address some review comments

config/config.go

@@ -271,8 +271,8 @@ type AgentConfig struct {
 	// this setting to true will skip the second run of processors.
 	SkipProcessorsAfterAggregators bool `toml:"skip_processors_after_aggregators"`
 
-	BufferStrategy      string `toml:"buffer_strategy"`
-	BufferFileDirectory string `toml:"buffer_file_directory"`
+	BufferStrategy  string `toml:"buffer_strategy"`
+	BufferDirectory string `toml:"buffer_directory"`
 }
 
 // InputNames returns a list of strings of the configured inputs.
@@ -1492,7 +1492,7 @@ func (c *Config) buildOutput(name string, tbl *ast.Table) (*models.OutputConfig,
 	c.getFieldString(tbl, "name_prefix", &oc.NamePrefix)
 	c.getFieldString(tbl, "startup_error_behavior", &oc.StartupErrorBehavior)
 	c.getFieldString(tbl, "buffer_strategy", &oc.BufferStrategy)
-	c.getFieldString(tbl, "buffer_file_directory", &oc.BufferFileDirectory)
+	c.getFieldString(tbl, "buffer_directory", &oc.BufferDirectory)
 
 	if c.hasErrs() {
 		return nil, c.firstErr()

models/buffer.go

@@ -10,12 +10,6 @@ var (
 	AgentMetricsDropped = selfstat.Register("agent", "metrics_dropped", map[string]string{})
 )
 
-const (
-	StrategyMemory   = "memory"
-	StrategyDisk     = "disk"
-	StrategyOverflow = "overflow"
-)
-
 type Buffer interface {
 
 	// Len returns the number of metrics currently in the buffer.
@@ -37,9 +31,9 @@ type Buffer interface {
 	Reject([]telegraf.Metric)
 }
 
-// BufferMetrics holds common metrics used for buffer implementations.
+// BufferStats holds common metrics used for buffer implementations.
 // Implementations of Buffer should embed this struct in them.
-type BufferMetrics struct {
+type BufferStats struct {
 	MetricsAdded   selfstat.Stat
 	MetricsWritten selfstat.Stat
 	MetricsDropped selfstat.Stat
@@ -51,26 +45,28 @@ type BufferMetrics struct {
 func NewBuffer(name string, alias string, capacity int, strategy string, path string) Buffer {
 	bm := NewBufferMetrics(name, alias, capacity)
 
-	if strategy == StrategyDisk {
+	switch strategy {
+	case "", "memory":
+		return NewMemoryBuffer(capacity, bm)
+	case "disk":
 		return NewDiskBuffer(name, capacity, path, bm)
-	} else if strategy == StrategyOverflow {
+	case "overflow":
 		// todo implementme
 		// todo log currently unimplemented
 		return NewMemoryBuffer(capacity, bm)
-	} else if strategy == StrategyMemory || strategy == "" {
-		return NewMemoryBuffer(capacity, bm)
 	}
+
 	// todo log invalid buffer strategy configuration provided, falling back to memory
 	return NewMemoryBuffer(capacity, bm)
 }
 
-func NewBufferMetrics(name string, alias string, capacity int) BufferMetrics {
+func NewBufferMetrics(name string, alias string, capacity int) BufferStats {
 	tags := map[string]string{"output": name}
 	if alias != "" {
 		tags["alias"] = alias
 	}
 
-	bm := BufferMetrics{
+	bm := BufferStats{
 		MetricsAdded: selfstat.Register(
 			"write",
 			"metrics_added",
@@ -102,17 +98,17 @@ func NewBufferMetrics(name string, alias string, capacity int) BufferMetrics {
 	return bm
 }
 
-func (b *BufferMetrics) metricAdded() {
+func (b *BufferStats) metricAdded() {
 	b.MetricsAdded.Incr(1)
 }
 
-func (b *BufferMetrics) metricWritten(metric telegraf.Metric) {
+func (b *BufferStats) metricWritten(metric telegraf.Metric) {
 	AgentMetricsWritten.Incr(1)
 	b.MetricsWritten.Incr(1)
 	metric.Accept()
 }
 
-func (b *BufferMetrics) metricDropped(metric telegraf.Metric) {
+func (b *BufferStats) metricDropped(metric telegraf.Metric) {
 	AgentMetricsDropped.Incr(1)
 	b.MetricsDropped.Incr(1)
 	metric.Reject()

models/buffer_disk.go

@@ -10,20 +10,20 @@ import (
 )
 
 type DiskBuffer struct {
-	BufferMetrics
+	BufferStats
 
 	walFile *wal.Log
 }
 
-func NewDiskBuffer(name string, capacity int, path string, metrics BufferMetrics) *DiskBuffer {
+func NewDiskBuffer(name string, capacity int, path string, stats BufferStats) *DiskBuffer {
 	// todo capacity
 	walFile, err := wal.Open(path+"/"+name, nil)
 	if err != nil {
 		return nil // todo error handling
 	}
 	return &DiskBuffer{
-		BufferMetrics: metrics,
-		walFile:       walFile,
+		BufferStats: stats,
+		walFile:     walFile,
 	}
 }
 

models/buffer_mem.go

@@ -9,7 +9,7 @@ import (
 // MemoryBuffer stores metrics in a circular buffer.
 type MemoryBuffer struct {
 	sync.Mutex
-	BufferMetrics
+	BufferStats
 
 	buf   []telegraf.Metric
 	first int // index of the first/oldest metric
@@ -21,14 +21,14 @@ type MemoryBuffer struct {
 	batchSize  int // number of metrics currently in the batch
 }
 
-func NewMemoryBuffer(capacity int, metrics BufferMetrics) *MemoryBuffer {
+func NewMemoryBuffer(capacity int, stats BufferStats) *MemoryBuffer {
 	return &MemoryBuffer{
-		BufferMetrics: metrics,
-		buf:           make([]telegraf.Metric, capacity),
-		first:         0,
-		last:          0,
-		size:          0,
-		cap:           capacity,
+		BufferStats: stats,
+		buf:         make([]telegraf.Metric, capacity),
+		first:       0,
+		last:        0,
+		size:        0,
+		cap:         capacity,
 	}
 }
 

models/running_output.go

@@ -37,8 +37,8 @@ type OutputConfig struct {
 	NamePrefix   string
 	NameSuffix   string
 
-	BufferStrategy      string
-	BufferFileDirectory string
+	BufferStrategy  string
+	BufferDirectory string
 }
 
 // RunningOutput contains the output configuration
@@ -99,7 +99,7 @@ func NewRunningOutput(
 	}
 
 	ro := &RunningOutput{
-		buffer:            NewBuffer(config.Name, config.Alias, bufferLimit, config.BufferStrategy, config.BufferFileDirectory),
+		buffer:            NewBuffer(config.Name, config.Alias, bufferLimit, config.BufferStrategy, config.BufferDirectory),
 		BatchReady:        make(chan time.Time, 1),
 		Output:            output,
 		Config:            config,