Initial commit.

Packages/Infrastructure/Sources/Internal/Extensions/String+Separators.swift

@@ -0,0 +1,5 @@
+extension String {
+    enum Separator {
+        static let comma = ","
+    }
+}

Packages/Infrastructure/Sources/Internal/Types/FNV1aHash.swift

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+import Foundation
+
+/// Hashes bytes with the FNV-1a 64-bit algorithm.
+///
+/// The hash is stable across processes and platforms, which `Hasher` deliberately is not, so it suits values that must agree between instances and survive
+/// restarts: the asset version token (``FingerprintAssets``) and the entity tags of the pre-rendered pages (`CachedHTMLResponse`).
+/// It is not cryptographic — a collision only risks serving a stale cached asset, not security.
+struct FNV1aHash {
+
+    // MARK: Properties
+
+    /// The running hash value.
+    private var hash: UInt64
+
+    // MARK: Initializers
+
+    /// Creates a hasher at the FNV-1a offset basis.
+    init() {
+        self.hash = 0xcbf2_9ce4_8422_2325
+    }
+
+    // MARK: Computed
+
+    /// The hash of everything combined so far, as a fixed-width, 16-character hexadecimal token.
+    ///
+    /// Reading it does not consume the running hash: more bytes can be combined afterwards.
+    var digest: String {
+        String(
+            format: "%016llx",
+            hash
+        )
+    }
+
+    // MARK: Functions
+
+    /// Folds the given bytes into the hash.
+    /// - Parameter bytes: the bytes to fold in.
+    mutating func combine(
+        _ bytes: some Sequence<UInt8>
+    ) {
+        for byte in bytes {
+            hash = (hash ^ UInt64(byte)) &* 0x100_0000_01b3
+        }
+    }
+
+}