Module fl_server_core.migrations.0008_globalmodel_preprocessing¶
View Source
# SPDX-FileCopyrightText: 2024 Benedikt Franke <benedikt.franke@dlr.de>
# SPDX-FileCopyrightText: 2024 Florian Heinrich <florian.heinrich@dlr.de>
#
# SPDX-License-Identifier: Apache-2.0
# Generated by Django 4.0.10 on 2024-04-25 07:57
from django.db import migrations, models
class Migration(migrations.Migration):
dependencies = [
('fl_server_core', '0007_globalmodel_input_shape'),
]
operations = [
migrations.AddField(
model_name='globalmodel',
name='preprocessing',
field=models.BinaryField(null=True),
),
]
Classes¶
Migration¶
The base class for all migrations.
Migration files will import this from django.db.migrations.Migration and subclass it as a class called Migration. It will have one or more of the following attributes:
- operations: A list of Operation instances, probably from django.db.migrations.operations
- dependencies: A list of tuples of (app_path, migration_name)
- run_before: A list of tuples of (app_path, migration_name)
- replaces: A list of migration_names
Note that all migrations come out of migrations and into the Loader or Graph as instances, having been initialized with their app label and name.
View Source
Ancestors (in MRO)¶
- django.db.migrations.migration.Migration
Class variables¶
Methods¶
apply¶
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration in a forwards order.
Return the resulting project state for efficient reuse by following Migrations.
View Source
def apply(self, project_state, schema_editor, collect_sql=False):
"""
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration
in a forwards order.
Return the resulting project state for efficient reuse by following
Migrations.
"""
for operation in self.operations:
# If this operation cannot be represented as SQL, place a comment
# there instead
if collect_sql:
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
schema_editor.collected_sql.append(
"-- MIGRATION NOW PERFORMS OPERATION THAT CANNOT BE WRITTEN AS "
"SQL:"
)
schema_editor.collected_sql.append("-- %s" % operation.describe())
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
continue
# Save the state before the operation has run
old_state = project_state.clone()
operation.state_forwards(self.app_label, project_state)
# Run the operation
atomic_operation = operation.atomic or (
self.atomic and operation.atomic is not False
)
if not schema_editor.atomic_migration and atomic_operation:
# Force a transaction on a non-transactional-DDL backend or an
# atomic operation inside a non-atomic migration.
with atomic(schema_editor.connection.alias):
operation.database_forwards(
self.app_label, schema_editor, old_state, project_state
)
else:
# Normal behaviour
operation.database_forwards(
self.app_label, schema_editor, old_state, project_state
)
return project_state
mutate_state¶
Take a ProjectState and return a new one with the migration's
operations applied to it. Preserve the original object state by default and return a mutated state from a copy.
View Source
def mutate_state(self, project_state, preserve=True):
"""
Take a ProjectState and return a new one with the migration's
operations applied to it. Preserve the original object state by
default and return a mutated state from a copy.
"""
new_state = project_state
if preserve:
new_state = project_state.clone()
for operation in self.operations:
operation.state_forwards(self.app_label, new_state)
return new_state
suggest_name¶
Suggest a name for the operations this migration might represent. Names
are not guaranteed to be unique, but put some effort into the fallback name to avoid VCS conflicts if possible.
View Source
def suggest_name(self):
"""
Suggest a name for the operations this migration might represent. Names
are not guaranteed to be unique, but put some effort into the fallback
name to avoid VCS conflicts if possible.
"""
if self.initial:
return "initial"
raw_fragments = [op.migration_name_fragment for op in self.operations]
fragments = [name for name in raw_fragments if name]
if not fragments or len(fragments) != len(self.operations):
return "auto_%s" % get_migration_name_timestamp()
name = fragments[0]
for fragment in fragments[1:]:
new_name = f"{name}_{fragment}"
if len(new_name) > 52:
name = f"{name}_and_more"
break
name = new_name
return name
unapply¶
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration in a reverse order.
The backwards migration process consists of two phases:
- The intermediate states from right before the first until right after the last operation inside this migration are preserved.
- The operations are applied in reverse order using the states recorded in step 1.
View Source
def unapply(self, project_state, schema_editor, collect_sql=False):
"""
Take a project_state representing all migrations prior to this one
and a schema_editor for a live database and apply the migration
in a reverse order.
The backwards migration process consists of two phases:
1. The intermediate states from right before the first until right
after the last operation inside this migration are preserved.
2. The operations are applied in reverse order using the states
recorded in step 1.
"""
# Construct all the intermediate states we need for a reverse migration
to_run = []
new_state = project_state
# Phase 1
for operation in self.operations:
# If it's irreversible, error out
if not operation.reversible:
raise IrreversibleError(
"Operation %s in %s is not reversible" % (operation, self)
)
# Preserve new state from previous run to not tamper the same state
# over all operations
new_state = new_state.clone()
old_state = new_state.clone()
operation.state_forwards(self.app_label, new_state)
to_run.insert(0, (operation, old_state, new_state))
# Phase 2
for operation, to_state, from_state in to_run:
if collect_sql:
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
schema_editor.collected_sql.append(
"-- MIGRATION NOW PERFORMS OPERATION THAT CANNOT BE WRITTEN AS "
"SQL:"
)
schema_editor.collected_sql.append("-- %s" % operation.describe())
schema_editor.collected_sql.append("--")
if not operation.reduces_to_sql:
continue
atomic_operation = operation.atomic or (
self.atomic and operation.atomic is not False
)
if not schema_editor.atomic_migration and atomic_operation:
# Force a transaction on a non-transactional-DDL backend or an
# atomic operation inside a non-atomic migration.
with atomic(schema_editor.connection.alias):
operation.database_backwards(
self.app_label, schema_editor, from_state, to_state
)
else:
# Normal behaviour
operation.database_backwards(
self.app_label, schema_editor, from_state, to_state
)
return project_state