file_access_network.h

/*************************************************************************/
/*  file_access_network.h                                                */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
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/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
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#ifndef FILE_ACCESS_NETWORK_H
#define FILE_ACCESS_NETWORK_H

#include "os/file_access.h"
#include "os/semaphore.h"
#include "os/thread.h"
#include "io/stream_peer_tcp.h"

class FileAccessNetwork;

class FileAccessNetworkClient {


    struct BlockRequest {

        int id;
        uint64_t offset;
        int size;
    };

    int ml;

    List<BlockRequest> block_requests;

    Semaphore *sem;
    Thread *thread;
    bool quit;
    Mutex *mutex;
    Mutex *blockrequest_mutex;
    Map<int,FileAccessNetwork*> accesses;
    Ref<StreamPeerTCP> client;
    int last_id;

    Vector<uint8_t> block;

    void _thread_func();
    static void _thread_func(void *s);

    void put_32(int p_32);
    void put_64(int64_t p_64);
    int get_32();
    int64_t get_64();
    int lockcount;
    void lock_mutex();
    void unlock_mutex();

friend class FileAccessNetwork;
    static FileAccessNetworkClient *singleton;

public:

    static FileAccessNetworkClient *get_singleton() { return singleton; }

    Error connect(const String& p_host,int p_port,const String& p_password="");

    FileAccessNetworkClient();
    ~FileAccessNetworkClient();

};

class FileAccessNetwork : public FileAccess {

    Semaphore *sem;
    Semaphore *page_sem;
    Mutex *buffer_mutex;
    bool opened;
    size_t total_size;
    mutable size_t pos;
    int id;
    mutable bool eof_flag;
    mutable int last_page;
    mutable uint8_t *last_page_buff;

    uint32_t page_size;
    int read_ahead;
    int max_pages;

    mutable int waiting_on_page;
    mutable int last_activity_val;
    struct Page {
        int activity;
        bool queued;
        Vector<uint8_t> buffer;
        Page() { activity=0; queued=false; }
    };

    mutable Vector<	Page > pages;

    mutable Error response;

    uint64_t exists_modtime;
friend class FileAccessNetworkClient;
    void _queue_page(int p_page) const;
    void _respond(size_t p_len,Error p_status);
    void _set_block(size_t p_offset,const Vector<uint8_t>& p_block);

public:

    enum Command {
        COMMAND_OPEN_FILE,
        COMMAND_READ_BLOCK,
        COMMAND_CLOSE,
        COMMAND_FILE_EXISTS,
        COMMAND_GET_MODTIME,
    };

    enum Response {
        RESPONSE_OPEN,
        RESPONSE_DATA,
        RESPONSE_FILE_EXISTS,
        RESPONSE_GET_MODTIME,
    };


    virtual Error _open(const String& p_path, int p_mode_flags); 
    virtual void close(); 
    virtual bool is_open() const; 

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

    virtual bool eof_reached() const; 

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

    virtual Error get_error() const; 

    virtual void store_8(uint8_t p_dest); 

    virtual bool file_exists(const String& p_path); 

    virtual uint64_t _get_modified_time(const String& p_file);

    FileAccessNetwork();
    ~FileAccessNetwork();
};

#endif // FILE_ACCESS_NETWORK_H