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Merge pull request #1521 from ckhroulev/netcdf4-repeated-attribute-modification

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Improve the fix for #350 included in #1119
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Ward Fisher 2019-11-14 17:01:09 -07:00 committed by GitHub
commit 1a6351dab2
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2 changed files with 127 additions and 11 deletions
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44
libhdf5/nc4hdf.c
View File

@ -512,7 +512,6 @@ put_att_grpa(NC_GRP_INFO_T *grp, int varid, NC_ATT_INFO_T *att)
hid_t existing_att_typeid = 0, existing_attid = 0, existing_spaceid = 0;
hsize_t dims[1]; /* netcdf attributes always 1-D. */
htri_t attr_exists;
int reuse_att = 0; /* Will be true if we can re-use an existing att. */
void *data;
int phoney_data = 99;
int retval = NC_NOERR;
@ -617,26 +616,49 @@ put_att_grpa(NC_GRP_INFO_T *grp, int varid, NC_ATT_INFO_T *att)
if ((npoints = H5Sget_simple_extent_npoints(existing_spaceid)) < 0)
BAIL(NC_EATTMETA);
/* Delete the attribute. */
if (file_typeid != existing_att_typeid || npoints != att->len)
/* For text attributes the size is specified in the datatype
and it is enough to compare types using H5Tequal(). */
if (!H5Tequal(file_typeid, existing_att_typeid) ||
(att->nc_typeid != NC_CHAR && npoints != att->len))
{
/* The attribute exists but we cannot re-use it. */
/* Delete the attribute. */
if (H5Adelete(locid, att->hdr.name) < 0)
BAIL(NC_EHDFERR);
/* Re-create the attribute with the type and length
reflecting the new value (or values). */
if ((attid = H5Acreate(locid, att->hdr.name, file_typeid, spaceid,
H5P_DEFAULT)) < 0)
BAIL(NC_EATTMETA);
/* Write the values, (even if length is zero). */
if (H5Awrite(attid, file_typeid, data) < 0)
BAIL(NC_EATTMETA);
}
else
{
reuse_att++;
/* The attribute exists and we can re-use it. */
/* Write the values, re-using the existing attribute. */
if (H5Awrite(existing_attid, file_typeid, data) < 0)
BAIL(NC_EATTMETA);
}
}
else
{
/* The attribute does not exist yet. */
/* Create the attribute. */
if ((attid = H5Acreate(locid, att->hdr.name, file_typeid, spaceid,
H5P_DEFAULT)) < 0)
BAIL(NC_EATTMETA);
/* Create the attribute. */
if ((attid = H5Acreate(locid, att->hdr.name, file_typeid, spaceid,
H5P_DEFAULT)) < 0)
BAIL(NC_EATTMETA);
/* Write the values, (even if length is zero). */
if (H5Awrite(attid, file_typeid, data) < 0)
BAIL(NC_EATTMETA);
/* Write the values, (even if length is zero). */
if (H5Awrite(attid, file_typeid, data) < 0)
BAIL(NC_EATTMETA);
}
exit:
if (file_typeid && H5Tclose(file_typeid))

94
nc_test4/tst_atts.c
View File

@ -424,5 +424,99 @@ main(int argc, char **argv)
free(data_in);
}
SUMMARIZE_ERR;
printf("*** testing modification of an attribute 2^16 times (changing size)...");
{
/* This test documents that if the size of an attribute changes
* from one modification to the next we have to delete and
* re-create it, incrementing HDF5's attribute creation order
* index. In this case after about 2^16 modifications this
* index reaches its maximum, making it impossible to modify
* this file's metadata because nc_enddef() will fail. */
int ncid = -1, i = -1, error_code = NC_NOERR;
int data[2] = {1, 2};
/* Create a file. Note that we use a different file name here
* because we will not be able to close this file. */
if (nc_create("tst_att_modification.nc", NC_NETCDF4|NC_CLOBBER, &ncid)) ERR;
if (nc_enddef(ncid)) ERR;
/* Modify an attribute 2^16 times. */
for (i = 0; i < 65536; ++i)
{
if (nc_redef(ncid)) ERR;
/* Note that the attribute size changes every time. */
if (nc_put_att_int(ncid, NC_GLOBAL, "attribute", NC_INT,
1 + i % 2, data)) ERR;
/* nc_enddef() synchronizes attributes. */
error_code = nc_enddef(ncid);
/* After a number of iterations nc_enddef() will fail with
* NC_EATTMETA. */
if (error_code == NC_EATTMETA)
break;
/* Catch other errors. */
if (error_code != NC_NOERR) ERR;
}
/* nc_close() will fail too: just like nc_enddef() it tries to
* write dirty attributes to disc. */
if (nc_close(ncid) != NC_EATTMETA) ERR;
/* In this test reaching the end of the loop without encountering
* NC_EATTMETA is a failure. */
if (error_code != NC_EATTMETA) ERR;
}
SUMMARIZE_ERR;
printf("*** testing modification of a scalar attribute 2^16 times (same type and size)...");
{
/* This test ensures that a scalar attribute can be modified
* 2^16 times as long as its type and size remain the same. */
int ncid = -1, i = -1;
/* Create a file. */
if (nc_create(FILE_NAME, NC_NETCDF4|NC_CLOBBER, &ncid)) ERR;
if (nc_enddef(ncid)) ERR;
/* Modify an attribute 2^16 times. */
for (i = 0; i < 65536; ++i)
{
if (nc_redef(ncid)) ERR;
/* All built-in attribute types except for NC_CHAR (but
* including NC_STRING) use the same logic so it is enough
* to test nc_put_att_int(). */
if (nc_put_att_int(ncid, NC_GLOBAL, "attribute", NC_INT, 1, &i)) ERR;
/* nc_enddef() synchronizes attributes. */
if (nc_enddef(ncid)) ERR;
}
if (nc_close(ncid)) ERR;
}
SUMMARIZE_ERR;
printf("*** testing modification of a text attribute 2^16 times (same size)...");
{
/* This test ensures that a text attribute can be modified
* 2^16 times as long as its size remains the same. */
int ncid = -1, i = -1;
const char *string = "test string"; /* 11 characters */
/* Create a file. */
if (nc_create(FILE_NAME, NC_NETCDF4|NC_CLOBBER, &ncid)) ERR;
if (nc_enddef(ncid)) ERR;
/* Modify an attribute 2^16 times. */
for (i = 0; i < 65536; ++i)
{
if (nc_redef(ncid)) ERR;
if (nc_put_att_text(ncid, NC_GLOBAL, "attribute", 11, string)) ERR;
/* nc_enddef() synchronizes attributes */
if (nc_enddef(ncid)) ERR;
}
if (nc_close(ncid)) ERR;
}
SUMMARIZE_ERR;
FINAL_RESULTS;
}