feat: add new key comparator for index entry

halo-dev · Jan 15, 2024 · 191f974 · 191f974
1 parent f880bd4
commit 191f974
Show file tree

Hide file tree

Showing 2 changed files with 99 additions and 1 deletion.
diff --git a/application/src/main/java/run/halo/app/extension/index/IndexEntryImpl.java b/application/src/main/java/run/halo/app/extension/index/IndexEntryImpl.java
@@ -37,14 +37,47 @@ public IndexEntryImpl(IndexDescriptor indexDescriptor) {
     Comparator<String> keyComparator() {
         var order = indexDescriptor.getSpec().getOrder();
         if (IndexSpec.OrderType.ASC.equals(order)) {
-            return Comparator.naturalOrder();
+            return KeyComparator.INSTANCE;
         } else if (IndexSpec.OrderType.DESC.equals(order)) {
             return Comparator.reverseOrder();
         } else {
             throw new IllegalArgumentException("Invalid order: " + order);
         }
     }
 
+    static class KeyComparator implements Comparator<String> {
+        public static final KeyComparator INSTANCE = new KeyComparator();
+
+        @Override
+        public int compare(String a, String b) {
+            int i = 0;
+            int j = 0;
+            while (i < a.length() && j < b.length()) {
+                if (Character.isDigit(a.charAt(i)) && Character.isDigit(b.charAt(j))) {
+                    // handle number part
+                    int num1 = 0;
+                    int num2 = 0;
+                    while (i < a.length() && Character.isDigit(a.charAt(i))) {
+                        num1 = num1 * 10 + (a.charAt(i++) - '0');
+                    }
+                    while (j < b.length() && Character.isDigit(b.charAt(j))) {
+                        num2 = num2 * 10 + (b.charAt(j++) - '0');
+                    }
+                    if (num1 != num2) {
+                        return num1 - num2;
+                    }
+                } else if (a.charAt(i) != b.charAt(j)) {
+                    // handle non-number part
+                    return a.charAt(i) - b.charAt(j);
+                } else {
+                    i++;
+                    j++;
+                }
+            }
+            return a.length() - b.length();
+        }
+    }
+
     @Override
     public void acquireReadLock() {
         this.rwl.readLock().lock();

diff --git a/application/src/test/java/run/halo/app/extension/index/IndexEntryImplTest.java b/application/src/test/java/run/halo/app/extension/index/IndexEntryImplTest.java
@@ -1,7 +1,10 @@
 package run.halo.app.extension.index;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
+import java.util.Arrays;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import org.junit.jupiter.api.Test;
@@ -105,4 +108,66 @@ void keyOrder() {
                 Map.entry("slug-4", "fake-name-3"));
         assertThat(entry2.indexedKeys()).containsSequence("slug-1", "slug-2", "slug-3", "slug-4");
     }
+
+    @Test
+    void keyComparator() {
+        var comparator = IndexEntryImpl.KeyComparator.INSTANCE;
+        String[] strings = {"103", "101", "102", "1011", "1013", "1021", "1022", "1012", "1023"};
+        Arrays.sort(strings, comparator);
+        assertThat(strings).isEqualTo(
+            new String[] {"101", "102", "103", "1011", "1012", "1013", "1021", "1022", "1023"});
+
+        Arrays.sort(strings, comparator.reversed());
+        assertThat(strings).isEqualTo(
+            new String[] {"1023", "1022", "1021", "1013", "1012", "1011", "103", "102", "101"});
+
+        // but if we use natural order, the result is:
+        Arrays.sort(strings, Comparator.naturalOrder());
+        assertThat(strings).isEqualTo(
+            new String[] {"101", "1011", "1012", "1013", "102", "1021", "1022", "1023", "103"});
+    }
+
+    @Test
+    void keyComparator2() {
+        var comparator = IndexEntryImpl.KeyComparator.INSTANCE;
+        String[] strings =
+            {"moment-101", "moment-102", "moment-103", "moment-1011", "moment-1013", "moment-1021",
+                "moment-1022", "moment-1012", "moment-1023"};
+        Arrays.sort(strings, comparator);
+        assertThat(strings).isEqualTo(new String[] {"moment-101", "moment-102", "moment-103",
+            "moment-1011", "moment-1012", "moment-1013", "moment-1021", "moment-1022",
+            "moment-1023"});
+
+        // 测试日期排序
+        strings =
+            new String[] {"2022-01-15", "2022-02-01", "2021-12-25", "2022-01-01", "2022-01-02"};
+        Arrays.sort(strings, comparator);
+        assertThat(strings).isEqualTo(
+            new String[] {"2021-12-25", "2022-01-01", "2022-01-02", "2022-01-15", "2022-02-01"});
+
+        // 测试字母和数字混合排序
+        strings = new String[] {"abc123", "abc45", "abc9", "abc100", "abc20"};
+        Arrays.sort(strings, comparator);
+        assertThat(strings).isEqualTo(
+            new String[] {"abc9", "abc20", "abc45", "abc100", "abc123"});
+
+        // 测试纯字母排序
+        strings = new String[] {"xyz", "abc", "def", "abcde", "xyzabc"};
+        Arrays.sort(strings, comparator);
+        assertThat(strings).isEqualTo(new String[] {"abc", "abcde", "def", "xyz", "xyzabc"});
+
+        // 测试空字符串
+        strings = new String[] {"", "abc", "123", "xyz"};
+        Arrays.sort(strings, comparator);
+        assertThat(strings).isEqualTo(new String[] {"", "123", "abc", "xyz"});
+
+        // 测试相同字符串
+        strings = new String[] {"abc", "abc", "abc", "abc"};
+        Arrays.sort(strings, comparator);
+        assertThat(strings).isEqualTo(new String[] {"abc", "abc", "abc", "abc"});
+
+        // 测试 null 元素
+        assertThatThrownBy(() -> Arrays.sort(new String[] {null, "abc", "123", "xyz"}, comparator))
+            .isInstanceOf(NullPointerException.class);
+    }
 }