support large file with namespace value length limit override

apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/ItemService.java

 package com.ctrip.framework.apollo.biz.service;
 
+import com.google.common.base.Strings;
+import com.google.gson.Gson;
+import com.google.gson.reflect.TypeToken;
+
 import com.ctrip.framework.apollo.biz.entity.Audit;
 import com.ctrip.framework.apollo.biz.entity.Item;
 import com.ctrip.framework.apollo.biz.entity.Namespace;
@@ -7,17 +11,30 @@ import com.ctrip.framework.apollo.biz.repository.ItemRepository;
 import com.ctrip.framework.apollo.common.utils.BeanUtils;
 import com.ctrip.framework.apollo.common.exception.BadRequestException;
 import com.ctrip.framework.apollo.common.exception.NotFoundException;
+import com.ctrip.framework.apollo.core.utils.ApolloThreadFactory;
 import com.ctrip.framework.apollo.core.utils.StringUtils;
+import com.dianping.cat.Cat;
+import com.dianping.cat.message.Message;
+import com.dianping.cat.message.Transaction;
 
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.lang.reflect.Type;
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.atomic.AtomicReference;
 
 @Service
-public class ItemService {
+public class ItemService implements InitializingBean {
+  private static final int DEFAULT_LIMIT_UPDATE_INTERVAL_IN_SECONDS = 60;
 
   @Autowired
   private ItemRepository itemRepository;
@@ -31,6 +48,61 @@ public class ItemService {
   @Autowired
   private ServerConfigService serverConfigService;
 
+  private AtomicInteger globalKeyLengthLimit;
+
+  private AtomicInteger globalValueLengthLimit;
+
+  private AtomicReference<Map<Long, Integer>> namespaceValueLengthOverride;
+
+  private Gson gson;
+
+  private ScheduledExecutorService executorService;
+
+  private static final Type namespaceValueLengthOverrideTypeReference =
+      new TypeToken<Map<Long, Integer>>() {
+      }.getType();
+
+  public ItemService() {
+    gson = new Gson();
+    globalKeyLengthLimit = new AtomicInteger(128);
+    globalValueLengthLimit = new AtomicInteger(20000);
+    namespaceValueLengthOverride = new AtomicReference<>();
+    executorService = Executors.newScheduledThreadPool(1, ApolloThreadFactory
+        .create("ItemServiceLimitUpdater", true));
+  }
+
+  @Override
+  public void afterPropertiesSet() throws Exception {
+    executorService.scheduleWithFixedDelay(() -> {
+      Transaction transaction = Cat.newTransaction("Apollo.ItemServiceLimitUpdater", "updateLimit");
+      try {
+        updateLimits();
+        transaction.setStatus(Message.SUCCESS);
+      } catch (Throwable ex) {
+        transaction.setStatus(ex);
+      } finally {
+        transaction.complete();
+      }
+    }, 0, getLimitUpdateIntervalInSeconds(), TimeUnit.SECONDS);
+  }
+
+  private void updateLimits() {
+    String keyLengthLimit = serverConfigService.getValue("item.key.length.limit", null);
+    if (!Strings.isNullOrEmpty(keyLengthLimit)) {
+      globalKeyLengthLimit.set(Integer.valueOf(keyLengthLimit));
+    }
+    String valueLengthLimit = serverConfigService.getValue("item.value.length.limit", null);
+    if (!Strings.isNullOrEmpty(valueLengthLimit)) {
+      globalValueLengthLimit.set(Integer.valueOf(valueLengthLimit));
+    }
+    String namespaceValueLengthOverrideString =
+        serverConfigService.getValue("namespace.value.length.limit.override", null);
+    if (!Strings.isNullOrEmpty(namespaceValueLengthOverrideString)) {
+      namespaceValueLengthOverride.set(gson.fromJson(
+          namespaceValueLengthOverrideString, namespaceValueLengthOverrideTypeReference));
+    }
+  }
+
   @Transactional
   public Item delete(long id, String operator) {
     Item item = itemRepository.findOne(id);
@@ -100,7 +172,7 @@ public class ItemService {
   @Transactional
   public Item save(Item entity) {
     checkItemKeyLength(entity.getKey());
-    checkItemValueLength(entity.getValue());
+    checkItemValueLength(entity.getNamespaceId(), entity.getValue());
 
     entity.setId(0);//protection
 
@@ -120,7 +192,7 @@ public class ItemService {
 
   @Transactional
   public Item update(Item item) {
-    checkItemValueLength(item.getValue());
+    checkItemValueLength(item.getNamespaceId(), item.getValue());
     Item managedItem = itemRepository.findOne(item.getId());
     BeanUtils.copyEntityProperties(item, managedItem);
     managedItem = itemRepository.save(managedItem);
@@ -131,20 +203,30 @@ public class ItemService {
     return managedItem;
   }
 
-  private boolean checkItemValueLength(String value) {
-    int lengthLimit = Integer.valueOf(serverConfigService.getValue("item.value.length.limit", "20000"));
-    if (!StringUtils.isEmpty(value) && value.length() > lengthLimit) {
-      throw new BadRequestException("value too long. length limit:" + lengthLimit);
+  private boolean checkItemValueLength(long namespaceId, String value) {
+    int limit = getItemValueLengthLimit(namespaceId);
+    if (!StringUtils.isEmpty(value) && value.length() > limit) {
+      throw new BadRequestException("value too long. length limit:" + limit);
     }
     return true;
   }
 
   private boolean checkItemKeyLength(String key) {
-    int lengthLimit = Integer.valueOf(serverConfigService.getValue("item.key.length.limit", "128"));
-    if (!StringUtils.isEmpty(key) && key.length() > lengthLimit) {
-      throw new BadRequestException("key too long. length limit:" + lengthLimit);
+    if (!StringUtils.isEmpty(key) && key.length() > globalKeyLengthLimit.get()) {
+      throw new BadRequestException("key too long. length limit:" + globalKeyLengthLimit.get());
     }
     return true;
   }
 
+  private int getItemValueLengthLimit(long namespaceId) {
+    if (namespaceValueLengthOverride.get() != null && namespaceValueLengthOverride.get()
+        .containsKey(namespaceId)) {
+      return namespaceValueLengthOverride.get().get(namespaceId);
+    }
+    return globalValueLengthLimit.get();
+  }
+
+  private int getLimitUpdateIntervalInSeconds() {
+    return DEFAULT_LIMIT_UPDATE_INTERVAL_IN_SECONDS;
+  }
 }