+++
id = "extending-guide-20250427"
title = "Maintenance and Extension Guide"
status = "draft"
doc_version = "1.0"
audience = ["developers", "maintainers"]
last_updated = "2025-04-27"
tags = ["maintenance", "extension", "transfer"]
related_docs = [
    "docs/features/transfer.md",
    "docs/api/transfer_api.md"
]
+++

# Maintenance and Extension Guide

## Extension Points

### 1. Transfer Protocol Customization

The transfer protocol can be extended by modifying the following components:

```cpp
// NetworkUtil class handles the actual transfer
NetworkUtil::instance()->tryTransApply(ip); // Initiate transfer
NetworkUtil::instance()->doSendFiles(fileList, targetIp); // Send files
NetworkUtil::instance()->cancelTrans(ip); // Cancel transfer
```

### 2. Transfer Status Handling

Customize transfer status handling by modifying:

```cpp
enum TransferStatus {
    Idle,        // No active transfer
    Connecting,  // Establishing connection
    Confirming,  // Waiting for confirmation
    Transfering, // Transfer in progress
    Failed       // Transfer failed
};
```

### 3. Progress Tracking

Override progress tracking logic in:

```cpp
void TransferHelper::updateTransProgress(uint64_t current) {
    // Custom progress calculation logic here
    updateProgress(progressValue, remainTime);
}
```

## Maintenance Best Practices

### 1. Error Handling

Key error scenarios to handle:

```cpp
case TRANS_EXCEPTION:
    if (path == "io_error") {
        // Handle disk space issues
    } else if (path == "net_error") {
        // Handle network issues
    }
    break;
```

### 2. Performance Optimization

Optimization opportunities:

1. **Chunk Size Tuning**:
   ```cpp
   // In NetworkUtil implementation
   setChunkSize(optimalSize); // Adjust based on network conditions
   ```

2. **Parallel Transfers**:
   ```cpp
   // Enable parallel file transfers
   setMaxParallelTransfers(4); 
   ```

### 3. Platform-Specific Implementations

Handle platform differences:

```cpp
#ifdef __linux__
    // Linux-specific implementations
    notice = new NoticeUtil(this);
#else
    // Windows/macOS implementations
    dialog = new CooperationTransDialog();
#endif
```

## Testing Recommendations

1. **Unit Tests**:
   - Test all TransferStatus transitions
   - Verify error handling paths

2. **Integration Tests**:
   ```cpp
   // In transfer_test.cpp
   TEST_F(TransferTest, testLargeFileTransfer) {
       // Test large file handling
   }
   ```

3. **Performance Tests**:
   - Measure transfer speeds with different chunk sizes
   - Test under various network conditions

## Version Compatibility

When making changes:

1. Maintain backward compatibility with:
   ```cpp
   // Old protocol compatibility
   void TransferHelper::compatTransJobStatusChanged();
   ```

2. Document breaking changes in:
   ```markdown
   ## Version History
   - v2.0: Changed transfer protocol format
   - v1.5: Added parallel transfer support
   ```

## Related Resources
- [Transfer Feature Documentation](docs/features/transfer.md)
- [API Reference](docs/api/transfer_api.md)
- [Source Code](src/lib/cooperation/core/net/helper/transferhelper.cpp)