Revert "Cache downloaded wheel when range requests aren't supported" (#6470)

## Summary

This reverts commit 7d92915f3d.

I thought this would be a net performance improvement, but we've now had
multiple reports that this made locking _extremely_ slow. I also tested
this today with a very large codebase against a registry that does not
support range requests, and the number of downloads was sort of wild to
watch. Reverting the reduced resolution time by over 50%.

Closes #6104.

crates/install-wheel-rs/src/metadata.rs

@@ -72,6 +72,43 @@ pub fn find_archive_dist_info<'a, T: Copy>(
     Ok((payload, dist_info_prefix))
 }
 
+/// Returns `true` if the file is a `METADATA` file in a `.dist-info` directory that matches the
+/// wheel filename.
+pub fn is_metadata_entry(path: &str, filename: &WheelFilename) -> Result<bool, Error> {
+    let Some((dist_info_dir, file)) = path.split_once('/') else {
+        return Ok(false);
+    };
+    if file != "METADATA" {
+        return Ok(false);
+    }
+    let Some(dist_info_prefix) = dist_info_dir.strip_suffix(".dist-info") else {
+        return Ok(false);
+    };
+
+    // Like `pip`, validate that the `.dist-info` directory is prefixed with the canonical
+    // package name, but only warn if the version is not the normalized version.
+    let Some((name, version)) = dist_info_prefix.rsplit_once('-') else {
+        return Err(Error::MissingDistInfoSegments(dist_info_prefix.to_string()));
+    };
+    if PackageName::from_str(name)? != filename.name {
+        return Err(Error::MissingDistInfoPackageName(
+            dist_info_prefix.to_string(),
+            filename.name.to_string(),
+        ));
+    }
+    if !Version::from_str(version).is_ok_and(|version| version == filename.version) {
+        warn!(
+            "{}",
+            Error::MissingDistInfoVersion(
+                dist_info_prefix.to_string(),
+                filename.version.to_string(),
+            )
+        );
+    }
+
+    Ok(true)
+}
+
 /// Given an archive, read the `METADATA` from the `.dist-info` directory.
 pub fn read_archive_metadata(
     filename: &WheelFilename,

crates/uv-client/src/error.rs

@@ -173,6 +173,10 @@ pub enum ErrorKind {
         #[source] Box<pypi_types::MetadataError>,
     ),
 
+    /// The metadata file was not found in the wheel.
+    #[error("Metadata file `{0}` was not found in {1}")]
+    MetadataNotFound(WheelFilename, String),
+
     /// An error that happened while making a request or in a reqwest middleware.
     #[error(transparent)]
     WrappedReqwestError(#[from] WrappedReqwestError),

crates/uv-client/src/registry_client.rs

@@ -4,17 +4,18 @@ use std::path::PathBuf;
 use std::str::FromStr;
 
 use async_http_range_reader::AsyncHttpRangeReader;
-use futures::FutureExt;
+use futures::{FutureExt, TryStreamExt};
 use http::HeaderMap;
 use reqwest::{Client, Response, StatusCode};
 use serde::{Deserialize, Serialize};
-use tokio_util::compat::TokioAsyncReadCompatExt;
+use tokio::io::AsyncReadExt;
+use tokio_util::compat::{FuturesAsyncReadCompatExt, TokioAsyncReadCompatExt};
 use tracing::{info_span, instrument, trace, warn, Instrument};
 use url::Url;
 
 use distribution_filename::{DistFilename, SourceDistFilename, WheelFilename};
 use distribution_types::{BuiltDist, File, FileLocation, IndexUrl, IndexUrls, Name};
-use install_wheel_rs::metadata::find_archive_dist_info;
+use install_wheel_rs::metadata::{find_archive_dist_info, is_metadata_entry};
 use pep440_rs::Version;
 use pep508_rs::MarkerEnvironment;
 use platform_tags::Platform;
@@ -593,7 +594,8 @@ impl RegistryClient {
             .instrument(info_span!("read_metadata_range_request", wheel = %filename))
         };
 
-        self.cached_client()
+        let result = self
+            .cached_client()
             .get_serde(
                 req,
                 &cache_entry,
@@ -601,8 +603,67 @@ impl RegistryClient {
                 read_metadata_range_request,
             )
             .await
+            .map_err(crate::Error::from);
+
+        match result {
+            Ok(metadata) => return Ok(metadata),
+            Err(err) => {
+                if err.is_http_range_requests_unsupported() {
+                    // The range request version failed. Fall back to streaming the file to search
+                    // for the METADATA file.
+                    warn!("Range requests not supported for {filename}; streaming wheel");
+                } else {
+                    return Err(err);
+                }
+            }
+        };
+
+        // Create a request to stream the file.
+        let req = self
+            .uncached_client()
+            .get(url.clone())
+            .header(
+                // `reqwest` defaults to accepting compressed responses.
+                // Specify identity encoding to get consistent .whl downloading
+                // behavior from servers. ref: https://github.com/pypa/pip/pull/1688
+                "accept-encoding",
+                reqwest::header::HeaderValue::from_static("identity"),
+            )
+            .build()
+            .map_err(ErrorKind::from)?;
+
+        // Stream the file, searching for the METADATA.
+        let read_metadata_stream = |response: Response| {
+            async {
+                let reader = response
+                    .bytes_stream()
+                    .map_err(|err| self.handle_response_errors(err))
+                    .into_async_read();
+
+                read_metadata_async_stream(filename, url.to_string(), reader).await
+            }
+            .instrument(info_span!("read_metadata_stream", wheel = %filename))
+        };
+
+        self.cached_client()
+            .get_serde(req, &cache_entry, cache_control, read_metadata_stream)
+            .await
             .map_err(crate::Error::from)
     }
+
+    /// Handle a specific `reqwest` error, and convert it to [`io::Error`].
+    fn handle_response_errors(&self, err: reqwest::Error) -> std::io::Error {
+        if err.is_timeout() {
+            std::io::Error::new(
+                std::io::ErrorKind::TimedOut,
+                format!(
+                    "Failed to download distribution due to network timeout. Try increasing UV_HTTP_TIMEOUT (current value: {}s).", self.timeout()
+                ),
+            )
+        } else {
+            std::io::Error::new(std::io::ErrorKind::Other, err)
+        }
+    }
 }
 
 /// Read a wheel's `METADATA` file from a zip file.
@@ -643,6 +704,50 @@ async fn read_metadata_async_seek(
     Ok(metadata)
 }
 
+/// Like [`read_metadata_async_seek`], but doesn't use seek.
+async fn read_metadata_async_stream<R: futures::AsyncRead + Unpin>(
+    filename: &WheelFilename,
+    debug_source: String,
+    reader: R,
+) -> Result<Metadata23, Error> {
+    let reader = futures::io::BufReader::with_capacity(128 * 1024, reader);
+    let mut zip = async_zip::base::read::stream::ZipFileReader::new(reader);
+
+    while let Some(mut entry) = zip
+        .next_with_entry()
+        .await
+        .map_err(|err| ErrorKind::Zip(filename.clone(), err))?
+    {
+        // Find the `METADATA` entry.
+        let path = entry
+            .reader()
+            .entry()
+            .filename()
+            .as_str()
+            .map_err(|err| ErrorKind::Zip(filename.clone(), err))?;
+
+        if is_metadata_entry(path, filename).map_err(ErrorKind::DistInfo)? {
+            let mut reader = entry.reader_mut().compat();
+            let mut contents = Vec::new();
+            reader.read_to_end(&mut contents).await.unwrap();
+
+            let metadata = Metadata23::parse_metadata(&contents).map_err(|err| {
+                ErrorKind::MetadataParseError(filename.clone(), debug_source, Box::new(err))
+            })?;
+            return Ok(metadata);
+        }
+
+        // Close current file to get access to the next one. See docs:
+        // https://docs.rs/async_zip/0.0.16/async_zip/base/read/stream/
+        zip = entry
+            .skip()
+            .await
+            .map_err(|err| ErrorKind::Zip(filename.clone(), err))?;
+    }
+
+    Err(ErrorKind::MetadataNotFound(filename.clone(), debug_source).into())
+}
+
 #[derive(
     Default, Debug, Serialize, Deserialize, rkyv::Archive, rkyv::Deserialize, rkyv::Serialize,
 )]

crates/uv-distribution/src/distribution_database.rs

@@ -198,31 +198,6 @@ impl<'a, Context: BuildContext> DistributionDatabase<'a, Context> {
                         hashes: archive.hashes,
                         filename: wheel.filename.clone(),
                     }),
-                    Err(Error::Client(err)) if err.is_http_streaming_unsupported() => {
-                        warn!(
-                            "Streaming unsupported for {dist}; downloading wheel to disk ({err})"
-                        );
-
-                        // If the request failed because streaming is unsupported, download the
-                        // wheel directly.
-                        let archive = self
-                            .download_wheel(
-                                url,
-                                &wheel.filename,
-                                wheel.file.size,
-                                &wheel_entry,
-                                dist,
-                                hashes,
-                            )
-                            .await?;
-
-                        Ok(LocalWheel {
-                            dist: Dist::Built(dist.clone()),
-                            archive: self.build_context.cache().archive(&archive.id),
-                            hashes: archive.hashes,
-                            filename: wheel.filename.clone(),
-                        })
-                    }
                     Err(Error::Extract(err)) => {
                         if err.is_http_streaming_unsupported() {
                             warn!(
@@ -308,36 +283,6 @@ impl<'a, Context: BuildContext> DistributionDatabase<'a, Context> {
                             filename: wheel.filename.clone(),
                         })
                     }
-                    Err(Error::Extract(err)) => {
-                        if err.is_http_streaming_unsupported() {
-                            warn!(
-                                "Streaming unsupported for {dist}; downloading wheel to disk ({err})"
-                            );
-                        } else if err.is_http_streaming_failed() {
-                            warn!("Streaming failed for {dist}; downloading wheel to disk ({err})");
-                        } else {
-                            return Err(Error::Extract(err));
-                        }
-
-                        // If the request failed because streaming is unsupported, download the
-                        // wheel directly.
-                        let archive = self
-                            .download_wheel(
-                                wheel.url.raw().clone(),
-                                &wheel.filename,
-                                None,
-                                &wheel_entry,
-                                dist,
-                                hashes,
-                            )
-                            .await?;
-                        Ok(LocalWheel {
-                            dist: Dist::Built(dist.clone()),
-                            archive: self.build_context.cache().archive(&archive.id),
-                            hashes: archive.hashes,
-                            filename: wheel.filename.clone(),
-                        })
-                    }
                     Err(err) => Err(err),
                 }
             }
@@ -443,11 +388,11 @@ impl<'a, Context: BuildContext> DistributionDatabase<'a, Context> {
 
         match result {
             Ok(metadata) => Ok(ArchiveMetadata::from_metadata23(metadata)),
-            Err(err) if err.is_http_range_requests_unsupported() => {
+            Err(err) if err.is_http_streaming_unsupported() => {
-                warn!("Range requests unsupported when fetching metadata for {dist}; downloading wheel directly ({err})");
+                warn!("Streaming unsupported when fetching metadata for {dist}; downloading wheel directly ({err})");
 
-                // If the request failed due to an error that could be resolved by downloading the
+                // If the request failed due to an error that could be resolved by
-                // wheel directly, try that.
+                // downloading the wheel directly, try that.
                 let wheel = self.get_wheel(dist, hashes).await?;
                 let metadata = wheel.metadata()?;
                 let hashes = wheel.hashes;

crates/uv/tests/pip_sync.rs

@@ -3340,6 +3340,7 @@ fn no_stream() -> Result<()> {
 
     ----- stderr -----
     Resolved 1 package in [TIME]
+    Prepared 1 package in [TIME]
     Installed 1 package in [TIME]
      + hashb-foxglove-protocolbuffers-python==25.3.0.1.20240226043130+465630478360
     "###