commit 85af9c856105d01e3de01a9fb767a916b7eb8d5b
author Michael Brown <mcb30@ipxe.org> Thu Jun 17 15:29:22 2021 +0100
committer Michael Brown <mcb30@ipxe.org> Thu Jun 17 15:29:22 2021 +0100
tree de652eaba02e346fb311573a209fdbb7993152d4
parent 51c88a4a62116d77a854b55100c6955d6f1eb6dc

[peerdist] Assume that most recently discovered peer can be reused

The peer discovery time has a significant impact on the overall
PeerDist download speed, since each block requires an individual
discovery attempt.  In most cases, a peer that responds for block N
will turn out to also respond for block N+1.

Assume that the most recently discovered peer (for any block) probably
has a copy of the next block to be discovered, thereby allowing the
peer download attempt to begin immediately.

In the case that this assumption is incorrect, the existing error
recovery path will allow for fallback to newly discovered peers (or to
the origin server).

Suggested-by: Andreas Hammarskjöld <junior@2PintSoftware.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>