forked from cerc-io/ipld-eth-server
readme fixes
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@ -359,8 +359,10 @@ or [StorageTransformerInitializer](https://github.com/vulcanize/maker-vulcanized
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* Design the transformers to work in the context of their [event](https://github.com/vulcanize/maker-vulcanizedb/blob/staging/libraries/shared/watcher/event_watcher.go#L83)
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or [storage](https://github.com/vulcanize/maker-vulcanizedb/blob/staging/libraries/shared/watcher/storage_watcher.go#L58) watcher execution modes
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* Create db migrations to run against vulcanizeDB so that we can store the transformer output
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* Specify migration locations for each transformer in the config with the `exporter.transformer.migrations` fields
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* Do not `goose fix` the transformer migrations
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* Specify migration locations for each transformer in the config with the `exporter.transformer.migrations` fields
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* If the base vDB migrations occupy this path as well, they need to be in their `goose fix`ed form
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as they are [here](https://github.com/vulcanize/vulcanizedb/tree/master/db/migrations)
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To update a plugin repository with changes to the core vulcanizedb repository, replace the vulcanizedb vendored in the plugin repo (`plugin_repo/vendor/github.com/vulcanize/vulcanizedb`)
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with the newly updated version
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@ -11,7 +11,7 @@ with our `checked_headers` table.
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This approach assumes you are running a vDB light sync which is itself run against a light Ethereum node,
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this approach also assumes there is a full node available.
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Looking forward, we will be building fetchers than enable sourcing data from IPFS instead of an ETH node.
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Looking forward, we will be building fetchers that enable sourcing data from IPFS instead of an ETH node.
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## Shared Code
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@ -25,7 +25,7 @@ Using the `compose` or `composeAndExecute` command, event watchers can be loaded
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### [Event Transformer](https://github.com/vulcanize/maker-vulcanizedb/blob/staging/libraries/shared/transformer/event_transformer.go)
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The event transformer is responsible for converting event logs into more useful data objects and storing them in postgres.
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The event transformer is responsible for converting event logs into more useful data objects and storing them in Postgres.
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The event transformer is composed of converter and repository interfaces and a config struct:
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```go
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type Transformer struct {
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@ -83,11 +83,11 @@ In order to watch events at a smart contract, for those events the developer mus
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1. Config - struct to hold configuration information (contract address, starting block, event name and signature).
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1. Entity - struct to unpack the event log into.
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1. Model - struct representing the final data model we want to write to Postres.
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1. Model - struct representing the final data model we want to write to Postgres.
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1. Converter - an interface which can unpack event logs into our entities and convert those entities to our models.
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1. Repository - an interface to write our models to Postgres.
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1. TransformerInitializer - a public variable which exports our configured transformer to be loaded as part of a plugin,
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1. DB migrations - migrations to generate the Posstgres schema, tables, views, function, etc that are needed to store and interface with the transformed data models.
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1. TransformerInitializer - a public variable which exports our configured transformer to be loaded as part of a plugin.
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1. DB migrations - migrations to generate the Postgres schema, tables, views, function, etc that are needed to store and interface with the transformed data models.
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The example event we will use looks like:
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```
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@ -97,7 +97,7 @@ event ExampleEvent(bytes32 indexed arg1, address indexed arg2, bytes32 arg3, uin
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### Config
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The config holds configuration variables for the event transformer, including a name for the transformer, the contract address
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it is working at, the contract's abi, the topic (e.g. event signature; topic0) that it is filtering for, and starting
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it is working at, the contract's ABI, the topic (e.g. event signature; topic0) that it is filtering for, and starting
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and ending block numbers.
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```go
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@ -118,9 +118,9 @@ TransactionIndex, and the Raw log are retained in order to link the data to it's
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```go
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type ExampleEntity struct {
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Arg1 [32]byte
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Arg1 common.Hash
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Arg2 common.Address
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Arg3 [32]byte
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Arg3 common.Hash
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Arg4 *big.Int
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Arg5 *big.Int
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LogIndex uint
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@ -200,7 +200,10 @@ func (converter ExampleConverter) ToModels(entities []interface{}) ([]interface{
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return nil, fmt.Errorf("entity of type %T, not %T", entity, ExampleModel{})
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}
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fractionSkimmed, err := hexutil.DecodeBig(entity.Arg3)
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fractionSkimmed, err := hexutil.DecodeBig(entity.Arg3.Hex())
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if err != nil {
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reuturn nil, err
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}
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position := new(big.Int)
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position.Sub(entity.Arg4, entity.Arg5)
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finalPosition := new(big.Int)
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@ -218,7 +221,7 @@ func (converter ExampleConverter) ToModels(entities []interface{}) ([]interface{
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}
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model := ExampleModel{
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EventHash: common.BytesToHash([]byte(entity.Arg1[:])).Hex(),
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EventHash: entity.Arg1.Hex(),
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UserAddress: entity.Arg2.Hex(),
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FractionSkimmed: fractionSkimmed.String(),
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Surplus: entity.Arg4.String(),
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@ -275,16 +278,6 @@ func (repository ExampleRepository) Create(headerID int64, models []interface{})
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return fmt.Errorf("model of type %T, not %T", model, ExampleModel{})
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}
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EventHash: common.BytesToHash([]byte(entity.Arg1[:])).Hex(),
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UserAddress: entity.Arg2.Hex(),
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FractionSkimmed: fractionSkimmed.String(),
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Surplus: entity.Arg4.String(),
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Deficit: entity.Arg5.String(),
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FinalPosition: finalPosition,
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LogIndex: entity.LogIndex,
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TransactionIndex: entity.TransactionIndex,
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Raw: rawLog,
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_, execErr := tx.Exec(
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`INSERT into example_schema.example_event (header_id, event_hash, user_address, fraction_skimmed, surplus, deficit, final_position, log_idx, tx_idx, raw_log)
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VALUES($1, $2, $3, $4, $5, $6, $7, $8, $9, $10)
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@ -363,10 +356,10 @@ CREATE TABLE example_schema.example_event (
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header_id INTEGER NOT NULL REFERENCES headers (id) ON DELETE CASCADE,
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event_hash CHARACTER VARYING(66) NOT NULL,
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user_address CHARACTER VARYING(66) NOT NULL,
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fraction_skimmed NUMERIC,
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surplus NUMERIC,
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deficit NUMERIC,
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final_position NUMERIC,
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fraction_skimmed NUMERIC NOT NULL,
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surplus NUMERIC NOT NULL,
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deficit NUMERIC NOT NULL,
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final_position NUMERIC NOT NULL,
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tx_idx INTEGER NOT NUll,
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log_idx INTEGER NOT NUll,
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raw_log JSONB,
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@ -389,8 +382,7 @@ of which headers we have already filtered through for this event.
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## Summary
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To create a transformer for a contract event, we need to create entities to unpack the raw log into, models to represent
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To create a transformer for a contract event we need to create entities for unpacking the raw log, models to represent
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the final data structure, a converter to mediate this unpacking and conversion between entities to models, a repository to write
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these models to Postres, db migrations to accommodate these models in Postgres, and a TransformerInitializer to export the
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configured transformer and load it as a plugin to the `compose` or `composeAndExecute` commands. Note that these commands also
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need a .toml config file, as described in the [main readme](https://github.com/vulcanize/maker-vulcanizedb/blob/staging/README.md#composeandexecute-configuration)
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these models to Postgres, db migrations to accommodate these models in Postgres, and a TransformerInitializer to export the
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configured transformer and load it as a plugin to the `compose` or `composeAndExecute` commands as described in the [main readme](https://github.com/vulcanize/maker-vulcanizedb/blob/staging/README.md#composeandexecute-configuration).
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