XDB v1.4.2 - add test mode API and prevent storage pollution

[1.4.2] - 2026-02-01

Added

• Test Mode API: Introduced db_set_test_mode() to suppress background maintenance tasks, ensuring a cleaner environment during automated testing.

Fixed

• Storage Pollution: Prevented snapshot triggering during unit tests to avoid unwanted data persistence in the data/ directory.

XDB v1.4.1 - resolve SIGSEGV and memory corruption

[1.4.1] - 2026-01-31

Fixed (Stability & Memory Integrity)

• Atomic Insert (Deep Copy): Resolved Use-After-Free memory corruption by implementing cJSON_Duplicate in the db_insert function. The database now maintains full memory ownership, isolated from the network layer request lifecycle.
• Safe Detach-Append Strategy: Replaced destructive in-place replacement with a Detach & Append strategy for update operations. This ensures internal Linked List pointer integrity during high-concurrency access.
• Thread-Safe Iteration: Replaced standard iteration macros with manual pointer navigation to prevent race conditions when the collection structure is modified by concurrent threads.
• SIGSEGV Prevention: Eliminated the primary cause of Segmentation Faults in the get_object_item function, previously triggered by dangling pointer access.

XDB v1.4.0 - implement selective update patch, enforce id immutability

[1.4.0] - 2026-01-30

Added

• Selective Update (Patch): Supported partial updates, allowing users to update specific fields without overwriting the entire document.

Enforced

• _id Immutability: Implemented strict protection to ensure any attempt to modify the unique identifier (_id) during an update is ignored, maintaining data integrity.

Optimized

• Memory Pointer Synchronization: Improved synchronization between g_index and the main document store to ensure data consistency and faster lookups.

XDB v1.3.0 - implement atomic update and upsert

[1.3.0] - 2026-01-30

Added

• Atomic Update: Implemented db_update function for efficient document updates without altering the _id.
• Upsert Logic: Introduced db_upsert function to automatically determine whether to perform an insert or update based on ID existence.
• Protocol Extension: Integrated update and upsert actions into server.c for network-layer access.
• Regression Tests: Added new test cases in test_crud.c to verify data update workflows.

Fixed

• Compiler Warnings: Added <stdlib.h> header in unit tests to resolve implicit free() declaration issues.
• Test Compatibility: Replaced ASSERT_STR_EQ macro with standard strcmp in test_crud.c to ensure compilation stability.

XDB v1.2.0 - implement in-memory indexing for O(1) ID lookups

[1.2.0] - 2026-01-29

Added

• Basic Indexing: Implemented an in-memory Hash Map (O(1) Lookups) for _id fields to replace linear scans during ID-based queries.
• Index Synchronization: Automatic index updates on document insertion and deletion to ensure data consistency.

Improved

• Search Performance: Significant latency reduction for large datasets when querying by unique identifier.

Fixed

• Deep Copy Indexing: Resolved empty data return in db_find by implementing Deep Copy indexing to ensure data persistence during retrieval.

XDB v1.1.0 - add database snapshot feature

[1.1.0] - 2026-01-29

Added

• Snapshot System: Added Auto-Snapshotting every 5 writes and Manual Snapshot action via TCP ({"action": "snapshot"}).

Fixed

• Empty Request Handling Added a filter to ignore whitespace-only or empty newline messages from clients

XDB v1.0.0 - initial release

[1.0.0] - 2026-01-27

Added

• Core Engine: Initial implementation of the JSON-based database engine.
• CRUD Operations: Full support for Create, Read, Update, and Delete operations.
• Dependency Management: Integrated cJSON library via Git Submodules for high-performance JSON parsing.
• CI/CD Pipeline:
  • Automated code formatting with clang-format.
  • Static analysis using cppcheck with a custom suppression list.
  • Multi-compiler build verification (GCC and Clang).
  • Memory safety validation using Valgrind for Pull Requests.
• Build System: Optimized Makefile for clean compilation and automated unit testing.
• Project Structure: Standardized C project layout (src, include, third_party).
• Documentation: Comprehensive README and initial project configuration files.