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/**
* To build this program, please make sure to reference linked library:
*
* gcc -lodccore -o odc-c-encode-row-major odc_encode_row_major.c
*/
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "odc/api/odc.h"
// Bitfield constants
#define Ob00000001 1
#define Ob00001011 11
#define Ob01101011 107
#define CHECK_RESULT(x) \
do { \
int rc = (x); \
if (rc != ODC_SUCCESS) { \
fprintf(stderr, "Error calling odc function \"%s\": %s\n", #x, odc_error_string(rc)); \
exit(1); \
} \
} while (false);
void usage() {
fprintf(stderr, "Usage:\n");
fprintf(stderr, " odc-c-encode-row-major <odb2 output file>\n\n");
}
void cycle_longs(long* list, int size, long* pool, int pool_size) {
int index = 0;
int i;
for (i = 0; i < size; i++) {
if (index == pool_size)
index = 0;
list[i] = pool[index];
index++;
}
}
void cycle_doubles(double* list, int size, double* pool, int pool_size) {
int index = 0;
int i;
for (i = 0; i < size; i++) {
if (index == pool_size)
index = 0;
list[i] = pool[index];
index++;
}
}
void create_scratch_data(long nrows, int ncols, double data[nrows][ncols]) {
// Prepare the current date as an integer
time_t rawtime;
time(&rawtime);
struct tm* timeinfo;
timeinfo = localtime(&rawtime);
int64_t date = 10000 * (timeinfo->tm_year + 1900) + 100 * (timeinfo->tm_mon + 1) + timeinfo->tm_mday;
// Prepare the list of integer values, including the missing value
long missing_integer;
CHECK_RESULT(odc_missing_integer(&missing_integer));
long integer_pool[] = {1234, 4321, missing_integer};
int integer_pool_size = sizeof(integer_pool) / sizeof(integer_pool[0]);
long missing_integers[nrows];
cycle_longs(missing_integers, nrows, integer_pool, integer_pool_size);
// Prepare the list of double values, including the missing value
double missing_double;
CHECK_RESULT(odc_missing_double(&missing_double));
double double_pool[] = {12.34, 43.21, missing_double};
int double_pool_size = sizeof(double_pool) / sizeof(double_pool[0]);
double missing_doubles[nrows];
cycle_doubles(missing_doubles, nrows, double_pool, double_pool_size);
// Prepare the list of bitfield values
long bitfield_pool[] = {Ob00000001, Ob00001011, Ob01101011};
int bitfield_pool_size = sizeof(bitfield_pool) / sizeof(bitfield_pool[0]);
long bitfield_values[nrows];
cycle_longs(bitfield_values, nrows, bitfield_pool, bitfield_pool_size);
int i;
// Fill in the passed data array with scratch values
for (i = 0; i < nrows; i++) {
memset(&data[i][0], 0, 5);
snprintf((char*)(&data[i][0]), 5, "xxxx"); // expver
*(int64_t*)(&data[i][1]) = date; // date@hdr
memset(&data[i][2], 0, 8);
snprintf((char*)(&data[i][2]), 7, "stat%02d", i); // statid@hdr
memset(&data[i][3], 0, 16);
snprintf((char*)(&data[i][3]), 16, "0-12345-0-678%02d", i); // wigos@hdr
*(double*)(&data[i][5]) = 12.3456 * i; // obsvalue@body
*(long*)(&data[i][6]) = missing_integers[i]; // integer_missing
*(double*)(&data[i][7]) = missing_doubles[i]; // double_missing
*(long*)(&data[i][8]) = bitfield_values[i]; // bitfield_column
}
}
int main(int argc, char* argv[]) {
if (argc != 2) {
usage();
return 1;
}
// Get output path from command argument
char* path = argv[1];
// Initialise API and set treatment of integers as longs
CHECK_RESULT(odc_initialise_api());
CHECK_RESULT(odc_integer_behaviour(ODC_INTEGERS_AS_LONGS));
// Define row and column count
const long nrows = 20;
const int ncols = 9;
// Allocate data array of rows x columns
double data[nrows][ncols];
// Set up the allocated array with scratch data
create_scratch_data(nrows, ncols, data);
// Initialise encoder
odc_encoder_t* encoder = NULL;
CHECK_RESULT(odc_new_encoder(&encoder));
// Define all column names and their types
CHECK_RESULT(odc_encoder_add_column(encoder, "expver", ODC_STRING));
CHECK_RESULT(odc_encoder_add_column(encoder, "date@hdr", ODC_INTEGER));
CHECK_RESULT(odc_encoder_add_column(encoder, "statid@hdr", ODC_STRING));
CHECK_RESULT(odc_encoder_add_column(encoder, "wigos@hdr", ODC_STRING));
CHECK_RESULT(odc_encoder_add_column(encoder, "obsvalue@body", ODC_REAL));
CHECK_RESULT(odc_encoder_add_column(encoder, "integer_missing", ODC_INTEGER));
CHECK_RESULT(odc_encoder_add_column(encoder, "double_missing", ODC_REAL));
CHECK_RESULT(odc_encoder_add_column(encoder, "bitfield_column", ODC_BITFIELD));
// Column `wigos@hdr` is a 16-byte string column, hence takes 2 columns in the array => ncols=9
CHECK_RESULT(odc_encoder_column_set_data_size(encoder, 3, 16));
// Column `bitfield_column` is an integer with 4 bitfield values in it
CHECK_RESULT(odc_encoder_column_add_bitfield(encoder, 7, "flag_a", 1));
CHECK_RESULT(odc_encoder_column_add_bitfield(encoder, 7, "flag_b", 2));
CHECK_RESULT(odc_encoder_column_add_bitfield(encoder, 7, "flag_c", 3));
CHECK_RESULT(odc_encoder_column_add_bitfield(encoder, 7, "flag_d", 1));
// Set input data array from which data will be encoded
// Zero value for last `columnMajorWidth` argument indicates the row-major layout
CHECK_RESULT(odc_encoder_set_data_array(encoder, data, ncols * sizeof(double), nrows, 0));
const char* property_key = "encoded_by";
const char* property_value = "odc_example";
// Add some key/value metadata to the frame
CHECK_RESULT(odc_encoder_add_property(encoder, property_key, property_value));
int file_descriptor = open(path, O_CREAT | O_TRUNC | O_WRONLY, 0666);
long size;
// Encode ODB-2 into an already open file descriptor
CHECK_RESULT(odc_encode_to_file_descriptor(encoder, file_descriptor, &size));
close(file_descriptor);
// Deallocate memory used up by the encoder
CHECK_RESULT(odc_free_encoder(encoder));
fprintf(stdout, "Written %ld rows to %s\n", nrows, path);
return 0;
}
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