diff options
Diffstat (limited to 'packages/meshbay-node/src')
| -rw-r--r-- | packages/meshbay-node/src/meshbay_node/transfers.py | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/packages/meshbay-node/src/meshbay_node/transfers.py b/packages/meshbay-node/src/meshbay_node/transfers.py index 2185547..dd382b4 100644 --- a/packages/meshbay-node/src/meshbay_node/transfers.py +++ b/packages/meshbay-node/src/meshbay_node/transfers.py @@ -417,9 +417,28 @@ class TransferSlots: # takes a slot. # # But "not leased" cannot mean "unbounded", or a client that simply omits `tr` -# transfers outside every cap and the caps are decoration. Two, because a viewer -# looks at *one* file — one photo, one document — and the second is there so -# that prefetching the next photo stays possible. +# transfers outside every cap and the caps are decoration. +# +# **The number comes from what the shipped client legitimately does, and it was +# wrong once already.** §3.4.1 of ~/next/improve-downloads.md argued for two, +# reasoning about *viewers*: a photo viewer shows one photo, a preview modal one +# document, and the second is for prefetching the next photo. That reasoning +# forgot the music player, which warms a read-ahead window — `prefetchDepth()` +# in music-player.js returns 5 on Wi-Fi, 3 otherwise — so playing an album has +# six files in flight and the fourth was refused with `transfer_required`. +# Reported the day MNP 3.0 shipped, as "I try to play a track and it tells me to +# download it instead". +# +# Twelve: six for the music read-ahead at its widest, two for a photo viewer +# and its own prefetch running at the same time in the same session, and the +# rest as headroom for the next app that reads ahead. `test_leaseless_reads.py` +# derives the floor from music-player.js itself, so raising the client's +# prefetch without raising this fails rather than reaching a person. +# +# Generosity is cheap here and refusal is not. This is a fairness control among +# cooperating clients, not a security boundary — a client that lies gets twelve +# files at a time instead of its member cap, which is bounded and audited — +# whereas refusing a legitimate read breaks a stated requirement. # # Deliberately a count of files and not a byte budget: a RAW photo out of a # camera is 60-80 MB and is browsing, a 40 MB archive is a download, and no @@ -431,7 +450,7 @@ class TransferSlots: # as the cap itself. **This is a fairness control among cooperating clients**, # not a defence against a member determined to saturate a node's disk. The # answer to that member is `member revoke`. -MAX_LEASELESS_IN_FLIGHT = 2 +MAX_LEASELESS_IN_FLIGHT = 12 # A leaseless read has no "close" message, so it ends when the last chunk goes # out — or, when a viewer is closed mid-file and simply stops asking, when it |