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Merge pull request #363

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4f19e68 blockchain: factor get_num_outpouts(amount) calls (moneromooo-monero)
275894c blockchain: always select random outs using triangular distribution (moneromooo-monero)
This commit is contained in:
Riccardo Spagni 2015-08-10 20:04:30 +02:00
commit 09cada45c4
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GPG key ID: 55432DF31CCD4FCD
6 changed files with 12 additions and 38 deletions
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13
src/blockchain_db/berkeleydb/db_bdb.cpp
View file

@ -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__);

2
src/blockchain_db/berkeleydb/db_bdb.h
View file

@ -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);

4
src/blockchain_db/blockchain_db.h
View file

@ -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;

13
src/blockchain_db/lmdb/db_lmdb.cpp
View file

@ -1637,19 +1637,6 @@ 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__);

2
src/blockchain_db/lmdb/db_lmdb.h
View file

@ -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);

16
src/cryptonote_core/blockchain.cpp
View file

@ -1473,6 +1473,7 @@ bool Blockchain::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUT
// from BlockchainDB where <n> is req.outs_count (number of mixins).
for (uint64_t amount : req.amounts)
{
auto num_outs = m_db->get_num_outputs(amount);
// create outs_for_amount struct and populate amount field
COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount& result_outs = *res.outs.insert(res.outs.end(), COMMAND_RPC_GET_RANDOM_OUTPUTS_FOR_AMOUNTS::outs_for_amount());
result_outs.amount = amount;
@ -1481,9 +1482,9 @@ bool Blockchain::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUT
// if there aren't enough outputs to mix with (or just enough),
// use all of them. Eventually this should become impossible.
if (m_db->get_num_outputs(amount) <= req.outs_count)
if (num_outs <= req.outs_count)
{
for (uint64_t i = 0; i < m_db->get_num_outputs(amount); i++)
for (uint64_t i = 0; i < num_outs; i++)
{
// get tx_hash, tx_out_index from DB
tx_out_index toi = m_db->get_output_tx_and_index(amount, i);
@ -1499,7 +1500,6 @@ bool Blockchain::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUT
else
{
// while we still need more mixins
auto num_outs = m_db->get_num_outputs(amount);
while (result_outs.outs.size() < req.outs_count)
{
// if we've gone through every possible output, we've gotten all we can
@ -1511,7 +1511,15 @@ bool Blockchain::get_random_outs_for_amounts(const COMMAND_RPC_GET_RANDOM_OUTPUT
// get a random output index from the DB. If we've already seen it,
// return to the top of the loop and try again, otherwise add it to the
// list of output indices we've seen.
uint64_t i = m_db->get_random_output(amount);
// triangular distribution over [a,b) with a=0, mode c=b=up_index_limit
uint64_t r = crypto::rand<uint64_t>() % ((uint64_t)1 << 53);
double frac = std::sqrt((double)r / ((uint64_t)1 << 53));
uint64_t i = (uint64_t)(frac*num_outs);
// just in case rounding up to 1 occurs after sqrt
if (i == num_outs)
--i;
if (seen_indices.count(i))
{
continue;