From fa05bffeac1b6b668acf30cb0972ee9a40965151 Mon Sep 17 00:00:00 2001
From: Mark Spanbroek <mark@spanbroek.net>
Date: Mon, 10 May 2021 13:47:15 +0200
Subject: [PATCH] Pay per-block price instead of per-peer price

---
 dagger/bitswap/engine.nim                    |  7 ++-----
 dagger/bitswap/engine/payments.nim           |  3 +--
 dagger/bitswap/peercontext.nim               |  5 +++++
 tests/dagger/bitswap/engine/testpayments.nim | 12 ++++++------
 tests/dagger/bitswap/testengine.nim          |  7 +++++--
 tests/dagger/examples.nim                    |  2 +-
 6 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/dagger/bitswap/engine.nim b/dagger/bitswap/engine.nim
index 05ef7ed9..615e02f3 100644
--- a/dagger/bitswap/engine.nim
+++ b/dagger/bitswap/engine.nim
@@ -194,11 +194,8 @@ proc payForBlocks(engine: BitswapEngine,
   if sendPayment.isNil:
     return
 
-  var amountOfBytes = 0
-  for blck in blocks:
-    amountOfBytes += blck.data.len
-
-  if payment =? engine.wallet.pay(peer, amountOfBytes):
+  let cids = blocks.mapIt(it.cid)
+  if payment =? engine.wallet.pay(peer, peer.price(cids)):
     sendPayment(peer.id, payment)
 
 proc blocksHandler*(
diff --git a/dagger/bitswap/engine/payments.nim b/dagger/bitswap/engine/payments.nim
index 78d3aaeb..567b8f63 100644
--- a/dagger/bitswap/engine/payments.nim
+++ b/dagger/bitswap/engine/payments.nim
@@ -30,9 +30,8 @@ func getOrOpenChannel(wallet: WalletRef, peer: BitswapPeerCtx): ?!ChannelId =
 
 func pay*(wallet: WalletRef,
           peer: BitswapPeerCtx,
-          amountOfBytes: int): ?!SignedState =
+          amount: UInt256): ?!SignedState =
   if pricing =? peer.pricing:
-    let amount = amountOfBytes.u256 * pricing.price
     let asset = Asset
     let receiver = pricing.address
     let channel = ?wallet.getOrOpenChannel(peer)
diff --git a/dagger/bitswap/peercontext.nim b/dagger/bitswap/peercontext.nim
index 52e74cb8..857c1fa3 100644
--- a/dagger/bitswap/peercontext.nim
+++ b/dagger/bitswap/peercontext.nim
@@ -46,3 +46,8 @@ func updatePresence*(context: BitswapPeerCtx, presence: Presence) =
   elif cid in context.peerHave and not presence.have:
     context.peerHave.keepItIf(it != cid)
     context.peerPrices.del(cid)
+
+func price*(context: BitswapPeerCtx, cids: seq[Cid]): UInt256 =
+  for cid in cids:
+    if price =? context.peerPrices.?[cid]:
+      result += price
diff --git a/tests/dagger/bitswap/engine/testpayments.nim b/tests/dagger/bitswap/engine/testpayments.nim
index e0e2c3cb..55427d0d 100644
--- a/tests/dagger/bitswap/engine/testpayments.nim
+++ b/tests/dagger/bitswap/engine/testpayments.nim
@@ -4,7 +4,7 @@ import ../../examples
 
 suite "engine payments":
 
-  let amountOfBytes = 42
+  let amount = 42.u256
 
   var wallet: WalletRef
   var peer: BitswapPeerCtx
@@ -14,19 +14,19 @@ suite "engine payments":
     peer = BitswapPeerCtx.example
     peer.pricing = Pricing.example.some
 
-  test "pays for received bytes":
-    let payment = !wallet.pay(peer, amountOfBytes)
+  test "pays for received blocks":
+    let payment = !wallet.pay(peer, amount)
     let pricing = !peer.pricing
     let balances = payment.state.outcome.balances(Asset)
     let destination = pricing.address.toDestination
-    check !balances[destination] == amountOfBytes.u256 * pricing.price
+    check !balances[destination] == amount
 
   test "no payment when no price is set":
     peer.pricing = Pricing.none
-    check wallet.pay(peer, amountOfBytes).isFailure
+    check wallet.pay(peer, amount).isFailure
 
   test "uses same channel for consecutive payments":
-    let payment1, payment2 = wallet.pay(peer, amountOfBytes)
+    let payment1, payment2 = wallet.pay(peer, amount)
     let channel1 = payment1.?state.?channel.?getChannelId
     let channel2 = payment2.?state.?channel.?getChannelId
     check channel1 == channel2
diff --git a/tests/dagger/bitswap/testengine.nim b/tests/dagger/bitswap/testengine.nim
index 80b7e8cd..93e701d1 100644
--- a/tests/dagger/bitswap/testengine.nim
+++ b/tests/dagger/bitswap/testengine.nim
@@ -1,4 +1,5 @@
 import std/sequtils
+import std/random
 
 import pkg/stew/byteutils
 import pkg/asynctest
@@ -153,10 +154,12 @@ suite "Bitswap engine handlers":
 
   test "sends payments for received blocks":
     let pricing = Pricing.example
-    engine.getPeerCtx(peerId).pricing = pricing.some
+    let peerContext = engine.getPeerCtx(peerId)
+    peerContext.pricing = pricing.some
+    peerContext.peerPrices = blocks.mapIt((it.cid, rand(uint16).u256)).toTable
 
     engine.request.sendPayment = proc(receiver: PeerID, payment: SignedState) =
-      let amount = blocks.mapIt(it.data.len).foldl(a+b).u256 * pricing.price
+      let amount = blocks.mapIt(peerContext.peerPrices[it.cid]).foldl(a+b)
       let balances = !payment.state.outcome.balances(Asset)
       check receiver == peerId
       check balances[pricing.address.toDestination] == amount
diff --git a/tests/dagger/examples.nim b/tests/dagger/examples.nim
index 1cdbc428..d36dcc99 100644
--- a/tests/dagger/examples.nim
+++ b/tests/dagger/examples.nim
@@ -37,7 +37,7 @@ proc example*(_: type SignedState): SignedState =
 proc example*(_: type Pricing): Pricing =
   Pricing(
     address: EthAddress.example,
-    price: uint32.example.u256
+    price: uint32.rand.u256
   )
 
 proc example*(_: type Block): Block =