1 files changed, 79 insertions, 0 deletions
diff --git a/std/hash/_fnv/fnv32.ts b/std/hash/_fnv/fnv32.ts
new file mode 100644
index 000000000..9547e1199
--- /dev/null
+++ b/std/hash/_fnv/fnv32.ts
@@ -0,0 +1,79 @@
+// Ported from Go:
+// https://github.com/golang/go/tree/go1.13.10/src/hash/fnv/fnv.go
+// Copyright 2011 The Go Authors. All rights reserved. BSD license.
+// https://github.com/golang/go/blob/master/LICENSE
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+import { mul32 } from "./util.ts";
+
+const offset32 = 2166136261;
+const prime32 = 16777619;
+
+abstract class Fnv32Base<T> {
+  #state: number;
+
+  constructor() {
+    this.#state = offset32;
+  }
+
+  protected _updateState(newState: number): void {
+    this.#state = newState;
+  }
+
+  reset(): void {
+    this.#state = offset32;
+  }
+
+  abstract write(data: Uint8Array): T;
+
+  size(): number {
+    return 4;
+  }
+
+  blockSize(): number {
+    return 1;
+  }
+
+  sum32(): number {
+    return this.#state;
+  }
+
+  sum(): Uint8Array {
+    return Uint8Array.from([
+      (this.#state >> 24) & 0xff,
+      (this.#state >> 16) & 0xff,
+      (this.#state >> 8) & 0xff,
+      this.#state & 0xff,
+    ]);
+  }
+}
+
+/** Fnv32 hash */
+export class Fnv32 extends Fnv32Base<Fnv32> {
+  write(data: Uint8Array): Fnv32 {
+    let hash = this.sum32();
+
+    data.forEach((c) => {
+      hash = mul32(hash, prime32);
+      hash ^= c;
+    });
+
+    this._updateState(hash);
+    return this;
+  }
+}
+
+/** Fnv32a hash */
+export class Fnv32a extends Fnv32Base<Fnv32a> {
+  write(data: Uint8Array): Fnv32a {
+    let hash = this.sum32();
+
+    data.forEach((c) => {
+      hash ^= c;
+      hash = mul32(hash, prime32);
+    });
+
+    this._updateState(hash);
+    return this;
+  }
+}