#pragma once
#include <functional>

class IStorageFactory
{
public:
    typedef void (*key_load_iterator)(const char *rgchKey, size_t cchKey);

    virtual ~IStorageFactory() {}
    virtual class IStorage *create(int db, key_load_iterator itr) = 0;
    virtual const char *name() const = 0;
};

class IStorage
{
public:
    typedef std::function<bool(const char *, size_t, const void *, size_t)> callback;
    typedef std::function<void(const char *, size_t, const void *, size_t)> callbackSingle;

    virtual ~IStorage();

    virtual void insert(const char *key, size_t cchKey, void *data, size_t cb, bool fOverwire) = 0;
    virtual bool erase(const char *key, size_t cchKey) = 0;
    virtual void retrieve(const char *key, size_t cchKey, callbackSingle fn) const = 0;
    virtual size_t clear() = 0;
    virtual bool enumerate(callback fn) const = 0;
    virtual size_t count() const = 0;

    virtual void beginWriteBatch() {} // NOP
    virtual void endWriteBatch() {} // NOP

    virtual void flush() = 0;

    /* This is permitted to be a shallow clone */
    virtual const IStorage *clone() const = 0;
};