netcdf-c/libsrc4/nc4grp.c

/* Copyright 2005-2018, University Corporation for Atmospheric
 * Research. See COPYRIGHT file for copying and redistribution
 * conditions. */
/**
 * @file 
 * @internal This file is part of netcdf-4, a netCDF-like interface
 * for HDF5, or a HDF5 backend for netCDF, depending on your point of
 * view.
 *
 * This file handles groups.
 * 
 * @author Ed Hartnett
*/

#include "nc4internal.h"
#include "nc4dispatch.h"
/**
 * @internal Given an ncid and group name (NULL gets root group),
 * return the ncid of that group. 
 *
 * @param ncid File and group ID.
 * @param name Pointer that gets name.
 * @param grp_ncid Pointer that gets group ncid.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @return ::NC_ENOTNC4 Not a netCDF-4 file.
 * @return ::NC_ENOGRP Group not found.
 * @author Ed Hartnett
*/
int
NC4_inq_ncid(int ncid, const char *name, int *grp_ncid)
{
   NC_GRP_INFO_T *grp, *g;
   NC_FILE_INFO_T *h5;
   char norm_name[NC_MAX_NAME + 1];
   int retval;

   LOG((2, "nc_inq_ncid: ncid 0x%x name %s", ncid, name));
   
   /* Find info for this file and group, and set pointer to each. */
   if ((retval = nc4_find_grp_h5(ncid, &grp, &h5)))
      return retval;
   assert(h5);

   /* Normalize name. */
   if ((retval = nc4_check_name(name, norm_name)))
      return retval;

   g = (NC_GRP_INFO_T*)ncindexlookup(grp->children,norm_name);
   if(g != NULL) 
   {
	 if (grp_ncid)
	    *grp_ncid = grp->nc4_info->controller->ext_ncid | g->hdr.id;
	 return NC_NOERR;
   }
   
   /* If we got here, we didn't find the named group. */
   return NC_ENOGRP;
}

/**
 * @internal Given a location id, return the number of groups it
 * contains, and an array of their locids. 
 *
 * @param ncid File and group ID.
 * @param numgrps Pointer that gets number of groups. Ignored if NULL.
 * @param ncids Pointer that gets array of ncids. Ignored if NULL.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @author Ed Hartnett
*/
int
NC4_inq_grps(int ncid, int *numgrps, int *ncids)
{
   NC_GRP_INFO_T *grp, *g;
   NC_FILE_INFO_T *h5;
   int num = 0;
   int retval;
   int i;

   LOG((2, "nc_inq_grps: ncid 0x%x", ncid));

   /* Find info for this file and group, and set pointer to each. */
   if ((retval = nc4_find_grp_h5(ncid, &grp, &h5)))
      return retval;
   assert(h5);

   /* Count the number of groups in this group. */
   for(i=0;i<ncindexsize(grp->children);i++)
   {
      g = (NC_GRP_INFO_T*)ncindexith(grp->children,i);
      if(g == NULL) continue;
      if (ncids)
      {
	 /* Combine the nc_grpid in a bitwise or with the ext_ncid,
	  * which allows the returned ncid to carry both file and
	  * group information. */
	 *ncids = g->hdr.id | g->nc4_info->controller->ext_ncid;
	 ncids++;
      }
      num++;
   }
   
   if (numgrps)
      *numgrps = num;

   return NC_NOERR;
}

/**
 * @internal Given locid, find name of group. (Root group is named
 * "/".) 
 *
 * @param ncid File and group ID.
 * @param name Pointer that gets name.

 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @author Ed Hartnett
*/
int
NC4_inq_grpname(int ncid, char *name)
{
   NC_GRP_INFO_T *grp;
   NC_FILE_INFO_T *h5;
   int retval;

   LOG((2, "nc_inq_grpname: ncid 0x%x", ncid));

   /* Find info for this file and group, and set pointer to each. */
   if ((retval = nc4_find_grp_h5(ncid, &grp, &h5)))
      return retval;
   assert(h5);

   /* Copy the name. */
   if (name)
      strcpy(name, grp->hdr.name);

   return NC_NOERR;
}

/**
 * @internal Find the full path name to the group represented by
 * ncid. Either pointer argument may be NULL; pass a NULL for the
 * third parameter to get the length of the full path name. The length
 * will not include room for a null pointer. 
 *
 * @param ncid File and group ID.
 * @param lenp Pointer that gets length of full name.
 * @param full_name Pointer that gets name.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @return ::NC_ENOMEM Out of memory.
 * @author Ed Hartnett
*/
int
NC4_inq_grpname_full(int ncid, size_t *lenp, char *full_name)
{
   char *name, grp_name[NC_MAX_NAME + 1];
   int g, id = ncid, parent_id, *gid;
   int i, ret = NC_NOERR;

   /* How many generations? */
   for (g = 0; !NC4_inq_grp_parent(id, &parent_id); g++, id = parent_id)
      ;

   /* Allocate storage. */
   if (!(name = malloc((g + 1) * (NC_MAX_NAME + 1) + 1)))
      return NC_ENOMEM;
   if (!(gid = malloc((g + 1) * sizeof(int))))
   {
      free(name);
      return NC_ENOMEM;
   }
   assert(name && gid);

   /* Always start with a "/" for the root group. */
   strcpy(name, NC_GROUP_NAME);

   /* Get the ncids for all generations. */
   gid[0] = ncid;
   for (i = 1; i < g && !ret; i++)
      ret = NC4_inq_grp_parent(gid[i - 1], &gid[i]);

   /* Assemble the full name. */
   for (i = g - 1; !ret && i >= 0 && !ret; i--)
   {
      if ((ret = NC4_inq_grpname(gid[i], grp_name)))
	 break;
      strcat(name, grp_name);
      if (i)
	 strcat(name, "/");
   }

   /* Give the user the length of the name, if he wants it. */
   if (!ret && lenp)
      *lenp = strlen(name);

   /* Give the user the name, if he wants it. */
   if (!ret && full_name)
      strcpy(full_name, name);

   free(gid);
   free(name);

   return ret;
}

/**
 * @internal Find the parent ncid of a group. For the root group,
 * return NC_ENOGRP error.  *Now* I know what kind of tinfoil hat
 * wearing nut job would call this function with a NULL pointer for
 * parent_ncid - Russ Rew!! 
 *
 * @param ncid File and group ID.
 * @param parent_ncid Pointer that gets the ncid of parent group.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @return ::NC_ENOGRP Root has no parent.
 * @author Ed Hartnett
*/
int
NC4_inq_grp_parent(int ncid, int *parent_ncid)
{
   NC_GRP_INFO_T *grp;
   NC_FILE_INFO_T *h5;
   int retval;

   LOG((2, "nc_inq_grp_parent: ncid 0x%x", ncid));

   /* Find info for this file and group. */
   if ((retval = nc4_find_grp_h5(ncid, &grp, &h5)))
      return retval;
   assert(h5);
   
   /* Set the parent ncid, if there is one. */
   if (grp->parent)
   {
      if (parent_ncid)
	 *parent_ncid = grp->nc4_info->controller->ext_ncid | grp->parent->hdr.id;
   }
   else
      return NC_ENOGRP;
   
   return NC_NOERR;
}

/**
 * @internal Given a full name and ncid, find group ncid. 
 *
 * @param ncid File and group ID.
 * @param full_name Full name of group.
 * @param grp_ncid Pointer that gets ncid of group.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @return ::NC_ENOGRP Group not found.
 * @return ::NC_ENOMEM Out of memory.
 * @return ::NC_EINVAL Name is required.
 * @author Ed Hartnett
*/
int
NC4_inq_grp_full_ncid(int ncid, const char *full_name, int *grp_ncid)
{
   NC_GRP_INFO_T *grp;
   NC_FILE_INFO_T *h5;
   int id1 = ncid, id2;
   char *cp, *full_name_cpy;
   int ret;

   if (!full_name)
      return NC_EINVAL;

   /* Find info for this file and group, and set pointer to each. */
   if ((ret = nc4_find_grp_h5(ncid, &grp, &h5)))
      return ret;
   assert(h5);

   /* Copy full_name because strtok messes with the value it works
    * with, and we don't want to mess up full_name. */
   if (!(full_name_cpy = strdup(full_name)))
      return NC_ENOMEM;

   /* Get the first part of the name. */
   if (!(cp = strtok(full_name_cpy, "/")))
   {
      /* If "/" is passed, and this is the root group, return the root
       * group id. */
      if (!grp->parent)
	 id2 = ncid;
      else
      {
	 free(full_name_cpy);
	 return NC_ENOGRP;
      }
   }
   else
   {
      /* Keep parsing the string. */
      for (; cp; id1 = id2)
      {
	 if ((ret = NC4_inq_ncid(id1, cp, &id2)))
	 {
	    free(full_name_cpy);
	    return ret;
	 }
	 cp = strtok(NULL, "/");
      }
   }

   /* Give the user the requested value. */
   if (grp_ncid)
      *grp_ncid = id2;

   free(full_name_cpy);

   return NC_NOERR;
}

/**
 * @internal Get a list of ids for all the variables in a group. 
 *
 * @param ncid File and group ID.
 * @param nvars Pointer that gets number of vars in group.
 * @param varids Pointer that gets array of var IDs.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @author Ed Hartnett
*/
int
NC4_inq_varids(int ncid, int *nvars, int *varids)
{
   NC_GRP_INFO_T *grp;
   NC_FILE_INFO_T *h5;
   NC_VAR_INFO_T *var;
   int num_vars = 0;
   int retval;
   int i;

   LOG((2, "nc_inq_varids: ncid 0x%x", ncid));

   /* Find info for this file and group, and set pointer to each. */
   if ((retval = nc4_find_grp_h5(ncid, &grp, &h5)))
      return retval;
   assert(h5);

   /* This is a netCDF-4 group. Round up them doggies and count
    * 'em. The list is in correct (i.e. creation) order. */
   for (i=0; i < ncindexsize(grp->vars); i++)
   {
      var = (NC_VAR_INFO_T*)ncindexith(grp->vars,i);
      if (!var) continue;
      if (varids)
         varids[num_vars] = var->hdr.id;
      num_vars++;
   }

   /* If the user wants to know how many vars in the group, tell
    * him. */
   if (nvars)
      *nvars = num_vars;

   return NC_NOERR;
}

/**
 * @internal This is the comparison function used for sorting dim
 * ids. Integer comparison: returns negative if b > a and positive if
 * a > b. 
 *
 * @param a A pointer to an item to compare to b.
 * @param b A pointer to an item to compare to a.
 *
 * @return a - b
 * @author Ed Hartnett
*/
int int_cmp(const void *a, const void *b)
{
   const int *ia = (const int *)a; 
   const int *ib = (const int *)b;
   return *ia  - *ib; 
}

/**
 * @internal Find all dimids for a location. This finds all dimensions
 * in a group, with or without any of its parents, depending on last
 * parameter. 
 *
 * @param ncid File and group ID.
 * @param ndims Pointer that gets number of dimensions available in group.
 * @param dimids Pointer that gets dim IDs.
 * @param include_parents If non-zero, include dimensions from parent
 * groups.
 *
 * @return ::NC_NOERR No error.
 * @return ::NC_EBADID Bad ncid.
 * @author Ed Hartnett
*/
int 
NC4_inq_dimids(int ncid, int *ndims, int *dimids, int include_parents)
{
   NC_GRP_INFO_T *grp, *g;
   NC_FILE_INFO_T *h5;
   NC_DIM_INFO_T *dim;
   int num = 0;
   int retval;

   LOG((2, "nc_inq_dimids: ncid 0x%x include_parents: %d", ncid, 
	include_parents));

   /* Find info for this file and group, and set pointer to each. */
   if ((retval = nc4_find_grp_h5(ncid, &grp, &h5)))
      return retval;
   assert(h5);

   /* First count them. */
   num = ncindexcount(grp->dim);
   if (include_parents) {
      for (g = grp->parent; g; g = g->parent)
	 num += ncindexcount(g->dim);
   }
   
   /* If the user wants the dimension ids, get them. */
   if (dimids)
   {
      int n = 0;
      int i;
      
      /* Get dimension ids from this group. */
      for(i=0;i<ncindexsize(grp->dim);i++) {
	 dim = (NC_DIM_INFO_T*)ncindexith(grp->dim,i);
	 if(dim == NULL) continue;
         dimids[n++] = dim->hdr.id;
      }
      
      /* Get dimension ids from parent groups. */
      if (include_parents)
         for (g = grp->parent; g; g = g->parent) {
	    for(i=0;i<ncindexsize(g->dim);i++) {
	       dim = (NC_DIM_INFO_T*)ncindexith(g->dim,i);
	       if(dim == NULL) continue;
               dimids[n++] = dim->hdr.id;
	    }
	 }      
      qsort(dimids, num, sizeof(int), int_cmp);
   }

   /* If the user wants the number of dims, give it. */
   if (ndims)
      *ndims = num;

   return NC_NOERR;
}