## Summary This PR consolidates the concurrency limits used throughout `uv` and exposes two limits, `UV_CONCURRENT_DOWNLOADS` and `UV_CONCURRENT_BUILDS`, as environment variables. Currently, `uv` has a number of concurrent streams that it buffers using relatively arbitrary limits for backpressure. However, many of these limits are conflated. We run a relatively small number of tasks overall and should start most things as soon as possible. What we really want to limit are three separate operations: - File I/O. This is managed by tokio's blocking pool and we should not really have to worry about it. - Network I/O. - Python build processes. Because the current limits span a broad range of tasks, it's possible that a limit meant for network I/O is occupied by tasks performing builds, reading from the file system, or even waiting on a `OnceMap`. We also don't limit build processes that end up being required to perform a download. While this may not pose a performance problem because our limits are relatively high, it does mean that the limits do not do what we want, making it tricky to expose them to users (https://github.com/astral-sh/uv/issues/1205, https://github.com/astral-sh/uv/issues/3311). After this change, the limits on network I/O and build processes are centralized and managed by semaphores. All other tasks are unbuffered (note that these tasks are still bounded, so backpressure should not be a problem). |
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|---|---|---|
| .. | ||
| bench | ||
| cache-key | ||
| distribution-filename | ||
| distribution-types | ||
| install-wheel-rs | ||
| once-map | ||
| pep440-rs | ||
| pep508-rs | ||
| platform-tags | ||
| pypi-types | ||
| requirements-txt | ||
| uv | ||
| uv-auth | ||
| uv-build | ||
| uv-cache | ||
| uv-client | ||
| uv-configuration | ||
| uv-dev | ||
| uv-dispatch | ||
| uv-distribution | ||
| uv-extract | ||
| uv-fs | ||
| uv-git | ||
| uv-installer | ||
| uv-interpreter | ||
| uv-normalize | ||
| uv-requirements | ||
| uv-resolver | ||
| uv-trampoline | ||
| uv-types | ||
| uv-version | ||
| uv-virtualenv | ||
| uv-warnings | ||
| uv-workspace | ||
| README.md | ||
Crates
bench
Functionality for benchmarking uv.
cache-key
Generic functionality for caching paths, URLs, and other resources across platforms.
distribution-filename
Parse built distribution (wheel) and source distribution (sdist) filenames to extract structured metadata.
distribution-types
Abstractions for representing built distributions (wheels) and source distributions (sdists), and the sources from which they can be downloaded.
install-wheel-rs
Install built distributions (wheels) into a virtual environment.]
once-map
A waitmap-like concurrent hash map for executing tasks
exactly once.
pep440-rs
Utilities for interacting with Python version numbers and specifiers.
pep508-rs
Utilities for interacting with PEP 508 dependency specifiers.
platform-host
Functionality for detecting the current platform (operating system, architecture, etc.).
platform-tags
Functionality for parsing and inferring Python platform tags as per PEP 425.
uv
Command-line interface for the uv package manager.
uv-build
A PEP 517-compatible build frontend for uv.
uv-cache
Functionality for caching Python packages and associated metadata.
uv-client
Client for interacting with PyPI-compatible HTTP APIs.
uv-dev
Development utilities for uv.
uv-dispatch
A centralized struct for resolving and building source distributions in isolated environments.
Implements the traits defined in uv-types.
uv-distribution
Client for interacting with built distributions (wheels) and source distributions (sdists). Capable of fetching metadata, distribution contents, etc.
uv-extract
Utilities for extracting files from archives.
uv-fs
Utilities for interacting with the filesystem.
uv-git
Functionality for interacting with Git repositories.
uv-installer
Functionality for installing Python packages into a virtual environment.
uv-interpreter
Functionality for detecting and leveraging the current Python interpreter.
uv-normalize
Normalize package and extra names as per Python specifications.
uv-package
Types and functionality for working with Python packages, e.g., parsing wheel files.
uv-requirements
Utilities for reading package requirements from pyproject.toml and requirements.txt files.
uv-resolver
Functionality for resolving Python packages and their dependencies.
uv-types
Shared traits for uv, to avoid circular dependencies.
pypi-types
General-purpose type definitions for types used in PyPI-compatible APIs.
uv-virtualenv
A venv replacement to create virtual environments in Rust.
uv-warnings
User-facing warnings for uv.
requirements-txt
Functionality for parsing requirements.txt files.