[409] | 1 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * |
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| 2 | * Copyright by The HDF Group. * |
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| 3 | * Copyright by the Board of Trustees of the University of Illinois. * |
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| 4 | * All rights reserved. * |
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| 5 | * * |
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| 6 | * This file is part of HDF5. The full HDF5 copyright notice, including * |
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| 7 | * terms governing use, modification, and redistribution, is contained in * |
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| 8 | * the files COPYING and Copyright.html. COPYING can be found at the root * |
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| 9 | * of the source code distribution tree; Copyright.html can be found at the * |
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| 10 | * root level of an installed copy of the electronic HDF5 document set and * |
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| 11 | * is linked from the top-level documents page. It can also be found at * |
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| 12 | * http://hdfgroup.org/HDF5/doc/Copyright.html. If you do not have * |
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| 13 | * access to either file, you may request a copy from help@hdfgroup.org. * |
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| 14 | * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ |
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| 15 | |
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| 16 | /* |
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| 17 | This code is a variant of the H5detect.c code from HDF5. |
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| 18 | Author: D. Heimbigner 10/7/2008 |
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| 19 | */ |
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| 20 | |
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| 21 | #include <stdlib.h> |
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| 22 | #include <string.h> |
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| 23 | #include <assert.h> |
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| 24 | #include <netcdf.h> |
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| 25 | |
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| 26 | #include "ncaux.h" |
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| 27 | |
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| 28 | struct NCAUX_FIELD { |
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| 29 | char* name; |
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| 30 | nc_type fieldtype; |
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| 31 | int ndims; |
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| 32 | int dimsizes[NC_MAX_VAR_DIMS]; |
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| 33 | size_t size; |
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| 34 | size_t offset; |
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| 35 | size_t alignment; |
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| 36 | }; |
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| 37 | |
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| 38 | struct NCAUX_CMPD { |
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| 39 | int ncid; |
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| 40 | int mode; |
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| 41 | char* name; |
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| 42 | int nfields; |
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| 43 | struct NCAUX_FIELD* fields; |
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| 44 | size_t size; |
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| 45 | size_t offset; /* cumulative as fields are added */ |
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| 46 | size_t alignment; |
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| 47 | }; |
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| 48 | |
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| 49 | static int ncaux_initialized = 0; |
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| 50 | |
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| 51 | static void compute_alignments(void); |
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| 52 | static int computefieldinfo(struct NCAUX_CMPD* cmpd); |
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| 53 | |
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| 54 | int |
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| 55 | ncaux_begin_compound(int ncid, const char *name, int alignmode, void** tagp) |
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| 56 | { |
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| 57 | int status = NC_NOERR; |
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| 58 | struct NCAUX_CMPD* cmpd = NULL; |
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| 59 | |
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| 60 | if(!ncaux_initialized) { |
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| 61 | compute_alignments(); |
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| 62 | ncaux_initialized = 1; |
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| 63 | } |
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| 64 | |
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| 65 | if(tagp) *tagp = NULL; |
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| 66 | |
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| 67 | cmpd = (struct NCAUX_CMPD*)calloc(1,sizeof(struct NCAUX_CMPD)); |
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| 68 | if(cmpd == NULL) {status = NC_ENOMEM; goto fail;} |
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| 69 | cmpd->ncid = ncid; |
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| 70 | cmpd->mode = alignmode; |
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| 71 | cmpd->nfields = 0; |
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| 72 | cmpd->name = strdup(name); |
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| 73 | if(cmpd->name == NULL) {status = NC_ENOMEM; goto fail;} |
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| 74 | |
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| 75 | if(tagp) *tagp = (void*)cmpd; |
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| 76 | |
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| 77 | return status; |
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| 78 | |
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| 79 | fail: |
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| 80 | ncaux_abort_compound((void*)cmpd); |
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| 81 | return status; |
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| 82 | } |
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| 83 | |
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| 84 | int |
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| 85 | ncaux_abort_compound(void* tag) |
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| 86 | { |
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| 87 | int i; |
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| 88 | struct NCAUX_CMPD* cmpd = (struct NCAUX_CMPD*)tag; |
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| 89 | if(cmpd == NULL) goto done; |
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| 90 | if(cmpd->name) free(cmpd->name); |
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| 91 | for(i=0;i<cmpd->nfields;i++) { |
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| 92 | struct NCAUX_FIELD* field = &cmpd->fields[i]; |
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| 93 | if(field->name) free(field->name); |
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| 94 | } |
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| 95 | if(cmpd->fields) free(cmpd->fields); |
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| 96 | free(cmpd); |
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| 97 | |
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| 98 | done: |
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| 99 | return NC_NOERR; |
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| 100 | } |
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| 101 | |
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| 102 | int |
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| 103 | ncaux_add_field(void* tag, const char *name, nc_type field_type, |
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| 104 | int ndims, const int* dimsizes) |
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| 105 | { |
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| 106 | int i; |
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| 107 | int status = NC_NOERR; |
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| 108 | struct NCAUX_CMPD* cmpd = (struct NCAUX_CMPD*)tag; |
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| 109 | struct NCAUX_FIELD* newfields = NULL; |
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| 110 | struct NCAUX_FIELD* field = NULL; |
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| 111 | |
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| 112 | if(cmpd == NULL) goto done; |
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| 113 | if(ndims < 0) {status = NC_EINVAL; goto done;} |
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| 114 | for(i=0;i<ndims;i++) { |
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| 115 | if(dimsizes[i] <= 0) {status = NC_EINVAL; goto done;} |
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| 116 | } |
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| 117 | if(cmpd->fields == NULL) { |
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| 118 | newfields = (struct NCAUX_FIELD*)calloc(1,sizeof(struct NCAUX_FIELD)); |
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| 119 | } else { |
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| 120 | newfields = (struct NCAUX_FIELD*)realloc(cmpd->fields,cmpd->nfields+1*sizeof(struct NCAUX_FIELD)); |
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| 121 | } |
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| 122 | if(cmpd->fields == NULL) {status = NC_ENOMEM; goto done;} |
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| 123 | cmpd->fields = newfields; |
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| 124 | field = &cmpd->fields[cmpd->nfields+1]; |
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| 125 | field->name = strdup(name); |
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| 126 | field->fieldtype = field_type; |
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| 127 | if(field->name == NULL) {status = NC_ENOMEM; goto done;} |
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| 128 | field->ndims = ndims; |
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| 129 | memcpy(field->dimsizes,dimsizes,sizeof(int)*ndims); |
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| 130 | cmpd->nfields++; |
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| 131 | |
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| 132 | done: |
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| 133 | return status; |
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| 134 | } |
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| 135 | |
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| 136 | static size_t |
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| 137 | dimproduct(int ndims, int* dimsizes) |
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| 138 | { |
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| 139 | int i; |
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| 140 | size_t product = 1; |
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| 141 | for(i=0;i<ndims;i++) product *= dimsizes[i]; |
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| 142 | return product; |
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| 143 | } |
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| 144 | |
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| 145 | int |
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| 146 | ncaux_end_compound(void* tag, nc_type* idp) |
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| 147 | { |
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| 148 | int i; |
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| 149 | int status = NC_NOERR; |
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| 150 | struct NCAUX_CMPD* cmpd = (struct NCAUX_CMPD*)tag; |
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| 151 | |
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| 152 | if(cmpd == NULL) {status = NC_EINVAL; goto done;} |
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| 153 | |
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| 154 | /* Compute field and compound info */ |
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| 155 | status = computefieldinfo(cmpd); |
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| 156 | if(status != NC_NOERR) goto done; |
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| 157 | |
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| 158 | status = nc_def_compound(cmpd->ncid, cmpd->size, cmpd->name, idp); |
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| 159 | if(status != NC_NOERR) goto done; |
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| 160 | |
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| 161 | for(i=0;i<cmpd->nfields;i++) { |
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| 162 | struct NCAUX_FIELD* field = &cmpd->fields[i]; |
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| 163 | if(field->ndims > 0) { |
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| 164 | status = nc_insert_compound(cmpd->ncid, *idp, field->name, |
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| 165 | field->offset, field->fieldtype); |
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| 166 | } else { |
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| 167 | status = nc_insert_array_compound(cmpd->ncid, *idp, field->name, |
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| 168 | field->offset, field->fieldtype, |
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| 169 | field->ndims,field->dimsizes); |
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| 170 | } |
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| 171 | if(status != NC_NOERR) goto done; |
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| 172 | } |
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| 173 | |
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| 174 | done: |
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| 175 | return status; |
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| 176 | } |
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| 177 | |
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| 178 | /**************************************************/ |
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| 179 | |
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| 180 | /* |
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| 181 | The heart of this is the following macro, |
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| 182 | which computes the offset of a field x |
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| 183 | when preceded by a char field. |
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| 184 | The assumptions appear to be as follows: |
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| 185 | 1. the offset produced in this situation indicates |
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| 186 | the alignment for x relative in such a way that it |
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| 187 | depends only on the types that precede it in the struct. |
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| 188 | 2. the compiler does not reorder fields. |
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| 189 | 3. arrays are tightly packed. |
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| 190 | 4. nested structs are alignd according to their first member |
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| 191 | (this actually follows from C language requirement that |
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| 192 | a struct can legally be cast to an instance of its first member). |
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| 193 | Given the alignments for the various common primitive types, |
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| 194 | it is assumed that one can use them anywhere to construct |
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| 195 | the layout of a struct of such types. |
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| 196 | It seems to work for HDF5 for a wide variety of machines. |
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| 197 | */ |
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| 198 | |
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| 199 | #define COMP_ALIGNMENT(DST,TYPE) {\ |
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| 200 | struct {char f1; TYPE x;} tmp; \ |
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| 201 | DST.typename = #TYPE ; \ |
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| 202 | DST.alignment = (size_t)((char*)(&(tmp.x)) - (char*)(&tmp));} |
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| 203 | |
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| 204 | /* Define indices for every primitive C type */ |
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| 205 | /* NAT => NOT-A-TYPE*/ |
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| 206 | #define NATINDEX 0 |
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| 207 | #define CHARINDEX 1 |
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| 208 | #define UCHARINDEX 2 |
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| 209 | #define SHORTINDEX 3 |
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| 210 | #define USHORTINDEX 4 |
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| 211 | #define INTINDEX 5 |
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| 212 | #define UINTINDEX 6 |
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| 213 | #define LONGINDEX 7 |
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| 214 | #define ULONGINDEX 8 |
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| 215 | #define LONGLONGINDEX 9 |
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| 216 | #define ULONGLONGINDEX 10 |
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| 217 | #define FLOATINDEX 11 |
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| 218 | #define DOUBLEINDEX 12 |
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| 219 | #define PTRINDEX 13 |
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| 220 | #define NCVLENINDEX 14 |
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| 221 | |
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| 222 | #define NCTYPES 15 |
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| 223 | |
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| 224 | typedef struct Alignment { |
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| 225 | char* typename; |
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| 226 | int alignment; |
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| 227 | } Alignment; |
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| 228 | |
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| 229 | typedef Alignment Typealignvec; |
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| 230 | |
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| 231 | /* Capture in struct and in a vector*/ |
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| 232 | typedef struct Typealignset { |
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| 233 | Alignment charalign; /* char*/ |
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| 234 | Alignment ucharalign; /* unsigned char*/ |
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| 235 | Alignment shortalign; /* short*/ |
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| 236 | Alignment ushortalign; /* unsigned short*/ |
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| 237 | Alignment intalign; /* int*/ |
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| 238 | Alignment uintalign; /* unsigned int*/ |
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| 239 | Alignment longalign; /* long*/ |
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| 240 | Alignment ulongalign; /* unsigned long*/ |
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| 241 | Alignment longlongalign; /* long long*/ |
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| 242 | Alignment ulonglongalign; /* unsigned long long*/ |
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| 243 | Alignment floatalign; /* float*/ |
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| 244 | Alignment doublealign; /* double*/ |
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| 245 | Alignment ptralign; /* void**/ |
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| 246 | Alignment ncvlenalign; /* nc_vlen_t*/ |
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| 247 | } Typealignset; |
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| 248 | |
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| 249 | static Typealignvec vec[NCTYPES]; |
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| 250 | static Typealignset set; |
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| 251 | |
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| 252 | static void |
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| 253 | compute_alignments(void) |
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| 254 | { |
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| 255 | /* Compute the alignments for all the common C data types*/ |
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| 256 | /* First for the struct*/ |
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| 257 | /* initialize*/ |
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| 258 | memset((void*)&set,0,sizeof(set)); |
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| 259 | memset((void*)vec,0,sizeof(vec)); |
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| 260 | |
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| 261 | COMP_ALIGNMENT(set.charalign,char); |
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| 262 | COMP_ALIGNMENT(set.ucharalign,unsigned char); |
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| 263 | COMP_ALIGNMENT(set.shortalign,short); |
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| 264 | COMP_ALIGNMENT(set.ushortalign,unsigned short); |
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| 265 | COMP_ALIGNMENT(set.intalign,int); |
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| 266 | COMP_ALIGNMENT(set.uintalign,unsigned int); |
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| 267 | COMP_ALIGNMENT(set.longalign,long); |
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| 268 | COMP_ALIGNMENT(set.ulongalign,unsigned long); |
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| 269 | COMP_ALIGNMENT(set.longlongalign,long long); |
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| 270 | COMP_ALIGNMENT(set.ulonglongalign,unsigned long long); |
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| 271 | COMP_ALIGNMENT(set.floatalign,float); |
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| 272 | COMP_ALIGNMENT(set.doublealign,double); |
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| 273 | COMP_ALIGNMENT(set.ptralign,void*); |
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| 274 | COMP_ALIGNMENT(set.ncvlenalign,nc_vlen_t); |
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| 275 | |
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| 276 | /* Then the vector*/ |
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| 277 | COMP_ALIGNMENT(vec[CHARINDEX],char); |
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| 278 | COMP_ALIGNMENT(vec[UCHARINDEX],unsigned char); |
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| 279 | COMP_ALIGNMENT(vec[SHORTINDEX],short); |
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| 280 | COMP_ALIGNMENT(vec[USHORTINDEX],unsigned short); |
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| 281 | COMP_ALIGNMENT(vec[INTINDEX],int); |
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| 282 | COMP_ALIGNMENT(vec[UINTINDEX],unsigned int); |
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| 283 | COMP_ALIGNMENT(vec[LONGINDEX],long); |
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| 284 | COMP_ALIGNMENT(vec[ULONGINDEX],unsigned long); |
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| 285 | COMP_ALIGNMENT(vec[LONGLONGINDEX],long long); |
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| 286 | COMP_ALIGNMENT(vec[ULONGLONGINDEX],unsigned long long); |
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| 287 | COMP_ALIGNMENT(vec[FLOATINDEX],float); |
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| 288 | COMP_ALIGNMENT(vec[DOUBLEINDEX],double); |
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| 289 | COMP_ALIGNMENT(vec[PTRINDEX],void*); |
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| 290 | COMP_ALIGNMENT(vec[NCVLENINDEX],nc_vlen_t); |
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| 291 | } |
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| 292 | |
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| 293 | static size_t |
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| 294 | nctypealignment(nc_type nctype) |
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| 295 | { |
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| 296 | Alignment* align = NULL; |
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| 297 | int index = 0; |
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| 298 | switch (nctype) { |
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| 299 | case NC_BYTE: index = UCHARINDEX; break; |
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| 300 | case NC_CHAR: index = CHARINDEX; break; |
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| 301 | case NC_SHORT: index = SHORTINDEX; break; |
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| 302 | case NC_INT: index = INTINDEX; break; |
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| 303 | case NC_FLOAT: index = FLOATINDEX; break; |
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| 304 | case NC_DOUBLE: index = DOUBLEINDEX; break; |
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| 305 | case NC_UBYTE: index = UCHARINDEX; break; |
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| 306 | case NC_USHORT: index = USHORTINDEX; break; |
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| 307 | case NC_UINT: index = UINTINDEX; break; |
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| 308 | case NC_INT64: index = LONGLONGINDEX; break; |
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| 309 | case NC_UINT64: index = ULONGLONGINDEX; break; |
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| 310 | case NC_STRING: index = PTRINDEX; break; |
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| 311 | case NC_VLEN: index = NCVLENINDEX; break; |
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| 312 | case NC_OPAQUE: index = UCHARINDEX; break; |
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| 313 | default: assert(0); |
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| 314 | } |
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| 315 | align = &vec[index]; |
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| 316 | return align->alignment; |
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| 317 | } |
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| 318 | |
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| 319 | static int |
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| 320 | getpadding(int offset, int alignment) |
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| 321 | { |
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| 322 | int rem = (alignment==0?0:(offset % alignment)); |
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| 323 | int pad = (rem==0?0:(alignment - rem)); |
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| 324 | return pad; |
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| 325 | } |
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| 326 | |
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| 327 | /* Find first primitive field of a possibly nested sequence of compounds */ |
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| 328 | static nc_type |
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| 329 | findfirstfield(int ncid, nc_type xtype) |
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| 330 | { |
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| 331 | int status = NC_NOERR; |
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| 332 | nc_type fieldtype = xtype; |
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| 333 | if(xtype <= NC_MAX_ATOMIC_TYPE) goto done; |
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| 334 | |
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| 335 | status = nc_inq_compound_fieldtype(ncid, xtype, 0, &fieldtype); |
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| 336 | if(status != NC_NOERR) goto done; |
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| 337 | fieldtype = findfirstfield(ncid,fieldtype); |
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| 338 | |
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| 339 | done: |
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| 340 | return (status == NC_NOERR?fieldtype:NC_NAT); |
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| 341 | } |
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| 342 | |
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| 343 | static int |
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| 344 | computefieldinfo(struct NCAUX_CMPD* cmpd) |
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| 345 | { |
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| 346 | int i; |
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| 347 | int status = NC_NOERR; |
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| 348 | size_t offset = 0; |
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| 349 | size_t totaldimsize; |
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| 350 | |
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| 351 | /* Assign the sizes for the fields */ |
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| 352 | for(i=0;i<cmpd->nfields;i++) { |
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| 353 | struct NCAUX_FIELD* field = &cmpd->fields[i]; |
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| 354 | status = nc_inq_type(cmpd->ncid,field->fieldtype,NULL,&field->size); |
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| 355 | if(status != NC_NOERR) goto done; |
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| 356 | totaldimsize = dimproduct(field->ndims,field->dimsizes); |
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| 357 | field->size *= totaldimsize; |
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| 358 | } |
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| 359 | |
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| 360 | for(offset=0,i=0;i<cmpd->nfields;i++) { |
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| 361 | struct NCAUX_FIELD* field = &cmpd->fields[i]; |
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| 362 | int alignment = 0; |
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| 363 | nc_type firsttype = findfirstfield(cmpd->ncid,field->fieldtype); |
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| 364 | |
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| 365 | /* only support 'c' alignment for now*/ |
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| 366 | switch (field->fieldtype) { |
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| 367 | case NC_OPAQUE: |
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| 368 | field->alignment = 1; |
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| 369 | break; |
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| 370 | case NC_ENUM: |
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| 371 | field->alignment = nctypealignment(firsttype); |
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| 372 | break; |
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| 373 | case NC_VLEN: /*fall thru*/ |
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| 374 | case NC_COMPOUND: |
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| 375 | field->alignment = nctypealignment(firsttype); |
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| 376 | break; |
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| 377 | default: |
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| 378 | field->alignment = nctypealignment(field->fieldtype); |
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| 379 | break; |
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| 380 | } |
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| 381 | offset += getpadding(offset,alignment); |
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| 382 | field->offset = offset; |
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| 383 | offset += field->size; |
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| 384 | } |
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| 385 | cmpd->size = offset; |
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| 386 | cmpd->alignment = cmpd->fields[0].alignment; |
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| 387 | |
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| 388 | done: |
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| 389 | return status; |
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| 390 | } |
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