docs: Update SDK documentation for v5.1.0 features

- Add session-level caching documentation to API reference
- Document clear_cache() and evict_cache() methods
- Add comprehensive bucket statistics examples
- Update list_buckets() with DeltaGliderStats metadata
- Add cache management patterns and best practices
- Update CHANGELOG comparison links

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

Co-Authored-By: Claude <noreply@anthropic.com>
This commit is contained in:
Simone Scarduzio
2025-10-10 18:34:44 +02:00
parent 3d04a407c0
commit dbd2632cae
3 changed files with 498 additions and 14 deletions

View File

@@ -156,7 +156,7 @@ for obj in response['Contents']:
#### `get_bucket_stats`
Get statistics for a bucket with optional detailed compression metrics.
Get statistics for a bucket with optional detailed compression metrics. Results are cached per client session for performance.
```python
def get_bucket_stats(
@@ -173,16 +173,46 @@ def get_bucket_stats(
- With `detailed_stats=False`: ~50ms for any bucket size (LIST calls only)
- With `detailed_stats=True`: ~2-3s per 1000 objects (adds HEAD calls for delta files)
##### Caching Behavior
- **Session-scoped cache**: Results cached within client instance lifetime
- **Automatic invalidation**: Cache cleared on bucket mutations (put, delete, bucket operations)
- **Intelligent reuse**: Detailed stats can serve quick stat requests
- **Manual cache control**: Use `clear_cache()` to invalidate all cached stats
##### Returns
`BucketStats`: Dataclass containing:
- **bucket** (`str`): Bucket name
- **object_count** (`int`): Total number of objects
- **total_size** (`int`): Original size in bytes (before compression)
- **compressed_size** (`int`): Actual stored size in bytes
- **space_saved** (`int`): Bytes saved through compression
- **average_compression_ratio** (`float`): Average compression ratio (0.0-1.0)
- **delta_objects** (`int`): Number of delta-compressed objects
- **direct_objects** (`int`): Number of directly stored objects
##### Examples
```python
# Quick stats for dashboard display
# Quick stats for dashboard display (cached after first call)
stats = client.get_bucket_stats('releases')
print(f"Objects: {stats.object_count}, Size: {stats.total_size}")
# Detailed stats for analytics (slower but accurate)
# Second call hits cache (instant response)
stats = client.get_bucket_stats('releases')
print(f"Space saved: {stats.space_saved} bytes")
# Detailed stats for analytics (slower but accurate, also cached)
stats = client.get_bucket_stats('releases', detailed_stats=True)
print(f"Compression ratio: {stats.average_compression_ratio:.1%}")
# Quick call after detailed call reuses detailed cache (more accurate)
quick_stats = client.get_bucket_stats('releases') # Uses detailed cache
# Clear cache to force refresh
client.clear_cache()
stats = client.get_bucket_stats('releases') # Fresh computation
```
#### `put_object`
@@ -304,7 +334,7 @@ client.delete_bucket(Bucket='old-releases')
#### `list_buckets`
List all S3 buckets (boto3-compatible).
List all S3 buckets (boto3-compatible). Includes cached statistics when available.
```python
def list_buckets(
@@ -315,7 +345,32 @@ def list_buckets(
##### Returns
Dict with list of buckets and owner information (identical to boto3).
Dict with list of buckets and owner information (identical to boto3). Each bucket may include optional `DeltaGliderStats` metadata if statistics have been previously cached.
##### Response Structure
```python
{
'Buckets': [
{
'Name': 'bucket-name',
'CreationDate': datetime(2025, 1, 1),
'DeltaGliderStats': { # Optional, only if cached
'Cached': True,
'Detailed': bool, # Whether detailed stats were fetched
'ObjectCount': int,
'TotalSize': int,
'CompressedSize': int,
'SpaceSaved': int,
'AverageCompressionRatio': float,
'DeltaObjects': int,
'DirectObjects': int
}
}
],
'Owner': {...}
}
```
##### Examples
@@ -324,6 +379,17 @@ Dict with list of buckets and owner information (identical to boto3).
response = client.list_buckets()
for bucket in response['Buckets']:
print(f"{bucket['Name']} - Created: {bucket['CreationDate']}")
# Check if stats are cached
if 'DeltaGliderStats' in bucket:
stats = bucket['DeltaGliderStats']
print(f" Cached stats: {stats['ObjectCount']} objects, "
f"{stats['AverageCompressionRatio']:.1%} compression")
# Fetch stats first, then list buckets to see cached data
client.get_bucket_stats('my-bucket', detailed_stats=True)
response = client.list_buckets()
# Now 'my-bucket' will include DeltaGliderStats in response
```
### Simple API Methods
@@ -460,6 +526,104 @@ else:
# Re-upload or investigate
```
### Cache Management Methods
DeltaGlider maintains two types of caches for performance optimization:
1. **Reference cache**: Binary reference files used for delta reconstruction
2. **Statistics cache**: Bucket statistics (session-scoped)
#### `clear_cache`
Clear all cached data including reference files and bucket statistics.
```python
def clear_cache(self) -> None
```
##### Description
Removes all cached reference files from the local filesystem and invalidates all bucket statistics. Useful for:
- Forcing fresh statistics computation
- Freeing disk space in long-running applications
- Ensuring latest data after external bucket modifications
- Testing and development workflows
##### Cache Types Cleared
1. **Reference Cache**: Binary reference files stored in `/tmp/deltaglider-*/`
- Encrypted at rest with ephemeral keys
- Content-addressed storage (SHA256-based filenames)
- Automatically cleaned up on process exit
2. **Statistics Cache**: Bucket statistics cached per client session
- Metadata about compression ratios and object counts
- Session-scoped (not persisted to disk)
- Automatically invalidated on bucket mutations
##### Examples
```python
# Long-running application
client = create_client()
# Work with files
for i in range(1000):
client.upload(f"file_{i}.zip", "s3://bucket/")
# Periodic cache cleanup to prevent disk buildup
if i % 100 == 0:
client.clear_cache()
# Force fresh statistics after external changes
stats_before = client.get_bucket_stats('releases') # Cached
# ... external tool modifies bucket ...
client.clear_cache()
stats_after = client.get_bucket_stats('releases') # Fresh data
# Development workflow
client.clear_cache() # Start with clean state
```
#### `evict_cache`
Remove a specific cached reference file from the local cache.
```python
def evict_cache(self, s3_url: str) -> None
```
##### Parameters
- **s3_url** (`str`): S3 URL of the reference file to evict (e.g., `s3://bucket/prefix/reference.bin`)
##### Description
Removes a specific reference file from the cache without affecting other cached files or statistics. Useful for:
- Selective cache invalidation when specific references are updated
- Memory management in applications with many delta spaces
- Testing specific delta compression scenarios
##### Examples
```python
# Evict specific reference after update
client.upload("new-reference.zip", "s3://releases/v2.0.0/")
client.evict_cache("s3://releases/v2.0.0/reference.bin")
# Next upload will fetch fresh reference
client.upload("similar-file.zip", "s3://releases/v2.0.0/")
# Selective eviction for specific delta spaces
delta_spaces = ["v1.0.0", "v1.1.0", "v1.2.0"]
for space in delta_spaces:
client.evict_cache(f"s3://releases/{space}/reference.bin")
```
##### See Also
- [docs/CACHE_MANAGEMENT.md](../../CACHE_MANAGEMENT.md): Complete cache management guide
- `clear_cache()`: Clear all caches
#### `lifecycle_policy`
Set lifecycle policy for S3 prefix (placeholder for future implementation).