INTERNAL: Add new merge method with improved performance to new SMGet…

…Result.
naver · Jan 26, 2024 · 5fb270d · 5fb270d
1 parent 3bb0cd7
commit 5fb270d
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Showing 2 changed files with 106 additions and 2 deletions.
diff --git a/src/main/java/net/spy/memcached/internal/result/SMGetResult.java b/src/main/java/net/spy/memcached/internal/result/SMGetResult.java
@@ -16,9 +16,9 @@ public abstract class SMGetResult<T>  {
 
   protected final List<String> missedKeyList;
   protected final Map<String, CollectionOperationStatus> missedKeyMap;
-  protected final List<SMGetTrimKey> mergedTrimmedKeys;
+  protected volatile List<SMGetTrimKey> mergedTrimmedKeys;
 
-  protected final List<SMGetElement<T>> mergedResult;
+  protected volatile List<SMGetElement<T>> mergedResult;
   protected volatile CollectionOperationStatus resultOperationStatus = null;
   protected volatile CollectionOperationStatus failedOperationStatus = null;
 

diff --git a/src/main/java/net/spy/memcached/internal/result/SMGetResultImpl.java b/src/main/java/net/spy/memcached/internal/result/SMGetResultImpl.java
@@ -1,5 +1,6 @@
 package net.spy.memcached.internal.result;
 
+import java.util.ArrayList;
 import java.util.List;
 
 import net.spy.memcached.collection.SMGetElement;
@@ -98,6 +99,68 @@ private void mergeSMGetElements(final List<SMGetElement<T>> eachResult) {
     }
   }
 
+  private void mergeSMGetElements2(final List<SMGetElement<T>> eachResult) {
+    if (mergedResult.isEmpty()) {
+      // merged result is empty, add all.
+      mergedResult.addAll(eachResult);
+
+      while (mergedResult.size() > count) {
+        mergedResult.remove(count);
+      }
+      return;
+    }
+
+    final int eachSize = eachResult.size();
+    final int mergedSize = mergedResult.size();
+    final List<SMGetElement<T>> newMergedResult = new ArrayList<SMGetElement<T>>(count);
+
+    int eachPos = 0, mergedPos = 0;
+    int comp, keyComp;
+
+    while (eachPos < eachSize && mergedPos < mergedSize && newMergedResult.size() < count) {
+      final SMGetElement<T> each = eachResult.get(eachPos);
+      final SMGetElement<T> merged = mergedResult.get(mergedPos);
+
+      comp = each.compareBkeyTo(merged);
+      if ((reverse) ? (comp > 0) : (comp < 0)) {
+        newMergedResult.add(each);
+        eachPos++;
+      } else if ((reverse) ? (comp < 0) : (comp > 0)) {
+        newMergedResult.add(merged);
+        mergedPos++;
+      } else {
+        // Duplicated bkey. Compare the "cache key".
+        keyComp = each.compareKeyTo(merged);
+        if ((reverse) ? (keyComp > 0) : (keyComp < 0)) {
+          newMergedResult.add(each);
+          eachPos++;
+
+          if (unique) {
+            // NOT the first cache key with the same bkey. do NOT insert.
+            mergedPos++;
+          }
+        } else {
+          newMergedResult.add(merged);
+          mergedPos++;
+
+          if (unique) {
+            // NOT the first cache key with the same bkey. do NOT insert.
+            eachPos++;
+          }
+        }
+      }
+    }
+
+    while (eachPos < eachSize && newMergedResult.size() < count) {
+      newMergedResult.add(eachResult.get(eachPos++));
+    }
+    while (mergedPos < mergedSize && newMergedResult.size() < count) {
+      newMergedResult.add(mergedResult.get(mergedPos++));
+    }
+
+    mergedResult = newMergedResult;
+  }
+
   private void mergeTrimmedKeys(final List<SMGetTrimKey> eachTrimmedResult) {
     if (mergedTrimmedKeys.isEmpty()) {
       mergedTrimmedKeys.addAll(eachTrimmedResult);
@@ -118,6 +181,47 @@ private void mergeTrimmedKeys(final List<SMGetTrimKey> eachTrimmedResult) {
     }
   }
 
+  private void mergeTrimmedKeys2(final List<SMGetTrimKey> eachTrimmedResult) {
+    if (mergedTrimmedKeys.isEmpty()) {
+      mergedTrimmedKeys.addAll(eachTrimmedResult);
+      return;
+    }
+
+    final int eachSize = eachTrimmedResult.size();
+    final int mergedSize = mergedTrimmedKeys.size();
+    final List<SMGetTrimKey> newMergedTrimmedKeys
+            = new ArrayList<SMGetTrimKey>(eachSize + mergedSize);
+
+    int eachPos = 0, mergedPos = 0;
+    int comp;
+
+    while (eachPos < eachSize && mergedPos < mergedSize) {
+      final SMGetTrimKey each = eachTrimmedResult.get(eachPos);
+      final SMGetTrimKey merged = mergedTrimmedKeys.get(mergedPos);
+
+      comp = each.compareTo(merged);
+      if ((reverse) ? (comp > 0) : (comp < 0)) {
+        newMergedTrimmedKeys.add(each);
+        eachPos++;
+      } else if ((reverse) ? (comp < 0) : (comp > 0)) {
+        newMergedTrimmedKeys.add(merged);
+        mergedPos++;
+      } else {
+        // comp == 0;
+        mergedPos++;
+      }
+    }
+
+    while (eachPos < eachSize) {
+      newMergedTrimmedKeys.add(eachTrimmedResult.get(eachPos++));
+    }
+    while (mergedPos < mergedSize) {
+      newMergedTrimmedKeys.add(mergedTrimmedKeys.get(mergedPos++));
+    }
+
+    mergedTrimmedKeys = newMergedTrimmedKeys;
+  }
+
   @Override
   public void makeResultOperationStatus() {
     if (!mergedTrimmedKeys.isEmpty() && count <= mergedResult.size()) {