set mongo structs strictly in one place

+ split file

cmd/mongo_struct.go

@@ -0,0 +1,46 @@
+package logmower
+
+import (
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson"
+)
+
+// when editing, also edit everything in this file!
+type mLog struct {
+	HostInfo    HostInfo
+	File        string
+	Offset      int64  // byte offset where log entry ends at
+	Content     string // TODO:
+	ShipTime    time.Time
+	CollectTime time.Time
+	StdErr      bool
+	Format      string // F or P TODO: what does it mean? Is there a well-defined log format for cri-o?
+}
+
+const (
+	mongoKeyHostInfo     = "host_info"
+	mongoKeyId           = "id"
+	mongoKeyHostInfoId   = mongoKeyHostInfo + "." + mongoKeyId
+	mongoKeyFileBasename = "file"
+	mongoKeyOffset       = "offset"
+)
+
+// not using marshal, since it is <0.1x performance
+func (l *mLog) toBson() bson.M {
+	// DO NOT USE QUOTED STRINGS! Move them to const and use variable instead
+	return bson.M{
+		mongoKeyHostInfo: bson.M{
+			mongoKeyId: l.HostInfo.id,
+			"name":     l.HostInfo.name,
+			"arch":     l.HostInfo.arch,
+		},
+		mongoKeyFileBasename: l.File,
+		mongoKeyOffset:       l.Offset,
+		"content":            l.Content,
+		"ship_time":          l.ShipTime,
+		"container_time":     l.CollectTime,
+		"stderr":             l.StdErr,
+		"format":             l.Format,
+	}
+}

cmd/sender.go

@@ -8,7 +8,6 @@ import (
 	"github.com/jtagcat/util"
 	prom "github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
-	"go.mongodb.org/mongo-driver/bson"
 	"go.uber.org/zap"
 )
 
@@ -124,33 +123,3 @@ func (s *submitter) sender(name string, sendQueue <-chan mLog) {
 		}
 	}
 }
-
-// when editing, also edit toBson(); all bson.D (and bson.M) uses
-type mLog struct {
-	HostInfo    HostInfo
-	File        string
-	Offset      int64  // byte offset where log entry ends at
-	Content     string // TODO:
-	ShipTime    time.Time
-	CollectTime time.Time
-	StdErr      bool
-	Format      string // F or P TODO: what does it mean? Is there a well-defined log format for cri-o?
-}
-
-// not using marshal, since it is <0.1x performance
-func (l *mLog) toBson() bson.M {
-	return bson.M{
-		"host_info": bson.M{
-			"id":   l.HostInfo.id,
-			"name": l.HostInfo.name,
-			"arch": l.HostInfo.arch,
-		},
-		"filename":       l.File,
-		"offset":         l.Offset,
-		"content":        l.Content,
-		"ship_time":      l.ShipTime,
-		"container_time": l.CollectTime,
-		"stderr":         l.StdErr,
-		"format":         l.Format,
-	}
-}

cmd/submit.go

@@ -83,8 +83,8 @@ func (s *submitter) shipFileRoutine(ctx context.Context, name string, sendQueue
 
 	// get files with offset
 	offsetResult, err := mongoWithErr(s.db.FindOne(mongoTimeoutCtx(ctx),
-		bson.D{{Key: "hostinfo.id", Value: s.hostInfo.id}, {Key: "file", Value: baseName}},
-		&mongoOpt.FindOneOptions{Sort: bson.D{{Key: "offset", Value: -1}}}, // sort descending (get largest)
+		bson.D{{Key: mongoKeyHostInfoId, Value: s.hostInfo.id}, {Key: mongoKeyFileBasename, Value: baseName}},
+		&mongoOpt.FindOneOptions{Sort: bson.D{{Key: mongoKeyOffset, Value: -1}}}, // sort descending (get largest)
 	))
 
 	if err != nil && !errors.Is(err, mongo.ErrNoDocuments) {