fix(storage): publish ER position after persistence

chat2db-community-server/chat2db-community-storage/src/main/java/ai/chat2db/community/storage/small/ERPositionStorage.java

@@ -4,6 +4,7 @@
 import cn.hutool.core.util.ObjectUtil;
 
 import java.io.File;
+import java.util.ArrayList;
 import java.util.List;
 
 public class ERPositionStorage extends SmallDataStorage<ERPosition> {
@@ -36,17 +37,49 @@ public String getPosition(Long dataSourceId, String databaseName, String schemaN
         return null;
     }
 
-    public void savePosition(ERPosition param) {
-        List<ERPosition> list = super.getDataList();
-        for (ERPosition p : list) {
-            if (p.getDataSourceId().equals(param.getDataSourceId()) &&
-                    ObjectUtil.equals(p.getDatabaseName(), param.getDatabaseName())
-                    && ObjectUtil.equals(p.getSchemaName(), param.getSchemaName())) {
-                p.setPosition(param.getPosition());
-                update(p);
-                return;
+    public synchronized void savePosition(ERPosition param) {
+        if (param == null) {
+            return;
+        }
+        List<ERPosition> candidateList = new ArrayList<>(dataMap.size() + 1);
+        ERPosition replacement = null;
+        for (ERPosition current : dataMap.values()) {
+            ERPosition candidate = copy(current);
+            if (replacement == null && samePositionKey(current, param)) {
+                candidate.setPosition(param.getPosition());
+                replacement = candidate;
             }
+            candidateList.add(candidate);
+        }
+        boolean inserted = replacement == null;
+        if (inserted) {
+            replacement = copy(param);
+            if (replacement.getId() == null) {
+                replacement.setId(generateId());
+            }
+            candidateList.add(replacement);
+        }
+
+        saveDataList(candidateList);
+        dataMap.put(replacement.getId(), replacement);
+        if (inserted) {
+            param.setId(replacement.getId());
         }
-        super.save(param);
+    }
+
+    private boolean samePositionKey(ERPosition current, ERPosition update) {
+        return current.getDataSourceId().equals(update.getDataSourceId())
+                && ObjectUtil.equals(current.getDatabaseName(), update.getDatabaseName())
+                && ObjectUtil.equals(current.getSchemaName(), update.getSchemaName());
+    }
+
+    private ERPosition copy(ERPosition source) {
+        ERPosition copy = new ERPosition();
+        copy.setId(source.getId());
+        copy.setDataSourceId(source.getDataSourceId());
+        copy.setDatabaseName(source.getDatabaseName());
+        copy.setSchemaName(source.getSchemaName());
+        copy.setPosition(source.getPosition());
+        return copy;
     }
 }

chat2db-community-server/chat2db-community-storage/src/test/java/ai/chat2db/community/storage/small/ERPositionStorageTest.java

@@ -5,9 +5,16 @@
 import org.junit.jupiter.api.io.TempDir;
 
 import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 
+import static org.junit.jupiter.api.Assertions.assertAll;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 /**
  * Regression test for {@link ERPositionStorage#savePosition}.
@@ -73,4 +80,43 @@ void getPositionReturnsNullForMissingKey() throws Exception {
         ERPositionStorage storage = createStorage();
         assertNull(storage.getPosition(99L, "missing", "missing"));
     }
+
+    @Test
+    void failedPositionReplacementKeepsMemoryFileAndReloadState() throws Exception {
+        File storageFile = storageFile();
+        FailingERPositionStorage storage = new FailingERPositionStorage(storageFile);
+        storage.savePosition(pos(1L, "db1", "schema1", "old"));
+        ERPosition before = storage.getDataList().get(0);
+        String persisted = Files.readString(storageFile.toPath(), StandardCharsets.UTF_8);
+        storage.failWrites = true;
+
+        assertThrows(RuntimeException.class,
+                () -> storage.savePosition(pos(1L, "db1", "schema1", "new")));
+
+        ERPositionStorage reloaded = new ERPositionStorage(storageFile);
+        assertAll(
+                () -> assertSame(before, storage.getDataList().get(0)),
+                () -> assertEquals("old", storage.getPosition(1L, "db1", "schema1")),
+                () -> assertEquals(persisted,
+                        Files.readString(storageFile.toPath(), StandardCharsets.UTF_8)),
+                () -> assertEquals("old", reloaded.getPosition(1L, "db1", "schema1"))
+        );
+    }
+
+    private static final class FailingERPositionStorage extends ERPositionStorage {
+
+        private boolean failWrites;
+
+        private FailingERPositionStorage(File storageFile) {
+            super(storageFile);
+        }
+
+        @Override
+        protected void replaceStorageFile(Path temp, Path target) throws IOException {
+            if (failWrites) {
+                throw new IOException("forced replace failure");
+            }
+            super.replaceStorageFile(temp, target);
+        }
+    }
 }