Implement offer cache.

fluffy/conf.nim

@@ -316,14 +316,30 @@ type
         "Size of the in memory local content cache. This is the max number " &
         "of content values that can be stored in the cache.",
       defaultValue: defaultPortalProtocolConfig.contentCacheSize,
-      name: "content-cache-size"
+      name: "debug-content-cache-size"
     .}: int
 
     disableContentCache* {.
       hidden,
       desc: "Disable the in memory local content cache",
       defaultValue: defaultPortalProtocolConfig.disableContentCache,
-      name: "disable-content-cache"
+      name: "debug-disable-content-cache"
+    .}: bool
+
+    offerCacheSize* {.
+      hidden,
+      desc:
+        "Size of the in memory local offer cache. This is the max number " &
+        "of content values that can be stored in the cache.",
+      defaultValue: defaultPortalProtocolConfig.offerCacheSize,
+      name: "debug-offer-cache-size"
+    .}: int
+
+    disableOfferCache* {.
+      hidden,
+      desc: "Disable the in memory local offer cache",
+      defaultValue: defaultPortalProtocolConfig.disableOfferCache,
+      name: "debug-disable-offer-cache"
     .}: bool
 
     disablePoke* {.

fluffy/fluffy.nim

@@ -183,7 +183,7 @@ proc run(
     portalProtocolConfig = PortalProtocolConfig.init(
       config.tableIpLimit, config.bucketIpLimit, config.bitsPerHop, config.radiusConfig,
       config.disablePoke, config.maxGossipNodes, config.contentCacheSize,
-      config.disableContentCache,
+      config.disableContentCache, config.offerCacheSize, config.disableOfferCache,
     )
 
     portalNodeConfig = PortalNodeConfig(

fluffy/network/beacon/beacon_network.nim

@@ -354,7 +354,9 @@ proc validateContent(
         return false
 
       let contentId = contentIdOpt.get()
-      n.portalProtocol.storeContent(contentKey, contentId, contentItem)
+      n.portalProtocol.storeContent(
+        contentKey, contentId, contentItem, cacheOffer = true
+      )
 
       debug "Received offered content validated successfully", contentKey
     else:

fluffy/network/history/history_network.nim

@@ -704,7 +704,9 @@ proc validateContent(
         error "Received offered content with invalid content key", contentKey
         return false
 
-      n.portalProtocol.storeContent(contentKey, contentId, contentItem)
+      n.portalProtocol.storeContent(
+        contentKey, contentId, contentItem, cacheOffer = true
+      )
 
       debug "Received offered content validated successfully", contentKey
     else:

fluffy/network/state/state_network.nim

@@ -182,7 +182,10 @@ proc processOffer*(
     return err("Received offered content with invalid content key")
 
   n.portalProtocol.storeContent(
-    contentKeyBytes, contentId, contentValue.toRetrievalValue().encode()
+    contentKeyBytes,
+    contentId,
+    contentValue.toRetrievalValue().encode(),
+    cacheOffer = true,
   )
 
   await gossipOffer(

fluffy/network/wire/portal_protocol.nim

@@ -75,10 +75,16 @@ declareCounter portal_gossip_without_lookup,
   "Portal wire protocol neighborhood gossip that did not require a node lookup",
   labels = ["protocol_id"]
 declareCounter portal_content_cache_hits,
-  "Portal wire protocol local content lookups that hit the cache",
+  "Portal wire protocol local content lookups that hit the content cache",
   labels = ["protocol_id"]
 declareCounter portal_content_cache_misses,
-  "Portal wire protocol local content lookups that don't hit the cache",
+  "Portal wire protocol local content lookups that don't hit the content cache",
+  labels = ["protocol_id"]
+declareCounter portal_offer_cache_hits,
+  "Portal wire protocol local content lookups that hit the offer cache",
+  labels = ["protocol_id"]
+declareCounter portal_offer_cache_misses,
+  "Portal wire protocol local content lookups that don't hit the offer cache",
   labels = ["protocol_id"]
 
 declareCounter portal_poke_offers,
@@ -161,8 +167,16 @@ type
 
   RadiusCache* = LRUCache[NodeId, UInt256]
 
+  # Caches content fetched from the network during lookups.
+  # Content outside our radius is also cached in order to improve performance
+  # of queries when we frequently lookup data outside our radius.
   ContentCache = LRUCache[ContentId, seq[byte]]
 
+  # Caches the most recently received content/offers.
+  # Content is only stored in this cache if it is within our radius and similarly
+  # the cache is only checked if the content id is within our radius.
+  OfferCache = LRUCache[ContentId, seq[byte]]
+
   ContentKV* = object
     contentKey*: ContentKeyByteList
     content*: seq[byte]
@@ -197,6 +211,7 @@ type
     radiusCache: RadiusCache
     offerQueue: AsyncQueue[OfferRequest]
     offerWorkers: seq[Future[void]]
+    offerCache: OfferCache
     pingTimings: Table[NodeId, chronos.Moment]
     config*: PortalProtocolConfig
 
@@ -401,6 +416,55 @@ proc handleFindNodes(p: PortalProtocol, fn: FindNodesMessage): seq[byte] =
       let enrs = List[ByteList[2048], 32](@[])
       encodeMessage(NodesMessage(total: 1, enrs: enrs))
 
+proc storeContent*(
+    p: PortalProtocol,
+    contentKey: ContentKeyByteList,
+    contentId: ContentId,
+    content: seq[byte],
+    cacheContent = false,
+    cacheOffer = false,
+): bool {.discardable.} =
+  if cacheContent and not p.config.disableContentCache:
+    # We cache content regardless of whether it is in our radius or not
+    p.contentCache.put(contentId, content)
+
+  # Always re-check that the key is still in the node range to make sure only
+  # content in range is stored.
+  if p.inRange(contentId):
+    p.dbPut(contentKey, contentId, content)
+
+    if cacheOffer and not p.config.disableOfferCache:
+      p.offerCache.put(contentId, content)
+
+    true
+  else:
+    false
+
+proc getLocalContent*(
+    p: PortalProtocol, contentKey: ContentKeyByteList, contentId: ContentId
+): Opt[seq[byte]] =
+  # The cache can contain content that is not in our radius
+  let maybeContent = p.contentCache.get(contentId)
+  if maybeContent.isSome():
+    portal_content_cache_hits.inc(labelValues = [$p.protocolId])
+    return maybeContent
+
+  portal_content_cache_misses.inc(labelValues = [$p.protocolId])
+
+  # Check first if content is in range, as this is a cheaper operation
+  # than the database lookup.
+  if p.inRange(contentId):
+    let maybeContent = p.offerCache.get(contentId)
+    if maybeContent.isSome():
+      portal_offer_cache_hits.inc(labelValues = [$p.protocolId])
+      return maybeContent
+
+    portal_offer_cache_misses.inc(labelValues = [$p.protocolId])
+
+    p.dbGet(contentKey, contentId)
+  else:
+    Opt.none(seq[byte])
+
 proc handleFindContent(
     p: PortalProtocol, fc: FindContentMessage, srcId: NodeId
 ): seq[byte] =
@@ -421,24 +485,21 @@ proc handleFindContent(
   )
 
   # Check first if content is in range, as this is a cheaper operation
-  if p.inRange(contentId):
-    let contentResult = p.dbGet(fc.contentKey, contentId)
-    if contentResult.isOk():
-      let content = contentResult.get()
-      if content.len <= maxPayloadSize:
-        return encodeMessage(
-          ContentMessage(
-            contentMessageType: contentType, content: ByteList[2048](content)
-          )
+  let contentResult = p.getLocalContent(fc.contentKey, contentId)
+  if contentResult.isOk():
+    let content = contentResult.get()
+    if content.len <= maxPayloadSize:
+      return encodeMessage(
+        ContentMessage(
+          contentMessageType: contentType, content: ByteList[2048](content)
         )
-      else:
-        let connectionId = p.stream.addContentRequest(srcId, content)
+      )
+    else:
+      let connectionId = p.stream.addContentRequest(srcId, content)
 
-        return encodeMessage(
-          ContentMessage(
-            contentMessageType: connectionIdType, connectionId: connectionId
-          )
-        )
+      return encodeMessage(
+        ContentMessage(contentMessageType: connectionIdType, connectionId: connectionId)
+      )
 
   # Node does not have the content, or content is not even in radius,
   # send closest neighbours to the requested content id.
@@ -479,7 +540,10 @@ proc handleOffer(p: PortalProtocol, o: OfferMessage, srcId: NodeId): seq[byte] =
       )
 
       if p.inRange(contentId):
-        if not p.dbContains(contentKey, contentId):
+        # Checking the offer cache first to reduce the load on the database
+        # for the case when the offer already exists and it was recently accepted
+        if not p.offerCache.contains(contentId) and
+            not p.dbContains(contentKey, contentId):
           contentKeysBitList.setBit(i)
           discard contentKeys.add(contentKey)
     else:
@@ -592,6 +656,8 @@ proc new*(
     stream: stream,
     radiusCache: RadiusCache.init(256),
     offerQueue: newAsyncQueue[OfferRequest](concurrentOffers),
+    offerCache:
+      OfferCache.init(if config.disableContentCache: 0 else: config.contentCacheSize),
     pingTimings: Table[NodeId, chronos.Moment](),
     config: config,
   )
@@ -955,7 +1021,7 @@ proc offer(
           if contentIdResult.isOk():
             let
               contentId = contentIdResult.get()
-              contentResult = p.dbGet(contentKey, contentId)
+              contentResult = p.getLocalContent(contentKey, contentId)
 
             var output = memoryOutput()
             if contentResult.isOk():
@@ -1600,44 +1666,6 @@ proc randomGossipDiscardPeers*(
 ): Future[void] {.async: (raises: [CancelledError]).} =
   discard await p.randomGossip(srcNodeId, contentKeys, content)
 
-proc storeContent*(
-    p: PortalProtocol,
-    contentKey: ContentKeyByteList,
-    contentId: ContentId,
-    content: seq[byte],
-    cacheContent = false,
-): bool {.discardable.} =
-  if cacheContent and not p.config.disableContentCache:
-    # We cache content regardless of whether it is in our radius or not
-    p.contentCache.put(contentId, content)
-
-  # Always re-check that the key is still in the node range to make sure only
-  # content in range is stored.
-  if p.inRange(contentId):
-    doAssert(p.dbPut != nil)
-    p.dbPut(contentKey, contentId, content)
-    true
-  else:
-    false
-
-proc getLocalContent*(
-    p: PortalProtocol, contentKey: ContentKeyByteList, contentId: ContentId
-): Opt[seq[byte]] =
-  # The cache can contain content that is not in our radius
-  let maybeContent = p.contentCache.get(contentId)
-  if maybeContent.isSome():
-    portal_content_cache_hits.inc(labelValues = [$p.protocolId])
-    return maybeContent
-
-  portal_content_cache_misses.inc(labelValues = [$p.protocolId])
-
-  # Check first if content is in range, as this is a cheaper operation
-  # than the database lookup.
-  if p.inRange(contentId):
-    p.dbGet(contentKey, contentId)
-  else:
-    Opt.none(seq[byte])
-
 proc seedTable*(p: PortalProtocol) =
   ## Seed the table with specifically provided Portal bootstrap nodes. These are
   ## nodes that must support the wire protocol for the specific content network.

fluffy/network/wire/portal_protocol_config.nim

@@ -43,6 +43,8 @@ type
     maxGossipNodes*: int
     contentCacheSize*: int
     disableContentCache*: bool
+    offerCacheSize*: int
+    disableOfferCache*: bool
 
 const
   defaultRadiusConfig* = RadiusConfig(kind: Dynamic)
@@ -51,6 +53,8 @@ const
   defaultMaxGossipNodes* = 4
   defaultContentCacheSize* = 100
   defaultDisableContentCache* = false
+  defaultOfferCacheSize* = 100
+  defaultDisableOfferCache* = false
   revalidationTimeout* = chronos.seconds(30)
 
   defaultPortalProtocolConfig* = PortalProtocolConfig(
@@ -61,6 +65,8 @@ const
     maxGossipNodes: defaultMaxGossipNodes,
     contentCacheSize: defaultContentCacheSize,
     disableContentCache: defaultDisableContentCache,
+    offerCacheSize: defaultOfferCacheSize,
+    disableOfferCache: defaultDisableOfferCache,
   )
 
 proc init*(
@@ -73,6 +79,8 @@ proc init*(
     maxGossipNodes: int,
     contentCacheSize: int,
     disableContentCache: bool,
+    offerCacheSize: int,
+    disableOfferCache: bool,
 ): T =
   PortalProtocolConfig(
     tableIpLimits:
@@ -83,6 +91,8 @@ proc init*(
     maxGossipNodes: maxGossipNodes,
     contentCacheSize: contentCacheSize,
     disableContentCache: disableContentCache,
+    offerCacheSize: offerCacheSize,
+    disableOfferCache: disableOfferCache,
   )
 
 func fromLogRadius*(T: type UInt256, logRadius: uint16): T =