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.

There are three ways to prune a blockchain:

- run monerod with --prune-blockchain
- run "prune_blockchain" in the monerod console
- run the monero-blockchain-prune utility

The first two will prune in place. Due to how LMDB works, this
will not reduce the blockchain size on disk. Instead, it will
mark parts of the file as free, so that future data will use
that free space, causing the file to not grow until free space
grows scarce.

The third way will create a second database, a pruned copy of
the original one. Since this is a new file, this one will be
smaller than the original one.

Once the database is pruned, it will stay pruned as it syncs.
That is, there is no need to use --prune-blockchain again, etc.

1 files changed, 26 insertions, 0 deletions

diff --git a/src/blockchain_db/lmdb/db_lmdb.h b/src/blockchain_db/lmdb/db_lmdb.h
index a60956ab1..c07ab8da5 100644
--- a/src/blockchain_db/lmdb/db_lmdb.h
+++ b/src/blockchain_db/lmdb/db_lmdb.h
@@ -40,6 +40,11 @@
 namespace cryptonote
 {
 
+typedef struct txindex {
+    crypto::hash key;
+    tx_data_t data;
+} txindex;
+
 typedef struct mdb_txn_cursors
 {
   MDB_cursor *m_txc_blocks;
@@ -53,6 +58,7 @@ typedef struct mdb_txn_cursors
   MDB_cursor *m_txc_txs_pruned;
   MDB_cursor *m_txc_txs_prunable;
   MDB_cursor *m_txc_txs_prunable_hash;
+  MDB_cursor *m_txc_txs_prunable_tip;
   MDB_cursor *m_txc_tx_indices;
   MDB_cursor *m_txc_tx_outputs;
 
@@ -62,6 +68,8 @@ typedef struct mdb_txn_cursors
   MDB_cursor *m_txc_txpool_blob;
 
   MDB_cursor *m_txc_hf_versions;
+
+  MDB_cursor *m_txc_properties;
 } mdb_txn_cursors;
 
 #define m_cur_blocks	m_cursors->m_txc_blocks
@@ -73,12 +81,14 @@ typedef struct mdb_txn_cursors
 #define m_cur_txs_pruned	m_cursors->m_txc_txs_pruned
 #define m_cur_txs_prunable	m_cursors->m_txc_txs_prunable
 #define m_cur_txs_prunable_hash	m_cursors->m_txc_txs_prunable_hash
+#define m_cur_txs_prunable_tip	m_cursors->m_txc_txs_prunable_tip
 #define m_cur_tx_indices	m_cursors->m_txc_tx_indices
 #define m_cur_tx_outputs	m_cursors->m_txc_tx_outputs
 #define m_cur_spent_keys	m_cursors->m_txc_spent_keys
 #define m_cur_txpool_meta	m_cursors->m_txc_txpool_meta
 #define m_cur_txpool_blob	m_cursors->m_txc_txpool_blob
 #define m_cur_hf_versions	m_cursors->m_txc_hf_versions
+#define m_cur_properties	m_cursors->m_txc_properties
 
 typedef struct mdb_rflags
 {
@@ -92,12 +102,14 @@ typedef struct mdb_rflags
   bool m_rf_txs_pruned;
   bool m_rf_txs_prunable;
   bool m_rf_txs_prunable_hash;
+  bool m_rf_txs_prunable_tip;
   bool m_rf_tx_indices;
   bool m_rf_tx_outputs;
   bool m_rf_spent_keys;
   bool m_rf_txpool_meta;
   bool m_rf_txpool_blob;
   bool m_rf_hf_versions;
+  bool m_rf_properties;
 } mdb_rflags;
 
 typedef struct mdb_threadinfo
@@ -232,6 +244,7 @@ public:
 
   virtual bool get_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const;
   virtual bool get_pruned_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const;
+  virtual bool get_prunable_tx_blob(const crypto::hash& h, cryptonote::blobdata &tx) const;
   virtual bool get_prunable_tx_hash(const crypto::hash& tx_hash, crypto::hash &prunable_hash) const;
 
   virtual uint64_t get_tx_count() const;
@@ -264,6 +277,11 @@ public:
   virtual bool get_txpool_tx_meta(const crypto::hash& txid, txpool_tx_meta_t &meta) const;
   virtual bool get_txpool_tx_blob(const crypto::hash& txid, cryptonote::blobdata &bd) const;
   virtual cryptonote::blobdata get_txpool_tx_blob(const crypto::hash& txid) const;
+  virtual uint32_t get_blockchain_pruning_seed() const;
+  virtual bool prune_blockchain(uint32_t pruning_seed = 0);
+  virtual bool update_pruning();
+  virtual bool check_pruning();
+
   virtual bool for_all_txpool_txes(std::function<bool(const crypto::hash&, const txpool_tx_meta_t&, const cryptonote::blobdata*)> f, bool include_blob = false, bool include_unrelayed_txes = true) const;
 
   virtual bool for_all_key_images(std::function<bool(const crypto::key_image&)>) const;
@@ -309,6 +327,11 @@ public:
 
   bool get_output_distribution(uint64_t amount, uint64_t from_height, uint64_t to_height, std::vector<uint64_t> &distribution, uint64_t &base) const;
 
+  // helper functions
+  static int compare_uint64(const MDB_val *a, const MDB_val *b);
+  static int compare_hash32(const MDB_val *a, const MDB_val *b);
+  static int compare_string(const MDB_val *a, const MDB_val *b);
+
 private:
   void do_resize(uint64_t size_increase=0);
 
@@ -361,6 +384,8 @@ private:
 
   inline void check_open() const;
 
+  bool prune_worker(int mode, uint32_t pruning_seed);
+
   virtual bool is_read_only() const;
 
   virtual uint64_t get_database_size() const;
@@ -393,6 +418,7 @@ private:
   MDB_dbi m_txs_pruned;
   MDB_dbi m_txs_prunable;
   MDB_dbi m_txs_prunable_hash;
+  MDB_dbi m_txs_prunable_tip;
   MDB_dbi m_tx_indices;
   MDB_dbi m_tx_outputs;