faster base58.

lib/bcoin/utils.js

@@ -161,9 +161,85 @@ utils.toBase58 = function toBase58(arr) {
     res = '1' + res;
   }
 
+  //utils.print(res);
+  //utils.print(utils.toBase582(arr));
+  // assert(utils.toBase582(arr) === res);
+
   return res;
 };
 
+// Ported from:
+// https://github.com/bitcoin/bitcoin/blob/master/src/base58.cpp
+utils.toBase582 = function toBase582(buf) {
+  var zeroes = 0;
+  var length = 0;
+  for (var i = 0; i < buf.length; i++) {
+    if (buf[i] !== 0)
+      break;
+    zeroes++;
+  }
+  var size = ((buf.length * 138 / 100) | 0) + 1;
+  var b58 = new Buffer(size);
+  b58.fill(0);
+  for (; i < buf.length; i++) {
+    var carry = buf[i];
+    var j = 0;
+    for (var k = b58.length - 1; k >= 0; k--, j++) {
+      if (carry === 0 && j >= length)
+        break;
+      carry += 256 * b58[k];
+      b58[k] = carry % 58;
+      carry = carry / 58 | 0;
+    }
+    assert(carry === 0);
+    length = j;
+  }
+  var i = size - length;
+  while (b58[i] === 0)
+    i++;
+  var str = '';
+  for (j = 0; j < zeroes; j++)
+    str += '1';
+  for (; i < b58.length; i++)
+    str += base58[b58[i]];
+  return str;
+};
+
+utils.fromBase582 = function fromBase58(str) {
+  var zeroes = 0;
+  var i = 0;
+  while (str[i] === '1') {
+    zeroes++;
+    i++;
+  }
+  var b256 = new Buffer(((str.length * 733) / 1000 | 0) + 1);
+  b256.fill(0);
+  while (str[i]) {
+    var ch = unbase58[str[i]];
+    if (ch == null)
+      return;
+    var carry = ch;
+    for (var j = b256.length - 1; j >= 0; j--) {
+      carry += 58 * b256[j];
+      b256[j] = carry % 256;
+      carry = carry / 256 | 0;
+    }
+    assert(carry === 0);
+    i++;
+  }
+  if (str[i] != null)
+    return;
+  i = 0;
+  while (b256[i] === 0)
+    i++;
+  var vch = new Buffer(zeroes + (b256.length - i));
+  for (j = 0; j < zeroes; j++)
+    vch[j] = 0;
+  for (; i < b256.length; i++)
+    vch[i] = b256[i];
+  return vch;
+};
+
 utils.fromBase58 = function fromBase58(str) {
   var i, zeroes, q, w, res, c, z;
 
@@ -198,7 +274,9 @@ utils.fromBase58 = function fromBase58(str) {
   for (i = 0; i < zeroes; i++)
     z.push(0);
 
-  return new Buffer(z.concat(res.toArray()));
+  var ret = new Buffer(z.concat(res.toArray()));
+  // assert(utils.isEqual(ret, utils.fromBase582(str)));
+  return ret;
 };
 
 utils.isBase58 = function isBase58(msg) {