAX, +) def read_current_millis(epoch_ms: int) -> int: @@ -26,11 +35,12 @@ def read_current_millis(epoch_ms: int) -> int: epoch_ms: The custom epoch expressed as Unix milliseconds. Returns: - The count of whole milliseconds between ``epoch_ms`` and now. Negative - if ``epoch_ms`` lies in the future. + The count of whole milliseconds between ``epoch_ms`` and now. May be + negative if ``epoch_ms`` lies in the future. """ - # TODO: реализуйте функцию (используйте своё решение части 1) - return 0 + # TODO: реализуйте функцию + now_ms = int(time.time() * 1000) + return now_ms - epoch_ms def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int: @@ -45,68 +55,72 @@ 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 (используйте своё решение части 1) - return 0 + snowflake_id_time = snowflake_id >> (NODE_ID_BITS + SEQUENCE_ID_BITS) + return snowflake_id_time + epoch_ms def decode_node_id(snowflake_id: int) -> int: """Read the node identifier field out of a Snowflake identifier. Args: - snowflake_id: An identifier produced by a generator from - :func:`get_snowflake_id_generator`. + snowflake_id: An identifier produced by :func:`generate_snowflake_id`. Returns: The node identifier packed into ``snowflake_id``, in the range ``[0, NODE_ID_MAX]``. """ - # TODO: реализуйте функцию (используйте своё решение части 1) - return 0 + # TODO: реализуйте функцию + snowflake_id_knot = snowflake_id >> SEQUENCE_ID_BITS + snowflake_id_knot = snowflake_id_knot & NODE_ID_MAX + return snowflake_id_knot def decode_sequence_id(snowflake_id: int) -> int: """Read the sequence counter field out of a Snowflake identifier. Args: - snowflake_id: An identifier produced by a generator from - :func:`get_snowflake_id_generator`. + snowflake_id: An identifier produced by :func:`generate_snowflake_id`. Returns: The per-millisecond sequence counter packed into ``snowflake_id``, in the range ``[0, SEQUENCE_ID_MAX]``. """ - # TODO: реализуйте функцию (используйте своё решение части 1) - return 0 + # TODO: реализуйте функцию + return snowflake_id & SEQUENCE_ID_MAX def get_snowflake_id_generator( node_id: int = NODE_ID_DEFAULT, epoch_ms: int = EPOCH_MS_DEFAULT, ) -> Callable[[], int | None] | None: - """Create a stateful Snowflake identifier generator bound to one node. - - The returned closure remembers the millisecond of its previous call and the - per-millisecond sequence counter, so callers never pass them in. - - Args: - node_id: The identifier of this node, in the range ``[0, NODE_ID_MAX]``. - Optional; defaults to ``NODE_ID_DEFAULT``. - epoch_ms: The start of the epoch as Unix milliseconds. Optional; - defaults to the original Twitter epoch (2010-11-04 01:42:54.657 - UTC). - - Returns: - A zero-argument function ``generate_snowflake_id``. Each call returns a - positive 63-bit integer identifier. It returns ``None`` (after printing - an explanatory message to stdout) if more than ``SEQUENCE_ID_MAX + 1`` - identifiers are requested within one millisecond, or if the elapsed - time no longer fits in the timestamp field (roughly 69 years after - ``epoch_ms``). A failed call does not break the generator: it recovers - once the clock moves on to the next millisecond. - - ``None`` is returned instead of a generator, after printing a message - to stdout, if ``node_id`` is outside ``[0, NODE_ID_MAX]`` or - ``epoch_ms`` lies in the future. - """ - # TODO: реализуйте функцию - return lambda: 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 read_current_millis(epoch_ms) < 0: + print(f"epoch_ms must not be in the future, got {epoch_ms}") + return None + last_time = read_current_millis(epoch_ms) + sequence_id = -1 + + def get_snowflake_id() -> int | None: + nonlocal last_time, sequence_id + now_time = read_current_millis(epoch_ms) + if last_time != now_time: + last_time = now_time + sequence_id = 0 + else: + sequence_id += 1 + if sequence_id > SEQUENCE_ID_MAX: + print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], got {sequence_id}") + return None + if now_time > TIMESTAMP_MS_MAX: + print(f"timestamp {now_time} ms overflows {TIMESTAMP_MS_MAX} ms") + return None + snowflake_id = ( + (now_time << (NODE_ID_BITS + SEQUENCE_ID_BITS)) + | (node_id << SEQUENCE_ID_BITS) + | sequence_id + ) + return snowflake_id + + return get_snowflake_id diff --git a/src/part5/storage.py b/src/part5/storage.py index fa8ef3bb..87968a07 100644 --- a/src/part5/storage.py +++ b/src/part5/storage.py @@ -39,6 +39,6 @@ type Product = dict[str, Any] # TODO: задайте имена полей записи (используйте своё решение части 4) -NAME_KEY: Final = "" -PRICE_KEY: Final = "" -QUANTITY_KEY: Final = "" +NAME_KEY: Final = "name" +PRICE_KEY: Final = "price" +QUANTITY_KEY: Final = "quantity" diff --git a/src/part5/utils.py b/src/part5/utils.py index b2ad4dc4..958193b1 100644 --- a/src/part5/utils.py +++ b/src/part5/utils.py @@ -1,120 +1,123 @@ -"""Standalone helpers shared by the part5 storage and CRUD modules. - -Normalisation: - -* :func:`normalize_price` rounds a raw :class:`~decimal.Decimal` amount to - the fixed number of fractional digits (:data:`PRICE_PRECISION`) that - every stored price uses, keeping currency values free of binary - floating-point error. -* :func:`normalize_product_name` strips surrounding whitespace from a - product name, collapses every internal run of whitespace to a single - space and lower-cases it, giving every stored name a single canonical - form. - -Presentation: - -* :func:`get_storage_str_representation` renders the whole store as a - text table meant to be printed to a terminal; each column is sized to - the longest value it holds in that particular call. -* :func:`get_stats_str_representation` renders the call statistics gathered - by :func:`~src.part5.decorators.collect_stats` as a table of the same - look, with the success rate of every command as a percentage. -""" - -from decimal import Decimal +from decimal import ROUND_HALF_UP, Decimal from typing import Final -from .decorators import Registry -from .storage import Product +from .decorators import FAILS_KEY, SUCCESS_KEY, Registry +from .storage import NAME_KEY, PRICE_KEY, QUANTITY_KEY, Product -# TODO: задайте число знаков после запятой и шаг квантования (используйте своё -# решение части 4) -PRICE_PRECISION: Final[int] = 0 -PRICE_STEP: Final = Decimal(0) +PRICE_PRECISION: Final[int] = 2 +PRICE_STEP: Final = Decimal(1).scaleb(-PRICE_PRECISION) +TABLE_HEADERS: Final[tuple[str, ...]] = ("ID", "name", "price", "quantity") +PRODUCT_FIELDS: Final[tuple[str, ...]] = (NAME_KEY, PRICE_KEY, QUANTITY_KEY) -# TODO: задайте заголовки столбцов таблицы (используйте своё решение части 4) -TABLE_HEADERS: Final[tuple[str, ...]] = () -# TODO: задайте заголовки столбцов таблицы статистики, см. TASK.md -STATS_TABLE_HEADERS: Final[tuple[str, ...]] = () +STATS_TABLE_HEADERS: Final[tuple[str, ...]] = ( + "command name", + "success", + "fails", + "success rate", +) def normalize_price(price: Decimal) -> Decimal: - """Round a price to the precision every stored record uses. + return price.quantize(PRICE_STEP, rounding=ROUND_HALF_UP) - Args: - price: The raw price amount. - Returns: - ``price`` quantised to :data:`PRICE_PRECISION` fractional digits, - with halves rounded up. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return Decimal(0) +def normalize_product_name(name: str) -> str: + return " ".join(name.lower().split()) -def normalize_product_name(name: str) -> str: - """Reduce a product name to the canonical form the store keeps. +def len_first_column(storage: dict[int, Product]) -> int: + max_len = max((len(str(s)) for s in storage), default=0) + return max(max_len, len(TABLE_HEADERS[0])) - Args: - name: The raw product name. - Returns: - ``name`` with every leading and trailing whitespace character - removed, every internal run of whitespace (spaces, tabs and the - like) collapsed to a single space, and the rest lower-cased. For - example ``"abc def\tghi\tjkl"`` becomes ``"abc def ghi jkl"``. - The result is an empty string when ``name`` holds nothing but - whitespace. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return "" +def len_other_column(storage: dict[int, Product], column_number: int) -> int: + field_key = PRODUCT_FIELDS[column_number - 1] + max_len = max( + (len(str(product[field_key])) for product in storage.values()), + default=0, + ) + return max(max_len, len(TABLE_HEADERS[column_number])) -# TODO: при необходимости добавьте свои вспомогательные функции +def line_string_headers( + max_len_column: list[int], + headers: tuple[str, ...] = TABLE_HEADERS, +) -> str: + line = "|" + for column_number, header in enumerate(headers): + line += " " + header.ljust(max_len_column[column_number]) + " |" + return line -def get_storage_str_representation(storage: dict[int, Product]) -> str: - """Render the product store as a text table with data-sized columns. +def line_string(product_id: int, storage_i: Product, max_len_column: list[int]) -> str: + line = "|" + line += " " + str(product_id).ljust(max_len_column[0]) + " |" + for column_number, field_key in enumerate(PRODUCT_FIELDS, start=1): + line += ( + " " + str(storage_i[field_key]).ljust(max_len_column[column_number]) + " |" + ) + return line + - The table has the columns named by :data:`TABLE_HEADERS` -- id, name, - price and quantity. Each column is made exactly as wide as the longest - value it carries in this call (its header counted), so the columns - line up when the string is printed to a terminal and no value is ever - truncated. +def line_void(max_len_column: list[int]) -> str: + line = "|" + for column_len in max_len_column: + line += "-" + "-" * column_len + "-|" + return line - Args: - storage: The product store to render. - Returns: - A multi-line string: a header row, a dashed separator row, then - one row per product in ``storage``, in insertion order. When - ``storage`` is empty only the header and separator rows are - returned, sized to the header labels. - """ - # TODO: реализуйте функцию (используйте своё решение части 4) - return "" +def max_len(storage: dict[int, Product]) -> list[int]: + max_len_column = [len_first_column(storage)] + max_len_column.extend( + len_other_column(storage, i) for i in range(1, len(TABLE_HEADERS)) + ) + return max_len_column + + +def get_storage_str_representation(storage: dict[int, Product]) -> str: + max_len_column = max_len(storage) + str_representation = "" + str_representation += line_string_headers(max_len_column) + "\n" + str_representation += line_void(max_len_column) + "\n" + for product_id, storage_i in storage.items(): + str_representation += line_string(product_id, storage_i, max_len_column) + "\n" + return str_representation.rstrip("\n") def get_stats_str_representation(registry: Registry) -> str: - """Render the call statistics as a text table with data-sized columns. - - The table has the columns named by :data:`STATS_TABLE_HEADERS` -- command - name, number of successful calls, number of failed calls and success - rate. It is laid out like the one from - :func:`get_storage_str_representation`: every column is as wide as the - longest value it carries, its header counted. - - Args: - registry: The statistics to render, a mapping of command name to the - counters kept by :func:`~src.part5.decorators.collect_stats`. - - Returns: - A multi-line string: a header row, a dashed separator row, then one - row per registry entry in insertion order. When ``registry`` is - empty only the header and separator rows are returned, sized to the - header labels. - """ - # TODO: реализуйте функцию - return "" + max_len_column = [len(header) for header in STATS_TABLE_HEADERS] + rows = [] + + for command_name, stats in registry.items(): + success = stats[SUCCESS_KEY] + fails = stats[FAILS_KEY] + total = success + fails + + if total == 0: + rate = 0.0 + else: + rate = success / total * 100 + + row = [command_name, str(success), str(fails), f"{rate:.2f}%"] + rows.append(row) + + for column_number, value in enumerate(row): + max_len_column[column_number] = max( + max_len_column[column_number], len(value) + ) + + str_representation = "" + str_representation += ( + line_string_headers(max_len_column, STATS_TABLE_HEADERS) + "\n" + ) + str_representation += line_void(max_len_column) + "\n" + + for row in rows: + line = "|" + for column_number, value in enumerate(row): + line += " " + value.ljust(max_len_column[column_number]) + " |" + str_representation += line + "\n" + + return str_representation.rstrip("\n") From 44007f443abbc1d5f2eac614399104aaf6a7dc9b Mon Sep 17 00:00:00 2001 From: Egor Vasilev Date: Tue, 10 Nov 2026 23:47:06 +0300 Subject: [PATCH 2/3] Update part 5 --- src/part5/utils.py | 1 + 1 file changed, 1 insertion(+) diff --git a/src/part5/utils.py b/src/part5/utils.py index 958193b1..d3462c72 100644 --- a/src/part5/utils.py +++ b/src/part5/utils.py @@ -109,6 +109,7 @@ def get_stats_str_representation(registry: Registry) -> str: ) str_representation = "" + str_representation += ( line_string_headers(max_len_column, STATS_TABLE_HEADERS) + "\n" ) From e6788fe787bce2f64f6d6dc6f3198aa15905aaea Mon Sep 17 00:00:00 2001 From: Egor Vasilev Date: Tue, 10 Nov 2026 23:52:18 +0300 Subject: [PATCH 3/3] Final fix for part 5 --- src/part5/utils.py | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/part5/utils.py b/src/part5/utils.py index d3462c72..28298e3a 100644 --- a/src/part5/utils.py +++ b/src/part5/utils.py @@ -109,10 +109,11 @@ def get_stats_str_representation(registry: Registry) -> str: ) str_representation = "" - + str_representation += ( line_string_headers(max_len_column, STATS_TABLE_HEADERS) + "\n" ) + str_representation += line_void(max_len_column) + "\n" for row in rows: