put expensive metrics under a Nim define (#310)

README.md

@@ -68,6 +68,7 @@ Please read the [GETTING_STARTED.md](docs/GETTING_STARTED.md) guide.
 
 ### Tutorials and Examples
 Example code can be found in the [examples folder](/examples).
+
 #### Direct Chat Tutorial
 - [Part I](https://our.status.im/nim-libp2p-tutorial-a-peer-to-peer-chat-example-1/): Set up the main function and use multi-thread for processing IO.
 - [Part II](https://our.status.im/nim-libp2p-tutorial-a-peer-to-peer-chat-example-2/): Dial remote peer and allow customized user input commands.
@@ -148,6 +149,13 @@ Packages that exist in the original libp2p specs and are under active developmen
 
 ** Note that the current stack reflects the minimal requirements for the upcoming Eth2 implementation.
 
+### Tips and tricks
+
+- enable expensive metrics:
+
+```bash
+nim c -d:libp2p_expensive_metrics some_file.nim
+```
 
 ## Contribute
 The libp2p implementation in Nim is a work in progress. We welcome contributors to help out! Specifically, you can:
@@ -168,4 +176,5 @@ or
 
 * Apache License, Version 2.0, ([LICENSE-APACHEv2](LICENSE-APACHEv2) or http://www.apache.org/licenses/LICENSE-2.0)
 
-at your option. This file may not be copied, modified, or distributed except according to those terms.
+at your option. These files may not be copied, modified, or distributed except according to those terms.
+

libp2p/muxers/mplex/mplex.nim

@@ -23,6 +23,7 @@ export muxer
 logScope:
   topics = "mplex"
 
+when defined(libp2p_expensive_metrics):
   declareGauge(libp2p_mplex_channels, "mplex channels", labels = ["initiator", "peer"])
 
 type
@@ -76,6 +77,7 @@ proc newStreamInternal*(m: Mplex,
     "channel slot already taken!")
 
   m.getChannelList(initiator)[id] = result
+  when defined(libp2p_expensive_metrics):
     libp2p_mplex_channels.set(
       m.getChannelList(initiator).len.int64,
       labelValues = [$initiator,
@@ -89,6 +91,7 @@ proc cleanupChann(m: Mplex, chann: LPChannel) {.async, inline.} =
     m.getChannelList(chann.initiator).del(chann.id)
     trace "cleaned up channel", id = chann.id
 
+  when defined(libp2p_expensive_metrics):
     libp2p_mplex_channels.set(
       m.getChannelList(chann.initiator).len.int64,
       labelValues = [$chann.initiator,

libp2p/protocols/pubsub/floodsub.nim

@@ -140,6 +140,7 @@ method publish*(f: FloodSub,
   # start the future but do not wait yet
   let published = await f.publishHelper(f.floodsub.getOrDefault(topic), @[msg], timeout)
 
+  when defined(libp2p_expensive_metrics):
     libp2p_pubsub_messages_published.inc(labelValues = [topic])
 
   trace "published message to peers", peers = published,

libp2p/protocols/pubsub/gossipsub.nim

@@ -518,6 +518,7 @@ method publish*(g: GossipSub,
     g.mcache.put(msgId, msg)
 
   let published = await g.publishHelper(peers, @[msg], timeout)
+  when defined(libp2p_expensive_metrics):
     if published > 0:
       libp2p_pubsub_messages_published.inc(labelValues = [topic])
 

libp2p/protocols/pubsub/pubsub.nim

@@ -27,6 +27,7 @@ declareGauge(libp2p_pubsub_peers, "pubsub peer instances")
 declareGauge(libp2p_pubsub_topics, "pubsub subscribed topics")
 declareCounter(libp2p_pubsub_validation_success, "pubsub successfully validated messages")
 declareCounter(libp2p_pubsub_validation_failure, "pubsub failed validated messages")
+when defined(libp2p_expensive_metrics):
   declarePublicCounter(libp2p_pubsub_messages_published, "published messages", labels = ["topic"])
 
 type

libp2p/protocols/pubsub/pubsubpeer.nim

@@ -21,6 +21,7 @@ import rpc/[messages, message, protobuf],
 logScope:
   topics = "pubsubpeer"
 
+when defined(libp2p_expensive_metrics):
   declareCounter(libp2p_pubsub_sent_messages, "number of messages sent", labels = ["id", "topic"])
   declareCounter(libp2p_pubsub_received_messages, "number of messages received", labels = ["id", "topic"])
   declareCounter(libp2p_pubsub_skipped_received_messages, "number of received skipped messages", labels = ["id"])
@@ -91,6 +92,7 @@ proc handle*(p: PubSubPeer, conn: Connection) {.async.} =
         let digest = $(sha256.digest(data))
         trace "read data from peer", data = data.shortLog
         if digest in p.recvdRpcCache:
+          when defined(libp2p_expensive_metrics):
             libp2p_pubsub_skipped_received_messages.inc(labelValues = [p.id])
           trace "message already received, skipping"
           continue
@@ -106,6 +108,7 @@ proc handle*(p: PubSubPeer, conn: Connection) {.async.} =
         # trigger hooks
         p.recvObservers(msg)
 
+        when defined(libp2p_expensive_metrics):
           for m in msg.messages:
             for t in m.topicIDs:
               # metrics
@@ -148,6 +151,7 @@ proc send*(
   let digest = $(sha256.digest(encoded))
   if digest in p.sentRpcCache:
     trace "message already sent to peer, skipping"
+    when defined(libp2p_expensive_metrics):
       libp2p_pubsub_skipped_sent_messages.inc(labelValues = [p.id])
     return
 
@@ -168,6 +172,7 @@ proc send*(
       p.sentRpcCache.put(digest)
       trace "sent pubsub message to remote"
 
+      when defined(libp2p_expensive_metrics):
         for x in mm.messages:
           for t in x.topicIDs:
             # metrics