Added AMX acceleration (#39)

* Added conformance of SimilarityIndex to Identifiable

* Added conformance to Hashable

* Removed print statements.

* Added AMX acceleration.

* Removed deprecated methods & added logger for save / load index operations.

Sources/SimilaritySearchKit/Core/Embeddings/Metrics/DistanceMetrics.swift

@@ -6,6 +6,7 @@
 //
 
 import Foundation
+import Accelerate
 
 /// A struct implementing the `DistanceMetricProtocol` using the dot product.
 ///
@@ -17,14 +18,22 @@ public struct DotProduct: DistanceMetricProtocol {
 
     public func findNearest(for queryEmbedding: [Float], in neighborEmbeddings: [[Float]], resultsCount: Int) -> [(Float, Int)] {
         let scores = neighborEmbeddings.map { distance(between: queryEmbedding, and: $0) }
-
         return sortedScores(scores: scores, topK: resultsCount)
     }
 
-    public func distance(between firstEmbedding: [Float], and secondEmbedding: [Float]) -> Float {
-        let dotProduct = zip(firstEmbedding, secondEmbedding).map(*).reduce(0, +)
-        return dotProduct
-    }
+
+	public func distance(between firstEmbedding: [Float], and secondEmbedding: [Float]) -> Float {
+		// Ensure the embeddings have the same length
+		precondition(firstEmbedding.count == secondEmbedding.count, "Embeddings must have the same length")
+
+		var dotProduct: Float = 0
+
+		// Calculate dot product using Accelerate
+		vDSP_dotpr(firstEmbedding, 1, secondEmbedding, 1, &dotProduct, vDSP_Length(firstEmbedding.count))
+
+		return dotProduct
+	}
+
 }
 
 /// A struct implementing the `DistanceMetricProtocol` using cosine similarity.
@@ -37,18 +46,31 @@ public struct CosineSimilarity: DistanceMetricProtocol {
 
     public func findNearest(for queryEmbedding: [Float], in neighborEmbeddings: [[Float]], resultsCount: Int) -> [(Float, Int)] {
         let scores = neighborEmbeddings.map { distance(between: queryEmbedding, and: $0) }
-
         return sortedScores(scores: scores, topK: resultsCount)
     }
 
-    public func distance(between firstEmbedding: [Float], and secondEmbedding: [Float]) -> Float {
-        // Calculate cosine distance
-        let dotProduct = zip(firstEmbedding, secondEmbedding).map(*).reduce(0, +)
-        let firstMagnitude = sqrt(firstEmbedding.map { $0 * $0 }.reduce(0, +))
-        let secondMagnitude = sqrt(secondEmbedding.map { $0 * $0 }.reduce(0, +))
-
-        return dotProduct / (firstMagnitude * secondMagnitude)
-    }
+
+	public func distance(between firstEmbedding: [Float], and secondEmbedding: [Float]) -> Float {
+		// Ensure the embeddings have the same length
+		precondition(firstEmbedding.count == secondEmbedding.count, "Embeddings must have the same length")
+
+		var dotProduct: Float = 0
+		var firstMagnitude: Float = 0
+		var secondMagnitude: Float = 0
+
+		// Calculate dot product and magnitudes using Accelerate
+		vDSP_dotpr(firstEmbedding, 1, secondEmbedding, 1, &dotProduct, vDSP_Length(firstEmbedding.count))
+		vDSP_svesq(firstEmbedding, 1, &firstMagnitude, vDSP_Length(firstEmbedding.count))
+		vDSP_svesq(secondEmbedding, 1, &secondMagnitude, vDSP_Length(secondEmbedding.count))
+
+		// Take square root of magnitudes
+		firstMagnitude = sqrt(firstMagnitude)
+		secondMagnitude = sqrt(secondMagnitude)
+
+		// Return cosine similarity
+		return dotProduct / (firstMagnitude * secondMagnitude)
+	}
+
 }
 
 /// A struct implementing the `DistanceMetricProtocol` using Euclidean distance.
@@ -57,18 +79,26 @@ public struct CosineSimilarity: DistanceMetricProtocol {
 ///
 /// - Note: Use this metric when the magnitudes of the embeddings are significant in your use case, and the embeddings are distributed in a Euclidean space.
 public struct EuclideanDistance: DistanceMetricProtocol {
+
     public init() {}
 
     public func findNearest(for queryEmbedding: [Float], in neighborEmbeddings: [[Float]], resultsCount: Int) -> [(Float, Int)] {
         let distances = neighborEmbeddings.map { distance(between: queryEmbedding, and: $0) }
-
         return sortedDistances(distances: distances, topK: resultsCount)
     }
-
-    public func distance(between firstEmbedding: [Float], and secondEmbedding: [Float]) -> Float {
-        let squaredDifferences = zip(firstEmbedding, secondEmbedding).map { ($0 - $1) * ($0 - $1) }
-        return sqrt(squaredDifferences.reduce(0, +))
-    }
+
+	public func distance(between firstEmbedding: [Float], and secondEmbedding: [Float]) -> Float {
+		// Ensure the embeddings have the same length
+		precondition(firstEmbedding.count == secondEmbedding.count, "Embeddings must have the same length")
+
+		var distance: Float = 0
+
+		// Calculate squared differences and sum them using Accelerate
+		vDSP_distancesq(firstEmbedding, 1, secondEmbedding, 1, &distance, vDSP_Length(firstEmbedding.count))
+
+		// Return the square root of the summed squared differences
+		return sqrt(distance)
+	}
 }
 
 // MARK: - Helpers

Sources/SimilaritySearchKit/Core/Index/SimilarityIndex.swift

@@ -6,6 +6,7 @@
 //
 
 import Foundation
+import OSLog
 
 // MARK: - Type Aliases
 
@@ -17,9 +18,21 @@ public typealias TextSplitterType = SimilarityIndex.TextSplitterType
 public typealias VectorStoreType = SimilarityIndex.VectorStoreType
 
 @available(macOS 11.0, iOS 15.0, *)
-public class SimilarityIndex {
+public class SimilarityIndex: Identifiable, Hashable {
+
+	public static func == (lhs: SimilarityIndex, rhs: SimilarityIndex) -> Bool {
+		return lhs.id == rhs.id
+	}
+
+	public func hash(into hasher: inout Hasher) {
+		hasher.combine(id)
+	}
+
     // MARK: - Properties
 
+	/// A unique identifier
+	public var id: UUID = UUID()
+
     /// The items stored in the index.
     public var indexItems: [IndexItem] = []
 
@@ -306,6 +319,7 @@ extension SimilarityIndex {
 
 @available(macOS 13.0, iOS 16.0, *)
 extension SimilarityIndex {
+
     public func saveIndex(toDirectory path: URL? = nil, name: String? = nil) throws -> URL {
         let indexName = name ?? self.indexName
         let basePath: URL
@@ -319,15 +333,15 @@ extension SimilarityIndex {
 
         let savedVectorStore = try vectorStore.saveIndex(items: indexItems, to: basePath, as: indexName)
 
-        print("Saved \(indexItems.count) index items to \(savedVectorStore.absoluteString)")
+		let bundleId: String = Bundle.main.bundleIdentifier ?? "com.similarity-search-kit.logger"
+		let logger: Logger = Logger(subsystem: bundleId, category: "similarityIndexSave")
 
         return savedVectorStore
     }
 
     public func loadIndex(fromDirectory path: URL? = nil, name: String? = nil) throws -> [IndexItem]? {
         if let indexPath = try getIndexPath(fromDirectory: path, name: name) {
             indexItems = try vectorStore.loadIndex(from: indexPath)
-            print("Loaded \(indexItems.count) index items from \(indexPath.absoluteString)")
             return indexItems
         }
 

Sources/SimilaritySearchKit/Core/Persistence/Json/JsonStore.swift

@@ -8,6 +8,7 @@
 import Foundation
 
 public class JsonStore: VectorStoreProtocol {
+
     public func saveIndex(items: [IndexItem], to url: URL, as name: String) throws -> URL {
         let encoder = JSONEncoder()
         let data = try encoder.encode(items)