dummy.h

#ifndef pjssaber
#define pjssaber
#define LEVELDB_EXPORT
#pragma once
#include<iostream>
#include<algorithm>
#include<vector>
#include <cassert>
namespace pjssaber{

// for little-endian datas, implement a method to transfer fixed size 32bit data to a U32 integer

class LEVELDB_EXPORT Slice {
 public:
  // Create an empty slice.
  Slice() : data_(""), size_(0) {}

  // Create a slice that refers to d[0,n-1].
  Slice(const char* d, size_t n) : data_(d), size_(n) {}

  // Create a slice that refers to the contents of "s"
  Slice(const std::string& s) : data_(s.data()), size_(s.size()) {}

  // Create a slice that refers to s[0,strlen(s)-1]
  Slice(const char* s) : data_(s), size_(strlen(s)) {}

  // Intentionally copyable.
  Slice(const Slice&) = default;
  Slice& operator=(const Slice&) = default;

  // Return a pointer to the beginning of the referenced data
  const char* data() const { return data_; }

  // Return the length (in bytes) of the referenced data
  size_t size() const { return size_; }

  // Return true iff the length of the referenced data is zero
  bool empty() const { return size_ == 0; }

  // Return the ith byte in the referenced data.
  // REQUIRES: n < size()
  char operator[](size_t n) const {
    assert(n < size());
    return data_[n];
  }

  // Change this slice to refer to an empty array
  void clear() {
    data_ = "";
    size_ = 0;
  }

  // Drop the first "n" bytes from this slice.
  void remove_prefix(size_t n) {
    assert(n <= size());
    data_ += n;
    size_ -= n;
  }
};

struct LRUHandle {
  void* value;
  void (*deleter)(const Slice&, void* value);
  LRUHandle* next_hash; // this is used for handle_table of same hash value
  LRUHandle* next;      // this 
  LRUHandle* prev;      //  two is used for LRU double-linked list
  size_t charge;  // TODO(opt): Only allow uint32_t?
  size_t key_length;
  bool in_cache;     // Whether entry is in the cache.
  uint32_t refs;     // References, including cache reference, if present.
  uint32_t hash;     // Hash of key(); used for fast sharding and comparisons
  char key_data[1];  // Beginning of key

  Slice key() const {
    // next is only equal to this if the LRU handle is the list head of an
    // empty list. List heads never have meaningful keys.
    assert(next != this);

    return Slice(key_data, key_length);
  }
};

inline bool operator!=(const Slice& x, const Slice& y) { return !(x == y); }





}
#endif