4. Сабуров Ярослав Семенович. 614

fix_and_test.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+# Auto-fix imports/format, then run tests.
+set -euo pipefail
+
+cd "$(dirname "$0")"
+
+if ! command -v uv >/dev/null 2>&1; then
+    echo "Error: uv is not installed. Install it: https://docs.astral.sh/uv/getting-started/installation/" >&2
+    exit 1
+fi
+
+echo "==> Install dependencies"
+uv sync --locked
+
+echo "==> Ruff fix (imports, lint)"
+uv run ruff check --fix src
+uv run ruff format src
+
+echo "==> Pytest"
+uv run pytest src/part4/tests
+
+echo "All done."

pyproject.toml

@@ -10,6 +10,7 @@ dependencies = []
 dev = [
     "mypy==2.3.1",
     "ruff==0.16.8",
+    "pytest==9.1.1",
 ]
 
 [tool.ruff]
@@ -33,3 +34,13 @@ avoid-escape = true
 [tool.ruff.lint.isort]
 lines-after-imports = 2
 split-on-trailing-comma = true
+
+[tool.mypy]
+strict = true
+files = ["src"]
+mypy_path = "src"
+explicit_package_bases = true
+
+[tool.pytest.ini_options]
+pythonpath = ["src"]
+testpaths = ["src/tests"]

src/part1/constants.py

@@ -15,24 +15,18 @@
 from typing import Final
 
 
-# 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
-
-# Здесь можно добавить собственные вспомогательные константы
-# (например, сдвиги полей при сборке идентификатора).
+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

src/part1/snowflake.py

@@ -13,12 +13,14 @@
 :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_BITS,
     NODE_ID_DEFAULT,
     NODE_ID_MAX,
+    SEQUENCE_ID_BITS,
     SEQUENCE_ID_MAX,
     TIMESTAMP_MS_MAX,
 )
@@ -34,8 +36,7 @@ def read_current_millis(epoch_ms: int) -> int:
         The count of whole milliseconds between ``epoch_ms`` and now. May be
         negative if ``epoch_ms`` lies in the future.
     """
-    # TODO: реализуйте функцию
-    return 0
+    return int(time.time() * 1000) - epoch_ms
 
 
 def decode_timestamp_ms(snowflake_id: int, epoch_ms: int = EPOCH_MS_DEFAULT) -> int:
@@ -50,8 +51,7 @@ 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
+    return epoch_ms + (snowflake_id >> (NODE_ID_BITS + SEQUENCE_ID_BITS))
 
 
 def decode_node_id(snowflake_id: int) -> int:
@@ -64,8 +64,7 @@ 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 >> SEQUENCE_ID_BITS) & ((1 << NODE_ID_BITS) - 1)
 
 
 def decode_sequence_id(snowflake_id: int) -> int:
@@ -78,8 +77,7 @@ 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) & ((1 << SEQUENCE_ID_BITS) - 1)
 
 
 def generate_snowflake_id(
@@ -110,5 +108,20 @@ 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}], received {node_id}")
+        return None
+    if not (0 <= sequence_id <= SEQUENCE_ID_MAX):
+        print(f"sequence_id must be in [0, {SEQUENCE_ID_MAX}], received {sequence_id}")
+        return None
+
+    elapsed = read_current_millis(epoch_ms)
+    if elapsed > TIMESTAMP_MS_MAX:
+        print("overflows")
+        return None
+
+    return (
+        (elapsed << (NODE_ID_BITS + SEQUENCE_ID_BITS))
+        | (node_id << SEQUENCE_ID_BITS)
+        | sequence_id
+    )