Pruning

The blockchain prunes seven eighths of prunable tx data.
This saves about two thirds of the blockchain size, while
keeping the node useful as a sync source for an eighth
of the blockchain.

No other data is currently pruned.

contrib/epee/include/string_tools.h

@@ -233,6 +233,15 @@ POP_WARNINGS
 		return boost::lexical_cast<std::string>(val);
 	}
 	//----------------------------------------------------------------------------
+	template<typename T> inline std::string to_string_hex(const T &val)
+	{
+		std::stringstream ss;
+		ss << std::hex << val;
+		std::string s;
+		ss >> s;
+		return s;
+	}
+	//----------------------------------------------------------------------------
 
 	inline bool compare_no_case(const std::string& str1, const std::string& str2)
 	{

src/blockchain_db/blockchain_db.cpp

@@ -29,6 +29,7 @@
 #include <boost/range/adaptor/reversed.hpp>
 
 #include "string_tools.h"
+#include "common/pruning.h"
 #include "blockchain_db.h"
 #include "cryptonote_basic/cryptonote_format_utils.h"
 #include "profile_tools.h"
@@ -265,9 +266,12 @@ void BlockchainDB::pop_block(block& blk, std::vector<transaction>& txs)
 
   remove_block();
 
+  CHECK_AND_ASSERT_THROW_MES(!blk.miner_tx.vin.empty(), "Miner tx has no inputs");
+  const uint64_t block_height = boost::get<cryptonote::txin_gen>(blk.miner_tx.vin.front()).height;
+  const bool has_unpruned_block = tools::has_unpruned_block(block_height, height(), get_blockchain_pruning_seed());
   for (const auto& h : boost::adaptors::reverse(blk.tx_hashes))
   {
-    txs.push_back(get_tx(h));
+    txs.push_back(has_unpruned_block ? get_tx(h) : get_pruned_tx(h));
     remove_transaction(h);
   }
   remove_transaction(get_transaction_hash(blk.miner_tx));
@@ -280,7 +284,7 @@ bool BlockchainDB::is_open() const
 
 void BlockchainDB::remove_transaction(const crypto::hash& tx_hash)
 {
-  transaction tx = get_tx(tx_hash);
+  transaction tx = get_pruned_tx(tx_hash);
 
   for (const txin_v& tx_input : tx.vin)
   {
@@ -325,6 +329,17 @@ bool BlockchainDB::get_tx(const crypto::hash& h, cryptonote::transaction &tx) co
   return true;
 }
 
+bool BlockchainDB::get_pruned_tx(const crypto::hash& h, cryptonote::transaction &tx) const
+{
+  blobdata bd;
+  if (!get_pruned_tx_blob(h, bd))
+    return false;
+  if (!parse_and_validate_tx_base_from_blob(bd, tx))
+    throw DB_ERROR("Failed to parse transaction base from blob retrieved from the db");
+
+  return true;
+}
+
 transaction BlockchainDB::get_tx(const crypto::hash& h) const
 {
   transaction tx;
@@ -333,6 +348,14 @@ transaction BlockchainDB::get_tx(const crypto::hash& h) const
   return tx;
 }
 
+transaction BlockchainDB::get_pruned_tx(const crypto::hash& h) const
+{
+  transaction tx;
+  if (!get_pruned_tx(h, tx))
+    throw TX_DNE(std::string("pruned tx with hash ").append(epee::string_tools::pod_to_hex(h)).append(" not found in db").c_str());
+  return tx;
+}
+
 void BlockchainDB::reset_stats()
 {
   num_calls = 0;

src/blockchain_db/blockchain_db.h

@@ -1126,6 +1126,17 @@ class BlockchainDB
    */
   virtual transaction get_tx(const crypto::hash& h) const;
 
+  /**
+   * @brief fetches the transaction base with the given hash
+   *
+   * If the transaction does not exist, the subclass should throw TX_DNE.
+   *
+   * @param h the hash to look for
+   *
+   * @return the transaction with the given hash
+   */
+  virtual transaction get_pruned_tx(const crypto::hash& h) const;
+
   /**
    * @brief fetches the transaction with the given hash
    *
@@ -1137,6 +1148,17 @@ class BlockchainDB
    */
   virtual bool get_tx(const crypto::hash& h, transaction &tx) const;
 
+  /**
+   * @brief fetches the transaction base with the given hash
+   *
+   * If the transaction does not exist, the subclass should return false.
+   *
+   * @param h the hash to look for
+   *
+   * @return true iff the transaction was found
+   */
+  virtual bool get_pruned_tx(const crypto::hash& h, transaction &tx) const;
+
   /**
    * @brief fetches the transaction blob with the given hash
    *
@@ -1165,6 +1187,21 @@ class BlockchainDB
    */
   virtual bool get_pruned_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const = 0;
 
+  /**
+   * @brief fetches the prunable transaction blob with the given hash
+   *
+   * The subclass should return the prunable transaction stored which has the given
+   * hash.
+   *
+   * If the transaction does not exist, or if we do not have that prunable data,
+   * the subclass should return false.
+   *
+   * @param h the hash to look for
+   *
+   * @return true iff the transaction was found and we have its prunable data
+   */
+  virtual bool get_prunable_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const = 0;
+
   /**
    * @brief fetches the prunable transaction hash
    *
@@ -1405,6 +1442,31 @@ class BlockchainDB
    */
   virtual cryptonote::blobdata get_txpool_tx_blob(const crypto::hash& txid) const = 0;
 
+  /**
+   * @brief get the blockchain pruning seed
+   * @return the blockchain pruning seed
+   */
+  virtual uint32_t get_blockchain_pruning_seed() const = 0;
+
+  /**
+   * @brief prunes the blockchain
+   * @param pruning_seed the seed to use, 0 for default (highly recommended)
+   * @return success iff true
+   */
+  virtual bool prune_blockchain(uint32_t pruning_seed = 0) = 0;
+
+  /**
+   * @brief prunes recent blockchain changes as needed, iff pruning is enabled
+   * @return success iff true
+   */
+  virtual bool update_pruning() = 0;
+
+  /**
+   * @brief checks pruning was done correctly, iff enabled
+   * @return success iff true
+   */
+  virtual bool check_pruning() = 0;
+
   /**
    * @brief runs a function over all txpool transactions
    *