mirror of
https://github.com/FlipsideCrypto/dcrd.git
synced 2026-02-06 19:06:51 +00:00
71500c80f2
This change begins the work of bringing committed filters to the network consensus daemon. Committed filters are designed to enable light wallets without many of the privacy issues associated with server-side bloom filtering. The new gcs package provides the primitives for creating and matching against Golomb-coded sets (GCS) filters while the blockcf package provides creation of filters and filter entries for data structures found in blocks. The wire package has been updated to define a new protocol version and service flag for advertising CF support and includes types for the following new messages: cfheaders, cfilter, cftypes, getcfheaders, getcfilter, getcftypes. The peer package and server implementation have been updated to include support for the new protocol version and messages. Filters are created using a collision probability of 2^-20 and are saved to a new optional database index when running with committed filter support enabled (the default). At first startup, if support is not disabled, the index will be created and populated with filters and filter headers for all preexisting blocks, and new filters will be recorded for processed blocks. Multiple filter types are supported. The regular filter commits to output scripts and previous outpoints that any non-voting wallet will require access to. Scripts and previous outpoints that can only be spent by votes and revocations are not committed to the filter. The extended filter is a supplementary filter which commits to all transaction hashes and script data pushes from the input scripts of non-coinbase regular and ticket purchase transactions. Creating these filters is based on the algorithm defined by BIP0158 but is modified to only commit "regular" data in stake transactions to prevent committed filters from being used to create SPV voting wallets. |
||
|---|---|---|
| .. | ||
| doc.go | ||
| example_test.go | ||
| export_test.go | ||
| log.go | ||
| lruinvcache_test.go | ||
| lruinvcache.go | ||
| lrunoncecache_test.go | ||
| lrunoncecache.go | ||
| peer_test.go | ||
| peer.go | ||
| README.md | ||
peer
Package peer provides a common base for creating and managing bitcoin network peers.
This package has intentionally been designed so it can be used as a standalone package for any projects needing a full featured bitcoin peer base to build on.
Overview
This package builds upon the wire package, which provides the fundamental primitives necessary to speak the bitcoin wire protocol, in order to simplify the process of creating fully functional peers. In essence, it provides a common base for creating concurrent safe fully validating nodes, Simplified Payment Verification (SPV) nodes, proxies, etc.
A quick overview of the major features peer provides are as follows:
- Provides a basic concurrent safe bitcoin peer for handling bitcoin communications via the peer-to-peer protocol
- Full duplex reading and writing of bitcoin protocol messages
- Automatic handling of the initial handshake process including protocol version negotiation
- Asynchronous message queueing of outbound messages with optional channel for notification when the message is actually sent
- Flexible peer configuration
- Caller is responsible for creating outgoing connections and listening for incoming connections so they have flexibility to establish connections as they see fit (proxies, etc)
- User agent name and version
- Bitcoin network
- Service support signalling (full nodes, bloom filters, etc)
- Maximum supported protocol version
- Ability to register callbacks for handling bitcoin protocol messages
- Inventory message batching and send trickling with known inventory detection and avoidance
- Automatic periodic keep-alive pinging and pong responses
- Random nonce generation and self connection detection
- Proper handling of bloom filter related commands when the caller does not
specify the related flag to signal support
- Disconnects the peer when the protocol version is high enough
- Does not invoke the related callbacks for older protocol versions
- Snapshottable peer statistics such as the total number of bytes read and written, the remote address, user agent, and negotiated protocol version
- Helper functions pushing addresses, getblocks, getheaders, and reject
messages
- These could all be sent manually via the standard message output function, but the helpers provide additional nice functionality such as duplicate filtering and address randomization
- Ability to wait for shutdown/disconnect
- Comprehensive test coverage
Installation and Updating
$ go get -u github.com/decred/dcrd/peer
Examples
- New Outbound Peer Example
Demonstrates the basic process for initializing and creating an outbound peer. Peers negotiate by exchanging version and verack messages. For demonstration, a simple handler for the version message is attached to the peer.
License
Package peer is licensed under the copyfree ISC License.