Enable HTTP/2, connection reuse, and improve download parallelism#371
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aruiz wants to merge 3 commits intorpm-software-management:masterfrom
Open
Enable HTTP/2, connection reuse, and improve download parallelism#371aruiz wants to merge 3 commits intorpm-software-management:masterfrom
aruiz wants to merge 3 commits intorpm-software-management:masterfrom
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added 3 commits
March 30, 2026 02:28
Set CURLOPT_HTTP_VERSION to CURL_HTTP_VERSION_2TLS in the default curl easy handle factory so all transfers attempt HTTP/2 over TLS with transparent fallback to HTTP/1.1. This eliminates redundant TLS handshakes when downloading multiple files from the same mirror via HTTP/2 multiplexing. Also expose the setting as a new LRO_HTTPVERSION handle option (with LRI_HTTPVERSION getinfo) so consumers can override per-handle if needed. A new LrHttpVersionType enum provides the valid values. Assisted-by: Claude
Each LrHandle now maintains a CURLSH share handle that pools DNS cache and TCP+TLS connections across all curl easy handles spawned from it. This allows connections to survive across sequential lr_download() calls, avoiding redundant DNS lookups and TLS handshakes when the same handle is used for multiple download passes (e.g. dnf5's sync-check then full-download pattern). A GMutex protects the shared state since curl_share can be accessed concurrently by multiple easy handles within a curl_multi session. Assisted-by: Claude
Raise LRO_MAXPARALLELDOWNLOADS_DEFAULT from 3 to 5 to better utilize HTTP/2 multiplexing and modern server capacity. Fix the parallelism calculation in lr_download() to scan all target handles and use the maximum maxparalleldownloads value, rather than only considering the first target's handle. This prevents a single handle with a conservative setting from bottlenecking a mixed batch of downloads from multiple handles. Assisted-by: Claude
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Summary
CURL_HTTP_VERSION_2TLS) with transparent fallback to HTTP/1.1. ExposeLRO_HTTPVERSIONoption as an escape hatch.CURLSHshare handle perLrHandleto pool DNS cache and TCP+TLS connections across sequentiallr_download()calls, avoiding redundant handshakes.lr_download()to use the maximum parallelism across all target handles rather than just the first one.Results
Benchmarked with
dnf5 --setopt=build_cache=0 --refresh makecacheagainst 9 enabled repos (Fedora 41, RPM Fusion, Chrome, VS Code, etc.):No changes required in dnf5 — all improvements take effect transparently.
Disclosure
This changeset was developed with assistance from Claude (Anthropic). Each commit is tagged
Assisted-by: Claude.