loadContainerState

Retrieves the stored KarlContainerState for the specified user from the database.

This method performs a parameterized query to fetch the user's container state and reconstructs the KarlContainerState object from the stored BLOB data and version information.

Query Operation:

SELECT state_data, version FROM container_states WHERE user_id = ?

Data Reconstruction:

• BLOB Deserialization: Converts stored binary data back to state object

• Version Restoration: Reconstructs version information for state tracking

• Null Handling: Returns null if no state exists for the specified user

Performance Characteristics:

• Primary Key Lookup: O(1) query performance via user_id primary key

• Memory Efficient: Only loads requested user's data

• Non-blocking: Executes on Dispatchers.IO for coroutine compatibility

Error Handling & Recovery:

• SQLException: Database access errors with comprehensive logging

• Graceful Degradation: Returns null on any error rather than throwing

• Resource Cleanup: Automatic closure of ResultSet and PreparedStatement

Return Value Semantics:

• Non-null: Valid KarlContainerState with data and version information

• Null: No stored state exists for the user OR error occurred during retrieval

Threading Context:

• All database operations execute on Dispatchers.IO

• Safe to call from any coroutine context

• Non-blocking operation suitable for reactive architectures

Usage Patterns:

val state = storage.loadContainerState("user123")
if (state != null) {
    // Process loaded state with data and version
    println("Loaded state version: ${state.version}")
} else {
    // No state exists or error occurred - initialize new state
    val newState = KarlContainerState.createDefault()
}

Parameters

See also