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download a stream of bytes, not single byte #123

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93 changes: 61 additions & 32 deletions src/client/object.rs
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
use futures_util::{stream, Stream, TryStream};
use reqwest::StatusCode;
use futures_util::{stream, Stream, StreamExt, TryStream, TryStreamExt};
use reqwest::{Response, StatusCode};

use crate::{
error::GoogleResponse,
Expand Down Expand Up @@ -262,20 +262,7 @@ impl<'a> ObjectClient<'a> {
}
}

/// Download the content of the object with the specified name in the specified bucket.
/// ### Example
/// ```no_run
/// # #[tokio::main]
/// # async fn main() -> Result<(), Box<dyn std::error::Error>> {
/// use cloud_storage::Client;
/// use cloud_storage::Object;
///
/// let client = Client::default();
/// let bytes = client.object().download("my_bucket", "path/to/my/file.png").await?;
/// # Ok(())
/// # }
/// ```
pub async fn download(&self, bucket: &str, file_name: &str) -> crate::Result<Vec<u8>> {
async fn download_response(&self, bucket: &str, file_name: &str) -> crate::Result<Response> {
let url = format!(
"{}/b/{}/o/{}?alt=media",
crate::BASE_URL,
Expand All @@ -289,13 +276,68 @@ impl<'a> ObjectClient<'a> {
.headers(self.0.get_headers().await?)
.send()
.await?;

if resp.status() == StatusCode::NOT_FOUND {
Err(crate::Error::Other(resp.text().await?))
} else {
Ok(resp.error_for_status()?.bytes().await?.to_vec())
Ok(resp.error_for_status()?)
}

@kosta kosta Oct 7, 2022

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I created a non-pub helper function download_response to unify the common download code paths. I also noticed checking for StatusCode::NOT_FOUND was only done for download, not download_streamed. I think it makes more sense to have that unified here, but it might be a breaking change?

Up for you to decide, I'm happy to move that error handling around.

Usability note: Often the google error responses include helpful content that is being discarded here. I think on http status errors, we should actually try to convert it into an Error::Google(GoogleErrorResponse). Maybe in a separate MR?

}

/// Download the content of the object with the specified name in the specified bucket.
/// ### Example
/// ```no_run
/// # #[tokio::main]
/// # async fn main() -> Result<(), Box<dyn std::error::Error>> {
/// use cloud_storage::Client;
/// use cloud_storage::Object;
///
/// let client = Client::default();
/// let bytes = client.object().download("my_bucket", "path/to/my/file.png").await?;
/// # Ok(())
/// # }
/// ```
pub async fn download(&self, bucket: &str, file_name: &str) -> crate::Result<Vec<u8>> {
Ok(self
.download_response(bucket, file_name)
.await?
.bytes()
.await?
.into())
}

@kosta kosta Oct 7, 2022

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The actual methods are now very straightfoward


/// Download the content of the object with the specified name in the specified bucket, without
/// allocating the whole file into a vector.
/// ### Example
/// ```no_run
/// # #[tokio::main]
/// # async fn main() -> Result<(), Box<dyn std::error::Error>> {
/// use cloud_storage::Client;
/// use cloud_storage::Object;
/// use futures_util::stream::StreamExt;
/// use tokio::fs::File;
/// use tokio::io::{AsyncWriteExt, BufWriter};
///
/// let client = Client::default();
/// let mut stream = client.object().download_bytes_stream("my_bucket", "path/to/my/file.png").await?;
/// let mut file = BufWriter::new(File::create("file.png").await?);
/// while let Some(bytes) = stream.next().await {
/// file.write_all(&bytes?).await?;
/// }
/// file.flush().await?;
/// # Ok(())
/// # }
/// ```
pub async fn download_bytes_stream(
&self,
bucket: &str,
file_name: &str,
) -> crate::Result<impl Stream<Item = crate::Result<crate::Bytes>> + Unpin> {
let response = self.download_response(bucket, file_name).await?;
let bytes = response.bytes_stream().map_err(crate::Error::from);
Ok(bytes)
}

/// Download the content of the object with the specified name in the specified bucket, without
/// allocating the whole file into a vector.
/// ### Example
Expand All @@ -318,26 +360,13 @@ impl<'a> ObjectClient<'a> {
/// # Ok(())
/// # }
/// ```
#[deprecated = "Streaming u8 is inefficient, use download_bytes_stream instead"]
pub async fn download_streamed(
&self,
bucket: &str,
file_name: &str,
) -> crate::Result<impl Stream<Item = crate::Result<u8>> + Unpin> {
use futures_util::{StreamExt, TryStreamExt};
let url = format!(
"{}/b/{}/o/{}?alt=media",
crate::BASE_URL,
percent_encode(bucket),
percent_encode(file_name),
);
let response = self
.0
.client
.get(&url)
.headers(self.0.get_headers().await?)
.send()
.await?
.error_for_status()?;
let response = self.download_response(bucket, file_name).await?;
let size = response.content_length();
let bytes = response
.bytes_stream()
Expand Down
3 changes: 3 additions & 0 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -98,6 +98,9 @@ mod error;
mod resources;
mod token;

/// re-exported type that appears in public api
pub use bytes::Bytes;

use crate::resources::service_account::ServiceAccount;
pub use crate::{
client::Client,
Expand Down
32 changes: 32 additions & 0 deletions src/resources/object.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -449,16 +449,48 @@ impl Object {
/// # }
/// ```
#[cfg(feature = "global-client")]
#[deprecated = "Streaming u8 is inefficient, use download_bytes_stream instead"]
pub async fn download_streamed(
bucket: &str,
file_name: &str,
) -> crate::Result<impl Stream<Item = crate::Result<u8>> + Unpin> {
#[allow(deprecated)] // this calling function is deprecated as well
crate::CLOUD_CLIENT
.object()
.download_streamed(bucket, file_name)
.await
}

/// Download the content of the object with the specified name in the specified bucket, without
/// allocating the whole file into a vector.
/// ### Example
/// ```no_run
/// # #[tokio::main]
/// # async fn main() -> Result<(), Box<dyn std::error::Error>> {
/// use cloud_storage::Object;
/// use futures_util::stream::StreamExt;
/// use std::fs::File;
/// use std::io::{BufWriter, Write};
///
/// let mut stream = Object::download_bytes_stream("my_bucket", "path/to/my/file.png").await?;
/// let mut file = BufWriter::new(File::create("file.png")?);
/// while let Some(bytes) = stream.next().await {
/// file.write_all(&bytes?)?;
/// }
/// # Ok(())
/// # }
/// ```
#[cfg(feature = "global-client")]
pub async fn download_bytes_stream(
bucket: &str,
file_name: &str,
) -> crate::Result<impl Stream<Item = crate::Result<crate::Bytes>> + Unpin> {
crate::CLOUD_CLIENT
.object()
.download_bytes_stream(bucket, file_name)
.await
}

/// Obtains a single object with the specified name in the specified bucket.
/// ### Example
/// ```no_run
Expand Down