It is not the responsibility of mempool to relay transactions, so
return a slice of transactions accepted to the mempool due to the
passed transaction to the caller.
This introduces a new indexing infrastructure for supporting optional
indexes using the new database and blockchain infrastructure along with
two concrete indexer implementations which provide both a
transaction-by-hash and a transaction-by-address index.
The new infrastructure is mostly separated into a package named indexers
which is housed under the blockchain package. In order to support this,
a new interface named IndexManager has been introduced in the blockchain
package which provides methods to be notified when the chain has been
initialized and when blocks are connected and disconnected from the main
chain. A concrete implementation of an index manager is provided by the
new indexers package.
The new indexers package also provides a new interface named Indexer
which allows the index manager to manage concrete index implementations
which conform to the interface.
The following is high level overview of the main index infrastructure
changes:
- Define a new IndexManager interface in the blockchain package and
modify the package to make use of the interface when specified
- Create a new indexers package
- Provides an Index interface which allows concrete indexes to plugin
to an index manager
- Provides a concrete IndexManager implementation
- Handles the lifecycle of all indexes it manages
- Tracks the index tips
- Handles catching up disabled indexes that have been reenabled
- Handles reorgs while the index was disabled
- Invokes the appropriate methods for all managed indexes to allow
them to index and deindex the blocks and transactions
- Implement a transaction-by-hash index
- Makes use of internal block IDs to save a significant amount of
space and indexing costs over the old transaction index format
- Implement a transaction-by-address index
- Makes use of a leveling scheme in order to provide a good tradeoff
between space required and indexing costs
- Supports enabling and disabling indexes at will
- Support the ability to drop indexes if they are no longer desired
The following is an overview of the btcd changes:
- Add a new index logging subsystem
- Add new options --txindex and --addrindex in order to enable the
optional indexes
- NOTE: The transaction index will automatically be enabled when the
address index is enabled because it depends on it
- Add new options --droptxindex and --dropaddrindex to allow the indexes
to be removed
- NOTE: The address index will also be removed when the transaction
index is dropped because it depends on it
- Update getrawtransactions RPC to make use of the transaction index
- Reimplement the searchrawtransaction RPC that makes use of the address
index
- Update sample-btcd.conf to include sample usage for the new optional
index flags
This commit is the first stage of several that are planned to convert
the blockchain package into a concurrent safe package that will
ultimately allow support for multi-peer download and concurrent chain
processing. The goal is to update btcd proper after each step so it can
take advantage of the enhancements as they are developed.
In addition to the aforementioned benefit, this staged approach has been
chosen since it is absolutely critical to maintain consensus.
Separating the changes into several stages makes it easier for reviewers
to logically follow what is happening and therefore helps prevent
consensus bugs. Naturally there are significant automated tests to help
prevent consensus issues as well.
The main focus of this stage is to convert the blockchain package to use
the new database interface and implement the chain-related functionality
which it no longer handles. It also aims to improve efficiency in
various areas by making use of the new database and chain capabilities.
The following is an overview of the chain changes:
- Update to use the new database interface
- Add chain-related functionality that the old database used to handle
- Main chain structure and state
- Transaction spend tracking
- Implement a new pruned unspent transaction output (utxo) set
- Provides efficient direct access to the unspent transaction outputs
- Uses a domain specific compression algorithm that understands the
standard transaction scripts in order to significantly compress them
- Removes reliance on the transaction index and paves the way toward
eventually enabling block pruning
- Modify the New function to accept a Config struct instead of
inidividual parameters
- Replace the old TxStore type with a new UtxoViewpoint type that makes
use of the new pruned utxo set
- Convert code to treat the new UtxoViewpoint as a rolling view that is
used between connects and disconnects to improve efficiency
- Make best chain state always set when the chain instance is created
- Remove now unnecessary logic for dealing with unset best state
- Make all exported functions concurrent safe
- Currently using a single chain state lock as it provides a straight
forward and easy to review path forward however this can be improved
with more fine grained locking
- Optimize various cases where full blocks were being loaded when only
the header is needed to help reduce the I/O load
- Add the ability for callers to get a snapshot of the current best
chain stats in a concurrent safe fashion
- Does not block callers while new blocks are being processed
- Make error messages that reference transaction outputs consistently
use <transaction hash>:<output index>
- Introduce a new AssertError type an convert internal consistency
checks to use it
- Update tests and examples to reflect the changes
- Add a full suite of tests to ensure correct functionality of the new
code
The following is an overview of the btcd changes:
- Update to use the new database and chain interfaces
- Temporarily remove all code related to the transaction index
- Temporarily remove all code related to the address index
- Convert all code that uses transaction stores to use the new utxo
view
- Rework several calls that required the block manager for safe
concurrency to use the chain package directly now that it is
concurrent safe
- Change all calls to obtain the best hash to use the new best state
snapshot capability from the chain package
- Remove workaround for limits on fetching height ranges since the new
database interface no longer imposes them
- Correct the gettxout RPC handler to return the best chain hash as
opposed the hash the txout was found in
- Optimize various RPC handlers:
- Change several of the RPC handlers to use the new chain snapshot
capability to avoid needlessly loading data
- Update several handlers to use new functionality to avoid accessing
the block manager so they are able to return the data without
blocking when the server is busy processing blocks
- Update non-verbose getblock to avoid deserialization and
serialization overhead
- Update getblockheader to request the block height directly from
chain and only load the header
- Update getdifficulty to use the new cached data from chain
- Update getmininginfo to use the new cached data from chain
- Update non-verbose getrawtransaction to avoid deserialization and
serialization overhead
- Update gettxout to use the new utxo store versus loading
full transactions using the transaction index
The following is an overview of the utility changes:
- Update addblock to use the new database and chain interfaces
- Update findcheckpoint to use the new database and chain interfaces
- Remove the dropafter utility which is no longer supported
NOTE: The transaction index and address index will be reimplemented in
another commit.
mempoolPolicy contains the values that configure the mempool policy.
This decouples the values from the internals of btcd to move closer
to a mempool package.
This creates a skeleton mining package that simply contains a few of the
definitions used by the mining and mempool code.
This is a step towards decoupling the mining code from the internals of
btcd and ultimately will house all of the code related to creating block
templates and CPU mining.
The main reason a skeleton package is being created before the full
blown package is ready is to avoid blocking mempool separation which
relies on these type definitions.
This introduces the concept of a new interface named TxSource which aims
to generically provide a concurrent safe source of transactions to be
considered for inclusion in a new block. This is a step towards
decoupling the mining code from the internals of btcd. Ultimately the
intent is to create a separate mining package.
The new TxSource interface relies on a new struct named miningTxDesc,
which describes each entry in the transaction source. Once this code is
refactored into a separate mining package, the mining prefix can simply
be dropped leaving the type exported as mining.TxDesc.
To go along with this, the existing TxDesc type in the mempool has been
renamed to mempoolTxDesc and changed to embed the new miningTxDesc type.
This allows the mempool to efficiently implement the MiningTxDescs
method needed to satisfy the TxSource interface.
This approach effectively separates the direct reliance of the mining
code on the mempool and its data structures. Even though the memory
pool will still be the default concrete implementation of the interface,
making it an interface offers much more flexibility in terms of testing
and even provides the potential to allow more than one source (perhaps
multiple independent relay networks, for example).
Finally, the memory pool and all of the mining code has been updated to
implement and use the new interface.
This does three things:
- Splits the priority calculation logic from the TxDesc type
- Modifies the calcPriority function to perform the value age
calculation instead of accepting it as a parameter
- Changes the starting priority to be calculated when the transaction is
added to the pool
The first is useful as it is a step towards decoupling the mining code
from the internals of the memory pool. Also, the concept of priority is
related to mining policy, so it makes more sense to have the
calculations separate than being defined on the memory pool tx
descriptor.
The second change has been made because everywhere that uses the
calcPriority function first has to calculate the value age anyways and
by making it part of the function it can be avoided altogether in
certain circumstances thereby provided a bit of optimization.
The third change ensure the starting priority is safe for reentrancy
which will be important once the mempool is split into a separate
package.
This is more efficient and prevents duplicate entries which can
lead to no-longer-orphans being attempted be added to the mempool
multiple times.
Bug found by me, debugged with @davecgh, and patch from @davecgh
This refactors the checkTransactionStandard function, along with related
constants, from the mempool to the policy.go file since it is strictly
related to policy.
In addition, it adds tests for the function which cover all code paths.
ProcessTransaction could have accepted a new transaction into mempool
but could have returned a reject message if a no-longer-orphan
transaction failed to be accepted. This would also skip any
additional no-longer-orphans, keeping them in the orphan pool.
Instead of returning an error incorrectly, log the error and skip
the no-longer-orphan transaction. This allows the rest of the
no-longer-orphans to be processed as well.
Introduce an ECDSA signature verification into btcd in order to
mitigate a certain DoS attack and as a performance optimization.
The benefits of SigCache are two fold. Firstly, usage of SigCache
mitigates a DoS attack wherein an attacker causes a victim's client to
hang due to worst-case behavior triggered while processing attacker
crafted invalid transactions. A detailed description of the mitigated
DoS attack can be found here: https://bitslog.wordpress.com/2013/01/23/fixed-bitcoin-vulnerability-explanation-why-the-signature-cache-is-a-dos-protection/
Secondly, usage of the SigCache introduces a signature verification
optimization which speeds up the validation of transactions within a
block, if they've already been seen and verified within the mempool.
The server itself manages the sigCache instance. The blockManager and
txMempool respectively now receive pointers to the created sigCache
instance. All read (sig triplet existence) operations on the sigCache
will not block unless a separate goroutine is adding an entry (writing)
to the sigCache. GetBlockTemplate generation now also utilizes the
sigCache in order to avoid unnecessarily double checking signatures
when generating a template after previously accepting a txn to the
mempool. Consequently, the CPU miner now also employs the same
optimization.
The maximum number of entries for the sigCache has been introduced as a
config parameter in order to allow users to configure the amount of
memory consumed by this new additional caching.
This commit converts all block height references to int32 instead of
int64. The current target block production rate is 10 mins per block
which means it will take roughly 40,800 years to reach the maximum
height an int32 affords. Even if the target rate were lowered to one
block per minute, it would still take roughly another 4,080 years to
reach the maximum.
In the mean time, there is no reason to use a larger type which results
in higher memory and disk space usage. However, for now, in order to
avoid having to reserialize a bunch of database information, the heights
are still serialized to the database as 8-byte uint64s.
This is being mainly being done in preparation for further upcoming
infrastructure changes which will use the smaller and more efficient
4-byte serialization in the database as well.
IsUnspendable takes a public key script and returns whether it is
spendable.
Additionally, hook this into the mempool isDust function, since
unspendable outputs can't be spent.
This mimics Bitcoin Core commit 0aad1f13b2430165062bf9436036c1222a8724da
This change moves IsFinalizedTransaction to txscript and also changes
the first argument to take a wire.MsgTx instead of btcutil.Tx. This
is needed for an upcoming diff in which txscript will require
IsFinalizedTransaction and we do not want to import the btcd/blockchain.
The option -maxorphantx allows the user to specify the number of
orphan transactions to keep in memory.
Also, lower the default max orphan count from 10000 to 1000.
Fix#303 by changing the addrindex key prefix to 3 characters so that
it's easy to check length when dropping the index. To drop the old
index, check to make sure we aren't dropping any entries that end in
"sx" or "tx" as those aren't part of the addrindex. Update test to
deal with the new prefix length.
Fix#346 by changing the pointers in the mempool's addrindex map to
wire.ShaHash 32-byte values. This lets them be deleted even if the
transaction data changes places in memory upon expanding the maps.
Change the way addrindex uint32s are stored to big-endian in order to
sort the transactions on disk in chronological/dependency order.
Change the "searchrawtransactions" RPC call to return transactions
from the database before the memory pool so that they're returned in
order. This commit DOES NOT do topological sorting of the memory pool
transactions to ensure they're returned in dependency order. This may
be a good idea for a future enhancement.
Add addrindex versioning to automatically drop the old/incompatible
version of the index and rebuild with the new sort method and key
prefix.
For every transaction in a newly accepted block, process the orphan
pool moving now no longer orphan transactions to the mempool.
Previously, no longer orphan transactions would remain in the orphan
pool.
This commit modifies finalized transaction check used by the memory pool
and block templates to use the network adjusted time instead of the
unadjusted local time. This helps keep the transactions accepted to the
memory pool, and hence allowed to relay, more consistent across nodes.
By exporting StandardVerifyFlags, clients can ensure they create
transactions that btcd will accept into its mempool.
This flag doesn't belong in txscript. It belongs in a
policy package. However, this is currently the least worse place.
This modifies the recently added code which rejects free/low-fee
transactions with insufficient priority to ignore resurrected transactions
from disconnected blocks. It also exempts resurrected transactions from
the free/low-fee rate limiting.
By default, have the mempool reject free and low-fee transactions that
have insufficient priority to be mined in the next block.
Addtionally, add a new configuration option, -norelaypriority, to
disable the check.
* Address index is built up concurrently with the `--addrindex` flag.
* Entire index can be deleted with `--dropaddrindex`.
* New RPC call: `searchrawtransaction`
* Returns all transacitons related to a particular address
* Includes mempool transactions
* Requires `--addrindex` to be activated and fully caught up.
* New `blockLogger` struct has been added to factor our common logging
code
* Wiki and docs updated with new features.
* When an inv is to be sent to the server for relaying, the sender
already has access to the underlying data. So
instead of requiring the relay to look up the data by
hash, the data is now coupled in the request message.
The mempool's MaybeAcceptTransaction methods have also been modified
to return a slice of transaction hashes referenced by the transaction
inputs which are unknown (totally spent or never seen). While this is
currently used to include the first hash in a ProcessTransaction error
message if inserting orphans is not allowed, it may also be used in
the future to request orphan transactions from peers.
This commit addresses a few nitpicks in the recent getrawmppol update
which populates the starting and current priority fields.
In particular:
- Move the new calcInputValueAge function before the function which
invokes it so it is consistent with the rest of the mempool code
- Double space after periods for consistency
- Correct the comments for calcInputValueAge to indiciate that inputs
which are in the the memory pool count as zero toward the value age
rather than the incorrect claim that that the overal input value age is
zero when one of them does
- Rename endingPriority to currentPriority to match the RPC field and its
actual function
- Make the comment about using zero when input transactions can't be found
for some reason more accurate since there can be (and frequently is)
more than one input transaction
This change removes transactions from a newly connected block
from the orphan pool if they exist. Additionally, any orphan
transactions that are no longer orphan transactions are moved
to the mempool and inv'd to the currently connected peers.
