StorageProvider.swift

StorageProvider Documentation

Overview

StorageProvider.swift defines the protocol for data persistence operations in the app. It establishes a consistent interface for saving, fetching, updating, and deleting entries and clusters, regardless of the underlying storage implementation.

Protocol Definition

Core Protocol

protocol StorageProvider {
    func saveEntry(_ entry: Entry) async throws
    func fetchClusters() async throws -> [Cluster]
    func updateCluster(_ cluster: Cluster) async throws
    func fetchEntries() async throws -> [Entry]
    func deleteEntry(_ id: UUID) async throws
    func deleteCluster(_ id: UUID) async throws
}

Error Types

enum StorageError: Error {
    case saveFailed
    case fetchFailed
    case updateFailed
    case deleteFailed
    case invalidData
    case fileNotFound
}

Required Methods

Entry Management

Save Entry

func saveEntry(_ entry: Entry) async throws

• Persists a single entry to storage

• Asynchronous operation

• Throws if save fails

Fetch Entries

func fetchEntries() async throws -> [Entry]

• Retrieves all stored entries

• Returns array of Entry objects

• Throws if fetch fails

Delete Entry

func deleteEntry(_ id: UUID) async throws

• Removes entry with specified ID

• Throws if deletion fails

• Asynchronous operation

Cluster Management

Fetch Clusters

func fetchClusters() async throws -> [Cluster]

• Retrieves all stored clusters

• Returns array of Cluster objects

• Throws if fetch fails

Update Cluster

func updateCluster(_ cluster: Cluster) async throws

• Updates existing cluster or adds new one

• Asynchronous operation

• Throws if update fails

Delete Cluster

func deleteCluster(_ id: UUID) async throws

• Removes cluster with specified ID

• Throws if deletion fails

• Asynchronous operation

Usage Examples

Basic Implementation

class MyStorageProvider: StorageProvider {
    func saveEntry(_ entry: Entry) async throws {
        // Implementation
    }
    
    func fetchClusters() async throws -> [Cluster] {
        // Implementation
    }
    
    // Other required methods...
}

Using the Provider

let storage: StorageProvider = try LocalStorageProvider()

// Save an entry
try await storage.saveEntry(newEntry)

// Fetch clusters
let clusters = try await storage.fetchClusters()

Error Handling

Error Cases

Error	Typical Cause
saveFailed	Write operation failed
fetchFailed	Read operation failed
updateFailed	Update operation failed
deleteFailed	Delete operation failed
invalidData	Data corruption or invalid format
fileNotFound	Storage location not found

Example Error Handling

do {
    try await storage.saveEntry(entry)
} catch StorageError.saveFailed {
    // Handle save failure
} catch StorageError.invalidData {
    // Handle invalid data
} catch {
    // Handle other errors
}

Best Practices

1. Implementation Guidelines

   • Use async/await for all operations

   • Implement proper error handling

   • Maintain data consistency

   • Handle concurrent access

2. Data Integrity

   • Validate data before saving

   • Handle corrupt data gracefully

   • Implement backup strategies

   • Version data structures

3. Performance

   • Optimize bulk operations

   • Cache when appropriate

   • Handle large datasets efficiently

   • Monitor storage space

4. Error Recovery

   • Implement retry logic

   • Provide fallback options

   • Log errors appropriately

   • Maintain data backups

Integration Points

With Entry Model

// Example entry storage
let entry = Entry(content: "text", embeddings: [...])
try await storageProvider.saveEntry(entry)

With Clustering Service

// Example cluster update
let clusters = try await storageProvider.fetchClusters()
let updatedCluster = updateCluster(clusters[0])
try await storageProvider.updateCluster(updatedCluster)

Common Implementation Patterns

1. Local Storage

   • FileManager-based

   • UserDefaults for small data

   • SQLite database

   • Core Data

2. Remote Storage

   • REST API

   • Cloud storage

   • Synchronized storage

   • Distributed systems

3. Hybrid Approaches

   • Local cache with remote backup

   • Offline-first architecture

   • Sync strategies

Related Components

• Entry Model: Data structure for entries

• Cluster Model: Data structure for clusters

• LocalStorageProvider: Concrete implementation

• Migration Service: Data structure updates