Merge PR #5952: Refactor Evidence Age Util + Governable Consensus Params

This commit is contained in:
Alexander Bezobchuk
2020-04-16 11:10:39 -04:00
committed by GitHub
parent b26109c5dc
commit 09a55f68b5
49 changed files with 521 additions and 665 deletions
+16 -9
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@@ -28,7 +28,7 @@ developers will create a custom type for their application, like so:
```go
type App struct {
// reference to a BaseApp
*bam.BaseApp
*baseapp.BaseApp
// list of application store keys
@@ -45,7 +45,7 @@ management logic.
## Type Definition
The `BaseApp` type holds many important parameters for any Cosmos SDK based application.
The `BaseApp` type holds many important parameters for any Cosmos SDK based application.
+++ https://github.com/cosmos/cosmos-sdk/blob/7d7821b9af132b0f6131640195326aa02b6751db/baseapp/baseapp.go#L54-L108
@@ -71,8 +71,7 @@ appropriate module for it to be processed. These `queries` are not ABCI messages
are relayed to the application from the underlying consensus engine via the ABCI message [`Query`](#query).
- [`TxDecoder`](https://godoc.org/github.com/cosmos/cosmos-sdk/types#TxDecoder): It is used to decode
raw transaction bytes relayed by the underlying Tendermint engine.
- `BaseKey`: This key is used to access the main store in the `CommitMultiStore`. The main store is
used to persist data related to the core of the application, like consensus parameters.
- [`ParamStore`](#paramstore): The parameter store used to get and set application consensus parameters.
- [`AnteHandler`](#antehandler): This handler is used to handle signature verification, fee payment,
and other pre-message execution checks when a transaction is received. It's executed during
[`CheckTx/RecheckTx`](#checktx) and [`DeliverTx`](#delivertx).
@@ -122,7 +121,7 @@ the node's `min-gas-prices`.
Naturally, developers can add additional `options` based on their application's needs.
## State Updates
## State Updates
The `BaseApp` maintains two primary volatile states and a root or main state. The main state
is the canonical state of the application and the volatile states, `checkState` and `deliverState`,
@@ -179,6 +178,14 @@ newly committed state and `deliverState` is set to `nil` to be reset on `BeginBl
![Commit](./baseapp_state-commit.png)
## ParamStore
During `InitChain`, the `RequestInitChain` provides `ConsensusParams` which contains parameters
related to block execution such as maximum gas and size in addition to evidence parameters. If these
parameters are non-nil, they are set in the BaseApp's `ParamStore`. Behind the scenes, the `ParamStore`
is actually managed by an `x/params` module `Subspace`. This allows the parameters to be tweaked via
on-chain governance.
## Routing
When messages and queries are received by the application, they must be routed to the appropriate module in order to be processed. Routing is done via `baseapp`, which holds a `router` for messages, and a `query router` for queries.
@@ -199,7 +206,7 @@ Just like the `router`, the `query router` is initilalized with all the query ro
## Main ABCI Messages
The [Application-Blockchain Interface](https://tendermint.com/docs/spec/abci/) (ABCI) is a generic interface that connects a state-machine with a consensus engine to form a functional full-node. It can be wrapped in any language, and needs to be implemented by each application-specific blockchain built on top of an ABCI-compatible consensus engine like Tendermint.
The [Application-Blockchain Interface](https://tendermint.com/docs/spec/abci/) (ABCI) is a generic interface that connects a state-machine with a consensus engine to form a functional full-node. It can be wrapped in any language, and needs to be implemented by each application-specific blockchain built on top of an ABCI-compatible consensus engine like Tendermint.
The consensus engine handles two main tasks:
@@ -376,17 +383,17 @@ Finally, `Commit` returns the hash of the commitment of `app.cms` back to the un
The [`Info` ABCI message](https://tendermint.com/docs/app-dev/abci-spec.html#info) is a simple query from the underlying consensus engine, notably used to sync the latter with the application during a handshake that happens on startup. When called, the `Info(res abci.ResponseInfo)` function from `baseapp` will return the application's name, version and the hash of the last commit of `app.cms`.
### Query
### Query
The [`Query` ABCI message](https://tendermint.com/docs/app-dev/abci-spec.html#query) is used to serve queries received from the underlying consensus engine, including queries received via RPC like Tendermint RPC. It is the main entrypoint to build interfaces with the application. The application must respect a few rules when implementing the `Query` method, which are outlined [here](https://tendermint.com/docs/app-dev/abci-spec.html#query).
Each `query` comes with a `path`, which contains multiple `string`s. By convention, the first element of the `path` (`path[0]`) contains the category of `query` (`app`, `p2p`, `store` or `custom`). The `baseapp` implementation of the `Query(req abci.RequestQuery)` method is a simple dispatcher serving these 4 main categories of queries:
- Application-related queries like querying the application's version, which are served via the `handleQueryApp` method.
- Direct queries to the multistore, which are served by the `handlerQueryStore` method. These direct queryeis are different from custom queries which go through `app.queryRouter`, and are mainly used by third-party service provider like block explorers.
- Direct queries to the multistore, which are served by the `handlerQueryStore` method. These direct queryeis are different from custom queries which go through `app.queryRouter`, and are mainly used by third-party service provider like block explorers.
- P2P queries, which are served via the `handleQueryP2P` method. These queries return either `app.addrPeerFilter` or `app.ipPeerFilter` that contain the list of peers filtered by address or IP respectively. These lists are first initialized via `options` in `baseapp`'s [constructor](#constructor).
- Custom queries, which encompass most queries, are served via the `handleQueryCustom` method. The `handleQueryCustom` cache-wraps the multistore before using the `queryRoute` obtained from [`app.queryRouter`](#query-routing) to map the query to the appropriate module's `querier`.
## Next {hide}
Learn more about [transactions](./transactions.md) {hide}
Learn more about [transactions](./transactions.md) {hide}
+9 -9
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@@ -12,7 +12,7 @@ A store is a data structure that holds the state of the application. {synopsis}
## Introduction to SDK Stores
The Cosmos SDK comes with a large set of stores to persist the state of applications. By default, the main store of SDK applications is a `multistore`, i.e. a store of stores. Developers can add any number of key-value stores to the multistore, depending on their application needs. The multistore exists to support the modularity of the Cosmos SDK, as it lets each module declare and manage their own subset of the state. Key-value stores in the multistore can only be accessed with a specific capability `key`, which is typically held in the [`keeper`](../building-modules/keeper.md) of the module that declared the store.
The Cosmos SDK comes with a large set of stores to persist the state of applications. By default, the main store of SDK applications is a `multistore`, i.e. a store of stores. Developers can add any number of key-value stores to the multistore, depending on their application needs. The multistore exists to support the modularity of the Cosmos SDK, as it lets each module declare and manage their own subset of the state. Key-value stores in the multistore can only be accessed with a specific capability `key`, which is typically held in the [`keeper`](../building-modules/keeper.md) of the module that declared the store.
```
+-----------------------------------------------------+
@@ -64,7 +64,7 @@ The `GetStoreType` is a simple method that returns the type of store, whereas a
+++ https://github.com/cosmos/cosmos-sdk/blob/7d7821b9af132b0f6131640195326aa02b6751db/store/types/store.go#L217-L238
Cache-wrapping is used ubiquitously in the Cosmos SDK and required to be implemented on every store type. A cache-wrapper creates a light snapshot of a store that can be passed around and updated without affecting the main underlying store. This is used to trigger temporary state-transitions that may be reverted later should an error occur. If a state-transition sequence is performed without issue, the cached store can be comitted to the underlying store at the end of the sequence.
Cache-wrapping is used ubiquitously in the Cosmos SDK and required to be implemented on every store type. A cache-wrapper creates a light snapshot of a store that can be passed around and updated without affecting the main underlying store. This is used to trigger temporary state-transitions that may be reverted later should an error occur. If a state-transition sequence is performed without issue, the cached store can be committed to the underlying store at the end of the sequence.
### Commit Store
@@ -76,9 +76,9 @@ The `Committer` is an interface that defines methods to persist changes to disk:
+++ https://github.com/cosmos/cosmos-sdk/blob/7d7821b9af132b0f6131640195326aa02b6751db/store/types/store.go#L17-L22
The `CommitID` is a deterministic commit of the state tree. Its hash is returned to the underlying consensus engine and stored in the block header. Note that commit store interfaces exist for various purposes, one of which is to make sure not every object can commit the store. As part of the [object-capabilities model](./ocap.md) of the Cosmos SDK, only `baseapp` should have the ability to commit stores. For example, this is the reason why the `ctx.KVStore()` method by which modules typically access stores returns a `KVStore` and not a `CommitKVStore`.
The `CommitID` is a deterministic commit of the state tree. Its hash is returned to the underlying consensus engine and stored in the block header. Note that commit store interfaces exist for various purposes, one of which is to make sure not every object can commit the store. As part of the [object-capabilities model](./ocap.md) of the Cosmos SDK, only `baseapp` should have the ability to commit stores. For example, this is the reason why the `ctx.KVStore()` method by which modules typically access stores returns a `KVStore` and not a `CommitKVStore`.
The Cosmos SDK comes with many types of stores, the most used being [`CommitMultiStore`](#multistore), [`KVStore`](#kvstore) and [`GasKv` store](#gaskv-store). [Other types of stores](#other-stores) include `Transient` and `TraceKV` stores.
The Cosmos SDK comes with many types of stores, the most used being [`CommitMultiStore`](#multistore), [`KVStore`](#kvstore) and [`GasKv` store](#gaskv-store). [Other types of stores](#other-stores) include `Transient` and `TraceKV` stores.
## Multistore
@@ -100,7 +100,7 @@ As for concrete implementation, the [`rootMulti.Store`] is the go-to implementat
+++ https://github.com/cosmos/cosmos-sdk/blob/7d7821b9af132b0f6131640195326aa02b6751db/store/rootmulti/store.go#L27-L43
The `rootMulti.Store` is a base-layer multistore built around a `db` on top of which multiple `KVStores` can be mounted, and is the default multistore store used in [`baseapp`](./baseapp.md).
The `rootMulti.Store` is a base-layer multistore built around a `db` on top of which multiple `KVStores` can be mounted, and is the default multistore store used in [`baseapp`](./baseapp.md).
### CacheMultiStore
@@ -114,11 +114,11 @@ Whenever the `rootMulti.Store` needs to be cached-wrapped, a [`cachemulti.Store`
### `KVStore` and `CommitKVStore` Interfaces
A `KVStore` is a simple key-value store used to store and retrieve data. A `CommitKVStore` is a `KVStore` that also implements a `Committer`. By default, stores mounted in `baseapp`'s main `CommitMultiStore` are `CommitKVStore`s. The `KVStore` interface is primarily used to restrict modules from accessing the committer.
A `KVStore` is a simple key-value store used to store and retrieve data. A `CommitKVStore` is a `KVStore` that also implements a `Committer`. By default, stores mounted in `baseapp`'s main `CommitMultiStore` are `CommitKVStore`s. The `KVStore` interface is primarily used to restrict modules from accessing the committer.
Individual `KVStore`s are used by modules to manage a subset of the global state. `KVStores` can be accessed by objects that hold a specific key. This `key` should only be exposed to the [`keeper`](../building-modules/keeper.md) of the module that defines the store.
Individual `KVStore`s are used by modules to manage a subset of the global state. `KVStores` can be accessed by objects that hold a specific key. This `key` should only be exposed to the [`keeper`](../building-modules/keeper.md) of the module that defines the store.
`CommitKVStore`s are declared by proxy of their respective `key` and mounted on the application's [multistore](#multistore) in the [main application file](../basics/app-anatomy.md#core-application-file). In the same file, the `key` is also passed to the module's `keeper` that is responsible for managing the store.
`CommitKVStore`s are declared by proxy of their respective `key` and mounted on the application's [multistore](#multistore) in the [main application file](../basics/app-anatomy.md#core-application-file). In the same file, the `key` is also passed to the module's `keeper` that is responsible for managing the store.
+++ https://github.com/cosmos/cosmos-sdk/blob/7d7821b9af132b0f6131640195326aa02b6751db/store/types/store.go#L163-L193
@@ -237,4 +237,4 @@ When `Store.Iterator()` is called, it does not simply prefix the `Store.prefix`,
## Next {hide}
Learn about [encoding](./encoding.md) {hide}
Learn about [encoding](./encoding.md) {hide}