This modifies the utxoset in the database and related UtxoViewpoint to
store and work with unspent transaction outputs on a per-output basis
instead of at a transaction level. This was inspired by similar recent
changes in Bitcoin Core.
The primary motivation is to simplify the code, pave the way for a
utxo cache, and generally focus on optimizing runtime performance.
The tradeoff is that this approach does somewhat increase the size of
the serialized utxoset since it means that the transaction hash is
duplicated for each output as a part of the key and some additional
details such as whether the containing transaction is a coinbase and the
block height it was a part of are duplicated in each output.
However, in practice, the size difference isn't all that large, disk
space is relatively cheap, certainly cheaper than memory, and it is much
more important to provide more efficient runtime operation since that is
the ultimate purpose of the daemon.
While performing this conversion, it also simplifies the code to remove
the transaction version information from the utxoset as well as the
spend journal. The logic for only serializing it under certain
circumstances is complicated and it isn't actually used anywhere aside
from the gettxout RPC where it also isn't used by anything important
either. Consequently, this also removes the version field of the
gettxout RPC result.
The utxos in the database are automatically migrated to the new format
with this commit and it is possible to interrupt and resume the
migration process.
Finally, it also updates the tests for the new format and adds a new
function to the tests to convert the old test data to the new format for
convenience. The data has already been converted and updated in the
commit.
An overview of the changes are as follows:
- Remove transaction version from both spent and unspent output entries
- Update utxo serialization format to exclude the version
- Modify the spend journal serialization format
- The old version field is now reserved and always stores zero and
ignores it when reading
- This allows old entries to be used by new code without having to
migrate the entire spend journal
- Remove version field from gettxout RPC result
- Convert UtxoEntry to represent a specific utxo instead of a
transaction with all remaining utxos
- Optimize for memory usage with an eye towards a utxo cache
- Combine details such as whether the txout was contained in a
coinbase, is spent, and is modified into a single packed field of
bit flags
- Align entry fields to eliminate extra padding since ultimately
there will be a lot of these in memory
- Introduce a free list for serializing an outpoint to the database
key format to significantly reduce pressure on the GC
- Update all related functions that previously dealt with transaction
hashes to accept outpoints instead
- Update all callers accordingly
- Only add individually requested outputs from the mempool when
constructing a mempool view
- Modify the spend journal to always store the block height and coinbase
information with every spent txout
- Introduce code to handle fetching the missing information from
another utxo from the same transaction in the event an old style
entry is encountered
- Make use of a database cursor with seek to do this much more
efficiently than testing every possible output
- Always decompress data loaded from the database now that a utxo entry
only consists of a specific output
- Introduce upgrade code to migrate the utxo set to the new format
- Store versions of the utxoset and spend journal buckets
- Allow migration process to be interrupted and resumed
- Update all tests to expect the correct encodings, remove tests that no
longer apply, and add new ones for the new expected behavior
- Convert old tests for the legacy utxo format deserialization code to
test the new function that is used during upgrade
- Update the utxostore test data and add function that was used to
convert it
- Introduce a few new functions on UtxoViewpoint
- AddTxOut for adding an individual txout versus all of them
- addTxOut to handle the common code between the new AddTxOut and
existing AddTxOuts
- RemoveEntry for removing an individual txout
- fetchEntryByHash for fetching any remaining utxo for a given
transaction hash
The cfilter BIP specifies that the filter type is a uint8. The
current code encodes it correctly on the wire, but everywhere else,
it's treated as a boolean (false for basic filter, true for
extended). This commit corrects that to account for possible
additional filter types in the future. All package changes are
done in one commit as they're all interdependent. The following
packages are updated:
* blockchain/indexers
* btcjson
* peer
* wire
* main (server.go and rpcserver.go)
The modifies the encoding of witness stacks in JSON responses to use a
slice of strings instead of a single space-separated string for
compatibility with Core.
Version 0.15.0 of Bitcoin Core will include a new RPC command that will
allow us to obtain the amount of time (in seconds) that the server has
been running.
The github markdown interpreter has been changed such that it no longer
allows spaces in between the brackets and parenthesis of links and now
requires a newline in between anchors and other formatting. This
updates all of the markdown files accordingly.
While here, it also corrects a couple of inconsistencies in some of the
README.md files.
This updates the GetNetworkInfoResult structure to include the latest
fields added to Core for compatibility purposes.
While here, also move the definitions of the subtypes for the result
before their use for consistency.
This commit updates the fields of GetBlockChainInfoResult to reflect
the current state of the RPC as widely implemented by other full-node
implementations.
This modifies the test for createrawtransaction to specify the constant
size passed as an int64. This is necessary because the NewCmd function
accepts the parameters as interfaces in order to support varargs and a
raw numeric constant is treated as an integer. Since the constant value
is larger than an int32, this causes certain platforms like ARM which
treat a raw integer as a 32-bit integer to fail to compile.
This is work towards #600.
rpcserver:
If the locktime is given, the transaction inputs will be set to a
non-max value, activating the locktime. The locktime for the
new transaction will be set to the given value.
This mimics Bitcoin Core commit 212bcca92089f406d9313dbe6d0e1d25143d61ff
First, it removes the documentation section from all the README.md files
and instead puts a web-based godoc badge and link at the top with the
other badges. This is being done since the local godoc tool no longer
ships with Go by default, so the instructions no longer work without
first installing godoc. Due to this, pretty much everyone uses the
web-based godoc these days anyways. Anyone who has manually installed
godoc won't need instructions.
Second, it makes sure the ISC license badge is at the top with the other
badges and removes the textual reference in the overview section.
Finally, it's modifies the Installation section to Installation and
Updating and adds a '-u' to the 'go get' command since it works for both
and thus is simpler.
