Do a POW (Node)

.gitignore

@@ -2,3 +2,4 @@
 /npm-debug.log
 /docs/
 /worker.browserify.js
+/build/

.npmignore

@@ -4,3 +4,4 @@
 /docs/
 /jsdoc.json
 /worker.browserify.js
+/build/

README.md

@@ -49,7 +49,7 @@ API documentation is available [here](https://bitchan.github.io/bitmessage/docs/
   - [ ] msg
   - [ ] broadcast
 - [x] WIF
-- [ ] POW
+- [x] POW
 - [ ] High-level classes
   - [ ] Address
     - [x] encode

binding.gyp

@@ -0,0 +1,10 @@
+{
+  "targets": [
+    {
+      "target_name": "worker",
+      "include_dirs": ["<!(node -e \"require('nan')\")"],
+      "cflags": ["-Wall", "-O2"],
+      "sources": ["src/worker.cc", "src/pow.cc"]
+    }
+  ]
+}

lib/platform.browser.js

@@ -26,8 +26,8 @@ exports.randomBytes = function(size) {
   return new Buffer(arr);
 };
 
+// See `platform.js` for comments.
 var B64 = new BN("18446744073709551616");
-
 exports.getTarget = function(opts) {
   var length = new BN(opts.payloadLength);
   length.iaddn(8);
@@ -50,15 +50,19 @@ var FAILBACK_POOL_SIZE = 8;
 // because of the WebCryptoAPI (see
 // <http://caniuse.com/#feat=cryptography>).
 exports.doPOW = function(opts) {
-  // Try to get native cores count then fallback to more or less
-  // reasonable value. See <https://stackoverflow.com/q/3289465> for
-  // details.
+  // Try to get CPU cores count otherwise fallback to default value.
+  // Currenty navigator's concurrency property available in Chrome and
+  // not available in Firefox; hope default value won't slow down POW
+  // speed much on systems with 1 or 2 cores. There are core estimator
+  // libraries exist (see <https://stackoverflow.com/q/3289465>) but
+  // they are buggy. Ulimately library user could adjust pool size
+  // manually.
   var poolSize = opts.poolSize || navigator.hardwareConcurrency;
   poolSize = poolSize || FAILBACK_POOL_SIZE;
 
   // Check all input params prematurely to not let promise executor or
   // worker to fail because of it.
-  assert(poolSize > 0, "Bad pool size");
+  assert(poolSize > 0, "Pool size is too low");
   assert(opts.workerUrl, "Bad worker URL");
   assert(typeof opts.target === "number", "Bad target");
   assert(Buffer.isBuffer(opts.initialHash), "Bad initial hash");
@@ -79,8 +83,8 @@ exports.doPOW = function(opts) {
         // It's very unlikely that execution will ever reach this place.
         // Currently the only reason why Worker may return value less
         // than zero is a 32-bit nonce overflow (see worker
-        // implementation). It's more than 4G double hashes.
-        reject();
+        // implementation). It's 4G double hashes.
+        reject(new Error("uint32_t nonce overflow"));
       }
     }
 
@@ -115,7 +119,7 @@ exports.doPOW = function(opts) {
       reject(e);
     };
   });
-  // Allow to stop POW via custom function added to the Promise
+  // Allow to stop a POW via custom function added to the Promise
   // instance.
   promise.cancel = cancel;
   return promise;

lib/platform.js

@@ -4,9 +4,14 @@
 
 "use strict";
 
+var os = require("os");
 var crypto = require("crypto");
+var promise = typeof Promise === "undefined" ?
+              require("es6-promise").Promise :
+              Promise;
 var bignum = require("bignum");
 var assert = require("./util").assert;
+var worker = require("./worker");
 
 var createHash = crypto.createHash;
 
@@ -45,3 +50,34 @@ exports.getTarget = function(opts) {
   assert(target <= 9007199254740991, "Unsafe target");
   return target;
 };
+
+exports.doPOW = function(opts) {
+  var poolSize = opts.poolSize || os.cpus().length;
+
+  // Check all input params prematurely to not let promise executor or
+  // worker to fail because of it.
+  // 1 - UINT32_MAX
+  assert(poolSize > 0, "Pool size is too low");
+  assert(poolSize <= 4294967295, "Pool size is too high");
+  // 0 - (2^53 - 1)
+  assert(typeof opts.target === "number", "Bad target");
+  assert(opts.target >= 0, "Target is too low");
+  assert(opts.target <= 9007199254740991, "Target is too high");
+  assert(Buffer.isBuffer(opts.initialHash), "Bad initial hash");
+
+  // TODO(Kagami): Allow to cancel a POW (see `platform.browser.js`).
+  return new promise(function(resolve, reject) {
+    worker.powAsync(
+      poolSize,
+      opts.target,
+      opts.initialHash,
+      function(err, nonce) {
+        if (err) {
+          reject(err);
+        } else {
+          resolve(nonce);
+        }
+      }
+    );
+  });
+};

lib/worker.js

@@ -0,0 +1,12 @@
+/**
+ * Worker routines for Node platform. This module tries to load native
+ * addon and makes it available for Node.
+ */
+
+try {
+  module.exports = require("../build/Release/worker");
+} catch(e) {
+  // Do nothing for a moment. Everything will work except the functions
+  // that uses worker routines.
+  // TODO(Kagami) Provide pure JS fallback.
+}

package.json

@@ -7,6 +7,7 @@
     "./lib/platform.js": "./lib/platform.browser.js"
   },
   "scripts": {
+    "install": "node-gyp rebuild || exit 0",
     "test": "ALL_TESTS=1 mocha && ALL_TESTS=1 npm run -s kc && ALL_TESTS=1 npm run -s kf && jshint .",
     "m": "mocha",
     "k": "npm run -s w && xvfb-run -a karma start",
@@ -53,7 +54,9 @@
     "bs58": "^2.0.0",
     "buffer-equal": "~0.0.1",
     "eccrypto": "^0.1.2",
+    "es6-promise": "^2.0.1",
     "hash.js": "^1.0.2",
+    "nan": "^1.4.1",
     "object-assign": "^2.0.0",
     "sha.js": "^2.3.0"
   }

src/pow.cc

@@ -0,0 +1,50 @@
+// Based on <https://github.com/grant-olson/bitmessage-powfaster>
+// fastcpu implementation.
+// TODO(Kagami): Port it to WIN32 (see bitmessage-powfaster for an
+// example).
+
+#include <stdint.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <openssl/sha.h>
+
+#define HASH_SIZE 64
+#define NTOHLL(x) ( ( (uint64_t)(ntohl( (unsigned int)((x << 32) >> 32) )) << 32) | ntohl( ((unsigned int)(x >> 32)) ) )
+#define MAX_SAFE_JS_INTEGER 9007199254740991
+
+int pow(uint32_t pool_size,
+        int64_t target,
+        const uint8_t* initial_hash,
+        int64_t* nonce) {
+  uint8_t message[HASH_SIZE+sizeof(uint64_t)];
+  uint8_t digest[HASH_SIZE];
+  uint64_t* be_nonce;
+  uint64_t* be_trial;
+  uint64_t i;
+  SHA512_CTX sha;
+
+  memcpy(message+sizeof(uint64_t), initial_hash, HASH_SIZE);
+  be_nonce = (uint64_t *)message;
+  be_trial = (uint64_t *)digest;
+  i = 0;
+  while (1) {
+    // This is very unlikely to be ever happen but it's better to be
+    // sure anyway.
+    if (i > MAX_SAFE_JS_INTEGER) {
+      return -1;
+    }
+    *be_nonce = NTOHLL(i);
+    SHA512_Init(&sha);
+    SHA512_Update(&sha, message, HASH_SIZE+sizeof(uint64_t));
+    SHA512_Final(digest, &sha);
+    SHA512_Init(&sha);
+    SHA512_Update(&sha, digest, HASH_SIZE);
+    SHA512_Final(digest, &sha);
+    if (NTOHLL(*be_trial) <= (uint64_t)target) {
+      break;
+    }
+    i++;
+  }
+  *nonce = i;
+  return 0;
+}

src/pow.h

@@ -0,0 +1,9 @@
+#ifndef BITMESSAGE_POW_H
+#define BITMESSAGE_POW_H
+
+int pow(uint32_t pool_size,
+        int64_t target,
+        const uint8_t* initial_hash,
+        int64_t* nonce);
+
+#endif

src/worker.cc

@@ -0,0 +1,90 @@
+#include <node.h>
+#include <nan.h>
+#include <stdlib.h>
+#include "./pow.h"
+
+using node::Buffer;
+using v8::Handle;
+using v8::Local;
+using v8::FunctionTemplate;
+using v8::Function;
+using v8::Value;
+using v8::Object;
+using v8::String;
+using v8::Integer;
+
+class PowWorker : public NanAsyncWorker {
+ public:
+  PowWorker(NanCallback* callback,
+            uint32_t pool_size,
+            int64_t target,
+            uint8_t* initial_hash)
+      : NanAsyncWorker(callback),
+        pool_size(pool_size),
+        target(target),
+        initial_hash(initial_hash) {}
+  ~PowWorker() {
+    free(initial_hash);
+  }
+
+  // Executed inside the worker-thread.
+  // It is not safe to access V8, or V8 data structures
+  // here, so everything we need for input and output
+  // should go on `this`.
+  void Execute () {
+    error = pow(pool_size, target, initial_hash, &nonce);
+  }
+
+  // Executed when the async work is complete
+  // this function will be run inside the main event loop
+  // so it is safe to use V8 again
+  void HandleOKCallback () {
+    NanScope();
+    if (error) {
+      Local<Value> argv[] = {NanError("Max safe integer overflow")};
+      callback->Call(1, argv);
+    } else {
+      Local<Value> argv[] = {NanNull(), NanNew<Integer>(nonce)};
+      callback->Call(2, argv);
+    }
+  }
+
+ private:
+  uint32_t pool_size;
+  int64_t target;
+  uint8_t* initial_hash;
+  int64_t nonce;
+  int error;
+};
+
+NAN_METHOD(PowAsync) {
+  NanScope();
+
+  NanCallback *callback = new NanCallback(args[3].As<Function>());
+  uint32_t pool_size = args[0]->Uint32Value();
+  int64_t target = args[1]->IntegerValue();
+  size_t length = Buffer::Length(args[2]->ToObject());
+  char* buf = Buffer::Data(args[2]->ToObject());
+  uint8_t* initial_hash = (uint8_t *)malloc(length);
+
+  if (initial_hash == NULL) {
+    Local<Value> argv[] = {NanError("Cannot allocate memory")};
+    callback->Call(1, argv);
+  } else {
+    memcpy(initial_hash, buf, length);
+    NanAsyncQueueWorker(
+        new PowWorker(callback, pool_size, target, initial_hash));
+  }
+
+  NanReturnUndefined();
+}
+
+// Expose synchronous and asynchronous access to our
+// Estimate() function
+void InitAll(Handle<Object> exports) {
+  exports->Set(
+      NanNew<String>("powAsync"),
+      NanNew<FunctionTemplate>(PowAsync)->GetFunction());
+}
+
+NODE_MODULE(worker, InitAll)

test.js

@@ -279,7 +279,7 @@ describe("POW", function() {
     expect(POW.check({nonce: 3122436, target: 4864647698763, initialHash: Buffer("8ff2d685db89a0af2e3dbfd3f700ae96ef4d9a1eac72fd778bbb368c7510cddda349e03207e1c4965bd95c6f7265e8f1a481a08afab3874eaafb9ade09a10880", "hex")})).to.be.false;
   });
 
-  if (allTests && typeof window !== "undefined") {
+  if (allTests) {
     it("should do a POW", function() {
       this.timeout(120000);
       return POW.do({workerUrl: "/base/worker.browserify.js", target: 10693764680411, initialHash: Buffer("8ff2d685db89a0af2e3dbfd3f700ae96ef4d9a1eac72fd778bbb368c7510cddda349e03207e1c4965bd95c6f7265e8f1a481a08afab3874eaafb9ade09a10880", "hex")})