Expand description
§Indexer1
Indexer1 is a library that provides a mechanism to index EVM-compatible blockchains.
It uses PostgreSQL to ensure consistent and fault-tolerant indexing, however re-implementing storage trait is available.
Indexer1 is lightweight, self-hosted and simple to use.
If you need a professional and extendable way of indexing EVM, you should definately prefer Indexer1
§Example
To make it work you only need to implement a Processor trait that gives you transaction and allow you to inject your custom logic of parsing and applying logs. It also gives you a transaction to work with database and does all the deduplication work for you. You are guaranteed to receive all events ordered.
pub struct TestProcessor;
impl Processor for TestProcessor {
async fn process<Postgres>(
&mut self,
_logs: &[alloy::rpc::types::Log],
_transaction: &mut sqlx::Transaction<'static, Postgres>,
_chain_id: u64,
) -> anyhow::Result<()> {
// put here any code to collect logs
Ok(())
}
}After you described processing, build indexer by specifying all connections and filter for events. If the filter will be changed, indexer will re-index all the data from the blockchain.
Indexer::builder()
.http_rpc_url(http_url)
.ws_rpc_url(ws_url)
.fetch_interval(Duration::from_secs(10))
// Add event filter
.filter(Filter::new().address(contract_address).events([
MockERC20::Transfer::SIGNATURE,
MockERC20::Approval::SIGNATURE,
]))
// Set up a function to process events
.set_processor(TestProcessor)
.sqlite_storage(pool)
.build()
.await
.unwrap()
.run()
.await?;