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/**
* To build this program, please make sure to reference linked libraries:
*
* g++ -std=c++11 -leckit -lodccore -o odc-cpp-index odc_index.cc
*/
#include "eckit/runtime/Main.h"
#include "odc/api/Odb.h"
#include <cstdint>
#include <iomanip>
#include <iostream>
#include <vector>
using namespace odc::api;
void usage() {
std::cerr << "Usage:\n odc-cpp-index <odb2 file>" << std::endl << std::endl;
}
class Printer : public SpanVisitor {
template <typename T>
void prnt(const std::string& columnName, const std::set<T>& vals) {
ASSERT(vals.size() == 1);
std::cout << columnName << "=" << *vals.begin() << " ";
}
void operator()(const std::string& columnName, const std::set<long>& vals) override { prnt(columnName, vals); }
void operator()(const std::string& columnName, const std::set<double>& vals) override { prnt(columnName, vals); }
void operator()(const std::string& columnName, const std::set<std::string>& vals) override {
prnt(columnName, vals);
}
};
void write_index(Span& span, long offset, long length) {
std::cout << "Archival unit: offset=" << offset << " length=" << length << std::endl;
std::cout << " Key: ";
// Dump the index values without decoding the frame data
Printer p;
span.visit(p);
std::cout << std::endl;
}
int main(int argc, char** argv) {
if (argc != 2) {
usage();
return 1;
}
char* path = argv[1];
eckit::Main::initialise(argc, argv);
// Initialise library
odc::api::Settings::treatIntegersAsDoubles(false);
bool aggregated = false;
// Open supplied path in non-aggregated mode
Reader reader(path, aggregated);
// Define which columns will be used as index keys
std::vector<std::string> index_keys{"key1", "key2", "key3"};
Frame frame;
Span lastSpan;
long offset = 0;
long length = 0;
bool first = true;
// Iterate over frames
while ((frame = reader.next())) {
// Enforce the constant values constraint
bool mustBeConstant = true;
// Get index values for the frame
Span span = frame.span(index_keys, mustBeConstant);
// If the index values are the same, just increase the length
if (span == lastSpan || first) {
length += span.length();
// Remember the first set of index values
if (first)
std::swap(lastSpan, span);
}
// If the index values differ, output the last set
else {
write_index(lastSpan, offset, length);
// Reset offset and length counters
offset = span.offset();
length = span.length();
// Remember the current set of index values
std::swap(lastSpan, span);
}
first = false;
}
// Output last set of index values
write_index(lastSpan, offset, length);
return 0;
}
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