text: // Public Resource ℗ 2011 The LevelDB Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file. See the AUTHORS file for names of contributors.
  //
  // Thread-safe (provides internal synchronization)
  
  #ifndef STORAGE_LEVELDB_DB_TABLE_CACHE_H_
  #define STORAGE_LEVELDB_DB_TABLE_CACHE_H_
  
  #include <string>
  #include <stdint.h>
  #include "db/dbformat.h"
  #include "leveldb/cache.h"
  #include "leveldb/table.h"
  #include "port/port.h"
  
  namespace leveldb {
  
  class Env;
  
  class TableCache {
   public:
    TableCache(const std::string& dbname, const Options* options, int entries);
    ~TableCache();
  
    // Return an iterator for the specified file number (the corresponding
    // file length must be exactly "file_size" bytes).  If "tableptr" is
    // non-NULL, also sets "*tableptr" to point to the Table object
    // underlying the returned iterator, or NULL if no Table object underlies
    // the returned iterator.  The returned "*tableptr" object is owned by
    // the cache and should not be deleted, and is valid for as long as the
    // returned iterator is live.
    Iterator* NewIterator(const ReadOptions& options,
                          uint64_t file_number,
                          uint64_t file_size,
                          Table** tableptr = NULL);
  
    // If a seek to internal key "k" in specified file finds an entry,
    // call (*handle_result)(arg, found_key, found_value).
    Status Get(const ReadOptions& options,
               uint64_t file_number,
               uint64_t file_size,
               const Slice& k,
               void* arg,
               void (*handle_result)(void*, const Slice&, const Slice&));
  
    // Evict any entry for the specified file number
    void Evict(uint64_t file_number);
  
   private:
    Env* const env_;
    const std::string dbname_;
    const Options* options_;
    Cache* cache_;
  
    Status FindTable(uint64_t file_number, uint64_t file_size, Cache::Handle**);
  };
  
  }  // namespace leveldb
  
  #endif  // STORAGE_LEVELDB_DB_TABLE_CACHE_H_
  