chore(web/js): delete proof-of-work-slow.mjs

This code has served its purpose and now needs to be retired to the
great beyond. There is no replacement for this, the fast implementation
will be used instead.

Signed-off-by: Xe Iaso <me@xeiaso.net>

web/js/main.mjs

@@ -1,9 +1,8 @@
-import processFast from "./proof-of-work.mjs";
-import processSlow from "./proof-of-work-slow.mjs";
+import process from "./proof-of-work.mjs";
 
 const algorithms = {
-  fast: processFast,
-  slow: processSlow,
+  fast: process,
+  slow: process,
 };
 
 // from Xeact

web/js/proof-of-work-slow.mjs

@@ -1,99 +0,0 @@
-// https://dev.to/ratmd/simple-proof-of-work-in-javascript-3kgm
-
-export default function process(
-  data,
-  difficulty = 5,
-  signal = null,
-  progressCallback = null,
-  _threads = 1,
-) {
-  console.debug("slow algo");
-  return new Promise((resolve, reject) => {
-    let webWorkerURL = URL.createObjectURL(
-      new Blob(["(", processTask(), ")()"], { type: "application/javascript" }),
-    );
-
-    let worker = new Worker(webWorkerURL);
-    let settled = false;
-
-    const cleanup = () => {
-      if (settled) return;
-      settled = true;
-      worker.terminate();
-      if (signal != null) {
-        signal.removeEventListener("abort", onAbort);
-      }
-      URL.revokeObjectURL(webWorkerURL);
-    };
-
-    const onAbort = () => {
-      console.log("PoW aborted");
-      cleanup();
-      reject(new DOMException("Aborted", "AbortError"));
-    };
-
-    if (signal != null) {
-      if (signal.aborted) {
-        return onAbort();
-      }
-      signal.addEventListener("abort", onAbort, { once: true });
-    }
-
-    worker.onmessage = (event) => {
-      if (typeof event.data === "number") {
-        progressCallback?.(event.data);
-      } else {
-        cleanup();
-        resolve(event.data);
-      }
-    };
-
-    worker.onerror = (event) => {
-      cleanup();
-      reject(event);
-    };
-
-    worker.postMessage({
-      data,
-      difficulty,
-    });
-  });
-}
-
-function processTask() {
-  return function () {
-    const sha256 = (text) => {
-      const encoded = new TextEncoder().encode(text);
-      return crypto.subtle.digest("SHA-256", encoded.buffer).then((result) =>
-        Array.from(new Uint8Array(result))
-          .map((c) => c.toString(16).padStart(2, "0"))
-          .join(""),
-      );
-    };
-
-    addEventListener("message", async (event) => {
-      let data = event.data.data;
-      let difficulty = event.data.difficulty;
-
-      let hash;
-      let nonce = 0;
-      do {
-        if ((nonce & 1023) === 0) {
-          postMessage(nonce);
-        }
-        hash = await sha256(data + nonce++);
-      } while (
-        hash.substring(0, difficulty) !== Array(difficulty + 1).join("0")
-      );
-
-      nonce -= 1; // last nonce was post-incremented
-
-      postMessage({
-        hash,
-        data,
-        difficulty,
-        nonce,
-      });
-    });
-  }.toString();
-}