Merge pull request #437

b13e7f2 blockchain_export can now export to a blocks.dat format (moneromooo-monero)
11db442 bootstrap_file: do not try to create a directory with an empty name (moneromooo-monero)
03bc610 hardfork: use DB transactions when reorganizing (moneromooo-monero)
439c455 hardfork: simplify work done on reload (moneromooo-monero)

src/blockchain_utilities/CMakeLists.txt

@@ -38,11 +38,13 @@ bitmonero_private_headers(blockchain_converter
 set(blockchain_import_sources
   blockchain_import.cpp
   bootstrap_file.cpp
+  blocksdat_file.cpp
   )
 
 set(blockchain_import_private_headers
   fake_core.h
   bootstrap_file.h
+  blocksdat_file.h
   bootstrap_serialization.h
   )
 
@@ -52,10 +54,12 @@ bitmonero_private_headers(blockchain_import
 set(blockchain_export_sources
   blockchain_export.cpp
   bootstrap_file.cpp
+  blocksdat_file.cpp
   )
 
 set(blockchain_export_private_headers
   bootstrap_file.h
+  blocksdat_file.h
   bootstrap_serialization.h
   )
 

src/blockchain_utilities/blockchain_export.cpp

@@ -27,6 +27,7 @@
 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "bootstrap_file.h"
+#include "blocksdat_file.h"
 #include "common/command_line.h"
 #include "version.h"
 
@@ -39,6 +40,7 @@ int main(int argc, char* argv[])
 {
   uint32_t log_level = 0;
   uint64_t block_stop = 0;
+  bool blocks_dat = false;
 
   boost::filesystem::path default_data_path {tools::get_default_data_dir()};
   boost::filesystem::path default_testnet_data_path {default_data_path / "testnet"};
@@ -54,6 +56,7 @@ int main(int argc, char* argv[])
       , "Run on testnet."
       , false
   };
+  const command_line::arg_descriptor<bool> arg_blocks_dat = {"blocksdat", "Output in blocks.dat format", blocks_dat};
 
 
   command_line::add_arg(desc_cmd_sett, command_line::arg_data_dir, default_data_path.string());
@@ -62,6 +65,7 @@ int main(int argc, char* argv[])
   command_line::add_arg(desc_cmd_sett, arg_testnet_on);
   command_line::add_arg(desc_cmd_sett, arg_log_level);
   command_line::add_arg(desc_cmd_sett, arg_block_stop);
+  command_line::add_arg(desc_cmd_sett, arg_blocks_dat);
 
   command_line::add_arg(desc_cmd_only, command_line::arg_help);
 
@@ -94,6 +98,7 @@ int main(int argc, char* argv[])
   LOG_PRINT_L0("Setting log level = " << log_level);
 
   bool opt_testnet = command_line::get_arg(vm, arg_testnet_on);
+  bool opt_blocks_dat = command_line::get_arg(vm, arg_blocks_dat);
 
   std::string m_config_folder;
 
@@ -155,8 +160,16 @@ int main(int argc, char* argv[])
   LOG_PRINT_L0("Source blockchain storage initialized OK");
   LOG_PRINT_L0("Exporting blockchain raw data...");
 
+  if (opt_blocks_dat)
+  {
+    BlocksdatFile blocksdat;
+    r = blocksdat.store_blockchain_raw(core_storage, NULL, output_file_path, block_stop);
+  }
+  else
+  {
     BootstrapFile bootstrap;
     r = bootstrap.store_blockchain_raw(core_storage, NULL, output_file_path, block_stop);
+  }
   CHECK_AND_ASSERT_MES(r, false, "Failed to export blockchain raw data");
   LOG_PRINT_L0("Blockchain raw data exported OK");
 }

src/blockchain_utilities/blockchain_utilities.h

@@ -0,0 +1,51 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#pragma once
+
+#include "version.h"
+
+
+// CONFIG: choose one of the three #define's
+//
+// DB_MEMORY is a sensible default for users migrating to LMDB, as it allows
+// the exporter to use the in-memory blockchain while the other binaries
+// work with LMDB, without recompiling anything.
+//
+#define SOURCE_DB DB_MEMORY
+//#define SOURCE_DB DB_LMDB
+// to use global compile-time setting (DB_MEMORY or DB_LMDB):
+// #define SOURCE_DB BLOCKCHAIN_DB
+
+
+// bounds checking is done before writing to buffer, but buffer size
+// should be a sensible maximum
+#define BUFFER_SIZE 1000000
+#define NUM_BLOCKS_PER_CHUNK 1
+#define BLOCKCHAIN_RAW "blockchain.raw"
+

src/blockchain_utilities/blocksdat_file.cpp

@@ -0,0 +1,170 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "blocksdat_file.h"
+
+
+namespace po = boost::program_options;
+
+using namespace cryptonote;
+using namespace epee;
+
+namespace
+{
+  std::string refresh_string = "\r                                    \r";
+}
+
+
+
+bool BlocksdatFile::open_writer(const boost::filesystem::path& file_path, uint64_t block_stop)
+{
+  const boost::filesystem::path dir_path = file_path.parent_path();
+  if (!dir_path.empty())
+  {
+    if (boost::filesystem::exists(dir_path))
+    {
+      if (!boost::filesystem::is_directory(dir_path))
+      {
+        LOG_PRINT_RED_L0("export directory path is a file: " << dir_path);
+        return false;
+      }
+    }
+    else
+    {
+      if (!boost::filesystem::create_directory(dir_path))
+      {
+        LOG_PRINT_RED_L0("Failed to create directory " << dir_path);
+        return false;
+      }
+    }
+  }
+
+  m_raw_data_file = new std::ofstream();
+
+  uint64_t num_blocks = 0;
+
+  LOG_PRINT_L0("creating file");
+
+  m_raw_data_file->open(file_path.string(), std::ios_base::binary | std::ios_base::out | std::ios::trunc);
+  if (m_raw_data_file->fail())
+    return false;
+
+  initialize_file(block_stop);
+
+  return true;
+}
+
+
+bool BlocksdatFile::initialize_file(uint64_t block_stop)
+{
+  const uint32_t nblocks = block_stop + 1;
+  unsigned char nblocksc[4];
+
+  nblocksc[0] = nblocks & 0xff;
+  nblocksc[1] = (nblocks >> 8) & 0xff;
+  nblocksc[2] = (nblocks >> 16) & 0xff;
+  nblocksc[3] = (nblocks >> 24) & 0xff;
+
+  // 4 bytes little endian
+  *m_raw_data_file << nblocksc[0];
+  *m_raw_data_file << nblocksc[1];
+  *m_raw_data_file << nblocksc[2];
+  *m_raw_data_file << nblocksc[3];
+
+  return true;
+}
+
+void BlocksdatFile::write_block(const crypto::hash& block_hash)
+{
+  const std::string data(block_hash.data, sizeof(block_hash));
+  *m_raw_data_file << data;
+}
+
+bool BlocksdatFile::close()
+{
+  if (m_raw_data_file->fail())
+    return false;
+
+  m_raw_data_file->flush();
+  delete m_raw_data_file;
+  return true;
+}
+
+
+#if SOURCE_DB == DB_MEMORY
+bool BlocksdatFile::store_blockchain_raw(blockchain_storage* _blockchain_storage, tx_memory_pool* _tx_pool, boost::filesystem::path& output_file, uint64_t requested_block_stop)
+#else
+bool BlocksdatFile::store_blockchain_raw(Blockchain* _blockchain_storage, tx_memory_pool* _tx_pool, boost::filesystem::path& output_file, uint64_t requested_block_stop)
+#endif
+{
+  uint64_t num_blocks_written = 0;
+  m_blockchain_storage = _blockchain_storage;
+  uint64_t progress_interval = 100;
+  block b;
+
+  uint64_t block_start = 0;
+  uint64_t block_stop = 0;
+  LOG_PRINT_L0("source blockchain height: " <<  m_blockchain_storage->get_current_blockchain_height()-1);
+  if ((requested_block_stop > 0) && (requested_block_stop < m_blockchain_storage->get_current_blockchain_height()))
+  {
+    LOG_PRINT_L0("Using requested block height: " << requested_block_stop);
+    block_stop = requested_block_stop;
+  }
+  else
+  {
+    block_stop = m_blockchain_storage->get_current_blockchain_height() - 1;
+    LOG_PRINT_L0("Using block height of source blockchain: " << block_stop);
+  }
+  LOG_PRINT_L0("Storing blocks raw data...");
+  if (!BlocksdatFile::open_writer(output_file, block_stop))
+  {
+    LOG_PRINT_RED_L0("failed to open raw file for write");
+    return false;
+  }
+  for (m_cur_height = block_start; m_cur_height <= block_stop; ++m_cur_height)
+  {
+    // this method's height refers to 0-based height (genesis block = height 0)
+    crypto::hash hash = m_blockchain_storage->get_block_id_by_height(m_cur_height);
+    write_block(hash);
+    if (m_cur_height % NUM_BLOCKS_PER_CHUNK == 0) {
+      num_blocks_written += NUM_BLOCKS_PER_CHUNK;
+    }
+    if (m_cur_height % progress_interval == 0) {
+      std::cout << refresh_string;
+      std::cout << "block " << m_cur_height << "/" << block_stop << std::flush;
+    }
+  }
+  // print message for last block, which may not have been printed yet due to progress_interval
+  std::cout << refresh_string;
+  std::cout << "block " << m_cur_height-1 << "/" << block_stop << ENDL;
+
+  LOG_PRINT_L0("Number of blocks exported: " << num_blocks_written);
+
+  return BlocksdatFile::close();
+}
+

src/blockchain_utilities/blocksdat_file.h

@@ -0,0 +1,90 @@
+// Copyright (c) 2014-2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#pragma once
+
+#include <boost/iostreams/stream_buffer.hpp>
+#include <boost/iostreams/stream.hpp>
+#include <boost/iostreams/device/back_inserter.hpp>
+
+#include <boost/iostreams/filtering_streambuf.hpp>
+
+#include "cryptonote_core/cryptonote_basic.h"
+#include "cryptonote_core/cryptonote_boost_serialization.h"
+#include "cryptonote_core/blockchain_storage.h"
+#include "cryptonote_core/blockchain.h"
+#include "blockchain_db/blockchain_db.h"
+#include "blockchain_db/lmdb/db_lmdb.h"
+
+#include <algorithm>
+#include <cstdio>
+#include <fstream>
+#include <boost/iostreams/copy.hpp>
+#include <atomic>
+
+#include "common/command_line.h"
+#include "version.h"
+
+#include "blockchain_utilities.h"
+
+
+using namespace cryptonote;
+
+
+class BlocksdatFile
+{
+public:
+
+#if SOURCE_DB == DB_MEMORY
+  bool store_blockchain_raw(cryptonote::blockchain_storage* cs, cryptonote::tx_memory_pool* txp,
+      boost::filesystem::path& output_file, uint64_t use_block_height=0);
+#else
+  bool store_blockchain_raw(cryptonote::Blockchain* cs, cryptonote::tx_memory_pool* txp,
+      boost::filesystem::path& output_file, uint64_t use_block_height=0);
+#endif
+
+protected:
+
+#if SOURCE_DB == DB_MEMORY
+  blockchain_storage* m_blockchain_storage;
+#else
+  Blockchain* m_blockchain_storage;
+#endif
+
+  std::ofstream * m_raw_data_file;
+
+  // open export file for write
+  bool open_writer(const boost::filesystem::path& file_path, uint64_t block_stop);
+  bool initialize_file(uint64_t block_stop);
+  bool close();
+  void write_block(const crypto::hash &block_hash);
+
+private:
+
+  uint64_t m_cur_height; // tracks current height during export
+};

src/blockchain_utilities/bootstrap_file.cpp

@@ -53,6 +53,8 @@ namespace
 bool BootstrapFile::open_writer(const boost::filesystem::path& file_path)
 {
   const boost::filesystem::path dir_path = file_path.parent_path();
+  if (!dir_path.empty())
+  {
     if (boost::filesystem::exists(dir_path))
     {
       if (!boost::filesystem::is_directory(dir_path))
@@ -69,6 +71,7 @@ bool BootstrapFile::open_writer(const boost::filesystem::path& file_path)
         return false;
       }
     }
+  }
 
   m_raw_data_file = new std::ofstream();
 

src/blockchain_utilities/bootstrap_file.h

@@ -49,24 +49,7 @@
 #include "common/command_line.h"
 #include "version.h"
 
-
-// CONFIG: choose one of the three #define's
-//
-// DB_MEMORY is a sensible default for users migrating to LMDB, as it allows
-// the exporter to use the in-memory blockchain while the other binaries
-// work with LMDB, without recompiling anything.
-//
-#define SOURCE_DB DB_MEMORY
-// #define SOURCE_DB DB_LMDB
-// to use global compile-time setting (DB_MEMORY or DB_LMDB):
-// #define SOURCE_DB BLOCKCHAIN_DB
-
-
-// bounds checking is done before writing to buffer, but buffer size
-// should be a sensible maximum
-#define BUFFER_SIZE 1000000
-#define NUM_BLOCKS_PER_CHUNK 1
-#define BLOCKCHAIN_RAW "blockchain.raw"
+#include "blockchain_utilities.h"
 
 
 using namespace cryptonote;

src/blocks/CMakeLists.txt

@@ -31,8 +31,8 @@ if(APPLE)
     set_target_properties(blocks PROPERTIES LINKER_LANGUAGE C)
 else()
     add_custom_command(OUTPUT blocks.o COMMAND cd ${CMAKE_CURRENT_SOURCE_DIR} && ld -r -b binary -o ${CMAKE_CURRENT_BINARY_DIR}/blocks.o blocks.dat)
-    add_library(blocks STATIC blocks.o blockexports.c)
+    add_custom_command(OUTPUT testnet_blocks.o COMMAND cd ${CMAKE_CURRENT_SOURCE_DIR} && ld -r -b binary -o ${CMAKE_CURRENT_BINARY_DIR}/testnet_blocks.o testnet_blocks.dat)
+    add_library(blocks STATIC blocks.o testnet_blocks.o blockexports.c)
     set_target_properties(blocks PROPERTIES LINKER_LANGUAGE C)
 endif()
 
-

src/blocks/blockexports.c

@@ -9,15 +9,21 @@ extern const struct mach_header _mh_execute_header;
 extern const struct mach_header_64 _mh_execute_header;
 #endif
 
-const unsigned char *get_blocks_dat_start()
+const unsigned char *get_blocks_dat_start(int testnet)
 {
     size_t size;
+    if (testnet)
+        return getsectiondata(&_mh_execute_header, "__DATA", "__testnet_blocks_dat", &size);
+    else
         return getsectiondata(&_mh_execute_header, "__DATA", "__blocks_dat", &size);
 }
 
-size_t get_blocks_dat_size()
+size_t get_blocks_dat_size(int testnet)
 {
     size_t size;
+    if (testnet)
+        getsectiondata(&_mh_execute_header, "__DATA", "__testnet_blocks_dat", &size);
+    else
         getsectiondata(&_mh_execute_header, "__DATA", "__blocks_dat", &size);
     return size;
 }
@@ -27,21 +33,33 @@ size_t get_blocks_dat_size()
 #if defined(_WIN32) && !defined(_WIN64)
 #define _binary_blocks_start binary_blocks_dat_start
 #define _binary_blocks_end binary_blocks_dat_end
+#define _binary_testnet_blocks_start binary_testnet_blocks_dat_start
+#define _binary_testnet_blocks_end binary_testnet_blocks_dat_end
 #else
 #define _binary_blocks_start _binary_blocks_dat_start
 #define _binary_blocks_end _binary_blocks_dat_end
+#define _binary_testnet_blocks_start _binary_testnet_blocks_dat_start
+#define _binary_testnet_blocks_end _binary_testnet_blocks_dat_end
 #endif
 
 extern const unsigned char _binary_blocks_start[];
 extern const unsigned char _binary_blocks_end[];
+extern const unsigned char _binary_testnet_blocks_start[];
+extern const unsigned char _binary_testnet_blocks_end[];
 
-const unsigned char *get_blocks_dat_start(void)
+const unsigned char *get_blocks_dat_start(int testnet)
 {
+	if (testnet)
+		return _binary_testnet_blocks_start;
+	else
 		return _binary_blocks_start;
 }
 
-size_t get_blocks_dat_size(void)
+size_t get_blocks_dat_size(int testnet)
 {
+	if (testnet)
+		return (size_t) (_binary_testnet_blocks_end - _binary_testnet_blocks_start);
+	else
 		return (size_t) (_binary_blocks_end - _binary_blocks_start);
 }
 

src/blocks/blocks.h

@@ -5,8 +5,8 @@
 extern "C" {
 #endif
 
-const unsigned char *get_blocks_dat_start();
-size_t get_blocks_dat_size();
+const unsigned char *get_blocks_dat_start(int testnet);
+size_t get_blocks_dat_size(int testnet);
 
 #ifdef __cplusplus
 }

src/cryptonote_core/blockchain.cpp

@@ -352,13 +352,14 @@ bool Blockchain::init(BlockchainDB* db, const bool testnet)
     m_async_pool.create_thread(boost::bind(&boost::asio::io_service::run, &m_async_service));
 
 #if defined(PER_BLOCK_CHECKPOINT)
-    if (m_fast_sync && !testnet && get_blocks_dat_start() != nullptr)
+    if (m_fast_sync && get_blocks_dat_start(testnet) != nullptr)
     {
-        if (get_blocks_dat_size() > 4)
+        if (get_blocks_dat_size(testnet) > 4)
         {
-            const unsigned char *p = get_blocks_dat_start();
-            uint32_t nblocks = *(uint32_t *) p;
-            if(nblocks > 0 && nblocks > m_db->height())
+            const unsigned char *p = get_blocks_dat_start(testnet);
+            const uint32_t nblocks = *p | ((*(p+1))<<8) | ((*(p+2))<<16) | ((*(p+3))<<24);
+            const size_t size_needed = 4 + nblocks * sizeof(crypto::hash);
+            if(nblocks > 0 && nblocks > m_db->height() && get_blocks_dat_size(testnet) >= size_needed)
             {
                 LOG_PRINT_L0("Loading precomputed blocks: " << nblocks);
                 p += sizeof(uint32_t);

src/cryptonote_core/hardfork.cpp

@@ -150,12 +150,15 @@ void HardFork::init()
     height = 1;
   }
   LOG_PRINT_L1("reorganizing from " << height);
-  reorganize_from_chain_height(height);
   if (populate) {
+    reorganize_from_chain_height(height);
     // reorg will not touch the genesis block, use this as a flag for populating done
     db.set_hard_fork_version(0, original_version);
     db.set_hard_fork_starting_height(original_version, 0);
   }
+  else {
+    rescan_from_chain_height(height);
+  }
   LOG_PRINT_L1("reorganization done");
 }
 
@@ -174,8 +177,8 @@ bool HardFork::reorganize_from_block_height(uint64_t height)
   if (height >= db.height())
     return false;
 
-  //db.set_batch_transactions(true);
-  //db.batch_start();
+  db.set_batch_transactions(true);
+  db.batch_start();
 
   versions.clear();
 
@@ -208,7 +211,7 @@ bool HardFork::reorganize_from_block_height(uint64_t height)
     add(get_block_version(h), h);
   }
 
-  //db.batch_stop();
+  db.batch_stop();
 
   return true;
 }
@@ -220,6 +223,39 @@ bool HardFork::reorganize_from_chain_height(uint64_t height)
   return reorganize_from_block_height(height - 1);
 }
 
+bool HardFork::rescan_from_block_height(uint64_t height)
+{
+  CRITICAL_REGION_LOCAL(lock);
+  if (height >= db.height())
+    return false;
+
+  versions.clear();
+
+  for (size_t n = 0; n < 256; ++n)
+    last_versions[n] = 0;
+  const uint64_t rescan_height = height >= (window_size - 1) ? height - (window_size  -1) : 0;
+  for (uint64_t h = rescan_height; h <= height; ++h) {
+    cryptonote::block b = db.get_block_from_height(h);
+    const uint8_t v = get_effective_version(b.major_version);
+    last_versions[v]++;
+    versions.push_back(v);
+  }
+
+  uint8_t lastv = db.get_hard_fork_version(height);
+  current_fork_index = 0;
+  while (current_fork_index + 1 < heights.size() && heights[current_fork_index].version != lastv)
+    ++current_fork_index;
+
+  return true;
+}
+
+bool HardFork::rescan_from_chain_height(uint64_t height)
+{
+  if (height == 0)
+    return false;
+  return rescan_from_block_height(height - 1);
+}
+
 int HardFork::get_voted_fork_index(uint64_t height) const
 {
   CRITICAL_REGION_LOCAL(lock);

src/cryptonote_core/hardfork.h

@@ -189,6 +189,9 @@ namespace cryptonote
     uint8_t get_effective_version(uint8_t version) const;
     bool add(uint8_t block_version, uint64_t height);
 
+    bool rescan_from_block_height(uint64_t height);
+    bool rescan_from_chain_height(uint64_t height);
+
   private:
 
     BlockchainDB &db;