Report on-disk size in gettxoutsetinfo

Author: sipa

src/coins.cpp

@@ -55,6 +55,7 @@ uint256 CCoinsViewBacked::GetBestBlock() const { return base->GetBestBlock(); }
 void CCoinsViewBacked::SetBackend(CCoinsView &viewIn) { base = &viewIn; }
 bool CCoinsViewBacked::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) { return base->BatchWrite(mapCoins, hashBlock); }
 CCoinsViewCursor *CCoinsViewBacked::Cursor() const { return base->Cursor(); }
+size_t CCoinsViewBacked::EstimateSize() const { return base->EstimateSize(); }
 
 SaltedTxidHasher::SaltedTxidHasher() : k0(GetRand(std::numeric_limits<uint64_t>::max())), k1(GetRand(std::numeric_limits<uint64_t>::max())) {}
 

src/coins.h

@@ -319,6 +319,9 @@ class CCoinsView
 
     //! As we use CCoinsViews polymorphically, have a virtual destructor
     virtual ~CCoinsView() {}
+
+    //! Estimate database size (0 if not implemented)
+    virtual size_t EstimateSize() const { return 0; }
 };
 
 
@@ -336,6 +339,7 @@ class CCoinsViewBacked : public CCoinsView
     void SetBackend(CCoinsView &viewIn);
     bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
     CCoinsViewCursor *Cursor() const;
+    size_t EstimateSize() const override;
 };
 
 

src/dbwrapper.h

@@ -305,7 +305,22 @@ class CDBWrapper
      * Return true if the database managed by this class contains no entries.
      */
     bool IsEmpty();
+
+    template<typename K>
+    size_t EstimateSize(const K& key_begin, const K& key_end) const
+    {
+        CDataStream ssKey1(SER_DISK, CLIENT_VERSION), ssKey2(SER_DISK, CLIENT_VERSION);
+        ssKey1.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
+        ssKey2.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
+        ssKey1 << key_begin;
+        ssKey2 << key_end;
+        leveldb::Slice slKey1(ssKey1.data(), ssKey1.size());
+        leveldb::Slice slKey2(ssKey2.data(), ssKey2.size());
+        uint64_t size = 0;
+        leveldb::Range range(slKey1, slKey2);
+        pdb->GetApproximateSizes(&range, 1, &size);
+        return size;
+    }
 };
 
 #endif // BITCOIN_DBWRAPPER_H
-

src/rpc/blockchain.cpp

@@ -782,6 +782,7 @@ struct CCoinsStats
     uint64_t nTransactions;
     uint64_t nTransactionOutputs;
     uint256 hashSerialized;
+    uint64_t nDiskSize;
     CAmount nTotalAmount;
 
     CCoinsStats() : nHeight(0), nTransactions(0), nTransactionOutputs(0), nTotalAmount(0) {}
@@ -826,6 +827,7 @@ static bool GetUTXOStats(CCoinsView *view, CCoinsStats &stats)
     }
     stats.hashSerialized = ss.GetHash();
     stats.nTotalAmount = nTotalAmount;
+    stats.nDiskSize = view->EstimateSize();
     return true;
 }
 
@@ -892,6 +894,7 @@ UniValue gettxoutsetinfo(const JSONRPCRequest& request)
             "  \"transactions\": n,      (numeric) The number of transactions\n"
             "  \"txouts\": n,            (numeric) The number of output transactions\n"
             "  \"hash_serialized\": \"hash\",   (string) The serialized hash\n"
+            "  \"disk_size\": n,         (numeric) The estimated size of the chainstate on disk\n"
             "  \"total_amount\": x.xxx          (numeric) The total amount\n"
             "}\n"
             "\nExamples:\n"
@@ -909,6 +912,7 @@ UniValue gettxoutsetinfo(const JSONRPCRequest& request)
         ret.push_back(Pair("transactions", (int64_t)stats.nTransactions));
         ret.push_back(Pair("txouts", (int64_t)stats.nTransactionOutputs));
         ret.push_back(Pair("hash_serialized_2", stats.hashSerialized.GetHex()));
+        ret.push_back(Pair("disk_size", stats.nDiskSize));
         ret.push_back(Pair("total_amount", ValueFromAmount(stats.nTotalAmount)));
     } else {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Unable to read UTXO set");

src/txdb.cpp

@@ -67,6 +67,11 @@ bool CCoinsViewDB::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) {
     return db.WriteBatch(batch);
 }
 
+size_t CCoinsViewDB::EstimateSize() const
+{
+    return db.EstimateSize(DB_COINS, (char)(DB_COINS+1));
+}
+
 CBlockTreeDB::CBlockTreeDB(size_t nCacheSize, bool fMemory, bool fWipe) : CDBWrapper(GetDataDir() / "blocks" / "index", nCacheSize, fMemory, fWipe) {
 }
 

src/txdb.h

@@ -78,6 +78,8 @@ class CCoinsViewDB : public CCoinsView
     uint256 GetBestBlock() const;
     bool BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock);
     CCoinsViewCursor *Cursor() const;
+
+    size_t EstimateSize() const override;
 };
 
 /** Specialization of CCoinsViewCursor to iterate over a CCoinsViewDB */

test/functional/blockchain.py

@@ -50,6 +50,9 @@ def _test_gettxoutsetinfo(self):
         assert_equal(res['height'], 200)
         assert_equal(res['txouts'], 200)
         assert_equal(res['bestblock'], node.getblockhash(200))
+        size = res['disk_size']
+        assert size > 6400
+        assert size < 64000
         assert_equal(len(res['bestblock']), 64)
         assert_equal(len(res['hash_serialized_2']), 64)