text: /*
   *  Copyright 1996, University Corporation for Atmospheric Research
   *  See netcdf/COPYRIGHT file for copying and redistribution conditions.
   */
  /* Id */
  
  #ifndef _NCIO_H_
  #define _NCIO_H_
  
  #include "ncconfig.h"
  
  #include <stddef.h> /* size_t */
  #ifndef NO_SYS_TYPES_H
  #  include <sys/types.h>  /* off_t */
  #endif /* NO_SYS_TYPES_H */
  #include "netcdf.h"
  
  typedef struct ncio ncio; /* forward reference */
  
  /*
   * A value which is an invalid off_t
   */
  #define OFF_NONE  ((off_t)(-1))
  
  /*
   * Flags used by the region layer,
   *  'rflags' argument to ncio.rel() and ncio.get().
   */
  #define RGN_NOLOCK  0x1 /* Don't lock region.
           * Used when contention control handled
           * elsewhere.
           */
  #define RGN_NOWAIT  0x2 /* return immediate if can't lock, else wait */
  
  #define RGN_WRITE 0x4 /* we intend to modify, else read only */
  
  #define RGN_MODIFIED  0x8 /* we did modify, else, discard */
  
  
  /*
   * The next four typedefs define the signatures
   * of function pointers in struct ncio below.
   * They are not used outside of this file and ncio.h,
   * They just make some casts in the ncio.c more readable.
   */
    /*
     * Indicate that you are done with the region which begins
     * at offset. Only reasonable flag value is RGN_MODIFIED.
     */
  typedef int ncio_relfunc(ncio *const nciop,
       off_t offset, int rflags);
  
    /*
     * Request that the region (offset, extent)
     * be made available through *vpp.
     */
  typedef int ncio_getfunc(ncio *const nciop,
        off_t offset, size_t extent,
        int rflags,
        void **const vpp);
  
    /*
     * Like memmove(), safely move possibly overlapping data.
     * Only reasonable flag value is RGN_NOLOCK.
     */
  typedef int ncio_movefunc(ncio *const nciop, off_t to, off_t from,
        size_t nbytes, int rflags);
  
    /*
     * Write out any dirty buffers to disk and
     * ensure that next read will get data from disk.
     */
  typedef int ncio_syncfunc(ncio *const nciop);
  
    /*
     * Don't call this. 
     * Internal function called at close to
     * free up anything hanging off pvt;
     */
  typedef void ncio_freefunc(void *const pvt);
  
  /* Get around cplusplus "const xxx in class ncio without constructor" error */
  #if defined(__cplusplus)
  #define NCIO_CONST
  #else
  #define NCIO_CONST const
  #endif
  
  /*
   * netcdf i/o abstraction
   */
  struct ncio {
    /*
     * A copy of the ioflags argument passed in to ncio_open()
     * or ncio_create().
     */
    int ioflags;
  
    /*
     * The file descriptor of the netcdf file.
     * This gets handed to the user as the netcdf id.
     */
    NCIO_CONST int fd;
  
    /* member functions do the work */
  
    ncio_relfunc *NCIO_CONST rel;
  
    ncio_getfunc *NCIO_CONST get;
  
    ncio_movefunc *NCIO_CONST move;
  
    ncio_syncfunc *NCIO_CONST sync;
  
    ncio_freefunc *NCIO_CONST free; /* Implementation private */
  
    /*
     * A copy of the 'path' argument passed in to ncio_open()
     * or ncio_create(). Used by ncabort() to remove (unlink)
     * the file and by error messages.
     */
    const char *path;
  
    /* implementation private stuff */
    void *NCIO_CONST pvt;
  };
  
  #undef NCIO_CONST
  
  extern int
  ncio_create(const char *path, int ioflags,
    size_t initialsz,
    off_t igeto, size_t igetsz, size_t *sizehintp,
    ncio **nciopp, void **const igetvpp);
  
  extern int
  ncio_open(const char *path,
    int ioflags,
    off_t igeto, size_t igetsz, size_t *sizehintp,
    ncio **nciopp, void **const igetvpp);
  
  extern int 
  ncio_close(ncio *nciop, int doUnlink);
  
  extern int
  ncio_filesize(ncio *nciop, off_t *filesizep);
  
  extern int
  ncio_pad_length(ncio *nciop, off_t length);
  
  #endif /* _NCIO_H_ */
  