子流

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Substreams is a powerful blockchain indexing technology developed for The Graph Network. It enables developers to write Rust modules, compose data streams alongside the community, and provide extremely high-performance indexing due to parallelization in a streaming-first approach.

With Substreams, developers can quickly extract data from different blockchains (Ethereum, BNB, Solana, ect.) and send it to various locations of their choice, such as a Postgres database, a Mongo database, or a Subgraph. Additionally, Substreams packages enable developers to specify which data they want to extract from the blockchain.

1. **您编写了一个Rust程序，定义了要应用于区块链数据的转换操作。**例如，以下的Rust函数从以太坊区块中提取相关信息（区块号、哈希和父哈希）。

fn get_my_block(blk: Block) -> Result<MyBlock, substreams::errors::Error> {
    let header = blk.header.as_ref().unwrap();

    Ok(MyBlock {
        number: blk.number,
        hash: Hex::encode(&blk.hash),
        parent_hash: Hex::encode(&header.parent_hash),
    })
}

2. 您只需运行一个命令行命令，就可以将您的Rust程序打包成一个WASM模块。

3. WASM容器被发送到Substreams端点执行。 Substreams提供商将区块链数据传送给WASM容器，然后执行转换操作。

4. You select a sink, a place where you want to send the transformed data (a Postgres database or a Subgraph, for example).

Substreams的官方文档目前由StreamingFast团队在StreamingFast的网站上维护。

To learn about the latest version of Substreams CLI, which enables developers to bootstrap a Substreams project without any code, please check Substreams Codegen.

• In order to develop and deploy a Substreams, you must install the Substreams CLI.
• Then, run your first Substreams by following the Quickstart Tutorial.

• Take a look at the Ethereum Explorer Tutorial to learn about the basic transformations you can create with Substreams.