From c6bb201a07d84e195be901acda2fcd0b886bf66f Mon Sep 17 00:00:00 2001
From: Thomas Winget <tewinget@gmail.com>
Date: Thu, 24 Mar 2016 20:03:02 -0400
Subject: [PATCH] Transaction pool documentation (and some cleanup)
tx_pool.h doxygen documentation completed.
Many notes made on areas for improvement, be that functionality or
code clarity.
Commented code and unused code removed.
---
src/cryptonote_core/tx_pool.cpp | 30 ++-
src/cryptonote_core/tx_pool.h | 418 ++++++++++++++++++++++++++------
2 files changed, 373 insertions(+), 75 deletions(-)
diff --git a/src/cryptonote_core/tx_pool.cpp b/src/cryptonote_core/tx_pool.cpp
index 5d67acdd2..183c39d9c 100644
--- a/src/cryptonote_core/tx_pool.cpp
+++ b/src/cryptonote_core/tx_pool.cpp
@@ -54,6 +54,9 @@ namespace cryptonote
{
namespace
{
+ //FIXME: constants such as these should at least be in the header,
+ // but probably somewhere more accessible to the rest of the
+ // codebase.
size_t const TRANSACTION_SIZE_LIMIT_V1 = (((CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V1 * 125) / 100) - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE);
size_t const TRANSACTION_SIZE_LIMIT_V2 = (((CRYPTONOTE_BLOCK_GRANTED_FULL_REWARD_ZONE_V2 * 125) / 100) - CRYPTONOTE_COINBASE_BLOB_RESERVED_SIZE);
time_t const MIN_RELAY_TIME = (60 * 5); // only start re-relaying transactions after that many seconds
@@ -116,11 +119,12 @@ namespace cryptonote
return false;
}
+ // fee per kilobyte, size rounded up.
uint64_t fee = inputs_amount - outputs_amount;
uint64_t needed_fee = blob_size / 1024;
needed_fee += (blob_size % 1024) ? 1 : 0;
needed_fee *= FEE_PER_KB;
- if (!kept_by_block && fee < needed_fee /*&& fee < MINING_ALLOWED_LEGACY_FEE*/)
+ if (!kept_by_block && fee < needed_fee)
{
LOG_PRINT_L1("transaction fee is not enough: " << print_money(fee) << ", minimum fee: " << print_money(needed_fee));
tvc.m_verifivation_failed = true;
@@ -135,7 +139,9 @@ namespace cryptonote
return false;
}
- //check key images for transaction if it is not kept by block
+ // if the transaction came from a block popped from the chain,
+ // don't check if we have its key images as spent.
+ // TODO: Investigate why not?
if(!kept_by_block)
{
if(have_tx_keyimges_as_spent(tx))
@@ -163,9 +169,10 @@ namespace cryptonote
CRITICAL_REGION_LOCAL(m_transactions_lock);
if(!ch_inp_res)
{
+ // if the transaction was valid before (kept_by_block), then it
+ // may become valid again, so ignore the failed inputs check.
if(kept_by_block)
{
- //anyway add this transaction to pool, because it related to block
auto txd_p = m_transactions.insert(transactions_container::value_type(id, tx_details()));
CHECK_AND_ASSERT_MES(txd_p.second, false, "transaction already exists at inserting in memory pool");
txd_p.first->second.blob_size = blob_size;
@@ -207,13 +214,14 @@ namespace cryptonote
tvc.m_should_be_relayed = true;
}
+ // assume failure during verification steps until success is certain
tvc.m_verifivation_failed = true;
- //update image_keys container, here should everything goes ok.
+
BOOST_FOREACH(const auto& in, tx.vin)
{
CHECKED_GET_SPECIFIC_VARIANT(in, const txin_to_key, txin, false);
std::unordered_set<crypto::hash>& kei_image_set = m_spent_key_images[txin.k_image];
- CHECK_AND_ASSERT_MES(kept_by_block || kei_image_set.size() == 0, false, "internal error: keeped_by_block=" << kept_by_block
+ CHECK_AND_ASSERT_MES(kept_by_block || kei_image_set.size() == 0, false, "internal error: kept_by_block=" << kept_by_block
<< ", kei_image_set.size()=" << kei_image_set.size() << ENDL << "txin.k_image=" << txin.k_image << ENDL
<< "tx_id=" << id );
auto ins_res = kei_image_set.insert(id);
@@ -223,7 +231,7 @@ namespace cryptonote
tvc.m_verifivation_failed = false;
m_txs_by_fee.emplace((double)blob_size / fee, id);
- //succeed
+
return true;
}
//---------------------------------------------------------------------------------
@@ -235,6 +243,9 @@ namespace cryptonote
return add_tx(tx, h, blob_size, tvc, keeped_by_block, relayed, version);
}
//---------------------------------------------------------------------------------
+ //FIXME: Can return early before removal of all of the key images.
+ // At the least, need to make sure that a false return here
+ // is treated properly. Should probably not return early, however.
bool tx_memory_pool::remove_transaction_keyimages(const transaction& tx)
{
CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -301,7 +312,7 @@ namespace cryptonote
);
}
//---------------------------------------------------------------------------------
- //proper tx_pool handling courtesy of CryptoZoidberg and Boolberry
+ //TODO: investigate whether boolean return is appropriate
bool tx_memory_pool::remove_stuck_transactions()
{
CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -332,6 +343,7 @@ namespace cryptonote
return true;
}
//---------------------------------------------------------------------------------
+ //TODO: investigate whether boolean return is appropriate
bool tx_memory_pool::get_relayable_transactions(std::list<std::pair<crypto::hash, cryptonote::transaction>> &txs) const
{
CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -380,6 +392,7 @@ namespace cryptonote
txs.push_back(tx_vt.second.tx);
}
//------------------------------------------------------------------
+ //TODO: investigate whether boolean return is appropriate
bool tx_memory_pool::get_transactions_and_spent_keys_info(std::vector<tx_info>& tx_infos, std::vector<spent_key_image_info>& key_image_infos) const
{
CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -556,6 +569,7 @@ namespace cryptonote
return ss.str();
}
//---------------------------------------------------------------------------------
+ //TODO: investigate whether boolean return is appropriate
bool tx_memory_pool::fill_block_template(block &bl, size_t median_size, uint64_t already_generated_coins, size_t &total_size, uint64_t &fee)
{
// Warning: This function takes already_generated_
@@ -646,6 +660,7 @@ namespace cryptonote
return n_removed;
}
//---------------------------------------------------------------------------------
+ //TODO: investigate whether only ever returning true is correct
bool tx_memory_pool::init(const std::string& config_folder)
{
CRITICAL_REGION_LOCAL(m_transactions_lock);
@@ -679,6 +694,7 @@ namespace cryptonote
}
//---------------------------------------------------------------------------------
+ //TODO: investigate whether only ever returning true is correct
bool tx_memory_pool::deinit()
{
if (m_config_folder.empty())
diff --git a/src/cryptonote_core/tx_pool.h b/src/cryptonote_core/tx_pool.h
index 71febcab6..0ecf90081 100644
--- a/src/cryptonote_core/tx_pool.h
+++ b/src/cryptonote_core/tx_pool.h
@@ -57,7 +57,9 @@ namespace cryptonote
/* */
/************************************************************************/
+ //! pair of <transaction fee, transaction hash> for organization
typedef std::pair<double, crypto::hash> tx_by_fee_entry;
+
class txCompare
{
public:
@@ -71,47 +73,255 @@ namespace cryptonote
}
};
+ //! container for sorting transactions by fee per unit size
typedef std::set<tx_by_fee_entry, txCompare> sorted_tx_container;
+ /**
+ * @brief Transaction pool, handles transactions which are not part of a block
+ *
+ * This class handles all transactions which have been received, but not as
+ * part of a block.
+ *
+ * This handling includes:
+ * storing the transactions
+ * organizing the transactions by fee per size
+ * taking/giving transactions to and from various other components
+ * saving the transactions to disk on shutdown
+ * helping create a new block template by choosing transactions for it
+ *
+ */
class tx_memory_pool: boost::noncopyable
{
public:
#if BLOCKCHAIN_DB == DB_LMDB
+ /**
+ * @brief Constructor
+ *
+ * @param bchs a Blockchain class instance, for getting chain info
+ */
tx_memory_pool(Blockchain& bchs);
#else
tx_memory_pool(blockchain_storage& bchs);
#endif
- bool add_tx(const transaction &tx, const crypto::hash &id, size_t blob_size, tx_verification_context& tvc, bool keeped_by_block, bool relayed, uint8_t version);
- bool add_tx(const transaction &tx, tx_verification_context& tvc, bool keeped_by_block, bool relayed, uint8_t version);
- //gets tx and remove it from pool
+
+
+ /**
+ * @copydoc add_tx(const transaction&, tx_verification_context&, bool, bool, uint8_t)
+ *
+ * @param id the transaction's hash
+ * @param blob_size the transaction's size
+ */
+ bool add_tx(const transaction &tx, const crypto::hash &id, size_t blob_size, tx_verification_context& tvc, bool kept_by_block, bool relayed, uint8_t version);
+
+ /**
+ * @brief add a transaction to the transaction pool
+ *
+ * Most likely the transaction will come from the network, but it is
+ * also possible for transactions to come from popped blocks during
+ * a reorg, or from local clients creating a transaction and
+ * submitting it to the network
+ *
+ * @param tx the transaction to be added
+ * @param tvc return-by-reference status about the transaction verification
+ * @param kept_by_block has this transaction been in a block?
+ * @param relayed was this transaction from the network or a local client?
+ * @param version the version used to create the transaction
+ *
+ * @return true if the transaction passes validations, otherwise false
+ */
+ bool add_tx(const transaction &tx, tx_verification_context& tvc, bool kept_by_block, bool relayed, uint8_t version);
+
+ /**
+ * @brief takes a transaction with the given hash from the pool
+ *
+ * @param id the hash of the transaction
+ * @param tx return-by-reference the transaction taken
+ * @param blob_size return-by-reference the transaction's size
+ * @param fee the transaction fee
+ * @param relayed return-by-reference was transaction relayed to us by the network?
+ *
+ * @return true unless the transaction cannot be found in the pool
+ */
bool take_tx(const crypto::hash &id, transaction &tx, size_t& blob_size, uint64_t& fee, bool &relayed);
+ /**
+ * @brief checks if the pool has a transaction with the given hash
+ *
+ * @param id the hash to look for
+ *
+ * @return true if the transaction is in the pool, otherwise false
+ */
bool have_tx(const crypto::hash &id) const;
+
+ /**
+ * @brief action to take when notified of a block added to the blockchain
+ *
+ * Currently does nothing
+ *
+ * @param new_block_height the height of the blockchain after the change
+ * @param top_block_id the hash of the new top block
+ *
+ * @return true
+ */
bool on_blockchain_inc(uint64_t new_block_height, const crypto::hash& top_block_id);
+
+ /**
+ * @brief action to take when notified of a block removed from the blockchain
+ *
+ * Currently does nothing
+ *
+ * @param new_block_height the height of the blockchain after the change
+ * @param top_block_id the hash of the new top block
+ *
+ * @return true
+ */
bool on_blockchain_dec(uint64_t new_block_height, const crypto::hash& top_block_id);
+
+ /**
+ * @brief action to take periodically
+ *
+ * Currently checks transaction pool for stale ("stuck") transactions
+ */
void on_idle();
+ /**
+ * @brief locks the transaction pool
+ */
void lock() const;
+
+ /**
+ * @brief unlocks the transaction pool
+ */
void unlock() const;
// load/store operations
+
+ /**
+ * @brief loads pool state (if any) from disk, and initializes pool
+ *
+ * @param config_folder folder name where pool state will be
+ *
+ * @return true
+ */
bool init(const std::string& config_folder);
+
+ /**
+ * @brief attempts to save the transaction pool state to disk
+ *
+ * Currently fails (returns false) if the data directory from init()
+ * does not exist and cannot be created, but returns true even if
+ * saving to disk is unsuccessful.
+ *
+ * @return true in most cases (see above)
+ */
bool deinit();
+
+ /**
+ * @brief Chooses transactions for a block to include
+ *
+ * @param bl return-by-reference the block to fill in with transactions
+ * @param median_size the current median block size
+ * @param already_generated_coins the current total number of coins "minted"
+ * @param total_size return-by-reference the total size of the new block
+ * @param fee return-by-reference the total of fees from the included transactions
+ *
+ * @return true
+ */
bool fill_block_template(block &bl, size_t median_size, uint64_t already_generated_coins, size_t &total_size, uint64_t &fee);
+
+ /**
+ * @brief get a list of all transactions in the pool
+ *
+ * @param txs return-by-reference the list of transactions
+ */
void get_transactions(std::list<transaction>& txs) const;
+
+ /**
+ * @brief get information about all transactions and key images in the pool
+ *
+ * see documentation on tx_info and spent_key_image_info for more details
+ *
+ * @param tx_infos return-by-reference the transactions' information
+ * @param key_image_infos return-by-reference the spent key images' information
+ *
+ * @return true
+ */
bool get_transactions_and_spent_keys_info(std::vector<tx_info>& tx_infos, std::vector<spent_key_image_info>& key_image_infos) const;
+
+ /**
+ * @brief get a specific transaction from the pool
+ *
+ * @param h the hash of the transaction to get
+ * @param tx return-by-reference the transaction requested
+ *
+ * @return true if the transaction is found, otherwise false
+ */
bool get_transaction(const crypto::hash& h, transaction& tx) const;
+
+ /**
+ * @brief get a list of all relayable transactions and their hashes
+ *
+ * "relayable" in this case means:
+ * nonzero fee
+ * hasn't been relayed too recently
+ * isn't old enough that relaying it is considered harmful
+ *
+ * @param txs return-by-reference the transactions and their hashes
+ *
+ * @return true
+ */
bool get_relayable_transactions(std::list<std::pair<crypto::hash, cryptonote::transaction>>& txs) const;
+
+ /**
+ * @brief tell the pool that certain transactions were just relayed
+ *
+ * @param txs the list of transactions (and their hashes)
+ */
void set_relayed(const std::list<std::pair<crypto::hash, cryptonote::transaction>>& txs);
+
+ /**
+ * @brief get the total number of transactions in the pool
+ *
+ * @return the number of transactions in the pool
+ */
size_t get_transactions_count() const;
+
+ /**
+ * @brief get a string containing human-readable pool information
+ *
+ * @param short_format whether to use a shortened format for the info
+ *
+ * @return the string
+ */
std::string print_pool(bool short_format) const;
+
+ /**
+ * @brief remove transactions from the pool which are no longer valid
+ *
+ * With new versions of the currency, what conditions render a transaction
+ * invalid may change. This function clears those which were received
+ * before a version change and no longer conform to requirements.
+ *
+ * @param version the version the transactions must conform to
+ *
+ * @return the number of transactions removed
+ */
size_t validate(uint8_t version);
- /*bool flush_pool(const std::strig& folder);
- bool inflate_pool(const std::strig& folder);*/
#define CURRENT_MEMPOOL_ARCHIVE_VER 11
+ /**
+ * @brief serialize the transaction pool to/from disk
+ *
+ * If the archive version passed is older than the version compiled
+ * in, this function does nothing, as it cannot deserialize after a
+ * format change.
+ *
+ * @tparam archive_t the archive class
+ * @param a the archive to serialize to/from
+ * @param version the archive version
+ */
template<class archive_t>
void serialize(archive_t & a, const unsigned int version)
{
@@ -123,97 +333,169 @@ namespace cryptonote
a & m_timed_out_transactions;
}
+ /**
+ * @brief information about a single transaction
+ */
struct tx_details
{
- transaction tx;
- size_t blob_size;
- uint64_t fee;
- crypto::hash max_used_block_id;
- uint64_t max_used_block_height;
- bool kept_by_block;
- //
- uint64_t last_failed_height;
- crypto::hash last_failed_id;
- time_t receive_time;
+ transaction tx; //!< the transaction
+ size_t blob_size; //!< the transaction's size
+ uint64_t fee; //!< the transaction's fee amount
+ crypto::hash max_used_block_id; //!< the hash of the highest block referenced by an input
+ uint64_t max_used_block_height; //!< the height of the highest block referenced by an input
- time_t last_relayed_time;
- bool relayed;
+ //! whether or not the transaction has been in a block before
+ /*! if the transaction was returned to the pool from the blockchain
+ * due to a reorg, then this will be true
+ */
+ bool kept_by_block;
+
+ //! the highest block the transaction referenced when last checking it failed
+ /*! if verifying a transaction's inputs fails, it's possible this is due
+ * to a reorg since it was created (if it used recently created outputs
+ * as inputs).
+ */
+ uint64_t last_failed_height;
+
+ //! the hash of the highest block the transaction referenced when last checking it failed
+ /*! if verifying a transaction's inputs fails, it's possible this is due
+ * to a reorg since it was created (if it used recently created outputs
+ * as inputs).
+ */
+ crypto::hash last_failed_id;
+
+ time_t receive_time; //!< the time when the transaction entered the pool
+
+ time_t last_relayed_time; //!< the last time the transaction was relayed to the network
+ bool relayed; //!< whether or not the transaction has been relayed to the network
};
private:
+
+ /**
+ * @brief remove old transactions from the pool
+ *
+ * After a certain time, it is assumed that a transaction which has not
+ * yet been mined will likely not be mined. These transactions are removed
+ * from the pool to avoid buildup.
+ *
+ * @return true
+ */
bool remove_stuck_transactions();
+
+ /**
+ * @brief check if a transaction in the pool has a given spent key image
+ *
+ * @param key_im the spent key image to look for
+ *
+ * @return true if the spent key image is present, otherwise false
+ */
bool have_tx_keyimg_as_spent(const crypto::key_image& key_im) const;
+
+ /**
+ * @brief check if any spent key image in a transaction is in the pool
+ *
+ * Checks if any of the spent key images in a given transaction are present
+ * in any of the transactions in the transaction pool.
+ *
+ * @note see tx_pool::have_tx_keyimg_as_spent
+ *
+ * @param tx the transaction to check spent key images of
+ *
+ * @return true if any spent key images are present in the pool, otherwise false
+ */
bool have_tx_keyimges_as_spent(const transaction& tx) const;
+
+ /**
+ * @brief forget a transaction's spent key images
+ *
+ * Spent key images are stored separately from transactions for
+ * convenience/speed, so this is part of the process of removing
+ * a transaction from the pool.
+ *
+ * @param tx the transaction
+ *
+ * @return false if any key images to be removed cannot be found, otherwise true
+ */
bool remove_transaction_keyimages(const transaction& tx);
+
+ /**
+ * @brief check if any of a transaction's spent key images are present in a given set
+ *
+ * @param kic the set of key images to check against
+ * @param tx the transaction to check
+ *
+ * @return true if any key images present in the set, otherwise false
+ */
static bool have_key_images(const std::unordered_set<crypto::key_image>& kic, const transaction& tx);
+
+ /**
+ * @brief append the key images from a transaction to the given set
+ *
+ * @param kic the set of key images to append to
+ * @param tx the transaction
+ *
+ * @return false if any append fails, otherwise true
+ */
static bool append_key_images(std::unordered_set<crypto::key_image>& kic, const transaction& tx);
+ /**
+ * @brief check if a transaction is a valid candidate for inclusion in a block
+ *
+ * @param txd the transaction to check (and info about it)
+ *
+ * @return true if the transaction is good to go, otherwise false
+ */
bool is_transaction_ready_to_go(tx_details& txd) const;
+
+ //! map a transactions (and related info) to their hashes
typedef std::unordered_map<crypto::hash, tx_details > transactions_container;
+
+ //TODO: confirm the below comments and investigate whether or not this
+ // is the desired behavior
+ //! map key images to transactions which spent them
+ /*! this seems odd, but it seems that multiple transactions can exist
+ * in the pool which both have the same spent key. This would happen
+ * in the event of a reorg where someone creates a new/different
+ * transaction on the assumption that the original will not be in a
+ * block again.
+ */
typedef std::unordered_map<crypto::key_image, std::unordered_set<crypto::hash> > key_images_container;
- mutable epee::critical_section m_transactions_lock;
- transactions_container m_transactions;
- key_images_container m_spent_key_images;
+ mutable epee::critical_section m_transactions_lock; //!< lock for the pool
+ transactions_container m_transactions; //!< container for transactions in the pool
+
+ //! container for spent key images from the transactions in the pool
+ key_images_container m_spent_key_images;
+
+ //TODO: this time should be a named constant somewhere, not hard-coded
+ //! interval on which to check for stale/"stuck" transactions
epee::math_helper::once_a_time_seconds<30> m_remove_stuck_tx_interval;
- //TODO: add fee_per_kb element to type tx_details and replace this
- //functionality by just making m_transactions a std::set
- sorted_tx_container m_txs_by_fee;
+ //TODO: look into doing this better
+ sorted_tx_container m_txs_by_fee; //!< container for transactions organized by fee per size
+ /**
+ * @brief get an iterator to a transaction in the sorted container
+ *
+ * @param id the hash of the transaction to look for
+ *
+ * @return an iterator, possibly to the end of the container if not found
+ */
sorted_tx_container::iterator find_tx_in_sorted_container(const crypto::hash& id) const;
+ //! transactions which are unlikely to be included in blocks
+ /*! These transactions are kept in RAM in case they *are* included
+ * in a block eventually, but this container is not saved to disk.
+ */
std::unordered_set<crypto::hash> m_timed_out_transactions;
- //transactions_container m_alternative_transactions;
-
- std::string m_config_folder;
+ std::string m_config_folder; //!< the folder to save state to
#if BLOCKCHAIN_DB == DB_LMDB
- Blockchain& m_blockchain;
+ Blockchain& m_blockchain; //!< reference to the Blockchain object
#else
blockchain_storage& m_blockchain;
#endif
- /************************************************************************/
- /* */
- /************************************************************************/
- /*class inputs_visitor: public boost::static_visitor<bool>
- {
- key_images_container& m_spent_keys;
- public:
- inputs_visitor(key_images_container& spent_keys): m_spent_keys(spent_keys)
- {}
- bool operator()(const txin_to_key& tx) const
- {
- auto pr = m_spent_keys.insert(tx.k_image);
- CHECK_AND_ASSERT_MES(pr.second, false, "Tried to insert transaction with input seems already spent, input: " << epee::string_tools::pod_to_hex(tx.k_image));
- return true;
- }
- bool operator()(const txin_gen& tx) const
- {
- CHECK_AND_ASSERT_MES(false, false, "coinbase transaction in memory pool");
- return false;
- }
- bool operator()(const txin_to_script& tx) const {return false;}
- bool operator()(const txin_to_scripthash& tx) const {return false;}
- }; */
- /************************************************************************/
- /* */
- /************************************************************************/
- class amount_visitor: public boost::static_visitor<uint64_t>
- {
- public:
- uint64_t operator()(const txin_to_key& tx) const
- {
- return tx.amount;
- }
- uint64_t operator()(const txin_gen& tx) const
- {
- CHECK_AND_ASSERT_MES(false, false, "coinbase transaction in memory pool");
- return 0;
- }
- uint64_t operator()(const txin_to_script& tx) const {return 0;}
- uint64_t operator()(const txin_to_scripthash& tx) const {return 0;}
- };
#if BLOCKCHAIN_DB == DB_LMDB
#else