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

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@@ -177,6 +177,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
- Delta compression for versioned artifacts
- 99%+ compression for similar files
[5.1.0]: https://github.com/beshu-tech/deltaglider/compare/v5.0.3...v5.1.0
[5.0.3]: https://github.com/beshu-tech/deltaglider/compare/v5.0.1...v5.0.3
[5.0.1]: https://github.com/beshu-tech/deltaglider/compare/v5.0.0...v5.0.1
[5.0.0]: https://github.com/beshu-tech/deltaglider/compare/v4.2.4...v5.0.0
[4.2.4]: https://github.com/beshu-tech/deltaglider/compare/v4.2.3...v4.2.4

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@@ -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).

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@@ -5,15 +5,17 @@ Real-world examples and patterns for using DeltaGlider in production application
## Table of Contents
1. [Performance-Optimized Bucket Listing](#performance-optimized-bucket-listing)
2. [Bucket Management](#bucket-management)
3. [Software Release Management](#software-release-management)
4. [Database Backup System](#database-backup-system)
5. [CI/CD Pipeline Integration](#cicd-pipeline-integration)
6. [Container Registry Storage](#container-registry-storage)
7. [Machine Learning Model Versioning](#machine-learning-model-versioning)
8. [Game Asset Distribution](#game-asset-distribution)
9. [Log Archive Management](#log-archive-management)
10. [Multi-Region Replication](#multi-region-replication)
2. [Bucket Statistics and Monitoring](#bucket-statistics-and-monitoring)
3. [Session-Level Cache Management](#session-level-cache-management)
4. [Bucket Management](#bucket-management)
5. [Software Release Management](#software-release-management)
6. [Database Backup System](#database-backup-system)
7. [CI/CD Pipeline Integration](#cicd-pipeline-integration)
8. [Container Registry Storage](#container-registry-storage)
9. [Machine Learning Model Versioning](#machine-learning-model-versioning)
10. [Game Asset Distribution](#game-asset-distribution)
11. [Log Archive Management](#log-archive-management)
12. [Multi-Region Replication](#multi-region-replication)
## Performance-Optimized Bucket Listing
@@ -199,6 +201,322 @@ performance_comparison('releases')
2. **Never Fetch for Non-Deltas**: The SDK automatically skips metadata fetching for non-delta files even when `FetchMetadata=True`.
## Bucket Statistics and Monitoring
DeltaGlider provides powerful bucket statistics with session-level caching for performance.
### Quick Dashboard Stats (Cached)
```python
from deltaglider import create_client
client = create_client()
def show_bucket_dashboard(bucket: str):
"""Display real-time bucket statistics with caching."""
# First call: computes stats (~50ms)
stats = client.get_bucket_stats(bucket)
# Second call: instant (cached)
stats = client.get_bucket_stats(bucket)
print(f"Dashboard for {stats.bucket}")
print(f"=" * 60)
print(f"Total Objects: {stats.object_count:,}")
print(f" Delta Objects: {stats.delta_objects:,}")
print(f" Direct Objects: {stats.direct_objects:,}")
print()
print(f"Original Size: {stats.total_size / (1024**3):.2f} GB")
print(f"Stored Size: {stats.compressed_size / (1024**3):.2f} GB")
print(f"Space Saved: {stats.space_saved / (1024**3):.2f} GB")
print(f"Compression Ratio: {stats.average_compression_ratio:.1%}")
# Example: Show stats for multiple buckets (each cached separately)
for bucket_name in ['releases', 'backups', 'archives']:
show_bucket_dashboard(bucket_name)
```
### Detailed Compression Analysis
```python
def detailed_compression_report(bucket: str):
"""Generate detailed compression report with accurate ratios."""
# Detailed stats fetch metadata for delta files (slower, accurate)
stats = client.get_bucket_stats(bucket, detailed_stats=True)
efficiency = (stats.space_saved / stats.total_size * 100) if stats.total_size > 0 else 0
print(f"Detailed Compression Report: {stats.bucket}")
print(f"=" * 60)
print(f"Object Distribution:")
print(f" Total: {stats.object_count:,}")
print(f" Delta-Compressed: {stats.delta_objects:,} ({stats.delta_objects/stats.object_count*100:.1f}%)")
print(f" Direct Storage: {stats.direct_objects:,} ({stats.direct_objects/stats.object_count*100:.1f}%)")
print()
print(f"Storage Efficiency:")
print(f" Original Data: {stats.total_size / (1024**3):.2f} GB")
print(f" Actual Storage: {stats.compressed_size / (1024**3):.2f} GB")
print(f" Space Saved: {stats.space_saved / (1024**3):.2f} GB")
print(f" Efficiency: {efficiency:.1f}%")
print(f" Avg Compression: {stats.average_compression_ratio:.2%}")
# Calculate estimated monthly costs (example: $0.023/GB S3 Standard)
cost_without = stats.total_size / (1024**3) * 0.023
cost_with = stats.compressed_size / (1024**3) * 0.023
monthly_savings = cost_without - cost_with
print()
print(f"Estimated Monthly S3 Costs ($0.023/GB):")
print(f" Without DeltaGlider: ${cost_without:.2f}")
print(f" With DeltaGlider: ${cost_with:.2f}")
print(f" Monthly Savings: ${monthly_savings:.2f}")
# Example: Detailed report
detailed_compression_report('releases')
```
### List Buckets with Cached Stats
```python
def list_buckets_with_stats():
"""List all buckets and show cached statistics if available."""
# Pre-fetch stats for important buckets
important_buckets = ['releases', 'backups']
for bucket_name in important_buckets:
client.get_bucket_stats(bucket_name, detailed_stats=True)
# List all buckets (includes cached stats automatically)
response = client.list_buckets()
print("All Buckets:")
print(f"{'Name':<30} {'Objects':<10} {'Compression':<15} {'Cached'}")
print("=" * 70)
for bucket in response['Buckets']:
name = bucket['Name']
# Check if stats are cached
if 'DeltaGliderStats' in bucket:
stats = bucket['DeltaGliderStats']
obj_count = f"{stats['ObjectCount']:,}"
compression = f"{stats['AverageCompressionRatio']:.1%}"
cached = "✓ (detailed)" if stats['Detailed'] else "✓ (quick)"
else:
obj_count = "N/A"
compression = "N/A"
cached = ""
print(f"{name:<30} {obj_count:<10} {compression:<15} {cached}")
# Example: List with stats
list_buckets_with_stats()
```
### Monitoring Dashboard (Real-Time)
```python
import time
def monitoring_dashboard(buckets: list[str], refresh_seconds: int = 60):
"""Real-time monitoring dashboard with periodic refresh."""
while True:
print("\033[2J\033[H") # Clear screen
print(f"DeltaGlider Monitoring Dashboard - {time.strftime('%Y-%m-%d %H:%M:%S')}")
print("=" * 80)
for bucket_name in buckets:
# Get cached stats (instant) or compute fresh
stats = client.get_bucket_stats(bucket_name)
print(f"\n{bucket_name}:")
print(f" Objects: {stats.object_count:,} | "
f"Delta: {stats.delta_objects:,} | "
f"Direct: {stats.direct_objects:,}")
print(f" Size: {stats.compressed_size/(1024**3):.2f} GB | "
f"Saved: {stats.space_saved/(1024**3):.2f} GB | "
f"Compression: {stats.average_compression_ratio:.1%}")
print(f"\n{'=' * 80}")
print(f"Refreshing in {refresh_seconds} seconds... (Ctrl+C to exit)")
time.sleep(refresh_seconds)
# Clear cache for fresh data on next iteration
client.clear_cache()
# Example: Monitor key buckets
try:
monitoring_dashboard(['releases', 'backups', 'archives'], refresh_seconds=30)
except KeyboardInterrupt:
print("\nMonitoring stopped.")
```
## Session-Level Cache Management
DeltaGlider maintains session-level caches for optimal performance in long-running applications.
### Long-Running Application Pattern
```python
from deltaglider import create_client
import time
def long_running_upload_service():
"""Upload service with periodic cache cleanup."""
client = create_client()
processed_count = 0
while True:
# Simulate file processing
files_to_upload = get_pending_files() # Your file queue
for file_path in files_to_upload:
try:
summary = client.upload(file_path, "s3://releases/")
processed_count += 1
print(f"Uploaded {file_path}: {summary.savings_percent:.0f}% saved")
# Periodic cache cleanup (every 100 files)
if processed_count % 100 == 0:
client.clear_cache()
print(f"Cache cleared after {processed_count} files")
except Exception as e:
print(f"Error uploading {file_path}: {e}")
time.sleep(60) # Check for new files every minute
# Example: Run upload service
# long_running_upload_service()
```
### Cache Invalidation After External Changes
```python
def handle_external_bucket_changes(bucket: str):
"""Refresh statistics after external tools modify bucket."""
# Get initial stats (cached)
stats_before = client.get_bucket_stats(bucket)
print(f"Before: {stats_before.object_count} objects")
# External process modifies bucket
print("External backup tool running...")
run_external_backup_tool(bucket) # Your external tool
# Clear cache to get fresh data
client.clear_cache()
# Get updated stats
stats_after = client.get_bucket_stats(bucket)
print(f"After: {stats_after.object_count} objects")
print(f"Added: {stats_after.object_count - stats_before.object_count} objects")
# Example usage
handle_external_bucket_changes('backups')
```
### Selective Cache Eviction
```python
def selective_cache_management():
"""Manage cache for specific delta spaces."""
client = create_client()
# Upload to multiple delta spaces
versions = ['v1.0.0', 'v1.1.0', 'v1.2.0']
for version in versions:
client.upload(f"app-{version}.zip", f"s3://releases/{version}/")
# Update reference for specific version
print("Updating v1.1.0 reference...")
client.upload("new-reference.zip", "s3://releases/v1.1.0/")
# Evict only v1.1.0 cache (others remain cached)
client.evict_cache("s3://releases/v1.1.0/reference.bin")
# Next upload to v1.1.0 fetches fresh reference
# v1.0.0 and v1.2.0 still use cached references
client.upload("similar-file.zip", "s3://releases/v1.1.0/")
# Example: Selective eviction
selective_cache_management()
```
### Testing with Clean Cache
```python
import pytest
from deltaglider import create_client
def test_upload_workflow():
"""Test with clean cache state."""
client = create_client()
client.clear_cache() # Start with clean state
# Test first upload (no reference exists)
summary1 = client.upload("file1.zip", "s3://test-bucket/prefix/")
assert not summary1.is_delta # First file is reference
# Test subsequent upload (uses cached reference)
summary2 = client.upload("file2.zip", "s3://test-bucket/prefix/")
assert summary2.is_delta # Should use delta
# Clear and test again
client.clear_cache()
summary3 = client.upload("file3.zip", "s3://test-bucket/prefix/")
assert summary3.is_delta # Still delta (reference in S3)
# Run test
# test_upload_workflow()
```
### Cache Performance Monitoring
```python
import time
def measure_cache_performance(bucket: str):
"""Measure performance impact of caching."""
client = create_client()
# Test 1: Cold cache
client.clear_cache()
start = time.time()
stats1 = client.get_bucket_stats(bucket, detailed_stats=True)
cold_time = (time.time() - start) * 1000
# Test 2: Warm cache
start = time.time()
stats2 = client.get_bucket_stats(bucket, detailed_stats=True)
warm_time = (time.time() - start) * 1000
# Test 3: Quick stats from detailed cache
start = time.time()
stats3 = client.get_bucket_stats(bucket, detailed_stats=False)
reuse_time = (time.time() - start) * 1000
print(f"Cache Performance for {bucket}:")
print(f" Cold Cache (detailed): {cold_time:.0f}ms")
print(f" Warm Cache (detailed): {warm_time:.0f}ms")
print(f" Cache Reuse (quick): {reuse_time:.0f}ms")
print(f" Speedup (detailed): {cold_time/warm_time:.1f}x")
print(f" Speedup (reuse): {cold_time/reuse_time:.1f}x")
# Example: Measure cache performance
measure_cache_performance('releases')
```
3. **Use Pagination**: For large buckets, use `MaxKeys` and `ContinuationToken` to paginate results.
4. **Cache Results**: If you need metadata frequently, consider caching the results to avoid repeated HEAD requests.