Strategic Advantage: We have official HDF5 C library as reference implementation! Approach: Port proven algorithms, not invent from scratch - Senior Go Developer mindset
Last Updated: 2025-01-29 | Current Version: v0.13.4 | Strategy: HDF5 2.0.0 compatible → security hardened → v1.0.0 LTS | Milestone: v0.13.4 RELEASED! (2025-01-29 attribute reading fix) → v1.0.0 LTS (Q3 2026)
Build a production-ready, pure Go HDF5 library with full read/write capabilities, leveraging the battle-tested HDF5 C library as our reference implementation.
✅ Reference Implementation Available
- Official HDF5 C library at
D:\projects\scigolibs\hdf5c\src(30+ years of development) - Well-documented algorithms and data structures
- Proven edge case handling
- Community knowledge base
✅ Not Starting From Scratch
- Port existing algorithms with Go best practices
- Use C library test cases for validation
- Follow established conventions
- Learn from production experience
- Senior Developer approach: Understand, adapt, improve
✅ Faster Development
- Direct code translation when appropriate
- Existing bug fixes and optimizations
- Clear implementation patterns
- 10x productivity with go-senior-architect agent
v0.10.0-beta (READ complete) ✅ RELEASED 2025-10-29
↓ (2 weeks)
v0.11.x-beta (WRITE features) ✅ COMPLETE 2025-11-13
↓ (~75% → ~100%)
v0.12.0 (FEATURE COMPLETE + STABLE) ✅ RELEASED 2025-11-13
↓ (1 day - HDF5 2.0.0 compatibility)
v0.13.0 (HDF5 2.0.0 + SECURITY) ✅ RELEASED 2025-11-13
↓ (same day - documentation correction)
v0.13.1 (HOTFIX - Documentation) ✅ RELEASED 2025-11-13
↓ (v0 superblock bug fix)
v0.13.2 (BUGFIX - V0 superblock) ✅ RELEASED 2025-01-17
↓ (compatibility improvements)
v0.13.3 (FEATURE - Named Datatypes, Soft Links) ✅ RELEASED 2025-01-28
↓ (community adoption + feedback + monitoring)
v0.13.x (maintenance phase) → Stable maintenance, bug fixes, minor enhancements
↓ (6-9 months production validation)
v1.0.0 LTS → Long-term support release (Q3 2026)
v0.12.0 = Stable release with feature-complete write support ✅ RELEASED
- Compound datatypes, soft/external links complete
- 433 official HDF5 test files validated (now 100% with v0.13.3)
- 100% write support achieved
- API stable, production-ready
v0.13.0 = HDF5 2.0.0 Format Specification v4.0 + Security hardening ✅ RELEASED
- HDF5 Format Spec v4.0 compliance (superblock v0, v2, v3)
- 64-bit chunk dimensions (>4GB chunks)
- AI/ML datatypes (FP8 E4M3/E5M2, bfloat16)
- 4 CVEs fixed (overflow protection throughout)
- 86.1% coverage, 0 linter issues
v0.13.1 = Documentation Correction Hotfix ✅ RELEASED (same day)
- Fixed incorrect "Superblock Version 4" references (non-existent)
- Reality: HDF5 Format Spec v4.0 defines superblock versions 0-3 only
- Added .codecov.yml to prevent false failures on documentation changes
- No functional changes, documentation only
v0.13.2 = V0 Superblock Bug Fix ✅ RELEASED (2025-01-17)
- Fixed Issue #9: V0 superblock files showing 0 children
- Corrected B-tree address endianness parsing
- Fixed local heap data segment address reading
- Added cycle detection for shared symbol tables
v0.13.3 = Major Compatibility Improvements ✅ RELEASED (2025-01-28)
- Fixed Issue #9 (continued): V1 object header message parsing
- Fixed V2 header parsing: CRC32 checksum + creation index handling
- Fixed soft link handling (CacheType=2) - lazy resolution like C library
- Added Named Datatype (committed datatype) support
- Official HDF5 test suite: 100% pass rate (378/378 valid files)
- Added flux.h5 to test suite, professional error testing for corrupt files
v0.13.4 = Attribute Reading Fix ✅ RELEASED (2025-01-29)
- Fixed Issue #14: Variable-length string attributes not readable
- Fixed V1/V2 attribute message 8-byte alignment (H5O_ALIGN_OLD macro)
- Fixed IsVariableString() detection (ClassBitField, not Properties)
- Fixed vlen string data format (4-byte length prefix + Global Heap reference)
- Files created by h5py now work correctly
v0.13.x = Stable Maintenance Phase (current)
- Monitoring for bug reports from production use
- Performance optimizations when identified
- Minor feature enhancements from community feedback
- NO breaking API changes
- Focus: Stability, reliability, community support
v1.0.0 = Production with ALL HDF5 format support
- Supports HDF5 v0, v2, v3 superblocks ✅
- Ready for their future HDF5 2.0.0 format (will be added in v1.x.x updates)
- Ultra-modern library = all formats from day one!
- Our v2.0.0 = only if WE change Go API (not HDF5 formats!)
Why stable at v0.12.0?: Feature complete + 98.2% official test suite validation + production quality. API proven stable through extensive testing. v1.0.0 = LTS guarantee.
See: docs/dev/notes/VERSIONING_STRATEGY.md for complete strategy
Phase: 🛡️ Stable Maintenance (monitoring, community support) HDF5 2.0.0 Format Spec v4.0: Complete! 🎉 Security: Hardened with 4 CVEs fixed! 🔒 AI/ML Support: FP8 & bfloat16 ready! 🤖
What Works:
- ✅ File creation (Truncate/Exclusive modes)
- ✅ HDF5 Format Spec v4.0 compliance (superblock v0, v2, v3 with CRC32 validation) ✨ v0.13.0
- ✅ 64-bit Chunk Dimensions (>4GB chunks for scientific datasets) ✨ v0.13.0
- ✅ AI/ML Datatypes (FP8 E4M3, FP8 E5M2, bfloat16 - IEEE 754 compliant) ✨ v0.13.0
- ✅ Security Hardening (4 CVEs fixed, overflow protection throughout) ✨ v0.13.0
- ✅ Datasets (all layouts: contiguous, chunked, compact)
- ✅ Dataset resizing with unlimited dimensions
- ✅ Variable-length datatypes: strings, ragged arrays
- ✅ Groups (symbol table format)
- ✅ Attributes (dense & compact storage)
- ✅ Attribute modification/deletion (RMW complete)
- ✅ Advanced datatypes (arrays, enums, references, opaque)
- ✅ Compression (GZIP, Shuffle, Fletcher32)
- ✅ Links (hard links, soft links, external links - all complete)
- ✅ Fractal heap with indirect blocks
- ✅ Smart B-tree rebalancing (4 modes)
- ✅ Compound datatypes (write support complete)
Read Enhancements:
- ✅ Hyperslab selection (efficient data slicing) - 10-250x faster!
- ✅ Chunk-aware partial reading
Validation:
- ✅ Official HDF5 Test Suite: 98.2% pass rate (380/387 files)
- ✅ 433 test files from HDF5 1.14.6
- ✅ Production quality confirmed
History: See CHANGELOG.md for complete release history
Goal: Address first real user feedback from MATLAB project ✅
Critical Features (User-Requested 🎉):
-
✅ TASK-013: Support datasets in nested groups (HIGH)
- Status: ✅ Complete (commit 6e68143, 2h, 36x faster)
- Feature: Datasets in nested groups fully working
- Tested: MATLAB v7.3 complex numbers validated by user
-
✅ TASK-014: Write attributes to groups (MEDIUM)
- Status: ✅ Complete (commit 36994ac, 2h, 30x faster)
- Feature: Group attributes fully working
- Tested: MATLAB v7.3 metadata validated by user
Additional Features: 3. ✅ TASK-015: Soft links and external links
- Status: ✅ Complete (commit a7ec762, 4h, 30x faster)
- Hard links: Full implementation with reference counting
- Soft/external links: MVP (API + validation, full in v0.12.0)
- Tests: 36 tests, 100% pass, 0 linter issues
- ✅ TASK-016: Indirect blocks for fractal heap (large objects)
- Status: ✅ Complete (commit 7f80b5d, 4h, 30x faster)
- Feature: Automatic scaling beyond 512KB
- Tested: 200+ attributes validated
Achievement: Sprint completed in 12 hours (estimated 3-4 weeks) - 30x faster! 🚀
User Validation: ✅ MATLAB project released using develop branch!
Target: 1-2 weeks ✅ DONE IN 12 HOURS!
Goal: Add advanced write features + read enhancement requested by community
Duration: 2-3 days (estimated 10-15 days) - 30x faster with AI! 🚀
Delivered:
- ✅ TASK-018: Dataset Resize and Extension
- Unlimited dimensions support
- Dynamic dataset growth/shrink
Resize()method with validation
- ✅ TASK-017: Variable-Length Datatypes
- 7 VLen types (strings, int/uint/float ragged arrays)
- Global heap writer infrastructure
- Full HDF5 spec compliance
- ✅ TASK-019: Hyperslab Selection (Data Slicing)
- Community request from C# HDF5 library author
- Simple and advanced APIs
- 10-250x performance improvement
- Chunk-aware reading optimization
Quality:
- 4,366 lines added (code + tests)
- 63 new tests (22 subtests), all passing
- 0 linter issues
- Coverage: 70.4%
Community Impact:
- Feature requested by apollo3zehn-h5 (PureHDF author)
- Expert technical guidance incorporated
- Standard HDF5 feature now available in Go
Current: v0.11.6-beta | Next: v0.12.0 | Target: v1.0.0 (Q3 2026)
Goal: ALL write features implemented + Official test suite validation ✅ ACHIEVED!
Duration: 1 week (estimated 10-15 days traditional, completed in 7 days with AI - 15x faster!)
Delivered Features:
-
✅ TASK-021: Compound Datatype Writing (COMPLETE)
- Full structured data support (C structs / Go structs)
- Nested compounds, all field types
- Scientific records, database-like storage
- 100% test coverage, 0 linter issues
-
✅ TASK-022: Soft/External Links Full Implementation (COMPLETE)
- Complete soft links (symbolic path references)
- Complete external links (cross-file references)
- Path resolution, security validation
- Full HDF5 spec compliance
-
✅ TASK-020: Official HDF5 Test Suite (COMPLETE)
- 433 official .h5 test files from HDF5 1.14.6
- 98.2% pass rate (380/387 valid single-file HDF5)
- Comprehensive format validation
- Edge cases and invalid files tested
- Production quality confirmed
What Was Achieved:
- ✅ 100% write support (up from ~95%)
- ✅ All HDF5 datatypes implemented
- ✅ All linking features working
- ✅ Official validation against C library test suite
- ✅ Production quality confirmed
Quality Metrics:
- ✅ Test coverage 86.1% (exceeded >70% target)
- ✅ Official HDF5 test suite 98.2% pass rate
- ✅ 0 linter issues (34+ linters)
- ✅ Comprehensive documentation (5 guides, 5 examples)
- ✅ Cross-platform (Linux, macOS, Windows)
Status:
- ✅ Feature complete
- ✅ API stable, production-ready
- ✅ Ready for community adoption
Goal: Production validation, stability, and community support
Status: Monitoring phase after v0.13.1 hotfix
Scope:
- 🐛 Bug fixes from production use (high priority)
- 🛡️ Security updates if needed (critical priority)
- ⚡ Performance optimizations based on profiling
- 📝 Documentation improvements from user feedback
- ✨ Minor feature enhancements (community-driven)
- ⛔ NO breaking API changes
Community Adoption:
- 👥 Real-world project validation
- 📊 Performance benchmarks and profiling
- 🔍 Edge case discovery and handling
- 💬 API refinement suggestions
- 🌐 Forum and GitHub Discussions engagement
Quality Focus:
- 📈 Maintain >70% test coverage
- 🔒 Zero security vulnerabilities
- ✅ >98% HDF5 test suite pass rate
- 📋 Responsive issue triage and resolution
Goal: Community-driven improvements and advanced features
Potential Focus Areas (priority TBD based on feedback):
Performance Optimizations:
- ⚡ Parallel chunk reading/writing (goroutine-based)
- 🧠 Intelligent caching strategies
- 📊 Memory-mapped I/O for large files
- 🔄 Lazy loading optimizations
Advanced Format Features:
- 📐 Object header v2 support (B-tree v2 indexed attributes)
- 🗂️ Group indexed format (B-tree v2 for large groups)
- 🔗 Advanced linking features (user-defined links)
- 📦 Dataset filters extensibility
Developer Experience:
- 🛠️ Higher-level APIs for common workflows
- 📚 More examples and tutorials
- 🧪 Testing utilities for users
- 📖 Comprehensive API documentation
Enterprise Features:
- 🔍 File validation and repair tools
- 📊 Performance profiling tools
- 🔒 Enhanced security options
- 📈 Metrics and telemetry
Note: Features will be prioritized based on:
- Community requests and votes
- Production use case needs
- HDF5 standard evolution
- Maintainability and complexity
Goal: LTS release with stability guarantees
Requirements:
- v0.12.x stable for 6+ months
- Positive community feedback
- No critical bugs
- API proven in production
LTS Guarantees:
- ✅ API stability (no breaking changes in v1.x.x)
- ✅ Long-term support (3+ years)
- ✅ Semantic versioning strictly followed
- ✅ ALL HDF5 formats supported (v0, v2, v3)
- ✅ Security updates and bug fixes
- ✅ Performance improvements
Official HDF5:
- Format Spec: https://docs.hdfgroup.org/hdf5/latest/_f_m_t3.html
- C Library: https://github.com/HDFGroup/hdf5
- Tools: h5dump, h5diff, h5stat
Development:
- CONTRIBUTING.md - How to contribute
- docs/dev/ - Development documentation
- Reference:
D:\projects\scigolibs\hdf5c\src(HDF5 C library)
Documentation:
- README.md - Project overview
- QUICKSTART.md - Get started quickly
- docs/guides/ - User guides
- CHANGELOG.md - Release history
Feedback:
- GitHub Issues - Bug reports and feature requests
- Discussions - Questions and help
Using C Library as Reference:
- Port proven algorithms with Go idioms
- Validate with h5dump and reference files
- Pure Go (no CGo dependencies)
- Round-trip validation (Go write → C read → verify)
Version 5.2 (Updated 2025-01-27) Current: v0.13.4 (STABLE) | Phase: Maintenance | Next: v0.14.0+ (community-driven) | Target: v1.0.0 LTS (Q3 2026)