mirror/netcdf-c
2
0
Fork 0
mirror of https://github.com/Unidata/netcdf-c.git synced 2024-11-21 03:13:42 +08:00
Code Issues Packages Projects Releases Wiki Activity

fixed bug that allowed for zero chunksize when one small, and two giant dimension sizes are used

Browse Source
This commit is contained in:
Ed Hartnett 2011-02-14 16:49:05 +00:00
parent b1afe7e09f
commit 3340b641fd
1 changed files with 70 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
libsrc4/nc4var.c
View File

@ -324,6 +324,74 @@ nc4_find_default_chunksizes(NC_GRP_INFO_T *grp, NC_VAR_INFO_T *var)
return NC_NOERR;
}
/* Find the default chunk nelems (i.e. length of chunk along each
* dimension). */
static int
nc4_find_default_chunksizes2(NC_GRP_INFO_T *grp, NC_VAR_INFO_T *var)
{
int d;
size_t type_size;
float num_values = 1, num_set = 0;
float total_chunk_size;
int retval;
if (var->type_info->nc_typeid == NC_STRING)
type_size = sizeof(char *);
else
type_size = var->type_info->size;
/* Later this will become the total number of bytes in the default
* chunk. */
total_chunk_size = type_size;
/* How many values in the variable (or one record, if there are
* unlimited dimensions); which is the largest dimension, and how
* long is it? */
for (d = 0; d < var->ndims; d++)
{
assert(var->dim[d]);
if (var->dim[d]->len)
num_values *= (float)var->dim[d]->len;
else
num_set++;
LOG((4, "d %d num_values %f", d, num_values));
}
/* Pick a chunk length for each dimension, if one has not already
* been picked above. */
for (d = 0; d < var->ndims; d++)
if (!var->chunksizes[d])
{
size_t suggested_size;
suggested_size = (pow((double)DEFAULT_CHUNK_SIZE/(num_values * type_size),
1/(double)(var->ndims - num_set)) * var->dim[d]->len - .5);
if (suggested_size > var->dim[d]->len)
suggested_size = var->dim[d]->len;
var->chunksizes[d] = suggested_size ? suggested_size : 1;
total_chunk_size *= var->chunksizes[d];
LOG((4, "nc_def_var_nc4: name %s dim %d DEFAULT_CHUNK_SIZE %d num_values %f type_size %d "
"chunksize %ld", var->name, d, DEFAULT_CHUNK_SIZE, num_values, type_size, var->chunksizes[d]));
}
LOG((4, "total_chunk_size %f", total_chunk_size));
/* But did this add up to a chunk that is too big? */
retval = check_chunksizes(grp, var, var->chunksizes);
if (retval)
{
/* Other error? */
if (retval != NC_EBADCHUNK)
return retval;
/* Chunk is too big! Reduce each dimension by half and try again. */
for ( ; retval == NC_EBADCHUNK; retval = check_chunksizes(grp, var, var->chunksizes))
for (d = 0; d < var->ndims; d++)
var->chunksizes[d] = var->chunksizes[d]/2 ? var->chunksizes[d]/2 : 1;
}
return NC_NOERR;
}
/* This is called when a new netCDF-4 variable is defined. Break it
* down! */
static int
@ -487,7 +555,7 @@ nc_def_var_nc4(int ncid, const char *name, nc_type xtype,
if (!(var->chunksizes = calloc(var->ndims, sizeof(size_t))))
return NC_ENOMEM;
if ((retval = nc4_find_default_chunksizes(grp, var)))
if ((retval = nc4_find_default_chunksizes2(grp, var)))
return retval;
/* Is this a variable with a chunksize greater than the current
@ -858,7 +926,7 @@ nc_def_var_extra(int ncid, int varid, int *shuffle, int *deflate,
{
/* Determine default chunksizes for this variable. */
if (!var->chunksizes[0])
if ((retval = nc4_find_default_chunksizes(grp, var)))
if ((retval = nc4_find_default_chunksizes2(grp, var)))
return retval;
/* Adjust the cache. */