add command pop_blocks

add new public method to Blockchain and update according to code review

update after review: better lock/unlock, try catch and coding style

2 files changed, 39 insertions, 0 deletions

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index bfc5dbbe0..009c5e2ed 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -576,6 +576,38 @@ bool Blockchain::deinit()
   return true;
 }
 //------------------------------------------------------------------
+// This function removes blocks from the top of blockchain.
+// It starts a batch and calls private method pop_block_from_blockchain().
+void Blockchain::pop_blocks(uint64_t nblocks)
+{
+  uint64_t i;
+  CRITICAL_REGION_LOCAL(m_tx_pool);
+  CRITICAL_REGION_LOCAL1(m_blockchain_lock);
+
+  while (!m_db->batch_start())
+  {
+    m_blockchain_lock.unlock();
+    m_tx_pool.unlock();
+    epee::misc_utils::sleep_no_w(1000);
+    m_tx_pool.lock();
+    m_blockchain_lock.lock();
+  }
+
+  try
+  {
+    for (i=0; i < nblocks; ++i)
+    {
+      pop_block_from_blockchain();
+    }
+  }
+  catch (const std::exception& e)
+  {
+    LOG_ERROR("Error when popping blocks, only " << i << " blocks are popped: " << e.what());
+  }
+
+  m_db->batch_stop();
+}
+//------------------------------------------------------------------
 // This function tells BlockchainDB to remove the top block from the
 // blockchain and then returns all transactions (except the miner tx, of course)
 // from it to the tx_pool
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index dfe833fb4..f1e366c9e 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -967,6 +967,13 @@ namespace cryptonote
      */
     std::vector<time_t> get_last_block_timestamps(unsigned int blocks) const;
 
+    /**
+     * @brief removes blocks from the top of the blockchain
+     *
+     * @param nblocks number of blocks to be removed
+     */
+    void pop_blocks(uint64_t nblocks);
+
   private:
 
     // TODO: evaluate whether or not each of these typedefs are left over from blockchain_storage