feat(media): Add image variant support - v1.4.0 Phase 2

Implement automatic generation of multiple image sizes for responsive
delivery and enhanced feed optimization.

Changes:
- Add migration 009 for media_variants table with CASCADE delete
- Define variant specs: thumb (150x150 crop), small (320px), medium (640px), large (1280px)
- Implement generate_variant() with center crop for thumbnails and aspect-preserving resize
- Implement generate_all_variants() with try/except cleanup, pass year/month/optimized_bytes explicitly
- Update save_media() to generate all variants after saving original
- Update get_note_media() to include variants dict (backwards compatible - only when variants exist)
- Record original as 'original' variant type

Technical details:
- Variants use explicit year/month parameters to avoid fragile path traversal
- Pass optimized_bytes to avoid redundant file I/O
- File cleanup on variant generation failure
- Skip generating variants larger than source image
- variants key only added to response when variants exist (pre-v1.4.0 compatibility)

All existing tests pass. Phase 2 complete.

Per design document: /home/phil/Projects/starpunk/docs/design/v1.4.0/media-implementation-design.md

Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
2025-12-10 18:19:24 -07:00
parent 1b51c82656
commit 501a711050
2 changed files with 234 additions and 7 deletions

View File

@@ -34,6 +34,14 @@ MIN_QUALITY = 70 # Minimum JPEG quality before rejection (v1.4.
MIN_DIMENSION = 640 # Minimum dimension before rejection (v1.4.0)
MAX_IMAGES_PER_NOTE = 4
# Variant specifications (v1.4.0 Phase 2)
VARIANT_SPECS = {
'thumb': {'size': (150, 150), 'crop': True},
'small': {'width': 320, 'crop': False},
'medium': {'width': 640, 'crop': False},
'large': {'width': 1280, 'crop': False},
}
def get_optimization_params(file_size: int) -> Tuple[int, int]:
"""
@@ -212,6 +220,154 @@ def optimize_image(image_data: bytes, original_size: int = None) -> Tuple[Image.
)
def generate_variant(
img: Image.Image,
variant_type: str,
base_path: Path,
base_filename: str,
file_ext: str
) -> Dict:
"""
Generate a single image variant
Args:
img: Source PIL Image
variant_type: One of 'thumb', 'small', 'medium', 'large'
base_path: Directory to save to
base_filename: Base filename (UUID without extension)
file_ext: File extension (e.g., '.jpg')
Returns:
Dict with variant metadata (path, width, height, size_bytes)
"""
spec = VARIANT_SPECS[variant_type]
work_img = img.copy()
if spec.get('crop'):
# Center crop for thumbnails using ImageOps.fit()
work_img = ImageOps.fit(
work_img,
spec['size'],
method=Image.Resampling.LANCZOS,
centering=(0.5, 0.5)
)
else:
# Aspect-preserving resize
target_width = spec['width']
if work_img.width > target_width:
ratio = target_width / work_img.width
new_height = int(work_img.height * ratio)
work_img = work_img.resize(
(target_width, new_height),
Image.Resampling.LANCZOS
)
# Generate variant filename
variant_filename = f"{base_filename}_{variant_type}{file_ext}"
variant_path = base_path / variant_filename
# Save with appropriate quality
save_kwargs = {'optimize': True}
if work_img.format in ['JPEG', 'JPG', None]:
save_kwargs['quality'] = 85
# Determine format from extension
save_format = 'JPEG' if file_ext.lower() in ['.jpg', '.jpeg'] else file_ext[1:].upper()
work_img.save(variant_path, format=save_format, **save_kwargs)
return {
'variant_type': variant_type,
'path': str(variant_path.relative_to(base_path.parent.parent)), # Relative to media root
'width': work_img.width,
'height': work_img.height,
'size_bytes': variant_path.stat().st_size
}
def generate_all_variants(
img: Image.Image,
base_path: Path,
base_filename: str,
file_ext: str,
media_id: int,
year: str,
month: str,
optimized_bytes: bytes
) -> List[Dict]:
"""
Generate all variants for an image and store in database
Args:
img: Source PIL Image (the optimized original)
base_path: Directory containing the original
base_filename: Base filename (UUID without extension)
file_ext: File extension
media_id: ID of parent media record
year: Year string (e.g., '2025') for path calculation
month: Month string (e.g., '01') for path calculation
optimized_bytes: Bytes of optimized original (avoids re-reading file)
Returns:
List of variant metadata dicts
"""
from starpunk.database import get_db
variants = []
db = get_db(current_app)
created_files = [] # Track files for cleanup on failure
try:
# Generate each variant type
for variant_type in ['thumb', 'small', 'medium', 'large']:
# Skip if image is smaller than target
spec = VARIANT_SPECS[variant_type]
target_width = spec.get('width') or spec['size'][0]
if img.width < target_width and variant_type != 'thumb':
continue # Skip variants larger than original
variant = generate_variant(img, variant_type, base_path, base_filename, file_ext)
variants.append(variant)
created_files.append(base_path / f"{base_filename}_{variant_type}{file_ext}")
# Insert into database
db.execute(
"""
INSERT INTO media_variants
(media_id, variant_type, path, width, height, size_bytes)
VALUES (?, ?, ?, ?, ?, ?)
""",
(media_id, variant['variant_type'], variant['path'],
variant['width'], variant['height'], variant['size_bytes'])
)
# Also record the original as 'original' variant
# Use explicit year/month for path calculation (avoids fragile parent traversal)
original_path = f"{year}/{month}/{base_filename}{file_ext}"
db.execute(
"""
INSERT INTO media_variants
(media_id, variant_type, path, width, height, size_bytes)
VALUES (?, ?, ?, ?, ?, ?)
""",
(media_id, 'original', original_path, img.width, img.height,
len(optimized_bytes)) # Use passed bytes instead of file I/O
)
db.commit()
return variants
except Exception as e:
# Clean up any created variant files on failure
for file_path in created_files:
try:
if file_path.exists():
file_path.unlink()
except OSError:
pass # Best effort cleanup
raise # Re-raise the original exception
def save_media(file_data: bytes, filename: str) -> Dict:
"""
Save uploaded media file
@@ -283,6 +439,20 @@ def save_media(file_data: bytes, filename: str) -> Dict:
db.commit()
media_id = cursor.lastrowid
# Generate variants (synchronous) - v1.4.0 Phase 2
# Pass year, month, and optimized_bytes to avoid fragile path traversal and file I/O
base_filename = stored_filename.rsplit('.', 1)[0]
variants = generate_all_variants(
optimized_img,
full_dir,
base_filename,
file_ext,
media_id,
year,
month,
optimized_bytes
)
return {
'id': media_id,
'filename': filename,
@@ -291,7 +461,8 @@ def save_media(file_data: bytes, filename: str) -> Dict:
'mime_type': mime_type,
'size': actual_size,
'width': width,
'height': height
'height': height,
'variants': variants
}
@@ -335,7 +506,7 @@ def attach_media_to_note(note_id: int, media_ids: List[int], captions: List[str]
def get_note_media(note_id: int) -> List[Dict]:
"""
Get all media attached to a note
Get all media attached to a note with variants (v1.4.0)
Returns list sorted by display_order
@@ -343,7 +514,7 @@ def get_note_media(note_id: int) -> List[Dict]:
note_id: Note ID to get media for
Returns:
List of media dicts with metadata
List of media dicts with metadata (includes 'variants' key if variants exist)
"""
from starpunk.database import get_db
@@ -369,8 +540,9 @@ def get_note_media(note_id: int) -> List[Dict]:
(note_id,)
).fetchall()
return [
{
media_list = []
for row in rows:
media_dict = {
'id': row[0],
'filename': row[1],
'stored_filename': row[2],
@@ -382,8 +554,42 @@ def get_note_media(note_id: int) -> List[Dict]:
'caption': row[8],
'display_order': row[9]
}
for row in rows
]
# Fetch variants for this media (v1.4.0 Phase 2)
variants = db.execute(
"""
SELECT variant_type, path, width, height, size_bytes
FROM media_variants
WHERE media_id = ?
ORDER BY
CASE variant_type
WHEN 'thumb' THEN 1
WHEN 'small' THEN 2
WHEN 'medium' THEN 3
WHEN 'large' THEN 4
WHEN 'original' THEN 5
END
""",
(row[0],)
).fetchall()
# Only add 'variants' key if variants exist (backwards compatibility)
# Pre-v1.4.0 media won't have variants, and consumers shouldn't
# expect the key to be present
if variants:
media_dict['variants'] = {
v[0]: {
'path': v[1],
'width': v[2],
'height': v[3],
'size_bytes': v[4]
}
for v in variants
}
media_list.append(media_dict)
return media_list
def delete_media(media_id: int) -> None: