Crate opendal

source ·
Expand description

Apache OpenDAL™ is a data access layer that allows users to easily and efficiently retrieve data from various storage services in a unified way.

§Quick Start

OpenDAL’s API entry points are Operator and BlockingOperator. All public APIs are accessible through the operator. To utilize OpenDAL, you need to:

§Init a service

The first step is to pick a service and init it with a builder. All supported services could be found at services.

Let’s take services::S3 as an example:

use opendal::services;
use opendal::Operator;
use opendal::Result;

fn main() -> Result<()> {
    // Pick a builder and configure it.
    let mut builder = services::S3::default().bucket("test");

    // Init an operator
    let op = Operator::new(builder)?.finish();
    Ok(())
}

§Compose layers

The next setup is to compose layers. Layers are modules that provide extra features for every operation. All builtin layers could be found at layers.

Let’s use layers::LoggingLayer as an example; this layer adds logging to every operation that OpenDAL performs.

use opendal::layers::LoggingLayer;
use opendal::services;
use opendal::Operator;
use opendal::Result;

#[tokio::main]
async fn main() -> Result<()> {
    // Pick a builder and configure it.
    let mut builder = services::S3::default().bucket("test");

    // Init an operator
    let op = Operator::new(builder)?
        // Init with logging layer enabled.
        .layer(LoggingLayer::default())
        .finish();

    Ok(())
}

§Use operator

The final step is to use the operator. OpenDAL supports both async Operator and blocking BlockingOperator. Please pick the one that fits your use case.

Every Operator API follows the same pattern, take read as an example:

  • read: Execute a read operation.
  • read_with: Execute a read operation with additional options, like range and if_match.
  • reader: Create a reader for streaming data, enabling flexible access.
  • reader_with: Create a reader with advanced options.
use opendal::layers::LoggingLayer;
use opendal::services;
use opendal::Operator;
use opendal::Result;

#[tokio::main]
async fn main() -> Result<()> {
    // Pick a builder and configure it.
    let mut builder = services::S3::default().bucket("test");

    // Init an operator
    let op = Operator::new(builder)?
        // Init with logging layer enabled.
        .layer(LoggingLayer::default())
        .finish();

    // Fetch this file's metadata
    let meta = op.stat("hello.txt").await?;
    let length = meta.content_length();

    // Read data from `hello.txt` with range `0..1024`.
    let bs = op.read_with("hello.txt").range(0..1024).await?;

    Ok(())
}

Modules§

  • docsdocsrs
    This module holds documentation for OpenDAL.
  • executors
    executors module provides implementations for the Execute trait for widely used runtimes.
  • layers
    Layer is the mechanism to intercept operations.
  • operator_functions
    Functions provides the functions generated by BlockingOperator
  • operator_futures
    Futures provides the futures generated by Operator
  • raw
    Raw modules provide raw APIs that used by underlying services
  • services
    Services will provide builders to build underlying backends.

Structs§

Enums§

  • EntryMode
    EntryMode represents the mode.
  • ErrorKind
    ErrorKind is all kinds of Error of opendal.
  • Metakey
    Metakey describes the metadata keys that can be stored or queried.
  • Scheme
    Services that OpenDAL supports

Traits§

  • Builder
    Builder is used to set up underlying services.
  • Configurator
    Configurator is used to configure the underlying service.
  • Execute
    Execute trait is used to execute task in background.

Type Aliases§

  • Result
    Result that is a wrapper of Result<T, opendal::Error>