src/vfer_datagram.h

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/*
 * Copyright 2005, 2006, Internet2
 * Legal conditions are in file LICENSE
 * (MD5 = c434f2e53b8089d8b4d0172c7ce07360).
 */
/**
 *
 * @file   vfer_datagram.h
 * @author Ivan Beschastnikh
 * @brief  Header file for use by datagram.c defines datagrams and datagrams list.
 *
 * -     02/18/06        ivan            created
 */

#ifndef VFER_DATAGRAM_H
#define VFER_DATAGRAM_H

/* 
 * includes 
 */

#include <sys/uio.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>

/* 
 * data types
 */

/* 
   longest combination of header and data iovecs for protocol: 
   [optional cc_ack header]->[data_header]->[data]
*/
#define MAX_VECS        3

/**
 * @brief Frame stats structure used by the context_t structure for functional reliability
 */
typedef struct frame_stats {
  uint32_t vec_acks;
  uint32_t first_frag_time;
  uint32_t last_frag_time;
  uint32_t frags_complete;
  uint32_t frags_incomplete;
} frame_stats;

/**
 * @brief Interval structure to track which intervals have not received any data yet (missing data intervals)
 */
typedef struct interval {
        uint32_t start;         /* start of interval */
        uint32_t end;           /* end of interval */
        struct interval* prev;  /* previous list element */
        struct interval* next;  /* next list element */
} interval_t;

/**
 * @brief Interval structure to track which intervals have not received any data yet (missing data intervals)
 */
typedef struct intervals {
        struct interval* head;  /* previous list element */
        uint32_t count;         /* number of intervals in the list */
} intervals_t;

/**
 * @brief Frame structure holding fragments, their indicators, and other info
 */
typedef struct frame {
        void* data;
        int len;                 /* total length of frame in bytes (must be <= num_frags * frag_size) */
        uint32_t frame_num;      /* frame number/identifier */
        intervals_t missing_data; /* interval list of missing data */
        char done;               /* a 0 indicates that the frame is not done and 1 indicates that the frame is done and awaits to be moved into the recvd_frames list */
        int urgency;             /* urgency of this frame */
        frame_stats stats;
} frame;

/**
 * @brief Frame link in a frames linked list
 */
typedef struct frame_link {
        struct frame frame;
        struct frame_link* next;
} frame_link;

/**
 * @brief Frames linked list such as recvd frames, or send frames
 */
typedef struct frame_list {
        int num;
        uint32_t length;        /* total size of bytes enqueued in this frame list */
        uint16_t last_frame_num;
        uint16_t first_frame_num;
        struct frame_link* first;
        struct frame_link* last;
} frame_list;

/* 
 * function prototypes
 */

inline int              Datagram_Enqueue        (frame_list* frames, const void* buffer, int len, int frame_num);
inline int              Datagram_Dequeue        (frame_list* frames, void* buffer, int len);
inline void             Datagram_Remove         (frame_list* list, frame_link* prev, frame_link* remove);
inline void             Datagram_Insert         (frame_list* list, frame_link* prev, frame_link* insert);
inline frame_link*      Datagram_Insert_Phantom (frame_list* list, frame_link* prev, int frame_num);
void                    Datagrams_Print         (frame_list* list);
inline void             Datagrams_Clear         (frame_list* list);

#endif /* VFER_DATAGRAM_H */

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