file_access_buffered.h

/*************************************************************************/
/*  file_access_buffered.h                                               */
/*************************************************************************/
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/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
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#ifndef FILE_ACCESS_BUFFERED_H
#define FILE_ACCESS_BUFFERED_H

#include "os/file_access.h"

#include "dvector.h"
#include "ustring.h"

class FileAccessBuffered : public FileAccess {

public:
    enum {
        DEFAULT_CACHE_SIZE = 128 * 1024,
    };

private:

    int cache_size;

    int cache_data_left() const;
    mutable Error last_error;

protected:

    Error set_error(Error p_error) const;

    mutable struct File {

        bool open;
        int size;
        int offset;
        String name;
        int access_flags;
    } file;

    mutable struct Cache {

        Vector<uint8_t> buffer;
        int offset;
    } cache;

    virtual int read_data_block(int p_offset, int p_size, uint8_t *p_dest = 0) const =0;

    void set_cache_size(int p_size);
    int get_cache_size();

public:

    virtual size_t get_pos() const; 
    virtual size_t get_len() const; 

    virtual void seek(size_t p_position); 
    virtual void seek_end(int64_t p_position=0); 

    virtual bool eof_reached() const;

    virtual uint8_t get_8() const;
    virtual int get_buffer(uint8_t *p_dst,int p_length) const; 

    virtual bool is_open() const;

    virtual Error get_error() const;

    FileAccessBuffered();
    virtual ~FileAccessBuffered();
};

#endif