Crate object_store

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object_store

This crate provides a uniform API for interacting with object storage services and local files via the the ObjectStore trait.

Create an ObjectStore implementation:

Adapters

ObjectStore instances can be composed with various adapters which add additional functionality:

List objects:

Use the ObjectStore::list method to iterate over objects in remote storage or files in the local filesystem:


use std::sync::Arc;
use object_store::{path::Path, ObjectStore};
use futures::stream::StreamExt;

// create an ObjectStore
let object_store: Arc<dyn ObjectStore> = Arc::new(get_object_store());

// Recursively list all files below the 'data' path.
// 1. On AWS S3 this would be the 'data/' prefix
// 2. On a local filesystem, this would be the 'data' directory
let prefix: Path = "data".try_into().unwrap();

// Get an `async` stream of Metadata objects:
 let list_stream = object_store
     .list(Some(&prefix))
     .await
     .expect("Error listing files");

 // Print a line about each object based on its metadata
 // using for_each from `StreamExt` trait.
 list_stream
     .for_each(move |meta|  {
         async {
             let meta = meta.expect("Error listing");
             println!("Name: {}, size: {}", meta.location, meta.size);
         }
     })
     .await;

Which will print out something like the following:

Name: data/file01.parquet, size: 112832
Name: data/file02.parquet, size: 143119
Name: data/child/file03.parquet, size: 100
...

Fetch objects

Use the ObjectStore::get method to fetch the data bytes from remote storage or files in the local filesystem as a stream.


use std::sync::Arc;
use object_store::{path::Path, ObjectStore};
use futures::stream::StreamExt;

// create an ObjectStore
let object_store: Arc<dyn ObjectStore> = Arc::new(get_object_store());

// Retrieve a specific file
let path: Path = "data/file01.parquet".try_into().unwrap();

// fetch the bytes from object store
let stream = object_store
    .get(&path)
    .await
    .unwrap()
    .into_stream();

// Count the '0's using `map` from `StreamExt` trait
let num_zeros = stream
    .map(|bytes| {
        let bytes = bytes.unwrap();
       bytes.iter().filter(|b| **b == 0).count()
    })
    .collect::<Vec<usize>>()
    .await
    .into_iter()
    .sum::<usize>();

println!("Num zeros in {} is {}", path, num_zeros);

Which will print out something like the following:

Num zeros in data/file01.parquet is 657

Put object

Use the ObjectStore::put method to save data in remote storage or local filesystem.

 use object_store::ObjectStore;
 use std::sync::Arc;
 use bytes::Bytes;
 use object_store::path::Path;

 let object_store: Arc<dyn ObjectStore> = Arc::new(get_object_store());
 let path: Path = "data/file1".try_into().unwrap();
 let bytes = Bytes::from_static(b"hello");
 object_store
     .put(&path, bytes)
     .await
     .unwrap();

Multipart put object

Use the ObjectStore::put_multipart method to save large amount of data in chunks.

 use object_store::ObjectStore;
 use std::sync::Arc;
 use bytes::Bytes;
 use tokio::io::AsyncWriteExt;
 use object_store::path::Path;

 let object_store: Arc<dyn ObjectStore> = Arc::new(get_object_store());
 let path: Path = "data/large_file".try_into().unwrap();
 let (_id, mut writer) =  object_store
     .put_multipart(&path)
     .await
     .unwrap();
 let bytes = Bytes::from_static(b"hello");
 writer.write_all(&bytes).await.unwrap();
 writer.flush().await.unwrap();
 writer.shutdown().await.unwrap();

Modules

aws
An object store implementation for S3
azure
An object store implementation for Azure blob storage
chunked
A ChunkedStore that can be used to test streaming behaviour
delimited
Utility for streaming newline delimited files from object storage
gcp
An object store implementation for Google Cloud Storage
http
An object store implementation for generic HTTP servers
limit
An object store that limits the maximum concurrency of the wrapped implementation
local
An object store implementation for a local filesystem
memory
An in-memory object store implementation
path
Path abstraction for Object Storage
prefix
An object store wrapper handling a constant path prefix
throttle
A throttling object store wrapper

Structs

BackoffConfig
Exponential backoff with jitter
ClientOptions
HTTP client configuration for remote object stores
ListResult
Result of a list call that includes objects, prefixes (directories) and a token for the next set of results. Individual result sets may be limited to 1,000 objects based on the underlying object storage’s limitations.
ObjectMeta
The metadata that describes an object.
RetryConfig
Contains the configuration for how to respond to server errors

Enums

Error
A specialized Error for object store-related errors
GetResult
Result for a get request

Traits

ObjectStore
Universal API to multiple object store services.

Type Definitions

DynObjectStore
An alias for a dynamically dispatched object store implementation.
MultipartId
Id type for multi-part uploads.
Result
A specialized Result for object store-related errors