blockchain: always select random outs using triangular distribution

It was only used by the older blockchain_storage.
We also move the code to the calling blockchain level, to avoid
replicating the code in every DB implementation. This also makes
the get_random_out method obsolete, and we delete it.

5 files changed, 0 insertions, 34 deletions

diff --git a/src/blockchain_db/berkeleydb/db_bdb.cpp b/src/blockchain_db/berkeleydb/db_bdb.cpp
index ad3febbd1..a990d7aaf 100644
--- a/src/blockchain_db/berkeleydb/db_bdb.cpp
+++ b/src/blockchain_db/berkeleydb/db_bdb.cpp
@@ -1264,19 +1264,6 @@ uint64_t BlockchainBDB::get_tx_block_height(const crypto::hash& h) const
     return (uint64_t)result - 1;
 }
 
-//FIXME: make sure the random method used here is appropriate
-uint64_t BlockchainBDB::get_random_output(const uint64_t& amount) const
-{
-    LOG_PRINT_L3("BlockchainBDB::" << __func__);
-    check_open();
-
-    uint64_t num_outputs = get_num_outputs(amount);
-    if (num_outputs == 0)
-        throw1(OUTPUT_DNE("Attempting to get a random output for an amount, but none exist"));
-
-    return crypto::rand<uint64_t>() % num_outputs;
-}
-
 uint64_t BlockchainBDB::get_num_outputs(const uint64_t& amount) const
 {
     LOG_PRINT_L3("BlockchainBDB::" << __func__);
diff --git a/src/blockchain_db/berkeleydb/db_bdb.h b/src/blockchain_db/berkeleydb/db_bdb.h
index 41f4bcb78..f92bbef68 100644
--- a/src/blockchain_db/berkeleydb/db_bdb.h
+++ b/src/blockchain_db/berkeleydb/db_bdb.h
@@ -295,8 +295,6 @@ public:
 
   virtual uint64_t get_tx_block_height(const crypto::hash& h) const;
 
-  virtual uint64_t get_random_output(const uint64_t& amount) const;
-
   virtual uint64_t get_num_outputs(const uint64_t& amount) const;
 
   virtual output_data_t get_output_key(const uint64_t& amount, const uint64_t& index);
diff --git a/src/blockchain_db/blockchain_db.h b/src/blockchain_db/blockchain_db.h
index ff15109b0..25a34fc09 100644
--- a/src/blockchain_db/blockchain_db.h
+++ b/src/blockchain_db/blockchain_db.h
@@ -104,7 +104,6 @@
  *   height      get_tx_block_height(hash)
  *
  * Outputs:
- *   index       get_random_output(amount)
  *   uint64_t    get_num_outputs(amount)
  *   pub_key     get_output_key(amount, index)
  *   tx_out      get_output(tx_hash, index)
@@ -463,9 +462,6 @@ public:
   // returns height of block that contains transaction with hash <h>
   virtual uint64_t get_tx_block_height(const crypto::hash& h) const = 0;
 
-  // return global output index of a random output of amount <amount>
-  virtual uint64_t get_random_output(const uint64_t& amount) const = 0;
-
   // returns the total number of outputs of amount <amount>
   virtual uint64_t get_num_outputs(const uint64_t& amount) const = 0;
 
diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp
index dd829f3b0..d231322f6 100644
--- a/src/blockchain_db/lmdb/db_lmdb.cpp
+++ b/src/blockchain_db/lmdb/db_lmdb.cpp
@@ -1620,19 +1620,6 @@ uint64_t BlockchainLMDB::get_tx_block_height(const crypto::hash& h) const
   return *(const uint64_t*)result.mv_data;
 }
 
-//FIXME: make sure the random method used here is appropriate
-uint64_t BlockchainLMDB::get_random_output(const uint64_t& amount) const
-{
-  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
-  check_open();
-
-  uint64_t num_outputs = get_num_outputs(amount);
-  if (num_outputs == 0)
-    throw1(OUTPUT_DNE("Attempting to get a random output for an amount, but none exist"));
-
-  return crypto::rand<uint64_t>() % num_outputs;
-}
-
 uint64_t BlockchainLMDB::get_num_outputs(const uint64_t& amount) const
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);
diff --git a/src/blockchain_db/lmdb/db_lmdb.h b/src/blockchain_db/lmdb/db_lmdb.h
index 0facb8713..b4c197803 100644
--- a/src/blockchain_db/lmdb/db_lmdb.h
+++ b/src/blockchain_db/lmdb/db_lmdb.h
@@ -157,8 +157,6 @@ public:
 
   virtual uint64_t get_tx_block_height(const crypto::hash& h) const;
 
-  virtual uint64_t get_random_output(const uint64_t& amount) const;
-
   virtual uint64_t get_num_outputs(const uint64_t& amount) const;
 
   virtual output_data_t get_output_key(const uint64_t& amount, const uint64_t& index);