deferred coin.

lib/bcoin/coins.js

@@ -76,7 +76,14 @@ Coins.prototype.has = function has(index) {
  */
 
 Coins.prototype.get = function get(index) {
-  return this.outputs[index];
+  var coin = this.outputs[index];
+  if (!coin)
+    return;
+
+  if (coin instanceof DeferredCoin)
+    coin = coin.toCoin(this, index);
+
+  return coin;
 };
 
 /**
@@ -179,6 +186,11 @@ Coins.prototype.toRaw = function toRaw(writer) {
       continue;
     }
 
+    if (output instanceof DeferredCoin) {
+      p.writeBytes(output.raw);
+      continue;
+    }
+
     prefix = 0;
 
     // Saves up to 7 bytes.
@@ -213,10 +225,10 @@ Coins.prototype.toRaw = function toRaw(writer) {
  * @returns {Object} A "naked" coins object.
  */
 
-Coins.parseRaw = function parseRaw(data, hash) {
+Coins.parseRaw = function parseRaw(data, hash, index) {
   var p = new BufferReader(data);
   var i = 0;
-  var version, height, coins, coin, mask, prefix;
+  var version, height, coins, mask, prefix, raw;
 
   version = p.readVarint();
   height = p.readU32();
@@ -233,43 +245,87 @@ Coins.parseRaw = function parseRaw(data, hash) {
     coins.height = -1;
 
   while (p.left()) {
+    p.start();
+
     mask = p.readU8();
 
     if (mask === 0xff) {
+      if (index != null) {
+        if (i === index)
+          return;
+        i++;
+        continue;
+      }
       coins.outputs.push(null);
       i++;
       continue;
     }
 
-    coin = {
-      version: coins.version,
-      coinbase: coins.coinbase,
-      height: coins.height,
-      hash: coins.hash,
-      index: i++,
-      script: null,
-      value: null
-    };
-
     prefix = mask & 3;
 
     if (prefix === 0)
-      coin.script = new bcoin.script(bcoin.protocol.parser.parseScript(p));
+      p.seek(p.readVarint());
-    else if (prefix === 1)
+    else if (prefix <= 2)
-      coin.script = bcoin.script.createPubkeyhash(p.readBytes(20));
+      p.seek(20);
-    else if (prefix === 2)
-      coin.script = bcoin.script.createScripthash(p.readBytes(20));
     else
       assert(false, 'Bad prefix.');
 
-    coin.value = p.readVarint();
+    p.readVarint();
 
-    coins.outputs.push(new bcoin.coin(coin));
+    if (index != null && i !== index) {
+      p.end();
+      i++;
+      continue;
+    }
+
+    raw = p.endData(true);
+
+    coins.outputs.push(new DeferredCoin(raw));
+
+    if (index != null)
+      return coins.outputs[0].toCoin(coins, i);
+
+    i++;
   }
 
   return coins;
 };
 
+function DeferredCoin(raw) {
+  this.raw = raw;
+}
+
+DeferredCoin.prototype.toCoin = function toCoin(coins, index) {
+  var p = new BufferReader(this.raw);
+  var prefix = p.readU8() & 3;
+  var script, value;
+
+  if (prefix === 0)
+    script = new bcoin.script(bcoin.protocol.parser.parseScript(p));
+  else if (prefix === 1)
+    script = bcoin.script.createPubkeyhash(p.readBytes(20));
+  else if (prefix === 2)
+    script = bcoin.script.createScripthash(p.readBytes(20));
+  else
+    assert(false, 'Bad prefix.');
+
+  value = p.readVarint();
+
+  return new bcoin.coin({
+    version: coins.version,
+    coinbase: coins.coinbase,
+    height: coins.height,
+    hash: coins.hash,
+    index: index,
+    script: script,
+    value: value
+  });
+};
+
+DeferredCoin.prototype.toRaw = function toRaw() {
+  return this.raw;
+};
+
 /**
  * Parse a single serialized coin.
  * @param {Buffer} data
@@ -279,65 +335,7 @@ Coins.parseRaw = function parseRaw(data, hash) {
  */
 
 Coins.parseCoin = function parseCoin(data, hash, index) {
-  var p = new BufferReader(data);
+  return Coins.parseCoins(data, hash, index);
-  var i = 0;
-  var mask, prefix, version, height, coinbase, script, value;
-
-  version = p.readVarint();
-  height = p.readU32();
-  coinbase = (height & 1) !== 0;
-  height >>>= 1;
-
-  if (height === 0x7fffffff)
-    height = -1;
-
-  while (p.left()) {
-    mask = p.readU8();
-
-    if (mask === 0xff) {
-      if (i === index)
-        break;
-      i++;
-      continue;
-    }
-
-    prefix = mask & 3;
-
-    if (i !== index) {
-      if (prefix === 0)
-        p.seek(p.readVarint());
-      else if (prefix <= 2)
-        p.seek(20);
-      else
-        assert(false, 'Bad prefix.');
-      p.readVarint();
-      i++;
-      continue;
-    }
-
-    if (prefix === 0)
-      script = new bcoin.script(bcoin.protocol.parser.parseScript(p));
-    else if (prefix === 1)
-      script = bcoin.script.createPubkeyhash(p.readBytes(20));
-    else if (prefix === 2)
-      script = bcoin.script.createScripthash(p.readBytes(20));
-    else
-      assert(false, 'Bad prefix.');
-
-    value = p.readVarint();
-
-    return new bcoin.coin({
-      version: version,
-      coinbase: coinbase,
-      height: height,
-      hash: hash,
-      index: i,
-      script: script,
-      value: value
-    });
-  }
-
-  assert(false, 'No coin.');
 };
 
 /**

lib/bcoin/reader.js

@@ -68,6 +68,7 @@ BufferReader.prototype.seek = function seek(off) {
 
 BufferReader.prototype.start = function start() {
   this.stack.push(this.offset);
+  return this.offset;
 };
 
 /**