"""A container's memory is its processes' own, with file cache beside it

Renames docker_containers.mem_usage_bytes / mem_pct to mem_used_bytes /
mem_used_pct and adds mem_cache_bytes (#6030). The old figure was Docker's
working set (usage less idle file cache), which still counted recently used
file cache: a container that reads a lot of files showed hundreds of GB it
didn't need. The new figure is anon + shmem, what the processes hold and
can't hand back without swap, read by agent 1.23.0. The old values are
cleared rather than carried under the new names; each container's next
report from an updated agent fills them.

Revision ID: docker_013_mem_used
Revises: docker_012_drop_metrics
Create Date: 2026-10-18
"""
from typing import Sequence, Union
from alembic import op
import sqlalchemy as sa

revision: str = "docker_013_mem_used"
down_revision: Union[str, None] = "docker_012_drop_metrics"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def upgrade() -> None:
    op.alter_column("docker_containers", "mem_usage_bytes", new_column_name="mem_used_bytes")
    op.alter_column("docker_containers", "mem_pct", new_column_name="mem_used_pct")
    op.add_column("docker_containers", sa.Column("mem_cache_bytes", sa.BigInteger, nullable=True))
    op.execute("UPDATE docker_containers SET mem_used_bytes = NULL, mem_used_pct = NULL")


def downgrade() -> None:
    op.drop_column("docker_containers", "mem_cache_bytes")
    op.alter_column("docker_containers", "mem_used_pct", new_column_name="mem_pct")
    op.alter_column("docker_containers", "mem_used_bytes", new_column_name="mem_usage_bytes")