* chore: bump dependencies, including nim-ethers with chronos v4 support
Bumps the following dependencies:
- nim-ethers to commit 507ac6a4cc71cec9be7693fa393db4a49b52baf9 which contains a pinned nim-eth version. This is to be replaced by a versioned library, so it will be pinned to a particular version. There is a crucial fix in this version of ethers that fixes nonce management which is causing issues in the Codex testnet.
- nim-json-rpc to v0.4.4
- nim-json-serialization to v0.2.8
- nim-serde to v1.2.2
- nim-serialization to v0.2.4
Currently, one of the integration tests is failing.
* fix integration test
- When a state's run was cancelled, it was being caught as an error due to catching all CatchableErrors. This caused a state transition to SaleErrored, however cancellation of run was not actually an error. Handling this correctly fixed the issue.
- Stopping of the clock was moved to after `HostInteractions` (sales) which avoided an assertion around getting time when the clock was not started.
* bump ethers to include nonce fix and filter not found fix
* bump ethers: fixes missing symbol not exported in ethers
* Fix cirdl test imports/exports
* Debugging in ci
* Handle CancelledErrors for state.run in one place only
* Rename `config` to `configuration`
There was a symbol clash preventing compilation and it was easiest to rename `config` to `configuration` in the contracts. Not even remotely ideal, but it was the only way.
* bump ethers to latest
Prevents an issue were `JsonNode.items` symbol could not be found
* More changes to support `config` > `configuration`
* cleanup
* testing to see if this fixes failure in ci
* bumps contracts
- ensures slot is free before allowing reservation
- renames config to configuration to avoid symbol clash
* feat: add `--payout-address`
Allows SPs to be paid out to a separate address, keeping their profits secure.
Supports https://github.com/codex-storage/codex-contracts-eth/pull/144 in the nim-codex client.
* Remove optional payoutAddress
Change --payout-address so that it is no longer optional. There is no longer an overload in `Marketplace.sol` for `fillSlot` accepting no `payoutAddress`.
* Update integration tests to include --payout-address
* move payoutAddress from fillSlot to freeSlot
* Update integration tests to use required payoutAddress
- to make payoutAddress required, the integration tests needed to avoid building the cli params until just before starting the node, otherwise if cli params were added ad-hoc, there would be an error after a non-required parameter was added before a required parameter.
* support client payout address
- withdrawFunds requires a withdrawAddress parameter, directs payouts for withdrawing of client funds (for a cancelled request) to go to that address.
* fix integration test
adds --payout-address to validators
* refactor: support withdrawFunds and freeSlot optional parameters
- withdrawFunds has an optional parameter for withdrawRecipient
- freeSlot has optional parameters for rewardRecipient and collateralRecipient
- change --payout-address to --reward-recipient to match contract signature naming
* Revert "Update integration tests to include --payout-address"
This reverts commit 8f9535cf35.
There are some valid improvements to the integration tests, but they can be handled in a separate PR.
* small fix
* bump contracts to fix marketplace spec
* bump codex-contracts-eth, now rebased on master
* bump codex-contracts-eth
now that feat/reward-address has been merged to master
* clean up, comments
* refactor(marketplace): move marketplace events to the Market abstraction
Move marketplace contract events to the Market abstraction so the types can be shared across all modules that call the Market abstraction.
* Remove unneeded conversion
* Switch to generic implementation of event querying
* change parent type to MarketplaceEvent
* add changes to use chronos v4 in compat mode
* switch chronos to compat fix branch
* use nimbus-build-system with configurable Nim repo
* add missing imports
* add missing await
* bump compat
* pin nim version in Makefile
* add await instead of asyncSpawn to advertisement queue loop
* bump DHT to v0.5.0
* allow error state of `onBatch` to propagate upwards in test code
* pin Nim compiler commit to avoid fetching stale branch
* make CI build against branch head instead of merge
* fix handling of return values in testslotqueue
* fix: make sure requestStorage is mined
* fix: correct place to plug confirm
* test: fixing contracts tests
* feat: one confirmation for all transactions
* fix: don't wait for confirmations only mined block
* Smart contracts update: Groth16Proof instead of bytes
* Use dummy verifier for now, until we can create ZK proofs
* Fix tests: submit proof only when slot is filled
* Submit dummy proofs for now
* More detailed log when proof submission failed
* Use dummy verifier for integration tests
For now at least
* Fix mistake in blanket renaming to ethProvider
* Update to latest codex-contracts-eth
* feat: zkey-hash from chain
* Fix zkeyHash
---------
Co-authored-by: Adam Uhlíř <adam@uhlir.dev>
* [sales] remove availability check before adding to slot queue
* [sales] add missing return statement
* [tests] remove 'eventuallyCheck' helper
* [sales] remove reservations from slot queue
* [tests] rename module `eventually` -> `always`
* [sales] increase slot queue size
Because it will now also hold items for which we haven't
checked availability yet.
## Slot queue
Adds a slot queue, as per the [slot queue design](https://github.com/codex-storage/codex-research/blob/master/design/sales.md#slot-queue).
Any time storage is requested, all slots from that request are immediately added to the queue. Finished, Canclled, Failed requests remove all slots with that request id from the queue. SlotFreed events add a new slot to the queue and SlotFilled events remove the slot from the queue. This allows popping of a slot each time one is processed, making things much simpler.
When an entire request of slots is added to the queue, the slot indices are shuffled randomly to hopefully prevent nodes that pick up the same storage requested event from clashing on the first processed slot index. This allowed removal of assigning a random slot index in the SalePreparing state and it also ensured that all SalesAgents will have a slot index assigned to them at the start thus the removal of the optional slotIndex.
Remove slotId from SlotFreed event as it was not being used. RequestId and slotIndex were added to the SlotFreed event earlier and those are now being used
The slot queue invariant that prioritises queue items added to the queue relies on a scoring mechanism to sort them based on the [sort order in the design document](https://github.com/codex-storage/codex-research/blob/master/design/sales.md#sort-order).
When a storage request is handled by the sales module, a slot index was randomly assigned and then the slot was filled. Now, a random slot index is only assigned when adding an entire request to the slot queue. Additionally, the slot is checked that its state is `SlotState.Free` before continuing with the download process.
SlotQueue should always ensure the underlying AsyncHeapQueue has one less than the maximum items, ensuring the SlotQueue can always have space to add an additional item regardless if it’s full or not.
Constructing `SlotQueue.workers` in `SlotQueue.new` calls `newAsyncQueue` which causes side effects, so the construction call had to be moved to `SlotQueue.start`.
Prevent loading request from contract (network request) if there is an existing item in queue for that request.
Check availability before adding request to queue.
Add ability to query market contract for past events. When new availabilities are added, the `onReservationAdded` callback is triggered in which past `StorageRequested` events are queried, and those slots are added to the queue (filtered by availability on `push` and filtered by state in `SalePreparing`).
#### Request Workers
Limit the concurrent requests being processed in the queue by using a limited pool of workers (default = 3). Workers are in a data structure of type `AsyncQueue[SlotQueueWorker]`. This allows us to await a `popFirst` for available workers inside of the main SlotQueue event loop
Add an `onCleanUp` that stops the agents and removes them from the sales module agent list. `onCleanUp` is called from sales end states (eg ignored, cancelled, finished, failed, errored).
Add a `doneProcessing` future to `SlotQueueWorker` to be completed in the `OnProcessSlot` callback. Each `doneProcessing` future created is cancelled and awaited in `SlotQueue.stop` (thanks to `TrackableFuturees`), which forced `stop` to become async.
- Cancel dispatched workers and the `onProcessSlot` callbacks, prevents zombie callbacks
#### Add TrackableFutures
Allow tracking of futures in a module so they can be cancelled at a later time. Useful for asyncSpawned futures, but works for any future.
### Sales module
The sales module needed to subscribe to request events to ensure that the request queue was managed correctly on each event. In the process of doing this, the sales agents were updated to avoid subscribing to events in each agent, and instead dispatch received events from the sales module to all created sales agents. This would prevent memory leaks on having too many eventemitters subscribed to.
- prevent removal of agents from sales module while stopping, otherwise the agents seq len is modified while iterating
An additional sales agent state was added, `SalePreparing`, that handles all state machine setup, such as retrieving the request and subscribing to events that were previously in the `SaleDownloading` state.
Once agents have parked in an end state (eg ignored, cancelled, finished, failed, errored), they were not getting cleaned up and the sales module was keeping a handle on their reference. An `onCleanUp` callback was created to be called after the state machine enters an end state, which could prevent a memory leak if the number of requests coming in is high.
Move the SalesAgent callback raises pragmas from the Sales module to the proc definition in SalesAgent. This avoids having to catch `Exception`.
- remove unneeded error handling as pragmas were moved
Move sales.subscriptions from an object containing named subscriptions to a `seq[Subscription]` directly on the sales object.
Sales tests: shut down repo after sales stop, to fix SIGABRT in CI
### Add async Promise API
- modelled after JavaScript Promise API
- alternative to `asyncSpawn` that allows handling of async calls in a synchronous context (including access to the synchronous closure) with less additional procs to be declared
- Write less code, catch errors that would otherwise defect in asyncspawn, and execute a callback after completion
- Add cancellation callbacks to utils/then, ensuring cancellations are handled properly
## Dependencies
- bump codex-contracts-eth to support slot queue (https://github.com/codex-storage/codex-contracts-eth/pull/61)
- bump nim-ethers to 0.5.0
- Bump nim-json-rpc submodule to 0bf2bcb
---------
Co-authored-by: Jaremy Creechley <creechley@gmail.com>
* [contracts] Add SlotFreed event
* [integration] allow test node to be stopped twice
* [cli] add --validator option
* [contracts] remove dead code
* [contracts] instantiate OnChainMarket and OnChainClock only once
* [contracts] add Validation
* [sales] remove duplicate import
* [market] add missing import
* [market] subscribe to all SlotFilled events
* [market] add freeSlot()
* [sales] fix warnings
* [market] subscribe to SlotFreed events
* [contracts] fix warning
* [validator] keep track of filled slots
* [validation] remove slots that have ended
* [proving] absorb Proofs into Market
Both Proofs and Market are abstractions around
the Marketplace contract, having them separately
is more trouble than it's worth at the moment.
* [market] add markProofAsMissing()
* [clock] speed up waiting for clock in tests
* [validator] mark proofs as missing
* [timer] fix error on node shutdown
* [cli] handle --persistence and --validator separately
* [market] allow retrieval of proof timeout value
* [validator] do not subscribe to SlotFreed events
Freed slots are already handled in
removeSlotsThatHaveEnded(), and onSlotsFreed()
interfered with its iterator.
* [validator] Start validation at the start of a new period
To decrease the likelihood that we hit the validation timeout.
* [validator] do not mark proofs as missing after timeout
* [market] check whether proof can be marked as missing
* [validator] simplify validation
Simulate a transaction to mark proof as missing, instead
of trying to keep track of all the conditions that may
lead to a proof being marked as missing.
* [build] use nim-ethers PR #40
Uses "pending" blocktag instead of "latest" blocktag
for better simulation of transactions before sending
them.
https://github.com/status-im/nim-ethers/pull/40
* [integration] integration test for validator
* [validator] monitor a maximum number of slots
Adds cli parameter --validator-max-slots.
* [market] fix missing collateral argument
After rebasing, add the new argument to fillSlot calls.
* [build] update to nim-ethers 0.2.5
* [validator] use Set instead of Table to keep track of slots
* [validator] add logging
* [validator] add test for slot failure
* [market] use "pending" blocktag to use more up to date block time
* [contracts] remove unused import
* [validator] fix: wait until after period ends
The smart contract checks that 'end < block.timestamp',
so we need to wait until the block timestamp is greater
than the period end.
* [marketplace] reservations module
- add de/serialization for Availability
- add markUsed/markUnused in persisted availability
- add query for unused
- add reserve/release
- reservation module tests
- split ContractInteractions into client contracts and host contracts
- remove reservations start/stop as the repo start/stop is being managed by the node
- remove dedicated reservations metadata store and use the metadata store from the repo instead
- Split ContractInteractions into:
- ClientInteractions (with purchasing)
- HostInteractions (with sales and proving)
- compilation fix for nim 1.2
[repostore] fix started flag, add tests
[marketplace] persist slot index
For loading the sales state from chain, the slot index was not previously persisted in the contract. Will retrieve the slot index from the contract when the sales state is loaded.
* Revert repostore changes
In favour of separate PR https://github.com/status-im/nim-codex/pull/374.
* remove warnings
* clean up
* tests: stop repostore during teardown
* change constructor type identifier
Change Contracts constructor to accept Contracts type instead of ContractInteractions.
* change constructor return type to Result instead of Option
* fix and split interactions tests
* clean up, fix tests
* find availability by slot id
* remove duplication in host/client interactions
* add test for finding availability by slotId
* log instead of raiseAssert when failed to mark availability as unused
* move to SaleErrored state instead of raiseAssert
* remove unneeded reverse
It appears that order is not preserved in the repostore, so reversing does not have the intended effect here.
* update open api spec for potential rest endpoint errors
* move functions about available bytes to repostore
* WIP: reserve and release availabilities as needed
WIP: not tested yet
Availabilities are marked as used when matched (just before downloading starts) so that future matching logic does not match an availability currently in use.
As the download progresses, batches of blocks are written to disk, and the equivalent bytes are released from the reservation module. The size of the availability is reduced as well.
During a reserve or release operation, availability updates occur after the repo is manipulated. If the availability update operation fails, the reserve or release is rolled back to maintain correct accounting of bytes.
Finally, once download completes, or if an error occurs, the availability is marked as unused so future matching can occur.
* delete availability when all bytes released
* fix tests + cleanup
* remove availability from SalesContext callbacks
Availability is no longer used past the SaleDownloading state in the state machine. Cleanup of Availability (marking unused) is handled directly in the SaleDownloading state, and no longer in SaleErrored or SaleFinished. Likewise, Availabilities shouldn’t need to be handled on node restart.
Additionally, Availability was being passed in SalesContext callbacks, and now that Availability is only used temporarily in the SaleDownloading state, Availability is contextually irrelevant to the callbacks, except in OnStore possibly, though it was not being consumed.
* test clean up
* - remove availability from callbacks and constructors from previous commit that needed to be removed (oopsie)
- fix integration test that checks availabilities
- there was a bug fixed that crashed the node due to a missing `return success` in onStore
- the test was fixed by ensuring that availabilities are remaining on the node, and the size has been reduced
- change Availability back to non-ref object and constructor back to init
- add trace logging of all state transitions in state machine
- add generally useful trace logging
* fixes after rebase
1. Fix onProve callbacks
2. Use Slot type instead of tuple for retrieving active slot.
3. Bump codex-contracts-eth that exposes getActivceSlot call.
* swap contracts branch to not support slot collateral
Slot collateral changes in the contracts require further changes in the client code, so we’ll skip those changes for now and add in a separate commit.
* modify Interactions and Deployment constructors
- `HostInteractions` and `ClientInteractions` constructors were simplified to take a contract address and no overloads
- `Interactions` prepared simplified so there are no overloads
- `Deployment` constructor updated so that it takes an optional string parameter, instead `Option[string]`
* Move `batchProc` declaration
`batchProc` needs to be consumed by both `node` and `salescontext`, and they can’t reference each other as it creates a circular dependency.
* [reservations] rename `available` to `hasAvailable`
* [reservations] default error message to inner error msg
* add SaleIngored state
When a storage request is handled but the request does match availabilities, the sales agent machine is sent to the SaleIgnored state. In addition, the agent is constructed in a way that if the request is ignored, the sales agent is removed from the list of active agents being tracked in the sales module.
* [build] disable XCannotRaiseY hint
There are too many {.raises:[Defect].} in the
libraries that we use, drowning out all other
warnings and hints
* [build] disable BareExcept warning
Not yet enabled in a released version of Nim,
so libraries that we depend on have not fixed
this yet, drowning out our own hints and warnings
* [build] disable DotLikeOps warning
dot-like ops were an experiment that is not going
land in Nim
* [build] compile log statements in tests
When running tests, all log statements are compiled.
They are filtered out at runtime during a test run.
* [build] do not build executable when running unit test
It's already built in the integration test
* [build] Fix warnings
- remove unused code
- remove unused imports
- stop using deprecated stuff
* [build] Put compiler flags behind nim version checks
* [CI] remove Nim 1.2 compatibility
* [marketplace] get active slots from chain
# Conflicts:
# codex/contracts/market.nim
* [marketplace] make on chain event callbacks async
# Conflicts:
# tests/codex/helpers/mockmarket.nim
* [marketplace] make availability optional for node restart
# Conflicts:
# tests/codex/testsales.nim
* [marketplace] add async state machine
Allows for `enterAsync` to be cancelled.
* [marketplace] move sale process to async state machine
* [marketplace] sales state machine tests
* bump dagger-contracts
* [marketplace] fix ci issue with chronicles output
* PR comments
- add slotIndex to `SalesAgent` constructor
- remove `SalesAgent.init`
- rename `SalesAgent.init` to `start` and `SalesAgent.deinit` to `stop`.
- rename `SalesAgent. populateRequest` to `SalesAgent.retreiveRequest`.
- move availability removal to the downloading state. once availability is persisted to disk, it should survive node restarts.
-
* [marketplace] handle slot filled by other host
Handle the case when in the downloading, proving, or filling states, that another host fills the slot.
* [marketplace] use requestId for mySlots
* [marketplace] infer slot index from slotid
prevents reassigning a random slot index when restoring state from chain
* [marketplace] update to work with latest contracts
* [marketplace] clean up
* [marketplace] align with contract changes
- getState / state > requestState
- getSlot > getRequestFromSlotId
- support MarketplaceConfig
- support slotState, remove unneeded Slot type
- collateral > config.collateral.initialAmount
- remove proofPeriod contract call
- Revert reason “Slot empty” > “Slot is free”
- getProofEnd > read SlotState
Tests for changes
* [marketplace] add missing file
* [marketplace] bump codex-contracts-eth
* [config] remove unused imports
* [sales] cleanup
* [sales] fix: do not crash when fetching state fails
* [sales] make slotIndex non-optional
* Rebase and update NBS commit
Rebase on top of main and update NBS commit to the CI fix.
* [marketplace] use async subscription event handlers
* [marketplace] support slotIndex no longer optional
Previously, SalesAgent.slotIndex had been moved to not optional. However, there were still many places where optionality was assumed. This commit removes those assumuptions.
* [marketplace] sales state machine: use slotState
Use `slotState` instead of `requestState` for sales state machine.
* [marketplace] clean up
* [statemachine] adds a statemachine for async workflows
Allows events to be scheduled synchronously.
See https://github.com/status-im/nim-codex/pull/344
Co-Authored-By: Ben Bierens <thatbenbierens@gmail.com>
Co-Authored-By: Eric Mastro <eric.mastro@gmail.com>
* [market] make market callbacks synchronous
* [statemachine] export Event
* [statemachine] ensure that no errors are raised
* [statemachine] add machine parameter to run method
* [statemachine] initialize queue on start
* [statemachine] check futures before cancelling them
* [sales] use new async state machine
- states use new run() method and event mechanism
- StartState starts subscriptions and loads request
* [statemachine] fix unsusbscribe before subscribe
* [sales] replace old state transition tests
* [sales] separate state machine from sales data
* [sales] remove reference from SalesData to Sales
* [sales] separate sales context from sales
* [sales] move decoupled types into their own modules
* [sales] move retrieveRequest to SalesData
* [sales] move subscription logic into SalesAgent
* [sales] unsubscribe when finished or errored
* [build] revert back to released version of nim-ethers
* [sales] remove SaleStart state
* [sales] add missing base method
* [sales] move asyncSpawn helper to utils
* [sales] fix imports
* [sales] remove unused variables
* [sales statemachine] add async state machine error handling (#349)
* [statemachine] add error handling to asyncstatemachine
- add error handling to catch errors during state.run
- Sales: add ErrorState to identify which state to transition to during an error. This had to be added to SalesAgent constructor due to circular dependency issues, otherwise it would have been added directly to SalesAgent.
- Sales: when an error during run is encountered, the SaleErrorState is constructed with the error, and by default (base impl) will return the error state, so the machine can transition to it. This can be overridden by individual states if needed.
* [sales] rename onSaleFailed to onSaleErrored
Because there is already a state named SaleFailed which is meant to react to an onchain RequestFailed event and also because this callback is called from SaleErrored, renaming to onSaleErrored prevents ambiguity and confusion as to what has happened at the callback callsite.
* [statemachine] forward error to state directly
without going through a machine method first
* [statemachine] remove unnecessary error handling
AsyncQueueFullError is already handled in schedule()
* [statemachine] test that cancellation ignores onError
* [sales] simplify error handling in states
Rely on the state machine error handling instead
of catching errors in the state run method
---------
Co-authored-by: Mark Spanbroek <mark@spanbroek.net>
* [statemachine] prevent memory leaks
prevent memory leaks and nil access defects by:
- allowing multiple subscribe/unsubscribes of salesagent
- disallowing individual salesagent subscription calls to be made externally (requires the .subscribed check)
- allowing mutiple start/stops of asyncstatemachine
- disregard asyncstatemachine schedules if machine not yet started
* [salesagent] add salesagent-specific tests
1. test multiple subscribe/unsubscribes
2. test scheduling machine without being started
3. test subscriptions are working correctly with external events
4. test errors can be overridden at the state level for ErrorHandlingStates.
---------
Co-authored-by: Eric Mastro <eric.mastro@gmail.com>
Co-authored-by: Mark Spanbroek <mark@spanbroek.net>
Co-authored-by: Ben Bierens <thatbenbierens@gmail.com>
* [purchasing] Simplify test
* [utils] Move StorageRequest.example up one level
* [purchasing] Load purchases from market
* [purchasing] load purchase states
* Implement myRequest() and getState() methods for OnChainMarket
* [proofs] Fix intermittently failing tests
Ensures that examples of proofs in tests are never of length 0;
these are considered invalid proofs by the smart contract logic.
* [contracts] Fix failing test
With the new solidity contracts update, a contract can only
be paid out after it started.
* [market] Add method to get request end time
* [purchasing] wait until purchase is finished
Purchase.wait() would previously wait until purchase
was started, now we wait until it is finished.
* [purchasing] Handle 'finished' and 'failed' states
* [marketplace] move to failed state once request fails
- Add support for subscribing to request failure events.
- Add supporting contract tests for subscribing to request failure events.
- Allow the PurchaseStarted state to move to PurchaseFailure once a request failure event is emitted
- Add supporting tests for moving from PurchaseStarted to PurchaseFailure
- Add state transition tests for PurchaseUnknown.
* [marketplace] Fix test with longer sleepAsync
* [integration] Add function to restart a codex node
* [purchasing] Set client address before requesting storage
To prevent the purchase id (which equals the request id)
from changing once it's been submitted.
* [contracts] Fix: OnChainMarket.getState()
Had the wrong method signature before
* [purchasing] Load purchases on node start
* [purchasing] Rename state 'PurchaseError' to 'PurchaseErrored'
Allows for an exception type called 'PurchaseError'
* [purchasing] Load purchases in background
No longer calls market.getRequest() for every purchase
on node start.
* [contracts] Add `$` for RequestId, SlotId and Nonce
To aid with debugging
* [purchasing] Add Purchasing.stop()
To ensure that all contract interactions have both a
start() and a stop() for
* [tests] Remove sleepAsync where possible
Use `eventually` loop instead, to make sure that we're
not waiting unnecessarily.
* [integration] Fix: handle non-json response in test
* [purchasing] Add purchase state to json
* [integration] Ensure that purchase is submitted before restart
Fixes test failure on slower CI
* [purchasing] re-implement `description` as method
Allows description to be set in the same module where the
state type is defined.
Co-authored-by: Eric Mastro <eric.mastro@gmail.com>
* [contracts] fix typo
Co-authored-by: Eric Mastro <eric.mastro@gmail.com>
* [market] Use more generic error type
Should we decide to change the provider type later
Co-authored-by: Eric Mastro <eric.mastro@gmail.com>
Co-authored-by: Eric Mastro <eric.mastro@gmail.com>
1. use `ProviderError` to catch contract errors instaed of `JsonRpcProviderError`.
2. Add tests for `isProofRequired`, `willProofBeRequired`, and `getProofEnd` when slot is empty (and is call is reverted)
3. bump nim-ethers to branch that has new `reverts` API and `ProviderError` support.
4. Update to new `reverts` API.
Support storage contract parameters to free slots after too many proofs missed, as well as fail a contract after too many slots have been freed.
# Conflicts:
# vendor/dagger-contracts
- remove RequestState as no longer being used
- remove RequestState check on purchase timeout
- add tests for `withdrawFunds` and `subscribeRequestCancelled`
- update `dagger-contracts` so that `RequestCancelled.requestId` property is indexed in the event
- rename `ContractId` to `SlotId`
- add `RequestId`, `PurchaseId`, `Nonce` types as aliases of `array[32, byte]`
- rename `Proving.contracts` to `Proving.slots`
- change signatures of `isSlotCancelled` and `isCancelled` to use `SlotId` and `RequestId` types, respectively.
- change all references to `RequestId`, `SlotId`, and `PurchaseId`
Eric
Adam Uhlíř
Giuliano Mega
markspanbroek
Eric Mastro
Eric Mastro
Michael Bradley