[sales] Add callback for clearing storage when no longer needed

codex/node.nim

@@ -312,10 +312,15 @@ proc start*(node: CodexNodeRef) {.async.} =
     await node.discovery.start()
 
   if contracts =? node.contracts:
-    contracts.sales.store = proc(cid: string) {.async.} =
+    contracts.sales.store = proc(cid: string, _: Availability) {.async.} =
+      # store data in local storage
       (await node.store(Cid.init(cid).tryGet())).tryGet()
+    contracts.sales.onClear = proc(availability: Availability, request: StorageRequest) =
+      # TODO: remove data from local storage
+      discard
     contracts.sales.prove = proc(cid: string): Future[seq[byte]] {.async.} =
-      return @[42'u8] # TODO: generate actual proof
+      # TODO: generate proof
+      return @[42'u8]
     await contracts.start()
 
   node.networkId = node.switch.peerInfo.peerId

codex/sales.nim

@@ -17,6 +17,7 @@ type
     available*: seq[Availability]
     store: ?Store
     prove: ?Prove
+    onClear: ?OnClear
     onSale: ?OnSale
   Availability* = object
     id*: array[32, byte]
@@ -33,8 +34,9 @@ type
     running: ?Future[void]
     waiting: ?Future[void]
     finished: bool
-  Store = proc(cid: string): Future[void] {.gcsafe, upraises: [].}
+  Store = proc(cid: string, availability: Availability): Future[void] {.gcsafe, upraises: [].}
   Prove = proc(cid: string): Future[seq[byte]] {.gcsafe, upraises: [].}
+  OnClear = proc(availability: Availability, request: StorageRequest) {.gcsafe, upraises: [].}
   OnSale = proc(availability: Availability, request: StorageRequest) {.gcsafe, upraises: [].}
 
 func new*(_: type Sales, market: Market, clock: Clock): Sales =
@@ -57,6 +59,9 @@ proc `store=`*(sales: Sales, store: Store) =
 proc `prove=`*(sales: Sales, prove: Prove) =
   sales.prove = some prove
 
+proc `onClear=`*(sales: Sales, onClear: OnClear) =
+  sales.onClear = some onClear
+
 proc `onSale=`*(sales: Sales, callback: OnSale) =
   sales.onSale = some callback
 
@@ -88,10 +93,12 @@ proc finish(agent: SalesAgent, success: bool) =
   if waiting =? agent.waiting:
     waiting.cancel()
 
-  if success and request =? agent.request:
-    if onSale =? agent.sales.onSale:
+  if success:
+    if onSale =? agent.sales.onSale and request =? agent.request:
       onSale(agent.availability, request)
   else:
+    if onClear =? agent.sales.onClear and request =? agent.request:
+      onClear(agent.availability, request)
     agent.sales.add(agent.availability)
 
 proc onFulfill(agent: SalesAgent, requestId: array[32, byte]) {.async.} =
@@ -139,7 +146,7 @@ proc start(agent: SalesAgent) {.async.} =
 
     agent.waiting = some agent.waitForExpiry()
 
-    await store(request.content.cid)
+    await store(request.content.cid, availability)
     let proof = await prove(request.content.cid)
     await market.fulfillRequest(request.id, proof)
   except CancelledError:

tests/codex/testsales.nim

@@ -32,8 +32,10 @@ suite "Sales":
     market = MockMarket.new()
     clock = MockClock.new()
     sales = Sales.new(market, clock)
-    sales.store = proc(_: string) {.async.} = discard
-    sales.prove = proc(_: string): Future[seq[byte]] {.async.} = return proof
+    sales.store = proc(cid: string, availability: Availability) {.async.} =
+      discard
+    sales.prove = proc(cid: string): Future[seq[byte]] {.async.} =
+      return proof
     await sales.start()
     request.expiry = (clock.now() + 42).u256
 
@@ -76,14 +78,18 @@ suite "Sales":
 
   test "retrieves and stores data locally":
     var storingCid: string
-    sales.store = proc(cid: string) {.async.} = storingCid = cid
+    var storingAvailability: Availability
+    sales.store = proc(cid: string, availability: Availability) {.async.} =
+      storingCid = cid
+      storingAvailability = availability
     sales.add(availability)
     discard await market.requestStorage(request)
     check storingCid == request.content.cid
 
   test "makes storage available again when data retrieval fails":
     let error = newException(IOError, "data retrieval failed")
-    sales.store = proc(cid: string) {.async.} = raise error
+    sales.store = proc(cid: string, availability: Availability) {.async.} =
+      raise error
     sales.add(availability)
     discard await market.requestStorage(request)
     check sales.available == @[availability]
@@ -114,16 +120,31 @@ suite "Sales":
     check soldAvailability == availability
     check soldRequest == request
 
+  test "calls onClear when storage becomes available again":
+    sales.prove = proc(cid: string): Future[seq[byte]] {.async.} =
+      raise newException(IOError, "proof failed")
+    var clearedAvailability: Availability
+    var clearedRequest: StorageRequest
+    sales.onClear = proc(availability: Availability, request: StorageRequest) =
+      clearedAvailability = availability
+      clearedRequest = request
+    sales.add(availability)
+    discard await market.requestStorage(request)
+    check clearedAvailability == availability
+    check clearedRequest == request
+
   test "makes storage available again when other host fulfills request":
     let otherHost = Address.example
-    sales.store = proc(_: string) {.async.} = await sleepAsync(1.hours)
+    sales.store = proc(cid: string, availability: Availability) {.async.} =
+      await sleepAsync(1.hours)
     sales.add(availability)
     discard await market.requestStorage(request)
     market.fulfillRequest(request.id, proof, otherHost)
     check sales.available == @[availability]
 
   test "makes storage available again when request expires":
-    sales.store = proc(_: string) {.async.} = await sleepAsync(1.hours)
+    sales.store = proc(cid: string, availability: Availability) {.async.} =
+      await sleepAsync(1.hours)
     sales.add(availability)
     discard await market.requestStorage(request)
     clock.set(request.expiry.truncate(int64))