monerod can now sync from pruned blocks

If the peer (whether pruned or not itself) supports sending pruned blocks
to syncing nodes, the pruned version will be sent along with the hash
of the pruned data and the block weight. The original tx hashes can be
reconstructed from the pruned txes and theur prunable data hash. Those
hashes and the block weights are hashes and checked against the set of
precompiled hashes, ensuring the data we received is the original data.
It is currently not possible to use this system when not using the set
of precompiled hashes, since block weights can not otherwise be checked
for validity.

This is off by default for now, and is enabled by --sync-pruned-blocks

1 files changed, 11 insertions, 4 deletions

diff --git a/src/blockchain_utilities/blocksdat_file.cpp b/src/blockchain_utilities/blocksdat_file.cpp
index f56ff5f94..df3c6cafc 100644
--- a/src/blockchain_utilities/blocksdat_file.cpp
+++ b/src/blockchain_utilities/blocksdat_file.cpp
@@ -99,17 +99,23 @@ bool BlocksdatFile::initialize_file(uint64_t block_stop)
   return true;
 }
 
-void BlocksdatFile::write_block(const crypto::hash& block_hash)
+void BlocksdatFile::write_block(const crypto::hash& block_hash, uint64_t weight)
 {
   m_hashes.push_back(block_hash);
+  m_weights.push_back(weight);
   while (m_hashes.size() >= HASH_OF_HASHES_STEP)
   {
     crypto::hash hash;
     crypto::cn_fast_hash(m_hashes.data(), HASH_OF_HASHES_STEP * sizeof(crypto::hash), hash);
     memmove(m_hashes.data(), m_hashes.data() + HASH_OF_HASHES_STEP, (m_hashes.size() - HASH_OF_HASHES_STEP) * sizeof(crypto::hash));
     m_hashes.resize(m_hashes.size() - HASH_OF_HASHES_STEP);
-    const std::string data(hash.data, sizeof(hash));
-    *m_raw_data_file << data;
+    const std::string data_hashes(hash.data, sizeof(hash));
+    *m_raw_data_file << data_hashes;
+    crypto::cn_fast_hash(m_weights.data(), HASH_OF_HASHES_STEP * sizeof(uint64_t), hash);
+    memmove(m_weights.data(), m_weights.data() + HASH_OF_HASHES_STEP, (m_weights.size() - HASH_OF_HASHES_STEP) * sizeof(uint64_t));
+    m_weights.resize(m_weights.size() - HASH_OF_HASHES_STEP);
+    const std::string data_weights(hash.data, sizeof(hash));
+    *m_raw_data_file << data_weights;
   }
 }
 
@@ -154,7 +160,8 @@ bool BlocksdatFile::store_blockchain_raw(Blockchain* _blockchain_storage, tx_mem
   {
     // 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);
+    uint64_t weight = m_blockchain_storage->get_db().get_block_weight(m_cur_height);
+    write_block(hash, weight);
     if (m_cur_height % NUM_BLOCKS_PER_CHUNK == 0) {
       num_blocks_written += NUM_BLOCKS_PER_CHUNK;
     }