Implemented full incremental backup creation:
internal/backup/incremental_postgres.go:
- CreateIncrementalBackup() - main entry point
- Validates base backup exists and is full backup
- Loads base backup metadata (.meta.json)
- Uses FindChangedFiles() to detect modifications
- Creates tar.gz with ONLY changed files
- Generates incremental metadata with:
- Base backup ID (SHA-256)
- Backup chain (base -> incr1 -> incr2...)
- Changed file count and total size
- Saves .meta.json with full incremental metadata
- Calculates SHA-256 checksum of archive
internal/backup/incremental_tar.go:
- createTarGz() - creates compressed archive
- addFileToTar() - adds individual files to tar
- Handles context cancellation
- Progress logging for each file
- Preserves file permissions and timestamps
Helper Functions:
- loadBackupInfo() - loads BackupMetadata from .meta.json
- buildBackupChain() - constructs restore chain
- CalculateFileChecksum() - SHA-256 for archive
Features:
✅ Creates tar.gz with ONLY changed files
✅ Much smaller than full backup
✅ Links to base backup via SHA-256
✅ Tracks complete restore chain
✅ Full metadata for restore validation
✅ Context-aware (cancellable)
Status: READY FOR TESTING
Next: Wire into backup engine, test with real PostgreSQL data
