internal/worker: rename and document multiEventHandler

Change-Id: I3fcd4206a9427b9f32c64397b34ae42bb076c08a
Reviewed-on: https://go-review.googlesource.com/c/vulndb/+/380954
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Julie Qiu <julie@golang.org>
diff --git a/go.sum b/go.sum
index da1f3ad..f37b282 100644
--- a/go.sum
+++ b/go.sum
@@ -21,6 +21,7 @@
 cloud.google.com/go v0.83.0/go.mod h1:Z7MJUsANfY0pYPdw0lbnivPx4/vhy/e2FEkSkF7vAVY=
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 cloud.google.com/go v0.87.0/go.mod h1:TpDYlFy7vuLzZMMZ+B6iRiELaY7z/gJPaqbMx6mlWcY=
+cloud.google.com/go v0.88.0/go.mod h1:dnKwfYbP9hQhefiUvpbcAyoGSHUrOxR20JVElLiUvEY=
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 cloud.google.com/go v0.93.3/go.mod h1:8utlLll2EF5XMAV15woO4lSbWQlk8rer9aLOfLh7+YI=
@@ -48,11 +49,17 @@
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+cloud.google.com/go/trace v1.0.0 h1:laKx2y7IWMjguCe5zZx6n7qLtREk4kyE69SXVC0VSN8=
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@@ -140,6 +147,8 @@
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+github.com/felixge/httpsnoop v1.0.2 h1:+nS9g82KMXccJ/wp0zyRW9ZBHFETmMGtkk+2CTTrW4o=
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@@ -168,7 +177,9 @@
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+github.com/go-logr/logr v1.2.2 h1:ahHml/yUpnlb96Rp8HCvtYVPY8ZYpxq3g7UYchIYwbs=
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@@ -180,8 +191,9 @@
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-github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e h1:1r7pUrabqp18hOBcwBwiTsbnFeTZHV9eER/QT5JVZxY=
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+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l8iNU+DwB5epxmsaqB+rhGL0m5jtYqE=
+github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
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@@ -250,6 +262,7 @@
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@@ -262,6 +275,8 @@
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@@ -469,13 +484,29 @@
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+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.24.0 h1:qW6j1kJU24yo2xIu16Py4m4AXn1dd+s2uKllGnTFAm0=
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.24.0/go.mod h1:7W3JSDYTtH3qKKHrS1fMiwLtK7iZFLPq1+7htfspX/E=
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+go.opentelemetry.io/otel v1.0.0-RC3/go.mod h1:Ka5j3ua8tZs4Rkq4Ex3hwgBgOchyPVq5S6P2lz//nKQ=
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@@ -581,6 +612,7 @@
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@@ -594,6 +626,7 @@
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@@ -753,6 +786,7 @@
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@@ -847,6 +881,7 @@
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 google.golang.org/genproto v0.0.0-20200618031413-b414f8b61790/go.mod h1:jDfRM7FcilCzHH/e9qn6dsT145K34l5v+OpcnNgKAAA=
 google.golang.org/genproto v0.0.0-20200729003335-053ba62fc06f/go.mod h1:FWY/as6DDZQgahTzZj3fqbO1CbirC29ZNUFHwi0/+no=
 google.golang.org/genproto v0.0.0-20200804131852-c06518451d9c/go.mod h1:FWY/as6DDZQgahTzZj3fqbO1CbirC29ZNUFHwi0/+no=
@@ -868,6 +903,8 @@
 google.golang.org/genproto v0.0.0-20210624195500-8bfb893ecb84/go.mod h1:SzzZ/N+nwJDaO1kznhnlzqS8ocJICar6hYhVyhi++24=
 google.golang.org/genproto v0.0.0-20210713002101-d411969a0d9a/go.mod h1:AxrInvYm1dci+enl5hChSFPOmmUF1+uAa/UsgNRWd7k=
 google.golang.org/genproto v0.0.0-20210716133855-ce7ef5c701ea/go.mod h1:AxrInvYm1dci+enl5hChSFPOmmUF1+uAa/UsgNRWd7k=
+google.golang.org/genproto v0.0.0-20210721163202-f1cecdd8b78a/go.mod h1:ob2IJxKrgPT52GcgX759i1sleT07tiKowYBGbczaW48=
+google.golang.org/genproto v0.0.0-20210722135532-667f2b7c528f/go.mod h1:ob2IJxKrgPT52GcgX759i1sleT07tiKowYBGbczaW48=
 google.golang.org/genproto v0.0.0-20210728212813-7823e685a01f/go.mod h1:ob2IJxKrgPT52GcgX759i1sleT07tiKowYBGbczaW48=
 google.golang.org/genproto v0.0.0-20210805201207-89edb61ffb67/go.mod h1:ob2IJxKrgPT52GcgX759i1sleT07tiKowYBGbczaW48=
 google.golang.org/genproto v0.0.0-20210813162853-db860fec028c/go.mod h1:cFeNkxwySK631ADgubI+/XFU/xp8FD5KIVV4rj8UC5w=
@@ -876,6 +913,7 @@
 google.golang.org/genproto v0.0.0-20210831024726-fe130286e0e2/go.mod h1:eFjDcFEctNawg4eG61bRv87N7iHBWyVhJu7u1kqDUXY=
 google.golang.org/genproto v0.0.0-20210903162649-d08c68adba83/go.mod h1:eFjDcFEctNawg4eG61bRv87N7iHBWyVhJu7u1kqDUXY=
 google.golang.org/genproto v0.0.0-20210909211513-a8c4777a87af/go.mod h1:eFjDcFEctNawg4eG61bRv87N7iHBWyVhJu7u1kqDUXY=
+google.golang.org/genproto v0.0.0-20210921142501-181ce0d877f6/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20210924002016-3dee208752a0/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211008145708-270636b82663/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
 google.golang.org/genproto v0.0.0-20211021150943-2b146023228c/go.mod h1:5CzLGKJ67TSI2B9POpiiyGha0AjJvZIUgRMt1dSmuhc=
diff --git a/internal/worker/server.go b/internal/worker/server.go
index 4e2fb62..548ea50 100644
--- a/internal/worker/server.go
+++ b/internal/worker/server.go
@@ -118,7 +118,7 @@
 		start := time.Now()
 		defer s.afterRequest()
 		traceID := r.Header.Get("X-Cloud-Trace-Context")
-		exporter := event.NewExporter(eventHandlers{
+		exporter := event.NewExporter(multiEventHandler{
 			log.NewGCPJSONHandler(os.Stderr, traceID),
 			s.traceHandler,
 		}, nil)
@@ -362,9 +362,12 @@
 	return tp, nil
 }
 
-type eventHandlers []event.Handler
+// multiEventHandler is an event.Handler that calls all of its contained handlers
+// on each event.
+type multiEventHandler []event.Handler
 
-func (eh eventHandlers) Event(ctx context.Context, ev *event.Event) context.Context {
+// Event implements event.Handler.Event.
+func (eh multiEventHandler) Event(ctx context.Context, ev *event.Event) context.Context {
 	for _, h := range eh {
 		ctx = h.Event(ctx, ev)
 	}