From 6102110245eee8b130533f33efd85a7a3e640d76 Mon Sep 17 00:00:00 2001
From: alexfisher <1823748191@qq.com>
Date: Sun, 1 Dec 2024 22:52:28 +0800
Subject: [PATCH] fix deletion bug for version 2

---
 CMakeLists.txt              | 4 ++--
 db/db_impl.cc               | 2 +-
 include/leveldb/slice.h     | 3 +++
 test/benchmark_4leveldb.cpp | 4 ++--
 4 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 019814b..91a44f2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -521,7 +521,7 @@ add_executable(db_test1
 "${PROJECT_SOURCE_DIR}/test/test.cpp"
       )
 target_link_libraries(db_test1 PRIVATE leveldb gtest)
-add_executable(db_test2
+add_executable(db_test_bench
 "${PROJECT_SOURCE_DIR}/test/benchmark_4leveldb.cpp"
       )
-target_link_libraries(db_test2 PRIVATE leveldb gtest)
\ No newline at end of file
+target_link_libraries(db_test_bench PRIVATE leveldb gtest)
\ No newline at end of file
diff --git a/db/db_impl.cc b/db/db_impl.cc
index d00a2fb..56d51ec 100644
--- a/db/db_impl.cc
+++ b/db/db_impl.cc
@@ -1044,7 +1044,7 @@ Status DBImpl::DoCompactionWork(CompactionState* compact) {
       Slice old_value=input->value();
       Slice new_value;
       std::string buf="";
-      if(old_value.data()[0]==(char)(0x00)){
+      if(old_value.size()==0||old_value.data()[0]==(char)(0x00)){//when it is a deletion, input->value() will be ""
         new_value=old_value;
       }
       else{
diff --git a/include/leveldb/slice.h b/include/leveldb/slice.h
index e97223a..d225f34 100644
--- a/include/leveldb/slice.h
+++ b/include/leveldb/slice.h
@@ -69,6 +69,9 @@ class LEVELDB_EXPORT Slice {
 
   // Drop the first "n" bytes from this slice.
   void remove_prefix(size_t n) {
+    if(n>size()){
+      assert(0);
+    }
     assert(n <= size());
     data_ += n;
     size_ -= n;
diff --git a/test/benchmark_4leveldb.cpp b/test/benchmark_4leveldb.cpp
index e5cd665..7573a04 100644
--- a/test/benchmark_4leveldb.cpp
+++ b/test/benchmark_4leveldb.cpp
@@ -7,11 +7,11 @@
 #include "leveldb/db.h"
 
 // 配置
-const int TEST_EXPONENT = 4;
+const int TEST_EXPONENT = 5;
 const int TEST_FREQUENCY = static_cast<int>(std::pow(10, TEST_EXPONENT));
 const int MIN_STR_LEN = 255;
 const int MAX_STR_LEN = 1024;
-const std::string DB_PATH = "./db_benchmark";
+const std::string DB_PATH = "db_benchmark";
 const std::string CHARSET = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
 
 // 多语言