a59ac5b18f
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
|
||
|---|---|---|
| addrmgr | ||
| blockchain | ||
| btcec | ||
| btcjson | ||
| chaincfg | ||
| cmd | ||
| connmgr | ||
| database | ||
| docs | ||
| integration | ||
| limits | ||
| mempool | ||
| mining | ||
| netsync | ||
| peer | ||
| release | ||
| rpcclient | ||
| txscript | ||
| wire | ||
| .gitignore | ||
| .travis.yml | ||
| btcd.go | ||
| CHANGES | ||
| config_test.go | ||
| config.go | ||
| doc.go | ||
| glide.lock | ||
| glide.yaml | ||
| goclean.sh | ||
| LICENSE | ||
| log.go | ||
| params.go | ||
| README.md | ||
| rpcadapters.go | ||
| rpcserver.go | ||
| rpcserverhelp_test.go | ||
| rpcserverhelp.go | ||
| rpcwebsocket.go | ||
| sample-btcd.conf | ||
| server.go | ||
| service_windows.go | ||
| signal.go | ||
| signalsigterm.go | ||
| upgrade.go | ||
| upnp.go | ||
| version.go | ||
btcd
btcd is an alternative full node bitcoin implementation written in Go (golang).
This project is currently under active development and is in a Beta state. It is extremely stable and has been in production use since October 2013.
It properly downloads, validates, and serves the block chain using the exact rules (including consensus bugs) for block acceptance as Bitcoin Core. We have taken great care to avoid btcd causing a fork to the block chain. It includes a full block validation testing framework which contains all of the 'official' block acceptance tests (and some additional ones) that is run on every pull request to help ensure it properly follows consensus. Also, it passes all of the JSON test data in the Bitcoin Core code.
It also properly relays newly mined blocks, maintains a transaction pool, and relays individual transactions that have not yet made it into a block. It ensures all individual transactions admitted to the pool follow the rules required by the block chain and also includes more strict checks which filter transactions based on miner requirements ("standard" transactions).
One key difference between btcd and Bitcoin Core is that btcd does NOT include wallet functionality and this was a very intentional design decision. See the blog entry here for more details. This means you can't actually make or receive payments directly with btcd. That functionality is provided by the btcwallet and Paymetheus (Windows-only) projects which are both under active development.
Requirements
Go 1.8 or newer.
Installation
Windows - MSI Available
https://github.com/btcsuite/btcd/releases
Linux/BSD/MacOSX/POSIX - Build from Source
-
Install Go according to the installation instructions here: http://golang.org/doc/install
-
Ensure Go was installed properly and is a supported version:
$ go version
$ go env GOROOT GOPATH
NOTE: The GOROOT and GOPATH above must not be the same path. It is
recommended that GOPATH is set to a directory in your home directory such as
~/goprojects to avoid write permission issues. It is also recommended to add
$GOPATH/bin to your PATH at this point.
- Run the following commands to obtain btcd, all dependencies, and install it:
$ go get -u github.com/Masterminds/glide
$ git clone https://github.com/btcsuite/btcd $GOPATH/src/github.com/btcsuite/btcd
$ cd $GOPATH/src/github.com/btcsuite/btcd
$ glide install
$ go install . ./cmd/...
- btcd (and utilities) will now be installed in
$GOPATH/bin. If you did not already add the bin directory to your system path during Go installation, we recommend you do so now.
Updating
Windows
Install a newer MSI
Linux/BSD/MacOSX/POSIX - Build from Source
- Run the following commands to update btcd, all dependencies, and install it:
$ cd $GOPATH/src/github.com/btcsuite/btcd
$ git pull && glide install
$ go install . ./cmd/...
Getting Started
btcd has several configuration options available to tweak how it runs, but all of the basic operations described in the intro section work with zero configuration.
Windows (Installed from MSI)
Launch btcd from your Start menu.
Linux/BSD/POSIX/Source
$ ./btcd
IRC
- irc.freenode.net
- channel #btcd
- webchat
Issue Tracker
The integrated github issue tracker is used for this project.
Documentation
The documentation is a work-in-progress. It is located in the docs folder.
GPG Verification Key
All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from the btcsuite developers. To verify the signature perform the following:
-
Download the Conformal public key: https://raw.githubusercontent.com/btcsuite/btcd/master/release/GIT-GPG-KEY-conformal.txt
-
Import the public key into your GPG keyring:
gpg --import GIT-GPG-KEY-conformal.txt -
Verify the release tag with the following command where
TAG_NAMEis a placeholder for the specific tag:git tag -v TAG_NAME
License
btcd is licensed under the copyfree ISC License.