From cca95c1c7aa7506c7ec0df9846807050911152eb Mon Sep 17 00:00:00 2001
From: moneromooo-monero <moneromooo-monero@users.noreply.github.com>
Date: Mon, 13 Feb 2017 19:05:30 +0000
Subject: [PATCH] blockchain_db: do not throw on expected partial results
 getting keys

When scanning for outputs used in a set of incoming blocks,
we expect that some of the inputs in their transactions will
not be found in the blockchain, as they could be in previous
blocks in that set. Those outputs will be scanned there at
a later point. In this case, we add a flag to control wehther
an output not being found is expected or not.
---
 src/blockchain_db/blockchain_db.h  | 2 +-
 src/blockchain_db/lmdb/db_lmdb.cpp | 9 ++++++++-
 src/blockchain_db/lmdb/db_lmdb.h   | 2 +-
 src/cryptonote_core/blockchain.cpp | 2 +-
 4 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/blockchain_db/blockchain_db.h b/src/blockchain_db/blockchain_db.h
index 3fdb62a7..b4079324 100644
--- a/src/blockchain_db/blockchain_db.h
+++ b/src/blockchain_db/blockchain_db.h
@@ -1184,7 +1184,7 @@ public:
    * @param offsets a list of amount-specific output indices
    * @param outputs return-by-reference a list of outputs' metadata
    */
-  virtual void get_output_key(const uint64_t &amount, const std::vector<uint64_t> &offsets, std::vector<output_data_t> &outputs) = 0;
+  virtual void get_output_key(const uint64_t &amount, const std::vector<uint64_t> &offsets, std::vector<output_data_t> &outputs, bool allow_partial = false) = 0;
   
   /*
    * FIXME: Need to check with git blame and ask what this does to
diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp
index 0a35325e..829aff22 100644
--- a/src/blockchain_db/lmdb/db_lmdb.cpp
+++ b/src/blockchain_db/lmdb/db_lmdb.cpp
@@ -2617,7 +2617,7 @@ void BlockchainLMDB::get_output_tx_and_index_from_global(const std::vector<uint6
   TXN_POSTFIX_RDONLY();
 }
 
-void BlockchainLMDB::get_output_key(const uint64_t &amount, const std::vector<uint64_t> &offsets, std::vector<output_data_t> &outputs)
+void BlockchainLMDB::get_output_key(const uint64_t &amount, const std::vector<uint64_t> &offsets, std::vector<output_data_t> &outputs, bool allow_partial)
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
   TIME_MEASURE_START(db3);
@@ -2635,7 +2635,14 @@ void BlockchainLMDB::get_output_key(const uint64_t &amount, const std::vector<ui
 
     auto get_result = mdb_cursor_get(m_cur_output_amounts, &k, &v, MDB_GET_BOTH);
     if (get_result == MDB_NOTFOUND)
+    {
+      if (allow_partial)
+      {
+        MDEBUG("Partial result: " << outputs.size() << "/" << offsets.size());
+        break;
+      }
       throw1(OUTPUT_DNE((std::string("Attempting to get output pubkey by global index (amount ") + boost::lexical_cast<std::string>(amount) + ", index " + boost::lexical_cast<std::string>(index) + ", count " + boost::lexical_cast<std::string>(get_num_outputs(amount)) + "), but key does not exist").c_str()));
+    }
     else if (get_result)
       throw0(DB_ERROR(lmdb_error("Error attempting to retrieve an output pubkey from the db", get_result).c_str()));
 
diff --git a/src/blockchain_db/lmdb/db_lmdb.h b/src/blockchain_db/lmdb/db_lmdb.h
index e7faf8cd..1c0005c8 100644
--- a/src/blockchain_db/lmdb/db_lmdb.h
+++ b/src/blockchain_db/lmdb/db_lmdb.h
@@ -221,7 +221,7 @@ public:
 
   virtual output_data_t get_output_key(const uint64_t& amount, const uint64_t& index);
   virtual output_data_t get_output_key(const uint64_t& global_index) const;
-  virtual void get_output_key(const uint64_t &amount, const std::vector<uint64_t> &offsets, std::vector<output_data_t> &outputs);
+  virtual void get_output_key(const uint64_t &amount, const std::vector<uint64_t> &offsets, std::vector<output_data_t> &outputs, bool allow_partial = false);
 
   virtual tx_out_index get_output_tx_and_index_from_global(const uint64_t& index) const;
   virtual void get_output_tx_and_index_from_global(const std::vector<uint64_t> &global_indices,
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index a8128663..d67c5f2b 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -3540,7 +3540,7 @@ void Blockchain::output_scan_worker(const uint64_t amount, const std::vector<uin
 {
   try
   {
-    m_db->get_output_key(amount, offsets, outputs);
+    m_db->get_output_key(amount, offsets, outputs, true);
   }
   catch (const std::exception& e)
   {