Merge pull request #1312 from dandi/asset-paths-design

dandiapi/api/asset_paths.py

@@ -0,0 +1,156 @@
+from __future__ import annotations
+
+import os
+
+from django.db import transaction
+from django.db.models import Count, F, QuerySet
+
+from dandiapi.api.models import Asset, AssetPath, AssetPathRelation, Version
+
+####################################################################
+# Dandiset and version deletion will cascade to asset path deletion.
+# Thus, no explicit action is needed for these.
+####################################################################
+
+
+def extract_paths(path: str) -> list[str]:
+    nodepaths: list[str] = path.split('/')
+    for i in range(len(nodepaths))[1:]:
+        nodepaths[i] = os.path.join(nodepaths[i - 1], nodepaths[i])
+
+    return nodepaths
+
+
+def get_root_paths(version: Version) -> QuerySet[AssetPath]:
+    """Return all root paths for a version."""
+    # Use prefetch_related here instead of select_related,
+    # as otherwise the resulting join is very large
+    qs = AssetPath.objects.prefetch_related(
+        'asset',
+        'asset__blob',
+        'asset__embargoed_blob',
+        'asset__zarr',
+    )
+    return (
+        qs.filter(version=version)
+        .alias(num_parents=Count('parent_links'))
+        .filter(num_parents=1)
+        .order_by('path')
+    )
+
+
+def get_path_children(path: AssetPath) -> QuerySet[AssetPath]:
+    """Get all direct children from an existing path."""
+    qs = AssetPath.objects.select_related(
+        'asset',
+        'asset__blob',
+        'asset__embargoed_blob',
+        'asset__zarr',
+    )
+    path_ids = (
+        AssetPathRelation.objects.filter(parent=path, depth=1)
+        .values_list('child', flat=True)
+        .distinct()
+    )
+    return qs.filter(id__in=path_ids).order_by('path')
+
+
+def search_asset_paths(query: str, version: Version) -> QuerySet[AssetPath] | None:
+    """Return all direct children of this path, if there are any."""
+    if not query:
+        return get_root_paths(version)
+
+    # Ensure no trailing slash
+    fixed_query = query.rstrip('/')
+
+    # Retrieve path
+    path = AssetPath.objects.filter(version=version, path=fixed_query).first()
+    if path is None:
+        return None
+
+    return get_path_children(path)
+
+
+# TODO: Make idempotent
+@transaction.atomic()
+def add_asset_paths(asset: Asset, version: Version):
+    # Get or create leaf path
+    leaf, created = AssetPath.objects.get_or_create(path=asset.path, asset=asset, version=version)
+    if not created:
+        return
+
+    # Create absolute paths (exclude leaf node)
+    nodepaths = extract_paths(asset.path)[:-1]
+
+    # Create nodes
+    AssetPath.objects.bulk_create(
+        [AssetPath(path=path, version=version, asset=None) for path in nodepaths],
+        ignore_conflicts=True,
+    )
+
+    # Retrieve all paths
+    paths = [*AssetPath.objects.filter(version=version, path__in=nodepaths).order_by('path'), leaf]
+
+    # Create relations between paths
+    links = []
+    for i in range(len(paths)):
+        links.extend(
+            [
+                AssetPathRelation(parent=paths[i], child=paths[j], depth=j - i)
+                for j in range(len(paths))[i:]
+            ]
+        )
+
+    # Create objects
+    AssetPathRelation.objects.bulk_create(links, ignore_conflicts=True)
+
+    # Get all relations (including leaf node)
+    parent_ids = (
+        AssetPathRelation.objects.filter(child=leaf)
+        .distinct('parent')
+        .values_list('parent', flat=True)
+    )
+
+    # Update size + file count
+    AssetPath.objects.filter(id__in=parent_ids).update(
+        aggregate_size=F('aggregate_size') + asset.size, aggregate_files=F('aggregate_files') + 1
+    )
+
+
+@transaction.atomic()
+def delete_asset_paths(asset: Asset, version: Version):
+    leaf: AssetPath = AssetPath.objects.get(asset=asset, version=version)
+
+    # Fetch parents
+    parent_ids = (
+        AssetPathRelation.objects.filter(child=leaf)
+        .distinct('parent')
+        .values_list('parent', flat=True)
+    )
+    parent_paths = AssetPath.objects.filter(id__in=parent_ids)
+
+    # Update parents
+    parent_paths.update(
+        aggregate_size=F('aggregate_size') - asset.size, aggregate_files=F('aggregate_files') - 1
+    )
+
+    # Ensure integrity
+    leaf.refresh_from_db()
+    assert leaf.aggregate_size == 0
+    assert leaf.aggregate_files == 0
+
+    # Delete leaf node and any other paths with no contained files
+    AssetPath.objects.filter(aggregate_files=0).delete()
+
+
+@transaction.atomic()
+def update_asset_paths(old_asset: Asset, new_asset: Asset, version: Version):
+    delete_asset_paths(old_asset, version)
+    add_asset_paths(new_asset, version)
+
+
+@transaction.atomic()
+def add_version_asset_paths(version: Version):
+    """Add every asset from a version."""
+    for asset in version.assets.iterator():
+        add_asset_paths(asset, version)

dandiapi/api/management/commands/ingest_asset_paths.py

@@ -0,0 +1,12 @@
+import djclick as click
+
+from dandiapi.api.asset_paths import add_version_asset_paths
+from dandiapi.api.models import Version
+
+
+@click.command()
+def ingest_asset_paths():
+    for version in Version.objects.iterator():
+        print(f'Version: {version}')
+        print(f'\t {version.assets.count()} assets')
+        add_version_asset_paths(version)

dandiapi/api/migrations/0038_assetpath_assetpathrelation_alter_asset_path_and_more.py

@@ -0,0 +1,127 @@
+# Generated by Django 4.1.1 on 2022-10-19 16:07
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+import dandiapi.api.models.asset
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('api', '0037_alter_version_status'),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='AssetPath',
+            fields=[
+                (
+                    'id',
+                    models.BigAutoField(
+                        auto_created=True, primary_key=True, serialize=False, verbose_name='ID'
+                    ),
+                ),
+                ('path', models.CharField(max_length=512)),
+                ('aggregate_files', models.PositiveBigIntegerField(default=0)),
+                ('aggregate_size', models.PositiveBigIntegerField(default=0)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='AssetPathRelation',
+            fields=[
+                (
+                    'id',
+                    models.BigAutoField(
+                        auto_created=True, primary_key=True, serialize=False, verbose_name='ID'
+                    ),
+                ),
+                ('depth', models.PositiveIntegerField()),
+            ],
+        ),
+        migrations.AlterField(
+            model_name='asset',
+            name='path',
+            field=models.CharField(
+                max_length=512, validators=[dandiapi.api.models.asset.validate_asset_path]
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name='asset',
+            constraint=models.CheckConstraint(
+                check=models.Q(
+                    ('path__regex', '^([A-z0-9(),&\\s#+~_=-]?\\/?\\.?[A-z0-9(),&\\s#+~_=-])+$')
+                ),
+                name='asset_path_regex',
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name='asset',
+            constraint=models.CheckConstraint(
+                check=models.Q(('path__startswith', '/'), _negated=True),
+                name='asset_path_no_leading_slash',
+            ),
+        ),
+        migrations.AddField(
+            model_name='assetpathrelation',
+            name='child',
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name='parent_links',
+                to='api.assetpath',
+            ),
+        ),
+        migrations.AddField(
+            model_name='assetpathrelation',
+            name='parent',
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name='child_links',
+                to='api.assetpath',
+            ),
+        ),
+        migrations.AddField(
+            model_name='assetpath',
+            name='asset',
+            field=models.ForeignKey(
+                blank=True,
+                null=True,
+                on_delete=django.db.models.deletion.PROTECT,
+                related_name='leaf_paths',
+                to='api.asset',
+            ),
+        ),
+        migrations.AddField(
+            model_name='assetpath',
+            name='version',
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name='asset_paths',
+                to='api.version',
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name='assetpathrelation',
+            constraint=models.UniqueConstraint(
+                fields=('parent', 'child'), name='unique-relationship'
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name='assetpath',
+            constraint=models.CheckConstraint(
+                check=models.Q(('path__endswith', '/'), _negated=True), name='consistent-slash'
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name='assetpath',
+            constraint=models.UniqueConstraint(
+                fields=('asset', 'version'), name='unique-asset-version'
+            ),
+        ),
+        migrations.AddConstraint(
+            model_name='assetpath',
+            constraint=models.UniqueConstraint(
+                fields=('version', 'path'), name='unique-version-path'
+            ),
+        ),
+    ]

dandiapi/api/models/__init__.py

@@ -1,4 +1,5 @@
 from .asset import Asset, AssetBlob, EmbargoedAssetBlob
+from .asset_paths import AssetPath, AssetPathRelation
 from .dandiset import Dandiset
 from .oauth import StagingApplication
 from .upload import EmbargoedUpload, Upload
@@ -8,6 +9,8 @@
 __all__ = [
     'Asset',
     'AssetBlob',
+    'AssetPath',
+    'AssetPathRelation',
     'Dandiset',
     'EmbargoedAssetBlob',
     'EmbargoedUpload',

dandiapi/api/models/asset.py

@@ -1,12 +1,13 @@
 from __future__ import annotations
 
 import datetime
+import re
 from urllib.parse import urlparse, urlunparse
 import uuid
 
 from django.conf import settings
 from django.contrib.postgres.indexes import HashIndex
-from django.core.exceptions import FieldError
+from django.core.exceptions import FieldError, ValidationError
 from django.core.validators import RegexValidator
 from django.db import models
 from django.db.models import Q
@@ -25,6 +26,18 @@
 from .dandiset import Dandiset
 from .version import Version
 
+ASSET_CHARS_REGEX = r'[A-z0-9(),&\s#+~_=-]'
+ASSET_PATH_REGEX = fr'^({ASSET_CHARS_REGEX}?\/?\.?{ASSET_CHARS_REGEX})+$'
+
+
+def validate_asset_path(path: str):
+    if path.startswith('/'):
+        raise ValidationError('Path must not begin with /')
+    if not re.match(ASSET_PATH_REGEX, path):
+        raise ValidationError('Path improperly formatted')
+
+    return path
+
 
 class BaseAssetBlob(TimeStampedModel):
     SHA256_REGEX = r'[0-9a-f]{64}'
@@ -106,7 +119,7 @@ class Status(models.TextChoices):
         INVALID = 'Invalid'
 
     asset_id = models.UUIDField(unique=True, default=uuid.uuid4)
-    path = models.CharField(max_length=512)
+    path = models.CharField(max_length=512, validators=[validate_asset_path])
     blob = models.ForeignKey(
         AssetBlob, related_name='assets', on_delete=models.CASCADE, null=True, blank=True
     )
@@ -145,6 +158,10 @@ class Meta:
                 name='asset_metadata_has_schema_version',
                 check=Q(metadata__schemaVersion__isnull=False),
             ),
+            models.CheckConstraint(name='asset_path_regex', check=Q(path__regex=ASSET_PATH_REGEX)),
+            models.CheckConstraint(
+                name='asset_path_no_leading_slash', check=~Q(path__startswith='/')
+            ),
         ]
 
     @property