From 83048eef3340f1af87aa7df793d4427a2134160c Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Mon, 8 Dec 2014 13:05:22 -0800
Subject: [PATCH] add get_tx_ldb.

---
 lib/bitcoind.js   |   8 +--
 src/bitcoindjs.cc | 121 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 126 insertions(+), 3 deletions(-)

diff --git a/lib/bitcoind.js b/lib/bitcoind.js
index cc9efed6..5e0d6bf9 100644
--- a/lib/bitcoind.js
+++ b/lib/bitcoind.js
@@ -405,8 +405,10 @@ Bitcoin.prototype.getTx = function(txid, blockhash, callback) {
   if (blockhash && typeof blockhash === 'string') {
     return bitcoindjs.getTransaction(txid, blockhash, traverse, function(err, tx) {
       if (err) return callback(err);
-      bitcoin.db.set('tx-block/' + txid,
-        { hash: blockhash }, utils.NOOP);
+      if (tx.blockhash) {
+        bitcoin.db.set('tx-block/' + txid,
+          { hash: tx.blockhash }, utils.NOOP);
+      }
       return callback(null, bitcoin.tx(tx));
     });
   }
@@ -414,7 +416,7 @@ Bitcoin.prototype.getTx = function(txid, blockhash, callback) {
     // Will traverse blockchain if no block - slow:
     return bitcoinjs.getTransaction(txid, block ? block.hash : '', traverse, function(err, tx) {
       if (err) return callback(err);
-      if (!block) {
+      if (!block && tx.blockhash) {
         bitcoin.db.set('tx-block/' + txid,
           { hash: tx.blockhash }, utils.NOOP);
       }
diff --git a/src/bitcoindjs.cc b/src/bitcoindjs.cc
index 5e2d2237..6e71d9b4 100644
--- a/src/bitcoindjs.cc
+++ b/src/bitcoindjs.cc
@@ -189,6 +189,8 @@ using namespace v8;
 // LevelDB options
 #define USE_LDB_ADDR 0
 #define USE_LDB_TX 0
+#define USE_LDB_GETTX 1
+#define USE_LDB_GETTX_MAIN 0
 
 /**
  * Node.js Exposed Function Templates
@@ -606,6 +608,11 @@ static ctx_list *
 read_addr(const std::string addr, const int64_t blockheight, const int64_t blocktime);
 #endif
 
+#if defined(USE_LDB_GETTX) || defined(USE_LDB_GETTX_MAIN)
+static bool
+get_tx_ldb(const uint256 itxid, CTransaction& rctx, uint256& rblockhash);
+#endif
+
 #if USE_LDB_TX
 static bool
 get_block_by_tx(const std::string itxid, CBlock& rcblock, CBlockIndex **rcblock_index);
@@ -1169,12 +1176,21 @@ async_get_tx(uv_work_t *req) {
   uint256 blockhash(data->blockhash);
   CTransaction ctx;
 
+#if USE_LDB_GETTX_MAIN
+  if (get_tx_ldb(hash, ctx, blockhash)) {
+    data->ctx = ctx;
+    data->blockhash = blockhash.GetHex();
+  } else {
+    data->err_msg = std::string("get_tx(): failed.");
+  }
+#else
   if (get_tx(hash, blockhash, data->traverse, ctx)) {
     data->ctx = ctx;
     data->blockhash = blockhash.GetHex();
   } else {
     data->err_msg = std::string("get_tx(): failed.");
   }
+#endif
 }
 
 static void
@@ -5849,6 +5865,9 @@ get_tx(uint256 txid, uint256& blockhash, const bool traverse, CTransaction& ctx)
   if (GetTransaction(txid, ctx, blockhash, true)) {
     return 1;
   } else if (traverse && blockhash != 0) {
+#if USE_LDB_GETTX
+    get_tx_ldb(txid, ctx, blockhash);
+#else
     CBlock block;
     CBlockIndex* pblockindex = mapBlockIndex[blockhash];
     if (ReadBlockFromDisk(block, pblockindex)) {
@@ -5860,6 +5879,7 @@ get_tx(uint256 txid, uint256& blockhash, const bool traverse, CTransaction& ctx)
         }
       }
     }
+#endif
   }
   return 0;
 }
@@ -6508,6 +6528,107 @@ error:
 }
 #endif
 
+#if defined(USE_LDB_GETTX) || defined(USE_LDB_GETTX_MAIN)
+/**
+ LevelDB Parser
+ DB: blocks/blk/revXXXXX.dat
+ */
+
+static bool
+get_tx_ldb(const uint256 itxid, CTransaction& rctx, uint256& rblockhash) {
+  leveldb::Iterator* pcursor = pblocktree->pdb->NewIterator(pblocktree->iteroptions);
+
+  pcursor->SeekToFirst();
+
+  while (pcursor->Valid()) {
+    boost::this_thread::interruption_point();
+    try {
+      leveldb::Slice slKey = pcursor->key();
+
+      CDataStream ssKey(slKey.data(), slKey.data() + slKey.size(), SER_DISK, CLIENT_VERSION);
+
+      char type;
+      ssKey >> type;
+
+      // Blockchain Index Structure:
+      // http://bitcoin.stackexchange.com/questions/28168
+
+      // Transaction Structure:
+      // 't' + 32-byte tx hash
+      //   Which block file the tx is stored in
+      //   Which offset in the block file the tx resides
+      //   The offset from the top of the block containing the tx
+      if (type == 't') {
+        uint256 txid;
+        ssKey >> txid;
+        if (txid == itxid) {
+          leveldb::Slice slValue = pcursor->value();
+
+          CDataStream ssValue(slValue.data(), slValue.data() + slValue.size(), SER_DISK, CLIENT_VERSION);
+
+          // struct CDiskBlockPos {
+          //   int nFile;
+          //   unsigned int nPos;
+          // };
+          // struct CDiskTxPos : public CDiskBlockPos {
+          //   unsigned int nTxOffset;
+          // };
+
+          CDiskTxPos txPos;
+          ssValue >> txPos;
+
+          CTransaction ctx;
+          uint256 blockhash;
+
+          if (!pblocktree->ReadTxIndex(txid, txPos)) {
+            goto error;
+          }
+
+          CAutoFile file(OpenBlockFile(txPos, true), SER_DISK, CLIENT_VERSION);
+          CBlockHeader header;
+          try {
+            file >> header;
+            fseek(file.Get(), txPos.nTxOffset, SEEK_CUR);
+            file >> ctx;
+          } catch (std::exception &e) {
+            goto error;
+          }
+          if (ctx.GetHash() != txid) {
+            goto error;
+          }
+          blockhash = header.GetHash();
+
+          CBlock cblock;
+          CBlockIndex* pblockindex = mapBlockIndex[blockhash];
+          if (ReadBlockFromDisk(cblock, pblockindex)) {
+            BOOST_FOREACH(const CTransaction& ctx, cblock.vtx) {
+              if (ctx.GetHash() == itxid) {
+                rblockhash = blockhash;
+                rctx = ctx;
+                delete pcursor;
+                return true;
+              }
+            }
+            goto error;
+          }
+
+          goto error;
+        }
+      }
+
+      pcursor->Next();
+    } catch (std::exception &e) {
+      delete pcursor;
+      return false;
+    }
+  }
+
+error:
+  delete pcursor;
+  return false;
+}
+#endif
+
 /**
  LevelDB Parser
  DB: blocks/blk/revXXXXX.dat