rpc: move getDifficulty.

lib/http/rpc.js

@@ -169,7 +169,7 @@ RPC.prototype.getInfo = co(function* getInfo(args, help) {
     timeoffset: this.network.time.offset,
     connections: this.pool.peers.size(),
     proxy: '',
-    difficulty: this.difficulty(),
+    difficulty: toDifficulty(this.chain.tip.bits),
     testnet: this.network !== Network.main,
     keypoololdest: 0,
     keypoolsize: 0,
@@ -453,7 +453,7 @@ RPC.prototype.getBlockchainInfo = co(function* getBlockchainInfo(args, help) {
     blocks: this.chain.height,
     headers: this.chain.height,
     bestblockhash: this.chain.tip.rhash(),
-    difficulty: this.difficulty(),
+    difficulty: toDifficulty(this.chain.tip.bits),
     mediantime: yield this.chain.tip.getMedianTime(),
     verificationprogress: this.chain.getProgress(),
     chainwork: this.chain.tip.chainwork.toString('hex', 64),
@@ -589,7 +589,7 @@ RPC.prototype.getDifficulty = co(function* getDifficulty(args, help) {
   if (help || args.length !== 0)
     throw new RPCError(errs.MISC_ERROR, 'getdifficulty');
 
-  return this.difficulty();
+  return toDifficulty(this.chain.tip.bits);
 });
 
 RPC.prototype.getMempoolInfo = co(function* getMempoolInfo(args, help) {
@@ -1353,6 +1353,7 @@ RPC.prototype.getMiningInfo = co(function* getMiningInfo(args, help) {
   var size = 0;
   var weight = 0;
   var txs = 0;
+  var diff = 0;
   var i, item;
 
   if (help || args.length !== 0)
@@ -1361,6 +1362,7 @@ RPC.prototype.getMiningInfo = co(function* getMiningInfo(args, help) {
   if (attempt) {
     weight = attempt.weight;
     txs = attempt.items.length + 1;
+    diff = attempt.getDifficulty();
     size = 1000;
     for (i = 0; i < attempt.items.length; i++) {
       item = attempt.items[i];
@@ -1373,7 +1375,7 @@ RPC.prototype.getMiningInfo = co(function* getMiningInfo(args, help) {
     currentblocksize: size,
     currentblockweight: weight,
     currentblocktx: txs,
-    difficulty: this.difficulty(),
+    difficulty: diff,
     errors: '',
     genproclimit: this.procLimit,
     networkhashps: yield this.getHashRate(120),
@@ -2365,28 +2367,6 @@ RPC.prototype.getBIP9Softforks = co(function* getBIP9Softforks() {
   return forks;
 });
 
-RPC.prototype.difficulty = function difficulty(entry) {
-  var shift, diff;
-
-  if (!entry)
-    entry = this.chain.tip;
-
-  shift = (entry.bits >>> 24) & 0xff;
-  diff = 0x0000ffff / (entry.bits & 0x00ffffff);
-
-  while (shift < 29) {
-    diff *= 256.0;
-    shift++;
-  }
-
-  while (shift > 29) {
-    diff /= 256.0;
-    shift--;
-  }
-
-  return diff;
-};
-
 RPC.prototype.getHashRate = co(function* getHashRate(lookup, height) {
   var tip = this.chain.tip;
   var i, minTime, maxTime, workDiff, timeDiff, ps, entry;
@@ -2573,7 +2553,7 @@ RPC.prototype.headerToJSON = co(function* headerToJSON(entry) {
     time: entry.ts,
     mediantime: medianTime,
     bits: entry.bits,
-    difficulty: this.difficulty(entry),
+    difficulty: toDifficulty(entry.bits),
     chainwork: entry.chainwork.toString('hex', 64),
     previousblockhash: entry.prevBlock !== encoding.NULL_HASH
       ? util.revHex(entry.prevBlock)
@@ -2614,7 +2594,7 @@ RPC.prototype.blockToJSON = co(function* blockToJSON(entry, block, details) {
     time: entry.ts,
     mediantime: mtp,
     bits: entry.bits,
-    difficulty: this.difficulty(entry),
+    difficulty: toDifficulty(entry.bits),
     chainwork: entry.chainwork.toString('hex', 64),
     previousblockhash: entry.prevBlock !== encoding.NULL_HASH
       ? util.revHex(entry.prevBlock)
@@ -2701,6 +2681,23 @@ function parseSecret(raw, network) {
   }
 }
 
+function toDifficulty(bits) {
+  var shift = (bits >>> 24) & 0xff;
+  var diff = 0x0000ffff / (bits & 0x00ffffff);
+
+  while (shift < 29) {
+    diff *= 256.0;
+    shift++;
+  }
+
+  while (shift > 29) {
+    diff /= 256.0;
+    shift--;
+  }
+
+  return diff;
+}
+
 /*
  * Expose
  */