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GRIB lightweight clone: WIP

This commit is contained in:
Shahram Najm 2023-11-27 17:20:49 +00:00
parent 9b68c6acc9
commit 2707c2fca2
1 changed files with 76 additions and 34 deletions
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110
src/grib_handle.cc
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@ -326,49 +326,91 @@ grib_handle* grib_handle_clone(const grib_handle* h)
return result;
}
static bool can_create_clone_light(const grib_handle* h)
{
// Only for GRIB, not BUFR etc
if (h->product_kind != PRODUCT_GRIB) return false;
// Spectral data does not have constant fields!
long isGridded = 0;
int err = grib_get_long(h, "isGridded", &isGridded);
if (err || !isGridded) return false;
return true;
}
grib_handle* grib_handle_clone_light(const grib_handle* h)
{
int err = 0;
size_t size1 = 0;
const void* msg1 = NULL;
long edition = 0;
int err = 0;
long edition = 0;
grib_handle* result = NULL;
// Only for GRIB, not BUFR etc
if (h->product_kind != PRODUCT_GRIB) {
grib_context_log(h->context, GRIB_LOG_ERROR, "%s: Only supported for %s",
__func__, codes_get_product_name(PRODUCT_GRIB));
return NULL;
}
err = grib_get_long(h, "edition", &edition);
if (!err && edition == 1) {
grib_context_log(h->context, GRIB_LOG_ERROR, "%s: Edition not supported", __func__);
return NULL;
}
err = grib_get_message_headers(h, &msg1, &size1);
if (err) return NULL;
size1 += 4;
grib_handle* result = grib_handle_new_from_partial_message_copy(h->context, msg1, size1);
result->buffer->data[ size1 - 4 ] = '7';
result->buffer->data[ size1 - 3 ] = '7';
result->buffer->data[ size1 - 2 ] = '7';
result->buffer->data[ size1 - 1 ] = '7';
result->buffer->ulength = size1;
result->product_kind = h->product_kind;
long off = 64; // This is only true for GRIB edition 2
err = grib_encode_unsigned_long( result->buffer->data, (unsigned long)size1, &off, 64);
if (err) {
printf("err=%s\n", grib_get_error_message(err));
if (!can_create_clone_light(h)) {
// Lightweight clone not possible. Do a normal clone
return grib_handle_clone(h);
}
char sample_name[1024]; /* name of the GRIB sample file */
grib_get_long(h, "edition", &edition);
snprintf(sample_name, sizeof(sample_name), "GRIB%ld", edition);
grib_handle* h_sample = grib_handle_new_from_samples(NULL, sample_name);
// Copy all sections except Bitmap and Data from h to h_sample
const int sections_to_copy = GRIB_SECTION_PRODUCT | GRIB_SECTION_LOCAL | GRIB_SECTION_GRID;
result = grib_util_sections_copy((grib_handle*)h, h_sample, sections_to_copy, &err);
if (!result || err) {
grib_context_log(h->context, GRIB_LOG_ERROR, "Failed to create lightweight clone");
grib_handle_delete(h_sample);
return NULL;
}
grib_handle_delete(h_sample);
return result;
}
// grib_handle* grib_handle_clone_light(const grib_handle* h)
// {
// int err = 0;
// size_t size1 = 0;
// const void* msg1 = NULL;
// long edition = 0;
// // Only for GRIB, not BUFR etc
// if (h->product_kind != PRODUCT_GRIB) {
// grib_context_log(h->context, GRIB_LOG_ERROR, "%s: Only supported for %s",
// __func__, codes_get_product_name(PRODUCT_GRIB));
// return NULL;
// }
// err = grib_get_long(h, "edition", &edition);
// if (!err && edition == 1) {
// grib_context_log(h->context, GRIB_LOG_ERROR, "%s: Edition not supported", __func__);
// return NULL;
// }
// err = grib_get_message_headers(h, &msg1, &size1);
// if (err) return NULL;
// size1 += 4;
// grib_handle* result = grib_handle_new_from_partial_message_copy(h->context, msg1, size1);
// result->buffer->data[ size1 - 4 ] = '7';
// result->buffer->data[ size1 - 3 ] = '7';
// result->buffer->data[ size1 - 2 ] = '7';
// result->buffer->data[ size1 - 1 ] = '7';
// result->buffer->ulength = size1;
// result->product_kind = h->product_kind;
// long off = 64; // This is only true for GRIB edition 2
// err = grib_encode_unsigned_long( result->buffer->data, (unsigned long)size1, &off, 64);
// if (err) {
// printf("err=%s\n", grib_get_error_message(err));
// return NULL;
// }
// return result;
// }
grib_handle* codes_handle_new_from_file(grib_context* c, FILE* f, ProductKind product, int* error)
{
if (product == PRODUCT_GRIB)