Add reverse-engineered documentation
- README.md: Overview, core concept diagram, component summary - architecture.md: System design, initialization flow, memory model - components.md: Deep dive on all classes and functions - data-flow.md: Complete read/write operation flows with diagrams - analysis.md: Performance analysis (latency, memory footprint, I/O) - drawbacks.md: 27 identified issues and limitations catalog - modernization.md: Python 3 migration guide with effort estimates
This commit is contained in:
Alexander
@@ -0,0 +1,479 @@
|
||||
# beetfs Drawbacks & Limitations
|
||||
|
||||
## Overview
|
||||
|
||||
This document catalogs all identified issues, limitations, and missing features in beetfs. Issues are categorized by severity and type.
|
||||
|
||||
---
|
||||
|
||||
## Critical Issues (🔴)
|
||||
|
||||
### 1. Full File Loading into Memory
|
||||
|
||||
**Location**: Lines 463, 480-481
|
||||
|
||||
```python
|
||||
self.inf = InterpolatedFLAC(self.file_object.read()) # Entire file
|
||||
# ...
|
||||
self.music_data = self.file_object.read() # Audio portion again
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- Memory usage = O(file_size) per open file
|
||||
- 50MB FLAC = ~50MB RAM
|
||||
- Library scan of 100 files = 5GB+ RAM
|
||||
- Out-of-memory crashes on large libraries
|
||||
|
||||
**Fix Required**: Implement lazy loading with seek-based reads.
|
||||
|
||||
---
|
||||
|
||||
### 2. MP3 Support Disabled
|
||||
|
||||
**Location**: Lines 475-477
|
||||
|
||||
```python
|
||||
elif self.format == "mp3":
|
||||
self.bound = 0 # disable interpolation for now
|
||||
self.music_offset = 0 # disable interpolation for now
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- MP3 files return original metadata, not database metadata
|
||||
- Breaks the core promise of metadata overlay
|
||||
- MP3 is still one of the most common formats
|
||||
|
||||
**Fix Required**: Implement `InterpolatedID3` header generation.
|
||||
|
||||
---
|
||||
|
||||
### 3. Python 2 Only
|
||||
|
||||
**Location**: Throughout
|
||||
|
||||
```python
|
||||
except fuse.FuseError, e: # Python 2 syntax
|
||||
if isinstance(value, basestring): # Removed in Python 3
|
||||
return reduce(lambda a, b: (a << 8) + ord(b), string, 0L) # Long literals
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- Python 2 EOL was January 2020
|
||||
- Security vulnerabilities unfixed
|
||||
- No modern library support
|
||||
- Cannot run on Python 3 without migration
|
||||
|
||||
**Fix Required**: Full Python 3 migration (see modernization.md).
|
||||
|
||||
---
|
||||
|
||||
### 4. Deprecated FUSE Library
|
||||
|
||||
**Location**: Line 25, 51
|
||||
|
||||
```python
|
||||
import fuse
|
||||
fuse.fuse_python_api = (0, 2)
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- fuse-python is unmaintained
|
||||
- Missing modern FUSE features (FUSE 3.x)
|
||||
- Compatibility issues with recent kernels
|
||||
- No async support
|
||||
|
||||
**Fix Required**: Migrate to pyfuse3 or llfuse.
|
||||
|
||||
---
|
||||
|
||||
### 5. Single-Threaded Execution
|
||||
|
||||
**Location**: Line 178
|
||||
|
||||
```python
|
||||
server.multithreaded = 0
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- All operations serialized
|
||||
- One slow open blocks all other operations
|
||||
- Cannot utilize multiple CPU cores
|
||||
- Poor performance under concurrent access
|
||||
|
||||
**Fix Required**: Enable multithreading with proper locking.
|
||||
|
||||
---
|
||||
|
||||
## Major Issues (🟡)
|
||||
|
||||
### 6. Limited Metadata Fields
|
||||
|
||||
**Location**: Lines 466-469, 540-547
|
||||
|
||||
```python
|
||||
# Only these 4 fields are actually used:
|
||||
self.inf["title"] = self.item.title
|
||||
self.inf["album"] = self.item.album
|
||||
self.inf["artist"] = self.item.artist
|
||||
self.inf["genre"] = self.item.genre
|
||||
```
|
||||
|
||||
**Defined but not implemented** (lines 55-77):
|
||||
- `composer`, `grouping`
|
||||
- `year`, `month`, `day`
|
||||
- `track`, `tracktotal`
|
||||
- `disc`, `disctotal`
|
||||
- `lyrics`, `comments`
|
||||
- `bpm`, `comp`
|
||||
- `albumartist` (not even defined)
|
||||
|
||||
**Impact**:
|
||||
- Track numbers not from database
|
||||
- Album artist not supported
|
||||
- Year/date not interpolated
|
||||
- Cover art not handled
|
||||
|
||||
---
|
||||
|
||||
### 7. No File Handle Caching/Eviction
|
||||
|
||||
**Location**: Lines 1004-1018
|
||||
|
||||
```python
|
||||
if path in self.files:
|
||||
self.files[path].open()
|
||||
else:
|
||||
self.files[path] = FileHandler(path, self.lib)
|
||||
```
|
||||
|
||||
**Missing**:
|
||||
- No maximum cache size
|
||||
- No LRU eviction
|
||||
- No memory pressure handling
|
||||
- Files stay in memory until explicitly closed
|
||||
|
||||
**Impact**:
|
||||
- Memory grows unbounded
|
||||
- No protection against OOM
|
||||
- Applications that open-then-close still leave data cached
|
||||
|
||||
---
|
||||
|
||||
### 8. Blocking Database Operations
|
||||
|
||||
**Location**: Lines 549-550
|
||||
|
||||
```python
|
||||
self.lib.store(self.item)
|
||||
self.lib.save()
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- SQLite operations in FUSE thread
|
||||
- Write operations block all reads
|
||||
- No transaction batching
|
||||
- Potential deadlocks with beets
|
||||
|
||||
---
|
||||
|
||||
### 9. No Library Hot Reload
|
||||
|
||||
**Issue**: Virtual directory tree built once at mount time.
|
||||
|
||||
**Location**: Lines 142-172
|
||||
|
||||
```python
|
||||
for item in lib.items():
|
||||
# Build tree...
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- New files added to beets library not visible
|
||||
- Deleted files still appear (ENOENT on access)
|
||||
- Metadata changes in beets not reflected until remount
|
||||
- Must unmount/remount to see changes
|
||||
|
||||
---
|
||||
|
||||
### 10. Static Path Format
|
||||
|
||||
**Location**: Lines 44-45
|
||||
|
||||
```python
|
||||
PATH_FORMAT = ("$artist/$album ($year) [$format_upper]/"
|
||||
"$track - $artist - $title.$format")
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- Cannot customize organization
|
||||
- Hard-coded template
|
||||
- No configuration option
|
||||
- Incompatible with different organizational preferences
|
||||
|
||||
---
|
||||
|
||||
### 11. No Extended Attribute Support
|
||||
|
||||
**Location**: Not implemented
|
||||
|
||||
**Impact**:
|
||||
- Cannot store/retrieve xattrs
|
||||
- Some applications use xattrs for metadata
|
||||
- macOS Finder metadata lost
|
||||
- Linux capabilities not supported
|
||||
|
||||
---
|
||||
|
||||
### 12. No Symlink Support
|
||||
|
||||
**Location**: Lines 758-765
|
||||
|
||||
```python
|
||||
def readlink(self, path):
|
||||
return -errno.EOPNOTSUPP
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- Cannot create symlinks in mount
|
||||
- Some applications expect symlink support
|
||||
- Cannot link to external files
|
||||
|
||||
---
|
||||
|
||||
### 13. Silent Error Swallowing
|
||||
|
||||
**Location**: Lines 705-707, 1019-1021, 1103-1104
|
||||
|
||||
```python
|
||||
except Exception as e:
|
||||
logging.error(e)
|
||||
return -errno.ENOENT # Always returns same error
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- All errors appear as "file not found"
|
||||
- Hard to debug issues
|
||||
- No distinction between permission, I/O, parse errors
|
||||
- Lost stack traces in many cases
|
||||
|
||||
---
|
||||
|
||||
## Minor Issues (🟢)
|
||||
|
||||
### 14. Global State
|
||||
|
||||
**Location**: Lines 125-140
|
||||
|
||||
```python
|
||||
global structure_split
|
||||
global structure_depth
|
||||
global library
|
||||
global directory_structure
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- Cannot mount multiple instances
|
||||
- Difficult to unit test
|
||||
- Tight coupling between components
|
||||
- No dependency injection
|
||||
|
||||
---
|
||||
|
||||
### 15. Hard-coded Log File
|
||||
|
||||
**Location**: Lines 624-625
|
||||
|
||||
```python
|
||||
LOG_FILENAME = "LOG"
|
||||
logging.basicConfig(filename=LOG_FILENAME, level=logging.INFO,)
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- Log file created in current directory
|
||||
- No log rotation
|
||||
- No configurable log level
|
||||
- Fills disk on busy systems
|
||||
|
||||
---
|
||||
|
||||
### 16. Reference Count Manual Management
|
||||
|
||||
**Location**: Lines 485-495
|
||||
|
||||
```python
|
||||
def open(self):
|
||||
self.instance_count = self.instance_count + 1
|
||||
|
||||
def release(self):
|
||||
if self.instance_count > 0:
|
||||
self.instance_count = self.instance_count - 1
|
||||
```
|
||||
|
||||
**Issues**:
|
||||
- Race conditions possible if multithreaded
|
||||
- No context manager support
|
||||
- Manual counting error-prone
|
||||
- Off-by-one potential
|
||||
|
||||
---
|
||||
|
||||
### 17. Inefficient Directory Building
|
||||
|
||||
**Location**: Lines 153-172
|
||||
|
||||
```python
|
||||
for level in range(0, structure_depth - 1):
|
||||
if level-1 in level_subbed:
|
||||
sub_elements.append(level_subbed[level-1])
|
||||
directory_structure.adddir(sub_elements, level_subbed[level])
|
||||
```
|
||||
|
||||
**Issues**:
|
||||
- Rebuilds path for every item
|
||||
- O(items × depth) complexity
|
||||
- String allocations in inner loop
|
||||
- Could use trie-based insertion
|
||||
|
||||
---
|
||||
|
||||
### 18. No Cover Art Handling
|
||||
|
||||
**Issue**: Cover art embedded in FLAC not addressed.
|
||||
|
||||
**Impact**:
|
||||
- Cover art from original file used, not database
|
||||
- Cannot replace/add cover art through overlay
|
||||
- PICTURE metadata blocks passed through unchanged
|
||||
|
||||
---
|
||||
|
||||
### 19. No Cue Sheet Support
|
||||
|
||||
**Issue**: Cue sheets not handled specially.
|
||||
|
||||
**Impact**:
|
||||
- `.cue` files point to original file paths
|
||||
- Cannot play cue-referenced tracks correctly
|
||||
- Split-by-cue not supported
|
||||
|
||||
---
|
||||
|
||||
### 20. File Size Mismatch Potential
|
||||
|
||||
**Issue**: Virtual file size differs from physical if header size changes.
|
||||
|
||||
**Location**: Lines 675-688
|
||||
|
||||
```python
|
||||
statinfo = os.stat(item)
|
||||
st = Stat(st_mode=statinfo.st_mode,
|
||||
st_size=statinfo.st_size, # Original size, not virtual!
|
||||
...)
|
||||
```
|
||||
|
||||
**Impact**:
|
||||
- `stat()` returns original file size
|
||||
- If generated header is larger/smaller, size is wrong
|
||||
- Some applications may fail on size mismatch
|
||||
- Range requests could break
|
||||
|
||||
---
|
||||
|
||||
## Missing Features
|
||||
|
||||
### Essential
|
||||
|
||||
| Feature | Status | Notes |
|
||||
|---------|--------|-------|
|
||||
| MP3 metadata interpolation | ❌ Disabled | Code exists but disabled |
|
||||
| OGG/Opus support | ❌ Missing | No implementation |
|
||||
| AAC/M4A support | ❌ Missing | No implementation |
|
||||
| Lazy file loading | ❌ Missing | Full file loaded |
|
||||
| Memory management | ❌ Missing | No limits or eviction |
|
||||
| Configuration file | ❌ Missing | Hard-coded values |
|
||||
|
||||
### Nice to Have
|
||||
|
||||
| Feature | Status | Notes |
|
||||
|---------|--------|-------|
|
||||
| Cover art interpolation | ❌ Missing | Would need PICTURE block handling |
|
||||
| ReplayGain from database | ❌ Missing | Tags not interpolated |
|
||||
| Lyrics from database | ❌ Missing | Listed in fields, not implemented |
|
||||
| Watch mode (hot reload) | ❌ Missing | No inotify integration |
|
||||
| Multiple mount points | ❌ Missing | Global state prevents |
|
||||
| Remote database | ❌ Missing | Local beets only |
|
||||
| Read-only mode | ❌ Missing | Always allows writes |
|
||||
| Custom path templates | ❌ Missing | Hard-coded PATH_FORMAT |
|
||||
|
||||
---
|
||||
|
||||
## Security Considerations
|
||||
|
||||
### 1. No Input Validation
|
||||
|
||||
**Location**: Throughout
|
||||
|
||||
```python
|
||||
pathsplit = path[1:].split('/')
|
||||
item_id = node.files[pathsplit[structure_depth-1]] # No bounds check
|
||||
```
|
||||
|
||||
**Risk**: Path traversal, injection attacks unlikely but possible.
|
||||
|
||||
### 2. Database Credentials Exposed
|
||||
|
||||
**Issue**: Uses beets library directly with stored credentials.
|
||||
|
||||
**Risk**: Low - local access only.
|
||||
|
||||
### 3. No Permission Enforcement
|
||||
|
||||
**Location**: Lines 749-756
|
||||
|
||||
```python
|
||||
if flags | os.R_OK:
|
||||
pass # TODO: actually check the file permissions
|
||||
if flags | os.W_OK:
|
||||
pass
|
||||
```
|
||||
|
||||
**Risk**: All users can read/write through mount.
|
||||
|
||||
---
|
||||
|
||||
## Compatibility Issues
|
||||
|
||||
| Component | Issue |
|
||||
|-----------|-------|
|
||||
| **Jellyfin** | May scan entire library, causing OOM |
|
||||
| **Plex** | Same library scan issue |
|
||||
| **Navidrome** | Expects certain tag fields not implemented |
|
||||
| **mpd** | Works for playback, database features limited |
|
||||
| **macOS** | fuse-python macOS support questionable |
|
||||
| **Docker** | FUSE in containers requires privileged mode |
|
||||
|
||||
---
|
||||
|
||||
## Summary Table
|
||||
|
||||
| Category | Critical | Major | Minor |
|
||||
|----------|----------|-------|-------|
|
||||
| Performance | 2 | 4 | 2 |
|
||||
| Functionality | 2 | 5 | 4 |
|
||||
| Code Quality | 2 | 2 | 4 |
|
||||
| **Total** | **6** | **11** | **10** |
|
||||
|
||||
---
|
||||
|
||||
## Prioritized Fix List
|
||||
|
||||
1. 🔴 **Memory**: Implement lazy loading (Critical for usability)
|
||||
2. 🔴 **Python 3**: Migrate to Python 3 (Required for any changes)
|
||||
3. 🔴 **FUSE lib**: Switch to pyfuse3/llfuse (Required for Python 3)
|
||||
4. 🔴 **MP3**: Enable MP3 interpolation (Core functionality)
|
||||
5. 🟡 **Metadata**: Implement all fields (Feature completeness)
|
||||
6. 🟡 **Threading**: Enable multithreading (Performance)
|
||||
7. 🟡 **Config**: Add configuration file (Usability)
|
||||
8. 🟡 **Hot reload**: Watch for library changes (Usability)
|
||||
9. 🟢 **Globals**: Remove global state (Code quality)
|
||||
10. 🟢 **Logging**: Configurable logging (Operations)
|
||||
Reference in New Issue
Block a user