56 lines
2.1 KiB
Markdown
56 lines
2.1 KiB
Markdown
Ethers uses a middleware-based architecture. You start the middleware stack with
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a [`Provider`](ethers_providers::Provider), and wrap it with additional
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middleware functionalities that you need.
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## Available Middleware
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- [`Signer`](./signer/struct.SignerMiddleware.html): Signs transactions locally,
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with a private key or a hardware wallet
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- [`Nonce Manager`](./nonce_manager/struct.NonceManagerMiddleware.html): Manages
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nonces locally, allowing the rapid broadcast of transactions without having to
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wait for them to be submitted
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- [`Gas Escalator`](./gas_escalator/struct.GasEscalatorMiddleware.html): Bumps
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transaction gas prices in the background
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- [`Gas Oracle`](./gas_oracle/struct.GasOracleMiddleware.html): Allows getting
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your gas price estimates from places other than `eth_gasPrice`.
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- [`Transformer`](./transformer/trait.Transformer.html): Allows intercepting and
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transforming a transaction to be broadcasted via a proxy wallet, e.g.
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[`DSProxy`](./transformer/struct.DsProxy.html).
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## Example of a middleware stack
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```no_run
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use ethers_providers::{Provider, Http};
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use ethers_signers::{LocalWallet, Signer};
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use ethers_middleware::{
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gas_escalator::{GasEscalatorMiddleware, GeometricGasPrice, Frequency},
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gas_oracle::{GasOracleMiddleware, EthGasStation, GasCategory},
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signer::SignerMiddleware,
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nonce_manager::NonceManagerMiddleware,
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};
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use ethers_core::rand;
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use std::convert::TryFrom;
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// Start the stack
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let provider = Provider::<Http>::try_from("http://localhost:8545").unwrap();
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// Escalate gas prices
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let escalator = GeometricGasPrice::new(1.125, 60u64, None::<u64>);
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let provider =
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GasEscalatorMiddleware::new(provider, escalator, Frequency::PerBlock);
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// Sign transactions with a private key
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let signer = LocalWallet::new(&mut rand::thread_rng());
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let address = signer.address();
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let provider = SignerMiddleware::new(provider, signer);
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// Use EthGasStation as the gas oracle
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let gas_oracle = EthGasStation::new(None);
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let provider = GasOracleMiddleware::new(provider, gas_oracle);
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// Manage nonces locally
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let provider = NonceManagerMiddleware::new(provider, address);
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// ... do something with the provider
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```
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