feat(std/hash): reimplement all hashes in WASM (#6292)

1 files changed, 76 insertions, 0 deletions

diff --git a/std/hash/_wasm/hash.ts b/std/hash/_wasm/hash.ts
new file mode 100644
index 000000000..d04a4d4a0
--- /dev/null
+++ b/std/hash/_wasm/hash.ts
@@ -0,0 +1,76 @@
+// Copyright 2018-2020 the Deno authors. All rights reserved. MIT license.
+
+import init, {
+  source,
+  create_hash as createHash,
+  update_hash as updateHash,
+  digest_hash as digestHash,
+  DenoHash,
+} from "./wasm.js";
+
+import * as hex from "../../encoding/hex.ts";
+import * as base64 from "../../encoding/base64.ts";
+import { Hasher, Message, OutputFormat } from "../hasher.ts";
+
+await init(source);
+
+const TYPE_ERROR_MSG = "hash: `data` is invalid type";
+
+export class Hash implements Hasher {
+  #hash: DenoHash;
+  #digested: boolean;
+
+  constructor(algorithm: string) {
+    this.#hash = createHash(algorithm);
+    this.#digested = false;
+  }
+
+  /**
+   * Update internal state
+   * @param data data to update
+   */
+  update(data: Message): this {
+    let msg: Uint8Array;
+
+    if (typeof data === "string") {
+      msg = new TextEncoder().encode(data as string);
+    } else if (typeof data === "object") {
+      if (data instanceof ArrayBuffer || ArrayBuffer.isView(data)) {
+        msg = new Uint8Array(data);
+      } else {
+        throw new Error(TYPE_ERROR_MSG);
+      }
+    } else {
+      throw new Error(TYPE_ERROR_MSG);
+    }
+
+    updateHash(this.#hash, msg);
+
+    return this;
+  }
+
+  /** Returns final hash */
+  digest(): ArrayBuffer {
+    if (this.#digested) throw new Error("hash: already digested");
+
+    this.#digested = true;
+    return digestHash(this.#hash);
+  }
+
+  /**
+   * Returns hash as a string of given format
+   * @param format format of output string (hex or base64). Default is hex
+   */
+  toString(format: OutputFormat = "hex"): string {
+    const finalized = new Uint8Array(this.digest());
+
+    switch (format) {
+      case "hex":
+        return hex.encodeToString(finalized);
+      case "base64":
+        return base64.encode(finalized);
+      default:
+        throw new Error("hash: invalid format");
+    }
+  }
+}