多字段-SerializeValue，ParseValue

db/NewDB.cc

@@ -19,6 +19,62 @@ NewDB::~NewDB() {
 
 }
 
+std::string NewDB::SerializeValue(const FieldArray& fields){
+    std::string value_str;
+    for(const auto& pair : fields){
+        std::string field = pair.first + ":" + pair.second;
+        uint32_t field_size = field.size();
+        char buffer[4];
+        EncodeFixed32(buffer, field_size);
+        value_str.append(buffer, 4);
+        value_str.append(field);
+    }
+    return value_str;
+
+    //   std::string s;
+    //   for(auto& field : fields){
+    //     PutLengthPrefixedSlice(&s, Slice(field.first));
+    //     PutLengthPrefixedSlice(&s, Slice(field.second));
+    //   }
+    //   return s;
+}
+
+FieldArray NewDB::ParseValue(const std::string& value_str){
+    FieldArray fields;
+    const char* data = value_str.data();
+    size_t length = value_str.size();
+
+    while (length >= 4) {
+        uint32_t field_size = DecodeFixed32(data);
+        if (length < 4 + field_size) {
+        break;
+        }
+
+        std::string field(data + 4, field_size);
+        size_t colon_pos = field.find(':');
+
+        std::string field_name = field.substr(0, colon_pos);
+        std::string field_value = field.substr(colon_pos + 1);
+
+        fields.push_back(std::make_pair(field_name,field_value));
+
+        data += 4 + field_size;
+        length -= 4 + field_size;
+    }
+
+    return fields;
+
+    //   Slice input(value_str);
+    //   Slice v1,v2;
+    //   FieldArray fields;
+    //   while(v1!=Slice()){
+    //     GetLengthPrefixedSlice(&input, &v1);
+    //     GetLengthPrefixedSlice(&input, &v2);
+    //     fields.push_back(std::make_pair(v1.ToString(), v2.ToString()));
+    //   }
+    //   return fields; 
+}
+
 Status NewDB::Open(const Options& options, const std::string& name, NewDB** dbptr) {
 
 }