修改sstable读取逻辑-陈予曈

leveldb_base/table/block.cc

@@ -15,7 +15,7 @@
 #include "util/coding.h"
 #include "util/logging.h"
 
-// 添加所需头文件-柠
+// 添加所需头文件-陈予曈
 #include <iostream>
 #include <sstream> 
 #include <iomanip>
@@ -168,6 +168,7 @@ class Block::Iter : public Iterator {
     } while (ParseNextKey() && NextEntryOffset() < original);
   }
 
+  // 修改sstable读取逻辑-陈予曈
   void Seek(const Slice& target) override {
     // Binary search in restart array to find the last restart point
     // with a key < target
@@ -228,28 +229,28 @@ class Block::Iter : public Iterator {
         return;
       }
       if (Compare(key_, target) >= 0) {
-        //重新解析record-柠       
+        // 重新解析record-陈予曈       
         std::string value_with_ttl(value_.data(), value_.size());
         if (value_with_ttl.size() >= 19) {
           std::string expiration_time_str = value_with_ttl.substr(value_with_ttl.size() - 19); // 提取过期时间戳
           std::tm tm = {};
           char* res = strptime(expiration_time_str.c_str(), "%Y-%m-%d %H:%M:%S", &tm);
-          if (res == nullptr) {
+          if (res == nullptr) {   // 解析时间戳失败
             value_ = Slice(value_.data(), value_.size()-19);
           } else {
             std::time_t expiration_time = std::mktime(&tm);
             std::time_t current_time = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());
-            if (expiration_time <= current_time) {
+            if (expiration_time <= current_time) {   // 数据过期
               //std::cerr << "notfound_sst" << std::endl;
               status_ = Status::NotFound(Slice());
               value_ = Slice(value_.data(), 0);
             }
-            else
+            else   //数据未过期
             {
               value_ = Slice(value_.data(), value_.size()-19);
             }
           }
-        } else {
+        } else {    // 时间戳信息不存在
           value_ = Slice(value_.data(), value_.size());
         }
         return;