Use min or max method of Math to improve readability (#2103)

server/src/main/java/org/apache/iotdb/db/engine/merge/selector/MaxFileMergeFileSelector.java

@@ -316,7 +316,7 @@ public class MaxFileMergeFileSelector implements IMergeFileSelector {
     long singleSeriesCost = calculateTightFileMemoryCost(seqFile, this::calculateMetadataSize);
     long multiSeriesCost = concurrentMergeNum * singleSeriesCost;
     long maxCost = calculateMetadataSize(seqFile);
-    return multiSeriesCost > maxCost ? maxCost : multiSeriesCost;
+    return Math.min(multiSeriesCost, maxCost);
   }
 
   // this method traverses all ChunkMetadata to find out which series has the most chunks and uses
@@ -325,7 +325,7 @@ public class MaxFileMergeFileSelector implements IMergeFileSelector {
     long singleSeriesCost = calculateTightFileMemoryCost(unseqFile, TsFileResource::getTsFileSize);
     long multiSeriesCost = concurrentMergeNum * singleSeriesCost;
     long maxCost = unseqFile.getTsFileSize();
-    return multiSeriesCost > maxCost ? maxCost : multiSeriesCost;
+    return Math.min(multiSeriesCost, maxCost);
   }
 
   @Override

server/src/main/java/org/apache/iotdb/db/engine/merge/task/MergeFileTask.java

@@ -223,7 +223,7 @@ class MergeFileTask {
         if (metaData.getStartTime() == startTime) {
           Chunk chunk = reader.readMemChunk(metaData);
           fileWriter.writeChunk(chunk, metaData);
-          maxVersion = metaData.getVersion() > maxVersion ? metaData.getVersion() : maxVersion;
+          maxVersion = Math.max(metaData.getVersion(), maxVersion);
           context.incTotalPointWritten(metaData.getNumOfPoints());
           break;
         }

server/src/main/java/org/apache/iotdb/db/utils/datastructure/BinaryTVList.java

@@ -47,7 +47,7 @@ public class BinaryTVList extends TVList {
     checkExpansion();
     int arrayIndex = size / ARRAY_SIZE;
     int elementIndex = size % ARRAY_SIZE;
-    minTime = minTime <= timestamp ? minTime : timestamp;
+    minTime = Math.min(minTime, timestamp);
     timestamps.get(arrayIndex)[elementIndex] = timestamp;
     values.get(arrayIndex)[elementIndex] = value;
     size++;

server/src/main/java/org/apache/iotdb/db/utils/datastructure/BooleanTVList.java

@@ -46,7 +46,7 @@ public class BooleanTVList extends TVList {
     checkExpansion();
     int arrayIndex = size / ARRAY_SIZE;
     int elementIndex = size % ARRAY_SIZE;
-    minTime = minTime <= timestamp ? minTime : timestamp;
+    minTime = Math.min(minTime, timestamp);
     timestamps.get(arrayIndex)[elementIndex] = timestamp;
     values.get(arrayIndex)[elementIndex] = value;
     size++;

server/src/main/java/org/apache/iotdb/db/utils/datastructure/DoubleTVList.java

@@ -47,7 +47,7 @@ public class DoubleTVList extends TVList {
     checkExpansion();
     int arrayIndex = size / ARRAY_SIZE;
     int elementIndex = size % ARRAY_SIZE;
-    minTime = minTime <= timestamp ? minTime : timestamp;
+    minTime = Math.min(minTime, timestamp);
     timestamps.get(arrayIndex)[elementIndex] = timestamp;
     values.get(arrayIndex)[elementIndex] = value;
     size++;

server/src/main/java/org/apache/iotdb/db/utils/datastructure/FloatTVList.java

@@ -48,7 +48,7 @@ public class FloatTVList extends TVList {
     checkExpansion();
     int arrayIndex = size / ARRAY_SIZE;
     int elementIndex = size % ARRAY_SIZE;
-    minTime = minTime <= timestamp ? minTime : timestamp;
+    minTime = Math.min(minTime, timestamp);
     timestamps.get(arrayIndex)[elementIndex] = timestamp;
     values.get(arrayIndex)[elementIndex] = value;
     size++;

server/src/main/java/org/apache/iotdb/db/utils/datastructure/IntTVList.java

@@ -46,7 +46,7 @@ public class IntTVList extends TVList {
     checkExpansion();
     int arrayIndex = size / ARRAY_SIZE;
     int elementIndex = size % ARRAY_SIZE;
-    minTime = minTime <= timestamp ? minTime : timestamp;
+    minTime = Math.min(minTime, timestamp);
     timestamps.get(arrayIndex)[elementIndex] = timestamp;
     values.get(arrayIndex)[elementIndex] = value;
     size++;

server/src/main/java/org/apache/iotdb/db/utils/datastructure/LongTVList.java

@@ -46,7 +46,7 @@ public class LongTVList extends TVList {
     checkExpansion();
     int arrayIndex = size / ARRAY_SIZE;
     int elementIndex = size % ARRAY_SIZE;
-    minTime = minTime <= timestamp ? minTime : timestamp;
+    minTime = Math.min(minTime, timestamp);
     timestamps.get(arrayIndex)[elementIndex] = timestamp;
     values.get(arrayIndex)[elementIndex] = value;
     size++;

server/src/main/java/org/apache/iotdb/db/utils/datastructure/TVList.java

@@ -187,7 +187,7 @@ public abstract class TVList {
       long time = getTime(i);
       if (time < lowerBound || time > upperBound) {
         set(i, newSize++);
-        minTime = time < minTime ? time : minTime;
+        minTime = Math.min(time, minTime);
       }
     }
     int deletedNumber = size - newSize;
@@ -245,7 +245,7 @@ public abstract class TVList {
   abstract void clearValue();
 
   /**
-   * The arrays for sorting are not including in write memory now, 
+   * The arrays for sorting are not including in write memory now,
    * the memory usage is considered as temporary memory.
    */
   abstract void clearSortedValue();
@@ -452,12 +452,12 @@ public abstract class TVList {
     long inPutMinTime = Long.MAX_VALUE;
     boolean inputSorted = true;
     for (int i = start; i < end; i++) {
-      inPutMinTime = inPutMinTime <= time[i] ? inPutMinTime : time[i];
+      inPutMinTime = Math.min(inPutMinTime, time[i]);
       if (inputSorted && i < length - 1 && time[i] > time[i + 1]) {
         inputSorted = false;
       }
     }
-    minTime = inPutMinTime < minTime ? inPutMinTime : minTime;
+    minTime = Math.min(inPutMinTime, minTime);
     sorted = sorted && inputSorted && (size == 0 || inPutMinTime >= getTime(size - 1));
   }
 

tsfile/src/main/java/org/apache/iotdb/tsfile/utils/ReadWriteForEncodingUtils.java

@@ -44,7 +44,7 @@ public class ReadWriteForEncodingUtils {
     int max = 1;
     for (int num : list) {
       int bitWidth = 32 - Integer.numberOfLeadingZeros(num);
-      max = bitWidth > max ? bitWidth : max;
+      max = Math.max(bitWidth, max);
     }
     return max;
   }
@@ -59,7 +59,7 @@ public class ReadWriteForEncodingUtils {
     int max = 1;
     for (long num : list) {
       int bitWidth = 64 - Long.numberOfLeadingZeros(num);
-      max = bitWidth > max ? bitWidth : max;
+      max = Math.max(bitWidth, max);
     }
     return max;
   }