Merge #15681: [mempool] Allow one extra single-ancestor transaction per package

50cede3f5a [mempool] Allow one extra single-ancestor transaction per package (Matt Corallo)

Pull request description:

  This implements the proposed policy change from [1], which allows
  certain classes of contract protocols involving revocation
  punishments to use CPFP. Note that some such use-cases may still
  want some form of one-deep package relay, though even this alone
  may greatly simplify some lightning fee negotiation.

  [1] https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html

ACKs for top commit:
  ajtowns:
    ACK 50cede3f5a -- looked over code again, compared with previous commit, compiles, etc.
  sdaftuar:
    ACK 50cede3f5a
  ryanofsky:
    utACK 50cede3f5a. Changes since last review: adding EXTRA_DESCENDANT_TX_SIZE_LIMIT constant, changing max ancestor size from 1,000,000 to nLimitAncestorSize constant (101,000), fixing test comment and getting rid of unused test node.

Tree-SHA512: b052c2a0f384855572b4579310131897b612201214b5abbb225167224e4f550049e300b471dbf320928652571e92ca2d650050b7cf39ac92b3bc1d2bcd386c1c
This commit is contained in:
Wladimir J. van der Laan
2019-07-19 19:56:12 +02:00
4 changed files with 108 additions and 1 deletions

View File

@@ -64,6 +64,12 @@ static const unsigned int DEFAULT_ANCESTOR_SIZE_LIMIT = 101;
static const unsigned int DEFAULT_DESCENDANT_LIMIT = 25;
/** Default for -limitdescendantsize, maximum kilobytes of in-mempool descendants */
static const unsigned int DEFAULT_DESCENDANT_SIZE_LIMIT = 101;
/**
* An extra transaction can be added to a package, as long as it only has one
* ancestor and is no larger than this. Not really any reason to make this
* configurable as it doesn't materially change DoS parameters.
*/
static const unsigned int EXTRA_DESCENDANT_TX_SIZE_LIMIT = 10000;
/** Default for -mempoolexpiry, expiration time for mempool transactions in hours */
static const unsigned int DEFAULT_MEMPOOL_EXPIRY = 336;
/** Maximum kilobytes for transactions to store for processing during reorg */