refactor: use the built-in max/min to simplify the code (#16617)

Signed-off-by: carrychair <linghuchong404@gmail.com>

tsdb/agent/db.go

@@ -613,10 +613,7 @@ Loop:
 			//
 			// Subtracting a duration from ts will add a buffer for when series are
 			// considered inactive and safe for deletion.
-			ts := db.rs.LowestSentTimestamp() - db.opts.MinWALTime
+			ts := max(db.rs.LowestSentTimestamp()-db.opts.MinWALTime, 0)
-			if ts < 0 {
-				ts = 0
-			}
 
 			// Network issues can prevent the result of getRemoteWriteTimestamp from
 			// changing. We don't want data in the WAL to grow forever, so we set a cap

tsdb/chunks/chunk_write_queue.go

@@ -88,10 +88,7 @@ func newChunkWriteQueue(reg prometheus.Registerer, size int, writeChunk writeChu
 		[]string{"operation"},
 	)
 
-	segmentSize := size
+	segmentSize := min(size, maxChunkQueueSegmentSize)
-	if segmentSize > maxChunkQueueSegmentSize {
-		segmentSize = maxChunkQueueSegmentSize
-	}
 
 	q := &chunkWriteQueue{
 		jobs:                  newWriteJobQueue(size, segmentSize),

tsdb/db.go

@@ -983,10 +983,7 @@ func open(dir string, l *slog.Logger, r prometheus.Registerer, opts *Options, rn
 
 	// Register metrics after assigning the head block.
 	db.metrics = newDBMetrics(db, r)
-	maxBytes := opts.MaxBytes
+	maxBytes := max(opts.MaxBytes, 0)
-	if maxBytes < 0 {
-		maxBytes = 0
-	}
 	db.metrics.maxBytes.Set(float64(maxBytes))
 	db.metrics.retentionDuration.Set((time.Duration(opts.RetentionDuration) * time.Millisecond).Seconds())
 

tsdb/exemplar.go

@@ -296,10 +296,7 @@ func (ce *CircularExemplarStorage) Resize(l int64) int {
 	ce.nextIndex = 0
 
 	// Replay as many entries as needed, starting with oldest first.
-	count := int64(len(oldBuffer))
+	count := min(l, int64(len(oldBuffer)))
-	if l < count {
-		count = l
-	}
 
 	migrated := 0
 

tsdb/head_read.go

@@ -568,10 +568,8 @@ func (s *memSeries) iterator(id chunks.HeadChunkID, c chunkenc.Chunk, isoState *
 					continue
 				}
 			}
-			stopAfter = numSamples - (appendIDsToConsider - index)
+			// Stopped in a previous chunk.
-			if stopAfter < 0 {
+			stopAfter = max(numSamples-(appendIDsToConsider-index), 0)
-				stopAfter = 0 // Stopped in a previous chunk.
-			}
 			break
 		}
 	}

tsdb/head_wal.go

@@ -281,10 +281,7 @@ Outer:
 			// cause thousands of very large in flight buffers occupying large amounts
 			// of unused memory.
 			for len(samples) > 0 {
-				m := 5000
+				m := min(len(samples), 5000)
-				if len(samples) < m {
-					m = len(samples)
-				}
 				for i := 0; i < concurrency; i++ {
 					if shards[i] == nil {
 						shards[i] = processors[i].reuseBuf()
@@ -346,10 +343,7 @@ Outer:
 			// cause thousands of very large in flight buffers occupying large amounts
 			// of unused memory.
 			for len(samples) > 0 {
-				m := 5000
+				m := min(len(samples), 5000)
-				if len(samples) < m {
-					m = len(samples)
-				}
 				for i := 0; i < concurrency; i++ {
 					if histogramShards[i] == nil {
 						histogramShards[i] = processors[i].reuseHistogramBuf()
@@ -382,10 +376,7 @@ Outer:
 			// cause thousands of very large in flight buffers occupying large amounts
 			// of unused memory.
 			for len(samples) > 0 {
-				m := 5000
+				m := min(len(samples), 5000)
-				if len(samples) < m {
-					m = len(samples)
-				}
 				for i := 0; i < concurrency; i++ {
 					if histogramShards[i] == nil {
 						histogramShards[i] = processors[i].reuseHistogramBuf()
@@ -813,10 +804,7 @@ func (h *Head) loadWBL(r *wlog.Reader, syms *labels.SymbolTable, multiRef map[ch
 			// cause thousands of very large in flight buffers occupying large amounts
 			// of unused memory.
 			for len(samples) > 0 {
-				m := 5000
+				m := min(len(samples), 5000)
-				if len(samples) < m {
-					m = len(samples)
-				}
 				for i := 0; i < concurrency; i++ {
 					if shards[i] == nil {
 						shards[i] = processors[i].reuseBuf()
@@ -869,10 +857,7 @@ func (h *Head) loadWBL(r *wlog.Reader, syms *labels.SymbolTable, multiRef map[ch
 			// cause thousands of very large in flight buffers occupying large amounts
 			// of unused memory.
 			for len(samples) > 0 {
-				m := 5000
+				m := min(len(samples), 5000)
-				if len(samples) < m {
-					m = len(samples)
-				}
 				for i := 0; i < concurrency; i++ {
 					if histogramShards[i] == nil {
 						histogramShards[i] = processors[i].reuseHistogramBuf()
@@ -901,10 +886,7 @@ func (h *Head) loadWBL(r *wlog.Reader, syms *labels.SymbolTable, multiRef map[ch
 			// cause thousands of very large in flight buffers occupying large amounts
 			// of unused memory.
 			for len(samples) > 0 {
-				m := 5000
+				m := min(len(samples), 5000)
-				if len(samples) < m {
-					m = len(samples)
-				}
 				for i := 0; i < concurrency; i++ {
 					if histogramShards[i] == nil {
 						histogramShards[i] = processors[i].reuseHistogramBuf()

tsdb/tombstones/tombstones.go

@@ -377,9 +377,6 @@ func (in Intervals) Add(n Interval) Intervals {
 	if n.Mint < in[mini].Mint {
 		in[mini].Mint = n.Mint
 	}
-	in[mini].Maxt = in[maxi+mini-1].Maxt
+	in[mini].Maxt = max(n.Maxt, in[maxi+mini-1].Maxt)
-	if n.Maxt > in[mini].Maxt {
-		in[mini].Maxt = n.Maxt
-	}
 	return append(in[:mini+1], in[maxi+mini:]...)
 }