This reworks the block index code such that it loads all of the headers
in the main chain at startup and constructs the full block index
accordingly.
Since the full index from the current best tip all the way back to the
genesis block is now guaranteed to be in memory, this also removes all
code related to dynamically loading the nodes and updates some of the
logic to take advantage of the fact traversing the block index can no
longer potentially fail. There are also many more optimizations and
simplifications that can be made in the future as a result of this.
Due to removing all of the extra overhead of tracking the dynamic state,
and ensuring the block node structs are aligned to eliminate extra
padding, the end result of a fully populated block index now takes quite
a bit less memory than the previous dynamically loaded version.
It also speeds up the initial startup process by roughly 2x since it is
faster to bulk load the nodes in order as opposed to dynamically loading
only the nodes near the tip in backwards order.
For example, here is some startup timing information before and after
this commit on a node that contains roughly 238,000 blocks:
7200 RPM HDD:
-------------
Startup time before this commit: ~7.71s
Startup time after this commit: ~3.47s
SSD:
----
Startup time before this commit: ~6.34s
Startup time after this commit: ~3.51s
Some additional benefits are:
- Since every block node is in memory, the code which reconstructs
headers from block nodes means that all headers can always be served
from memory which will be important since the network will be moving
to header-based semantics
- Several of the error paths can be removed since they are no longer
necessary
- It is no longer expensive to calculate CSV sequence locks or median
times of blocks way in the past
- It is much less expensive to calculate the initial states for the
various intervals such as the stake and voter version
- It will be possible to create much more efficient iteration and
simplified views of the overall index
An overview of the logic changes are as follows:
- Move AncestorNode from blockIndex to blockNode and greatly simplify
since it no longer has to deal with the possibility of dynamically
loading nodes and related failures
- Replace nodeAtHeightFromTopNode from BlockChain with RelativeAncestor
on blockNode and define it in terms of AncestorNode
- Move CalcPastMedianTime from blockIndex to blockNode and remove no
longer necessary test for nil
- Remove findNode and replace all of its uses with direct queries of the
block index
- Remove blockExists and replace all of its uses with direct queries of
the block index
- Remove all functions and fields related to dynamically loading nodes
- children and parentHash fields from blockNode
- depNodes from blockIndex
- loadBlockNode from blockIndex
- PrevNodeFromBlock from blockIndex
- {p,P}revNodeFromNode from blockIndex
- RemoveNode
- Replace all instances of iterating backwards through nodes to directly
access the parent now that nodes don't potentially need to be
dynamically loaded
- Introduce a lookupNode function on blockIndex which allows the
initialization code to locklessly query the index
- No longer take the chain lock when only access to the block index,
which has its own lock, is needed
- Removed the error paths from several functions that can no longer fail
- getReorganizeNodes
- findPrevTestNetDifficulty
- sumPurchasedTickets
- findStakeVersionPriorNode
- Removed all error paths related to node iteration that can no longer
fail
- Modify FetchUtxoView to return an empty view for the genesis block
|
||
|---|---|---|
| addrmgr | ||
| blockchain | ||
| certgen | ||
| chaincfg | ||
| cmd | ||
| connmgr | ||
| database | ||
| dcrec | ||
| dcrjson | ||
| dcrutil | ||
| docs | ||
| gcs | ||
| hdkeychain | ||
| limits | ||
| mempool | ||
| mining | ||
| peer | ||
| release | ||
| rpcclient | ||
| rpctest | ||
| sampleconfig | ||
| txscript | ||
| wire | ||
| .dockerignore | ||
| .gitignore | ||
| .travis.yml | ||
| blocklogger.go | ||
| blockmanager.go | ||
| CHANGES | ||
| config.go | ||
| cpuminer.go | ||
| dcrd.go | ||
| doc.go | ||
| Dockerfile-1.9 | ||
| Dockerfile-1.10 | ||
| go.mod | ||
| go.modverify | ||
| Gopkg.lock | ||
| Gopkg.toml | ||
| ipc.go | ||
| LICENSE | ||
| log.go | ||
| mining_test.go | ||
| mining.go | ||
| miningerror.go | ||
| params.go | ||
| README.md | ||
| rpcserver_test.go | ||
| rpcserver.go | ||
| rpcserverhelp_test.go | ||
| rpcserverhelp.go | ||
| rpcwebsocket.go | ||
| run_tests.sh | ||
| server.go | ||
| service_windows.go | ||
| signal.go | ||
| signalsigterm.go | ||
| upnp.go | ||
| version.go | ||
dcrd
dcrd is a Decred full node implementation written in Go (golang).
This acts as a chain daemon for the Decred cryptocurrency. dcrd maintains the entire past transactional ledger of Decred and allows relaying of transactions to other Decred nodes across the world. To read more about Decred please see the project documentation.
Note: To send or receive funds and join Proof-of-Stake mining, you will also need dcrwallet.
This project is currently under active development and is in a Beta state. It is extremely stable and has been in production use since February 2016.
It is forked from btcd which is a bitcoin full node implementation written in Go. btcd is a ongoing project under active development. Because dcrd is constantly synced with btcd codebase, it will get the benefit of btcd's ongoing upgrades to peer and connection handling, database optimization and other blockchain related technology improvements.
Requirements
Go 1.9 or newer.
Getting Started
- dcrd (and utilities) will now be installed in either
$GOROOT/binor$GOPATH/bindepending on your configuration. 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
-
Dep
Dep is used to manage project dependencies and provide reproducible builds. To install:
go get -u github.com/golang/dep/cmd/dep
Unfortunately, the use of dep prevents a handy tool such as go get from
automatically downloading, building, and installing the source in a single
command. Instead, the latest project and dependency sources must be first
obtained manually with git and dep, and then go is used to build and
install the project.
Getting the source:
For a first time installation, the project and dependency sources can be
obtained manually with git and dep (create directories as needed):
git clone https://github.com/decred/dcrd $GOPATH/src/github.com/decred/dcrd
cd $GOPATH/src/github.com/decred/dcrd
dep ensure
go install . ./cmd/...
To update an existing source tree, pull the latest changes and install the matching dependencies:
cd $GOPATH/src/github.com/decred/dcrd
git pull
dep ensure
go install . ./cmd/...
For more information about Decred and how to set up your software please go to our docs page at docs.decred.org.
Docker
All tests and linters may be run in a docker container using the script
run_tests.sh. This script defaults to using the current supported version of
go. You can run it with the major version of Go you would like to use as the
only arguement to test a previous on a previous version of Go (generally Decred
supports the current version of Go and the previous one).
./run_tests.sh 1.9
To run the tests locally without docker:
./run_tests.sh local
Contact
If you have any further questions you can find us at:
- irc.freenode.net (channel #decred)
- webchat
- forum.decred.org
- decred.slack.com
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.
License
dcrd is licensed under the copyfree ISC License.
