netcdf-c/libsrc4/nc4grp.c
Dennis Heimbigner 25f062528b This completes (for now) the refactoring of libsrc4.
The file docs/indexing.dox tries to provide design
information for the refactoring.

The primary change is to replace all walking of linked
lists with the use of the NCindex data structure.
Ncindex is a combination of a hash table (for name-based
lookup) and a vector (for walking the elements in the index).
Additionally, global vectors are added to NC_HDF5_FILE_INFO_T
to support direct mapping of an e.g. dimid to the NC_DIM_INFO_T
object. These global vectors exist for dimensions, types, and groups
because they have globally unique id numbers.

WARNING:
1. since libsrc4 and libsrchdf4 share code, there are also
   changes in libsrchdf4.
2. Any outstanding pull requests that change libsrc4 or libhdf4
   are likely to cause conflicts with this code.
3. The original reason for doing this was for performance improvements,
   but as noted elsewhere, this may not be significant because
   the meta-data read performance apparently is being dominated
   by the hdf5 library because we do bulk meta-data reading rather
   than lazy reading.
2018-03-16 11:46:18 -06:00

603 lines
15 KiB
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 Create a group. Its ncid is returned in the new_ncid
* pointer.
*
* @param parent_ncid Parent group.
* @param name Name of new group.
* @param new_ncid Pointer that gets ncid for new group.
*
* @return ::NC_NOERR No error.
* @return ::NC_EBADID Bad ncid.
* @return ::NC_ESTRICTNC3 Classic model in use for this file.
* @return ::NC_ENOTNC4 Not a netCDF-4 file.
* @author Ed Hartnett
*/
int
NC4_def_grp(int parent_ncid, const char *name, int *new_ncid)
{
NC_GRP_INFO_T *grp, *g;
NC_HDF5_FILE_INFO_T *h5;
char norm_name[NC_MAX_NAME + 1];
int retval;
LOG((2, "%s: parent_ncid 0x%x name %s", __func__, parent_ncid, name));
/* Find info for this file and group, and set pointer to each. */
if ((retval = nc4_find_grp_h5(parent_ncid, &grp, &h5)))
return retval;
assert(h5);
/* Check and normalize the name. */
if ((retval = nc4_check_name(name, norm_name)))
return retval;
/* Check that this name is not in use as a var, grp, or type. */
if ((retval = nc4_check_dup_name(grp, norm_name)))
return retval;
/* No groups in netcdf-3! */
if (h5->cmode & NC_CLASSIC_MODEL)
return NC_ESTRICTNC3;
/* If it's not in define mode, switch to define mode. */
if (!(h5->flags & NC_INDEF))
if ((retval = NC4_redef(parent_ncid)))
return retval;
/* Update internal lists to reflect new group. The actual HDF5
* group creation will be done when metadata is written by a
* sync. */
if ((retval = nc4_grp_list_add(grp, norm_name, &g)))
return retval;
if (new_ncid)
*new_ncid = grp->nc4_info->controller->ext_ncid | g->hdr.id;
return NC_NOERR;
}
/**
* @internal Rename a group.
*
* @param grpid Group ID.
* @param name New name for group.
*
* @return ::NC_NOERR No error.
* @return ::NC_EBADID Bad ncid.
* @return ::NC_ENOTNC4 Not a netCDF-4 file.
* @return ::NC_EPERM File opened read-only.
* @return ::NC_EBADGRPID Renaming root forbidden.
* @return ::NC_EHDFERR HDF5 function returned error.
* @return ::NC_ENOMEM Out of memory.
* @author Ed Hartnett
*/
int
NC4_rename_grp(int grpid, const char *name)
{
NC_GRP_INFO_T *grp, *parent;
NC_HDF5_FILE_INFO_T *h5;
char norm_name[NC_MAX_NAME + 1];
int retval;
LOG((2, "nc_rename_grp: grpid 0x%x name %s", grpid, name));
/* Find info for this file and group, and set pointer to each. */
if ((retval = nc4_find_grp_h5(grpid, &grp, &h5)))
return retval;
assert(h5);
if (h5->no_write)
return NC_EPERM; /* attempt to write to a read-only file */
/* Do not allow renaming the root group */
if (grp->parent == NULL)
return NC_EBADGRPID;
parent = grp->parent;
/* Check and normalize the name. */
if ((retval = nc4_check_name(name, norm_name)))
return retval;
/* Check that this name is not in use as a var, grp, or type in the
* parent group (i.e. the group that grp is in). */
if ((retval = nc4_check_dup_name(parent, norm_name)))
return retval;
/* If it's not in define mode, switch to define mode. */
if (!(h5->flags & NC_INDEF))
if ((retval = NC4_redef(grpid)))
return retval;
/* Rename the group, if it exists in the file */
if (grp->hdf_grpid)
{
/* Close the group */
if (H5Gclose(grp->hdf_grpid) < 0)
return NC_EHDFERR;
grp->hdf_grpid = 0;
/* Attempt to rename & re-open the group, if the parent group is open */
if (grp->parent->hdf_grpid)
{
/* Rename the group */
if (H5Gmove(parent->hdf_grpid, grp->hdr.name, name) < 0)
return NC_EHDFERR;
/* Reopen the group, with the new name */
if ((grp->hdf_grpid = H5Gopen2(parent->hdf_grpid, name, H5P_DEFAULT)) < 0)
return NC_EHDFERR;
}
}
/* Give the group its new name in metadata. UTF8 normalization
* has been done. */
free(grp->hdr.name);
if (!(grp->hdr.name = strdup(norm_name)))
return NC_ENOMEM;
grp->hdr.hashkey = NC_hashmapkey(grp->hdr.name,strlen(grp->hdr.name)); /* Fix hash key */
if(!ncindexrebuild(parent->children))
return NC_EINTERNAL;
return NC_NOERR;
}
/**
* @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_HDF5_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_HDF5_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_HDF5_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_HDF5_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_HDF5_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_HDF5_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_HDF5_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;
}