When the disk (or memory) tier is at cap or the volume returns ENOSPC,
ops currently look like random misses with no clear "we are dropping
data." Count those events as capacity_pressure_events on /metrics and
log tier plus reason so operators can tell capacity pressure from a
cold cache, without changing the existing evictions counter.
Link: #36
promoteToFast read FileInfo.Size from Stat after the VFS lock was
released, while WriteCloser.Close updated Size on the same live
object. Concurrent Create/Open on overlapping keys tripped the race
detector.
Stat now returns a FileInfo snapshot, and promotion uses the
ReadAll length for the fast-tier Create size. Promotion stays
best-effort.
#21
- Added metrics for bytes saved from cache to improve performance insights.
- Updated cache eviction strategies in MemoryFS and DiskFS to include metrics tracking for hits and evictions.
- Enhanced README.md with updated garbage collection algorithm descriptions and recommendations for cache usage.
- Introduced new madviseSequential functionality for improved memory access hints on Unix systems.
- Adjusted validation configuration in examples to better reflect realistic usage scenarios.
- Introduced coalescing logic in `coalescing.go` to handle concurrent identical upstream fetches, including a state machine and response buffering for improved performance.
- Implemented a new cache file format in `format.go`, supporting serialization and deserialization of HTTP responses, along with range request handling.
- Developed an HTTP handler in `handler.go` to manage requests, including special endpoint handling and metrics reporting.
- Added rate limiting functionality in `ratelimit.go` to control per-client and global request rates, enhancing security and performance.
- Created service management capabilities in `service.go` to define and manage cacheable services, including user-agent detection.
- Updated tests in `steamcache_test.go` to cover new functionalities, ensuring robustness and reliability across the codebase.
- Updated `disk.New` to support asynchronous initialization for large caches, improving responsiveness during startup.
- Introduced an eviction function parameter to `disk.New`, ensuring proper handling of over-capacity scenarios.
- Enhanced error handling in various components, including memory and disk tests, to ensure robustness and clarity.
- Refactored tests to validate new behaviors, including checks for delayed attachment and proper error propagation.
- Removed obsolete error handling code and tests related to the now-deleted errors package, streamlining the codebase.
- Updated the 'bench' target in the Makefile to run all benchmarks for MemoryFS and DiskFS, improving clarity and coverage.
- Added explicit post-eviction consistency checks in DiskFS tests to ensure on-disk files are removed after eviction.
- Introduced new benchmarks for memory eviction strategies under pressure, enhancing test coverage for memory management.
- Improved error handling in benchmark tests for both disk and memory file systems, ensuring robustness during performance evaluations.
- Refactored key generation in tests for consistency and clarity.
- Updated the caching logic to utilize a predictive cache warmer, enhancing content prefetching based on access patterns.
- Replaced the legacy warming system with a more efficient predictive approach, allowing for better performance and resource management.
- Refactored memory management to integrate dynamic cache size adjustments based on system memory usage, improving overall efficiency.
- Simplified the VFS interface and improved concurrency handling with sharded locks for better performance in multi-threaded environments.
- Enhanced tests to validate the new caching and memory management behaviors, ensuring reliability and performance improvements.
- Changed module name from `s1d3sw1ped/SteamCache2` to `s1d3sw1ped/steamcache2` for consistency.
- Updated all import paths and references throughout the codebase to reflect the new module name.
- Adjusted README and Makefile to use the updated module name, ensuring clarity in usage instructions.
- Updated caching logic to support size-based promotion filtering, ensuring that not all files may be promoted based on size constraints.
- Implemented adaptive caching strategies with a new AdaptiveCacheManager to analyze access patterns and adjust caching strategies dynamically.
- Introduced predictive caching features with a PredictiveCacheManager to prefetch content based on access patterns.
- Added a CacheWarmer to preload popular content into the cache, improving access times for frequently requested files.
- Refactored memory management with a DynamicCacheManager to adjust cache sizes based on system memory usage.
- Enhanced VFS interface and file metadata handling to support new features and improve performance.
- Updated tests to validate new caching behaviors and ensure reliability of the caching system.
- Replaced SHA1 hash calculations with SHA256 for improved security and consistency in cache key generation.
- Introduced a new TestURLHashing function to validate the new cache key generation logic.
- Removed outdated hash calculation tests and streamlined the caching process to focus on URL-based hashing.
- Implemented lightweight validation methods in ServeHTTP to enhance performance and reliability of cached responses.
- Added batched time updates in VFS implementations for better performance during access time tracking.
- Introduced a YAML-based configuration system, allowing for automatic generation of a default `config.yaml` file.
- Updated the application to load configuration settings from the YAML file, improving flexibility and ease of use.
- Added a Makefile to streamline development tasks, including running the application, testing, and managing dependencies.
- Enhanced `.gitignore` to include build artifacts and configuration files.
- Removed unused Prometheus metrics and related code to simplify the codebase.
- Updated dependencies in `go.mod` and `go.sum` for improved functionality and performance.
- Added AccessCount field to FileInfo struct for improved tracking of file access frequency.
- Updated NewFileInfo and NewFileInfoFromOS functions to initialize AccessCount.
- Modified DiskFS and MemoryFS to preserve and increment AccessCount during file operations.
- Enhanced garbage collection methods (LRU, LFU, FIFO, Largest, Smallest, Hybrid) to utilize AccessCount for more effective space reclamation.
revert Enhance FileInfo structure and DiskFS functionality
- Added CTime (creation time) and AccessCount fields to FileInfo struct for better file metadata tracking.
- Updated NewFileInfo and NewFileInfoFromOS functions to initialize new fields.
- Enhanced DiskFS to maintain access counts and file metadata, including flushing to JSON files.
- Modified Open and Create methods to increment access counts and set creation times appropriately.
- Updated garbage collection logic to utilize real access counts for files.
- Added CTime (creation time) and AccessCount fields to FileInfo struct for better file metadata tracking.
- Updated NewFileInfo and NewFileInfoFromOS functions to initialize new fields.
- Enhanced DiskFS to maintain access counts and file metadata, including flushing to JSON files.
- Modified Open and Create methods to increment access counts and set creation times appropriately.
- Updated garbage collection logic to utilize real access counts for files.
- Updated disk_test.go to replace Set and Get with Create and Open methods for better clarity and functionality.
- Modified fileinfo.go to include package comment.
- Refactored gc.go to streamline garbage collection handling and removed unused statistics.
- Updated gc_test.go to comment out large random tests for future implementation.
- Enhanced memory.go to implement LRU caching and metrics for memory usage.
- Updated memory_test.go to replace Set and Get with Create and Open methods.
- Removed sync.go as it was redundant and not utilized.
- Updated vfs.go to reflect changes in the VFS interface, replacing Set and Get with Create and Open.
- Added package comments to vfserror.go for consistency.
- Added Prometheus client library for metrics collection.
- Refactored garbage collection strategy from random deletion to LRU (Least Recently Used) deletion.
- Introduced per-key locking in cache to prevent race conditions.
- Enhanced logging with structured log messages for cache hits and misses.
- Implemented a retry mechanism for upstream requests with exponential backoff.
- Updated Go modules and indirect dependencies for better compatibility and performance.
- Removed unused sync filesystem implementation.
- Added version initialization to ensure a default version string.