This commit extends the work started by roasbeef in the
previous commit to bring full cancellation of pending
connection requests. It also adds minor refactors to
channel send/receives to help cleanup potentially
lingering go routines.
This commit adds the ability for callers to remove pending connections
via a call to the Remove() method. With this change, upstream users of
this package can use the connmgr for more elaborate connectivity needs
as they can now cancel pending connections that are no longer needed.
The btclog package has been changed to defining its own logging
interface (rather than seelog's) and provides a default implementation
for callers to use.
There are two primary advantages to the new logger implementation.
First, all log messages are created before the call returns. Compared
to seelog, this prevents data races when mutable variables are logged.
Second, the new logger does not implement any kind of artifical rate
limiting (what seelog refers to as "adaptive logging"). Log messages
are outputted as soon as possible and the application will appear to
perform much better when watching standard output.
Because log rotation is not a feature of the btclog logging
implementation, it is handled by the main package by importing a file
rotation package that provides an io.Reader interface for creating
output to a rotating file output. The rotator has been configured
with the same defaults that btcd previously used in the seelog config
(10MB file limits with maximum of 3 rolls) but now compresses newly
created roll files. Due to the high compressibility of log text, the
compressed files typically reduce to around 15-30% of the original
10MB file.
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.
A DNS lookup was being attempted on onion addresses causing
connections to fail. This has been fixed by introducing type
onionAddr (which implements a net.Addr interface) and passing
it to btcdDial.
Also, the following onion related fixes have been made:
* getaddednodeinfo - updated to handle onion addrs.
* TorLookupIP - fixed err being shadowed.
* newServer - rename tcpAddr to netAddr
* addrStringToNetAddr - skip if host is already an IP addr.
* addrStringToNetAddr - err if tor is disabled
* getaddednodeinfo - check if host is already an IP addr.
Replace assignments to individual fields of wire.NetAddress with
creating the entire object at once, as one would do if the type was
immutable.
In some places this replaces the creation of a NetAddress with a
high-precision timestamp with a call to a 'constructor' that converts
the timestamp to single second precision. For consistency, the tests
have also been changed to use single-precision timestamps.
Lastly, the number of allocations in readNetAddress have been reduced by
reading the services directly into the NetAddress instead of first into
a temporary variable.
This commit modifies the `ConnManager` to use the `net.Add` interface
through the package instead of a plain string to represent and
manipulate addresses. This change makes the package much more general as
users of the package can possibly utilize custom implementations of the
`net.Addr` interface to establish connections.
More precisely, the `ConnReq` struct has been modified to use a net.Addr
instance explicitly, and the `DialFunc` type has also been modified to
take a `net.Addr` directly. This latter change gives functions that
adhere to the `DialFunc` type more flexibility as to exactly how the
connection is established.
Additionally, the `connmgr.Config.GetNewAddress` configuration option
now directly returns a `net.Addr. This change allows the `connmgr` to be
decoupled from all DNS queries which allows callers to preferentially
select more secure methods like performing DNS lookups over a Tor proxy.
This modifies the connection manager to provide support for accepting
inbound connections on a caller-provided set of listeners and notify the
caller via a callback.
This is only the minimum work necessary to get inbound support into the
connection manager. The intention for future commits is to move more
connection-related logic such as limiting the maximum number of overall
connections and banned peer tracking into the connection manager.
This removes the type definitions for the callback functions in favor of
declaring them directly in the Config struct. This is more consistent
with the rest of the code base and is preferred since it means callers
reviewing the documentation don't have to follow another level of
indirection to figure out the signature.
This commit introduces package connmgr which contains connection
management related functionality.
The following is an overview of the features the package provides:
- Maintain fixed number of outbound connections
- Optional connect-only mode
- Retry persistent connections with increasing back-off
- Source peers from DNS seeds
- Use Tor to resolve DNS
- Dynamic ban scores
- Test coverage
In addition, btcd has been refactored to make use of the new package by
extending the connection manager to work with the server to source and
maintain peer connections. The following is a broad overview of the
changes to integrate the package:
- Simplify peer state by removing pending, retry peers
- Refactor to remove retries which are now handled by connmgr
- Use callback to add addresses sourced from the DNS seed
Finally the following connection-related things have been improved as a
part of this refactor:
- Fixes 100% cpu usage when network is down (#129)
- Fixes issues with max peers (#577)
- Simplify outbound peer connections management
