feat(backend): move command execution logic into separate impl class

Author: BrotherJing

scalable-ot-core/src/main/java/com/brotherjing/core/executor/CommandExecutorRegistry.java

@@ -0,0 +1,32 @@
+package com.brotherjing.core.executor;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Component;
+
+import com.brotherjing.proto.BaseProto;
+
+@Component
+public class CommandExecutorRegistry {
+
+    private List<ICommandExecutor> executorList;
+
+    private Map<BaseProto.DocType, ICommandExecutor> executorMap;
+
+    @Autowired
+    public CommandExecutorRegistry(List<ICommandExecutor> executorList) {
+        this.executorList = executorList;
+        this.executorMap = new HashMap<>();
+        for (ICommandExecutor executor : executorList) {
+            executorMap.put(executor.getSupportedType(), executor);
+        }
+    }
+
+    public ICommandExecutor getCommandExecutor(BaseProto.DocType docType) {
+        return executorMap.get(docType);
+    }
+
+}

scalable-ot-core/src/main/java/com/brotherjing/core/executor/ICommandExecutor.java

@@ -0,0 +1,12 @@
+package com.brotherjing.core.executor;
+
+import com.brotherjing.core.dto.SnapshotDto;
+import com.brotherjing.proto.BaseProto;
+
+public interface ICommandExecutor {
+
+    BaseProto.DocType getSupportedType();
+
+    void applySingle(SnapshotDto dto, BaseProto.Command command);
+
+}

scalable-ot-core/src/main/java/com/brotherjing/core/executor/impl/TextCommandExecutor.java

@@ -0,0 +1,68 @@
+package com.brotherjing.core.executor.impl;
+
+import java.util.Collections;
+import java.util.List;
+
+import lombok.extern.slf4j.Slf4j;
+
+import org.springframework.stereotype.Component;
+
+import com.brotherjing.core.dto.SnapshotDto;
+import com.brotherjing.core.executor.ICommandExecutor;
+import com.brotherjing.proto.BaseProto;
+import com.brotherjing.proto.TextProto;
+import com.google.protobuf.InvalidProtocolBufferException;
+
+@Slf4j
+@Component
+public class TextCommandExecutor implements ICommandExecutor {
+
+    @Override
+    public BaseProto.DocType getSupportedType() {
+        return BaseProto.DocType.PLAIN_TEXT;
+    }
+
+    @Override
+    public void applySingle(SnapshotDto dto, BaseProto.Command command) {
+        log.info("command type is {}", command.getOp().getTypeUrl());
+        try {
+            if (command.getOp().is(TextProto.Operation.class)) {
+                TextProto.Operation op = command.getOp().unpack(TextProto.Operation.class);
+                applyTextOp(dto, op);
+            }
+        } catch (InvalidProtocolBufferException e) {
+            e.printStackTrace();
+        }
+    }
+
+    private void applyTextOp(SnapshotDto dto, TextProto.Operation op) {
+        List<TextProto.Operation> operations;
+        if (op.hasMultiple()) {
+            operations = op.getMultiple().getOpsList();
+        } else {
+            operations = Collections.singletonList(op);
+        }
+        String data = dto.getData();
+        int index = 0;
+        for (TextProto.Operation operation : operations) {
+            switch (operation.getType()) {
+            case RETAIN:
+                index += operation.getRetain();
+                break;
+            case INSERT:
+                data = data.substring(0, index)
+                           .concat(operation.getInsert())
+                           .concat(data.substring(index));
+                index += operation.getInsert().length();
+                break;
+            case DELETE:
+                int right = Math.min(data.length(), index + operation.getDelete().getDelete());
+                data = data.substring(0, index).concat(data.substring(right));
+                break;
+            default:
+                break;
+            }
+        }
+        dto.setData(data);
+    }
+}

scalable-ot-core/src/main/java/com/brotherjing/core/service/impl/DocServiceImpl.java

@@ -15,20 +15,23 @@
 import com.brotherjing.core.dao.DocDao;
 import com.brotherjing.core.dto.CommandDto;
 import com.brotherjing.core.dto.SnapshotDto;
+import com.brotherjing.core.executor.CommandExecutorRegistry;
+import com.brotherjing.core.executor.ICommandExecutor;
 import com.brotherjing.core.service.DocService;
 import com.brotherjing.core.util.Converter;
 import com.brotherjing.core.util.IDUtils;
 import com.brotherjing.core.util.ShortUUID;
 import com.brotherjing.proto.BaseProto;
-import com.brotherjing.proto.TextProto;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
-import com.google.protobuf.InvalidProtocolBufferException;
 
 @Slf4j
 @Service
 public class DocServiceImpl implements DocService {
 
+    @Autowired
+    private CommandExecutorRegistry registry;
+
     @Autowired
     private DocDao docDao;
 
@@ -119,60 +122,20 @@ public BaseProto.Snapshot apply(String docId, List<BaseProto.Command> commands)
     }
 
     private void apply(SnapshotDto dto, List<BaseProto.Command> commands) {
-        if (commands == null) {
+        if (commands == null || commands.isEmpty()) {
+            return;
+        }
+        ICommandExecutor executor = registry.getCommandExecutor(commands.get(0).getType());
+        if (executor == null) {
+            log.error("Cannot find executor for this command type: {}", commands.get(0).getType().name());
             return;
         }
         for (BaseProto.Command command : commands) {
-            applySingle(dto, command);
+            executor.applySingle(dto, command);
             dto.setVersion(dto.getVersion() + 1);
         }
     }
 
-    private void applySingle(SnapshotDto dto, BaseProto.Command command) {
-        if (BaseProto.DocType.PLAIN_TEXT.equals(command.getType())) {
-            log.info("command type is {}", command.getOp().getTypeUrl());
-            try {
-                if (command.getOp().is(TextProto.Operation.class)) {
-                    TextProto.Operation op = command.getOp().unpack(TextProto.Operation.class);
-                    applyTextOp(dto, op);
-                }
-            } catch (InvalidProtocolBufferException e) {
-                e.printStackTrace();
-            }
-        }
-    }
-
-    private void applyTextOp(SnapshotDto dto, TextProto.Operation op) {
-        List<TextProto.Operation> operations;
-        if (op.hasMultiple()) {
-            operations = op.getMultiple().getOpsList();
-        } else {
-            operations = Collections.singletonList(op);
-        }
-        String data = dto.getData();
-        int index = 0;
-        for (TextProto.Operation operation : operations) {
-            switch (operation.getType()) {
-            case RETAIN:
-                index += operation.getRetain();
-                break;
-            case INSERT:
-                data = data.substring(0, index)
-                           .concat(operation.getInsert())
-                           .concat(data.substring(index));
-                index += operation.getInsert().length();
-                break;
-            case DELETE:
-                int right = Math.min(data.length(), index + operation.getDelete().getDelete());
-                data = data.substring(0, index).concat(data.substring(right));
-                break;
-            default:
-                break;
-            }
-        }
-        dto.setData(data);
-    }
-
     /**
      * Try take snapshot at certain intervals
      *

scripts/mongo-start.sh

@@ -1,3 +1,3 @@
 #!/usr/bin/env bash
 
-docker run -d -p 27017-27019:27017-27019 --name mongodb mongo
+docker run -d -p 27017-27019:27017-27019 --name mongodb --rm mongo