NameHash.h

// -*- c++ -*-

#ifndef __NAME_HASH_H__
#define __NAME_HASH_H__

// tools
#include "tools/ToolsConfig.h"
#include "tools/NoCopy.h"

// storage
#include "storage/FileAllocator.h"



class NameHash
{
public:
    
    static const uint32_t anchor_size = 8;
    
    NameHash(FileAllocator &fa, FileOffset anchor);

    void init(uint32_t ht_size=1009);

    void reattach();

    bool insert(const stdString &name, const stdString &ID_txt, FileOffset ID);

    class Entry
    {
    public:
        virtual ~Entry();
        
        virtual const stdString &getName() const = 0;
        
        virtual const stdString &getIdTxt() const = 0;
    
        virtual FileOffset getId() const = 0;
    };

    Entry *find(const stdString &name);

    class Iterator : public Entry
    {
    public:
        virtual ~Iterator();
        
        virtual bool isValid() const = 0;
        
        virtual void next() = 0;
    };
    
    Iterator *iterator();

    void showStats(FILE *f);

private:

    friend class PrivateIterator;

    PROHIBIT_DEFAULT_COPY(NameHash);
    
    FileAllocator &fa;
    FileOffset anchor;       // Where offset gets deposited in file
    uint32_t ht_size;   // Hash Table size (entries, not bytes)
    FileOffset table_offset; // Start of HT in file
    
    uint32_t hash(const stdString &name) const;  

    FileOffset read_HT_entry(uint32_t hash_value) const;
    
    void write_HT_entry(uint32_t hash_value, FileOffset offset) const;
};


#endif