* Increment Zebra versions
* Initial draft changelog
* Add blog post to the release checklist
* Say "user testing"
Co-authored-by: teor <teor@riseup.net>
* update zebra to 1.0.0-beta.13
* add changelog
* update the release date
* Update changelog for cryptographic batch PRs
* Add `bitvec` to the changelog
* Update CHANGELOG.md
* Add zebra-network fix and tokio version bump
* Recommend that users update their rust compiler
* Update disk and network usage for recent large blocks
* Fix spacing
* Add disk and network usage update to README
* apply size suggestions
Co-authored-by: teor <teor@riseup.net>
* add known performance issues
* update changelog
* change release date
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* try to do deserialization of transaction in a rayon thread
* Try tokio::task::block_in_place instead
* fix tests
* add deserialize block into rayon pool
* fill some docs
Co-authored-by: teor <teor@riseup.net>
* Update Zebra to 1.0.0-beta.12
* Simplify tower-* versioning by updating both to 0.2.27
* Simplify version search and replace by removing an old version from the docs
* Update Cargo.lock
* Add draft changelog as of PR #4693
* Update CHANGELOG to PR #4680
* change `initial_mainnet_peers` and `initial_testnet_peers` type to `IndexSet`
* add tests for zebra config files
* add serde feature to indexmap
* remove async
* update config
* fix `stored_config_path()`
* skip tests if config is not found
* improve error
* use CARGO_MANIFEST_DIR
* remove `stored_config_is_newest` test
* move `stored_config_works` test to the end of `valid_generated_config_test`
* space
* Always activate tokio/tracing feature
And always build tests with all tokio features.
* Refactor tracing-subscriber init to simplify it
* Add the tokio-console feature and dependencies
* Add optional tokio-console support, and log the installed tracing layers at info level
Uses a tracing Registry for tokio-console, and a fmt::Subscriber otherwise.
* Add some TODOs based on tracing-subscriber features
* Fix up some spans
* Add a TODO for fixing a log filter bug in tokio-console mode
* use `humantime_serde` for config durations
* move debug config option to the bottom
* fix deserialization
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* Bump crate versions
* Increment the protocol user agent
* Increment the version in `README.md`
* Increment the version in `install.md`
* Update `README.md`
* Update the changelog
* Increment the versions of crates that depend on other crates
* Update `Cargo.lock`
* Upgrade tracing and related dependencies
```sh
cargo upgrade --workspace
tracing-error
tracing-subscrber
color-eyre
tracing-flame
tracing-journald
sentry
sentry-tracing
metrics
metrics-exporter-prometheus
reqwest
```
* Update duplicate dependency checks
* Enable the tracing/env-filter feature
* Fix type inference for metrics
Manual changes, plus:
```sh
fastmod "as _" "as f64"
```
* Tidy up some unrelated test code
* Update metrics-exporter-prometheus API
And make unused dependencies optional.
* Adjust test regexes to new tracing format
Also fix some regex bugs, and refactor to simplify.
* Disable color-eyre span traces and track caller in release builds
* Add a feature that enables extra debugging in release builds
* Clean up some redundant features
* Increase a test timeout
* bump versions
* add the changelog for beta 10
* Update CHANGELOG.md
Co-authored-by: Marek <mail@marek.onl>
* Distinguish CI and Rust dependency updates
* Include all the dep bumps in PR #4405
* join 2 dependencies
* Include incrementalmerkletree dep bump in changelog
Co-authored-by: Deirdre Connolly <durumcrustulum@gmail.com>
Co-authored-by: Marek <mail@marek.onl>
* Update changelog for 1.0.0-beta.8
* Bump Zebra crate versions
The tower crates and their dependencies haven't changed,
so their versions don't need to be bumped.
Some Zebra crates haven't changed,
but I bumped all the versions to keep them consistent.
* Explicitly say that we support NU5 testnet 2
* Expand PR #3799 into changelog entries
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* Update changelog for v1.0.0-beta.7
* Increment all crate versions
* Remove redundant release test that is now covered by CI
* Remove completed NU5 README check task from the release template
* Add Merge Freeze tool to the release checklist
* Simplify release checklist by removing unused steps
* Upgrade some dependencies
* Upgrade some dependencies
* Upgrade dependencies for zebrad
* Upgrade tracing dependencies
* Revert `tor` & `arti`
* Upgrade `criterion` & `pin-project` in `deny.toml`
* Remove some dependencies from `skip-tree` in `deny.toml`
* Revert some the versions of dependencies because of duplicates
* Revert proptest regressions
* Upgrade dependencies, then ignore some more duplicates (#3716)
* feat(actions)!: add full sync test (#3582)
* add(tests): full sync test
* fix(test): add build
* fix(deploy): escape double dashes '--' correctly
* fix(test): remove unexpected --no-capture arg
error: Found argument '--nocapture' which wasn't expected, or isn't valid in this context
* refactor(docker): use default executable as entrypoint
* refactor(startup): add a custom entrypoint
* fix(test): add missing TEST_FULL_SYNC variable
* test(timeout): use the biggest machine
* fix
* fix(deploy): use latest successful image
* typo
* refactor(docker): generate config file at startup
* revert(build): changes were made to docker
* fix(docker): send variables correctly to the entrypoint
* test different conf file approach
* fix(env): add RUN_TEST env variable
* ref: use previous approach
* fix(color): use environment variable
* fix(resources): use our normal machine size
* fix(ci): double CPU and RAM for full sync test
* fix(test): check for zebrad test output in the correct order
The mempool is only activated once, so we must check for that log first.
After mempool activation, the stop regex is logged at least once.
(It might be logged before as well, but we can't rely on that.)
When checking that the mempool didn't activate,
wait for the `zebrad` command to exit,
then check the entire log.
* fix(ci): run full sync test with full compiler optimisations
* fix(tests): reintroduce tests and run full sync on approval
* fix(tests): reduce the changelog
Co-authored-by: teor <teor@riseup.net>
* fix(ci): update CI job path triggers (#3692)
* ci(test): re-run tests when snapshot data changes
* fix(ci): rebuild state when disk format changes
* fix(ci): rebuild rust docs when code or dependencies change
* doc(ci): explain why we run jobs when files change
Co-authored-by: Gustavo Valverde <gustavo@iterativo.do>
* fix(build): use the right multistage target (#3700)
* fix(review): only assign one reviewer to general Rust reviews (#3708)
If we assign two teams, GitHub assigns two reviewers.
* fix(ci): change the color-eyre ignore to a tracing-subscriber ignore
* fix(ci): ignore duplicate darling dependencies
* doc(ci): remove an alternative resolution doc
Co-authored-by: Gustavo Valverde <gustavo@iterativo.do>
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Gustavo Valverde <gustavo@iterativo.do>
* fix(network): split synthetic NotFoundRegistry from message NotFoundResponse
* docs(network): Improve `notfound` message documentation
* refactor(network): Rename MustUseOneshotSender to MustUseClientResponseSender
```
fastmod MustUseOneshotSender MustUseClientResponseSender zebra*
```
* docs(network): fix a comment typo
* refactor(network): remove generics from MustUseClientResponseSender
* refactor(network): add an inventory collector to Client, but don't use it yet
* feat(network): register missing peer responses as missing inventory
We register this missing inventory based on peer responses,
or connection errors or timeouts.
Inbound message inventory tracking requires peers to send `notfound` messages.
But `zcashd` skips `notfound` for blocks, so we can't rely on peer messages.
This missing inventory tracking works regardless of peer `notfound` messages.
* refactor(network): rename ResponseStatus to InventoryResponse
```sh
fastmod ResponseStatus InventoryResponse zebra*
```
* refactor(network): rename InventoryStatus::inner() to to_inner()
* fix(network): remove a redundant runtime.enter() in a test
* doc(network): the exact time used to filter outbound peers doesn't matter
* fix(network): handle block requests slightly more efficiently
* doc(network): fix a typo
* fmt(network): `cargo fmt` after rename ResponseStatus to InventoryResponse
* doc(test): clarify some test comments
* test(network): test synthetic notfound from connection errors and peer inventory routing
* test(network): improve inbound test diagnostics
* feat(network): add a proptest-impl feature to zebra-network
* feat(network): add a test-only connect_isolated_with_inbound function
* test(network): allow a response on the isolated peer test connection
* test(network): fix failures in test synthetic notfound
* test(network): Simplify SharedPeerError test assertions
* test(network): test synthetic notfound from partially successful requests
* test(network): MissingInventoryCollector ignores local NotFoundRegistry errors
* fix(network): decrease the inventory rotation interval
This stops us waiting 3-4 sync resets (4 minutes) before we retry a missing block.
Now we wait 1-2 sync resets (2 minutes), which is still a reasonable rate limit.
This should speed up syncing near the tip, and on testnet.
* fmt(network): cargo fmt --all
* cleanup(network): remove unnecessary allow(dead_code)
* cleanup(network): stop importing the whole sync module into tests
* doc(network): clarify syncer inventory retry constraint
* doc(network): add a TODO for a fix to ensure API behaviour remains consistent
* doc(network): fix a function doc typo
* doc(network): clarify how we handle peers that don't send `notfound`
* docs(network): clarify a test comment
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* fix(network): allow more inbound than outbound connections
* refactor(network): access constants using consistent paths
* fixup! fix(network): allow more inbound than outbound connections
* fixup! fixup! fix(network): allow more inbound than outbound connections
* refactor(network): convert to standard test module layout
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* Updating zebra-test to v1.0.0-beta.4
* Updating tower-fallback to v0.2.16
* Updating tower-batch to v0.2.20
* Updating zebra-chain to v1.0.0-beta.4
* Updating zebra-script to v1.0.0-beta.4
* Updating zebra-network to v1.0.0-beta.4
* Updating zebra-state to v1.0.0-beta.4
* Updating zebra-consensus to v1.0.0-beta.4
* Updating zebra-utils to v1.0.0-beta.4
* Updating zebrad to v1.0.0-beta.4
* Update Cargo.lock with updated crate versions
* Add section for 1.0.0-beta.4 in the CHANGELOG
* Update CHANGELOG.md
Co-authored-by: teor <teor@riseup.net>
* Update README.md
Co-authored-by: teor <teor@riseup.net>
* Update book/src/user/install.md
Co-authored-by: teor <teor@riseup.net>
* Update release description to mention Rust 2021
Update the changelog to mention that all crates now use Rust 2021
Edition.
* Elaborate on Section 3.6 documentation entry
Add the title of the section and mention that it's a section of the
Zcash protocol specification.
* Make changelog entries consistent
Use the same format for entries related to consensus rule documentation.
Co-authored-by: Marek <mail@marek.onl>
* Update README about validated consensus rules
Zebra now validates all documented consensus rules.
* Add changelog entry for newly merged PR
Describe the security fix in the changelog.
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Marek <mail@marek.onl>
* Add arti as a zebra-network dependency
* Add a method for isolated anonymised Tor connections to a specific hostname
* Add tests for isolated tor connections
* Use a shared tor client instance for all isolated connections
* Silence a spurious tor warning in tests
* Make tor support optional, activate it via a new "tor" feature
* Extra Cargo.lock changes
* fastmod AsyncReadWrite PeerTransport zebra*
* Remove unnecessary PeerTransport generics
* Refactor common test code into a function
* Don't drop the stream until the end of the test
Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
* Stop checking the entire AddressBook for each connection attempt
* Stop redundant peer time checks within the address book
* Stop calling `Instant::now` 3 times for each address book update
* Only get the time once each time an address book method is called
* Update outdated comment
* Use an OrderedMap to efficiently store address book peers
* Add address book order tests
Zebra's latest beta continues implementing zero-knowledge proof and note commitment tree validation. In this release, we have finished implementing transaction header, transaction amount, and Zebra-specific NU5 validation. (NU5 mainnet validation is waiting on an `orchard` crate update, and some consensus parameter updates.)
We also fix a number of security issues that could pose a local denial of service risk, or make it easier for an attacker to make a node follow a false chain.
As of this release, Zebra will automatically download and cache the Sprout and Sapling Groth16 circuit parameters. The cache uses around 1 GB of disk space. These cached parameters are shared across all Zebra and `zcashd` instances run by the same user.
See CHANGELOG.md for the full list of changes in this release.
* Rewrite PeerSet comments to split long sentences
* Replace peer set integer indexes with address-based indexes
Also improve documentation and logging.
* Security: Stop using peer addresses to choose inventory routing order
* Minor doc and code cleanups
* Stop re-using a drained HashSet
* Replace used `_cancel` with `cancel`
* Reword a comment
* Replace cloned with copied
* Update `tower` to version `0.4.9`
Update to latest version to add support for Tokio version 1.
* Replace usage of `ServiceExt::ready_and`
It was deprecated in favor of `ServiceExt::ready`.
* Update Tokio dependency to version `1.13.0`
This will break the build because the code isn't ready for the update,
but future commits will fix the issues.
* Replace import of `tokio::stream::StreamExt`
Use `futures::stream::StreamExt` instead, because newer versions of
Tokio don't have the `stream` feature.
* Use `IntervalStream` in `zebra-network`
In newer versions of Tokio `Interval` doesn't implement `Stream`, so the
wrapper types from `tokio-stream` have to be used instead.
* Use `IntervalStream` in `inventory_registry`
In newer versions of Tokio the `Interval` type doesn't implement
`Stream`, so `tokio_stream::wrappers::IntervalStream` has to be used
instead.
* Use `BroadcastStream` in `inventory_registry`
In newer versions of Tokio `broadcast::Receiver` doesn't implement
`Stream`, so `tokio_stream::wrappers::BroadcastStream` instead. This
also requires changing the error type that is used.
* Handle `Semaphore::acquire` error in `tower-batch`
Newer versions of Tokio can return an error if the semaphore is closed.
This shouldn't happen in `tower-batch` because the semaphore is never
closed.
* Handle `Semaphore::acquire` error in `zebrad` test
On newer versions of Tokio `Semaphore::acquire` can return an error if
the semaphore is closed. This shouldn't happen in the test because the
semaphore is never closed.
* Update some `zebra-network` dependencies
Use versions compatible with Tokio version 1.
* Upgrade Hyper to version 0.14
Use a version that supports Tokio version 1.
* Update `metrics` dependency to version 0.17
And also update the `metrics-exporter-prometheus` to version 0.6.1.
These updates are to make sure Tokio 1 is supported.
* Use `f64` as the histogram data type
`u64` isn't supported as the histogram data type in newer versions of
`metrics`.
* Update the initialization of the metrics component
Make it compatible with the new version of `metrics`.
* Simplify build version counter
Remove all constants and use the new `metrics::incement_counter!` macro.
* Change metrics output line to match on
The snapshot string isn't included in the newer version of
`metrics-exporter-prometheus`.
* Update `sentry` to version 0.23.0
Use a version compatible with Tokio version 1.
* Remove usage of `TracingIntegration`
This seems to not be available from `sentry-tracing` anymore, so it
needs to be replaced.
* Add sentry layer to tracing initialization
This seems like the replacement for `TracingIntegration`.
* Remove unnecessary conversion
Suggested by a Clippy lint.
* Update Cargo lock file
Apply all of the updates to dependencies.
* Ban duplicate tokio dependencies
Also ban git sources for tokio dependencies.
* Stop allowing sentry-tracing git repository in `deny.toml`
* Allow remaining duplicates after the tokio upgrade
* Use C: drive for CI build output on Windows
GitHub Actions uses a Windows image with two disk drives, and the
default D: drive is smaller than the C: drive. Zebra currently uses a
lot of space to build, so it has to use the C: drive to avoid CI build
failures because of insufficient space.
Co-authored-by: teor <teor@riseup.net>
* Increment the crates that have new commits since the last version
* Increment the crates that depend on crates that have changed
* Increment the version of `zebra-script`
* Use the `zebrad` version in the `zebra-network` user agent string
* Use the `v1.0.0-alpha.19` git tag in `README.md`
* Copy the draft changelog into `CHANGELOG.md`
* Delete bumps
* Update CHANGELOG.md
Co-authored-by: teor <teor@riseup.net>
* Add newly merged PRs
Co-authored-by: teor <teor@riseup.net>
* Update versions for zebra v1.0.0-alpha.18 release
* WIP: Initial PR list
* Remove uninteresting version bumps from CHANGELOG
* Categorise and group PRs in CHANGELOG, removing uninteresting PRs
* Further refine and categorise changelog entries
* Fix tag url
* Final changes to CHANGELOG
* Add a changelog description
* Spacing
* Clarify and fix changelog PR descriptions
* Add PRs that are about to be merged
* More slight clarifications
* Spacing
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Janito Vaqueiro Ferreira Filho <janito.vff@gmail.com>
* Update versions for zebra v1.0.0-alpha.12 release
* Update Cargo.lock
* Update release checklist with latest version changes to help keep track for future releases
* Remove reference to the fact that tower-fallback was not updated
* Rename field to `wait_next_handshake`
Make the name a bit more clear regarding to the field's purpose.
* Move `MIN_PEER_CONNECTION_INTERVAL` to `constants`
Move it to the `constants` module so that it is placed closer to other
constants for consistency and to make it easier to see any relationships
when changing them.
* Rate limit calls to `CandidateSet::update()`
This effectively rate limits requests asking for more peer addresses
sent to the same peer. A new `min_next_crawl` field was added to
`CandidateSet`, and `update` only sends requests for more peer addresses
if the call happens after the instant specified by that field. After
sending the requests, the field value is updated so that there is a
`MIN_PEER_GET_ADDR_INTERVAL` wait time until the next `update` call
sends requests again.
* Include `update_initial` in rate limiting
Move the rate limiting code from `update` to `update_timeout`, so that
both `update` and `update_initial` get rate limited.
* Test `CandidateSet::update` rate limiting
Create a `CandidateSet` that uses a mocked `PeerService`. The mocked
service always returns an empty list of peers, but it also checks that
the requests only happen after expected instants, determined by the
fanout amount and the rate limiting interval.
* Refactor to create a `mock_peer_service` helper
Move the code from the test to a utility function so that another test
will be able to use it as well.
* Check number of times service was called
Use an `AtomicUsize` shared between the service and the test body that
the service increments on every call. The test can then verify if the
service was called the number of times it expected.
* Test calling `update` after `update_initial`
The call to `update` should be skipped because the call to
`update_initial` should also be considered in the rate limiting.
* Mention that call to `update` may be skipped
Make it clearer that in this case the rate limiting causes calls to be
skipped, and not that there's an internal sleep that happens.
Also remove "to the same peers", because it's more general than that.
Co-authored-by: teor <teor@riseup.net>
* Allow use listen address in config without port
* update comments
* remove not used alias
* use Network::default_port
* Move tests and use toml instead json
* change error message
* Make match more readable
Co-authored-by: teor <teor@riseup.net>
* Make proptest dependencies consistent between chain and network
* Implement Arbitrary for InventoryHash and use it in tests
* Impl Arbitrary for MetaAddr and use it in tests
Also test some extreme times in MetaAddr sanitization.
Zebra's latest alpha checkpoints on Canopy activation, continues our work on NU5, and fixes a security issue.
Some notable changes include:
## Added
- Log address book metrics when PeerSet or CandidateSet don't have many peers (#1906)
- Document test coverage workflow (#1919)
- Add a final job to CI, so we can easily require all the CI jobs to pass (#1927)
## Changed
- Zebra has moved its mandatory checkpoint from Sapling to Canopy (#1898, #1926)
- This is a breaking change for users that depend on the exact height of the mandatory checkpoint.
## Fixed
- tower-batch: wake waiting workers on close to avoid hangs (#1908)
- Assert that pre-Canopy blocks use checkpointing (#1909)
- Fix CI disk space usage by disabling incremental compilation in coverage builds (#1923)
## Security
- Stop relying on unchecked length fields when preallocating vectors (#1925)
* add hint for port error
* add issue filter for port panic
* add lock file hint
* add metrics endpoint port conflict hint
* add hint for tracing endpoint port conflict
* add acceptance test for resource conflics
* Split out common conflict test code into a function
* Add state, metrics, and tracing conflict tests
* Add a full set of stderr acceptance test functions
This change makes the stdout and stderr acceptance test interfaces
identical.
* move Zcash listener opening
* add todo about hint for disk full
* add constant for lock file
* match path in state cache
* don't match windows cache path
* Use Display for state path logs
Avoids weird escaping on Windows when using Debug
* Add Windows conflict error messages
* Turn PORT_IN_USE_ERROR into a regex
And add another alternative Windows-specific port error
Co-authored-by: teor <teor@riseup.net>
Co-authored-by: Jane Lusby <jane@zfnd.org>
* Bump versions where appropriate
Tested with cargo install --locked --path etc
* Remove fixed panics from 'Known Issues'
* Change to alpha release series in the README
Co-authored-by: teor <teor@riseup.net>
## Motivation
This PR is motivated by the regression identified in https://github.com/ZcashFoundation/zebra/issues/1349. That PR notes that the metrics stopped working for most of the crates other than `zebrad`.
## Solution
This PR resolves the regression by deduplicating the `metrics` crate dependency. During a recent change we upgraded the metrics version in `zebrad` and a couple other of our crates, but we never updated the dependencies in `zebra-state`, `zebra-consensus`, or `zebra-network`. This caused the metrics macros to attempt to retrieve the current metrics exporter through the wrong function. We would install the metrics exporter in `0.13`, but then attempt to look it up through the `0.12` crate, which contains a different instance of the metrics exporter static variable which is unset. Doing this causes the metrics macros to return `None` for the current exporter after which they just silently give up.
## Related Issues
closes https://github.com/ZcashFoundation/zebra/issues/1349
## Follow Up Work
I noticed we have quite a few duplicate dependencies in our tree. We might be able to save some compilation time by auditing those and deduplicating them as much as possible.
- https://github.com/ZcashFoundation/zebra/issues/1582
Co-authored-by: teor <teor@riseup.net>
Previously we set the crate versions to 3.x, so that the major version was
aligned with the NU version. But we want to be able to make API changes
independently of the NU schedule.
This change is mostly mechanical, with the exception of the changes to the
`tower-batch` middleware. This middleware was adapted from `tower::buffer`,
and the `tower::buffer` code was changed to implement its own bounded queue,
because Tokio 0.3 removed the `mpsc::Sender::poll_send` method. See
ddc64e8d4d
for more context on the Tower changes. To match Tower as closely as possible
in order to be able to upstream `tower-batch`, those changes are copied from
`tower::Buffer` to `tower-batch`.
This addresses at least three pain points:
- we were affected by bugs that were already fixed in git, but not in
the released crate;
- we can use service combinators to transform requests and responses;
- we can use the hedge middleware.
The version in git is still marked as 0.3.1 but these changes will be
part of tower 0.4: https://github.com/tower-rs/tower/issues/431
We had a brief discussion on discord and it seemed like we had consensus on the
following versioning policy:
* zebrad: match major version to NU version, so we will start by releasing
zebrad 3.0.0;
* zebra-* libraries: start by matching zebrad's version, then increment major
versions of each library as we need to make breaking changes (potentially
faster than the zebrad version, always respecting semver but making no
guarantees about the longevity of major releases).
This commit sets all of the crate versions to 3.0.0-alpha.0 -- the -alpha.0
marks it as a prerelease not subject to perfect adherence to compatibility
guarantees.
Failure uses a distinct Fail trait rather than the standard library's
Error trait, which causes a lot of interoperability problems with tower
and other Error-using crates. Since failure was created, the standard
library's Error trait was improved, and its conveniences are now
available without the custom Fail trait using `thiserror` (for easy
error derives) and `anyhow` (for a better boxed Error).
* Don't expose submodules of zebra_network::peer.
* PeerSet, PeerDiscover stubs.
Co-authored-by: Deirdre Connolly <deirdre@zfnd.org>
* Initial work on PeerSet.
This is adapted from the MIT-licensed tower-balance implementation.
* Use PeerSet in the connect stub.
* Fix authorship, license information.
I *thought* I had done a sed pass over the Cargo defaults when doing
repository initialization, but I guess I missed it or something.
Anyways, fixed now.
Add a tower-based peer implementation.
Tower provides middleware for request-response oriented protocols, while Bitcoin/Zcash just send messages which could be interpreted either as requests or responses, depending on context. To bridge this mismatch we define our own internal request/response protocol, and implement a per-peer event loop that scans incoming messages and interprets them either as requests from the remote peer to our node, or as responses to requests we made previously. This is performed by the `PeerService` task, and a corresponding `PeerClient: tower::Service` can send it requests. These tasks are themselves created by a `PeerConnector: tower::Service` which dials a remote peer and performs a handshake.
This provides a significantly cleaner API to consumers, because it
allows using adaptors that convert a TCP stream to a stream of messages,
and potentially allows more efficient message handling.
Because we want to be able to read messages from async sources (like a
tcp socket), we need to have at least async header parsing logic, so
that we can correctly determine how many bytes to await to parse each
message, so it makes sense for the entire message parsing functions
to be async.
Because we perform message serialization into async readers and writers
in the context of sending messages over the network, code using these
functions is more clear with these names.