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#include "pg_compat.h"
extern "C" {
#include "postgres.h"
#include "yql/read_table.h"
}
#include <yql/essentials/parser/pg_catalog/catalog.h>
struct yql_table_iterator {
const TVector<TMaybe<TString>>* Data;
char* Error;
size_t NumColumns;
size_t* ColumnsRemap;
size_t Pos;
size_t RowStep;
};
extern "C" struct yql_table_iterator* yql_read_table(const char* name, int num_columns, const char* columns[]) {
yql_table_iterator* res = (yql_table_iterator*)palloc(sizeof(yql_table_iterator));
Zero(*res);
if (!name || num_columns < 0 || !columns) {
res->Error = pstrdup("bad arguments");
return res;
}
TString fullName = name;
auto pos = fullName.find('.');
if (pos == TString::npos) {
res->Error = pstrdup("expected full table name");
return res;
}
auto schema = fullName.substr(0, pos);
auto table = fullName.substr(pos + 1);
res->NumColumns = num_columns;
res->Pos = 0;
if (num_columns) {
res->ColumnsRemap = (size_t*)palloc(sizeof(size_t) * res->NumColumns);
}
TVector<TString> columnNames(res->NumColumns);
for (size_t i = 0; i < res->NumColumns; ++i) {
columnNames[i] = columns[i];
}
try {
res->Data = NYql::NPg::ReadTable(NYql::NPg::TTableInfoKey{schema, table}, columnNames, res->ColumnsRemap, res->RowStep);
} catch (yexception& e) {
res->Error = pstrdup(e.what());
}
return res;
}
extern "C" const char* yql_iterator_error(struct yql_table_iterator* iterator) {
if (!iterator) {
return nullptr;
}
return iterator->Error;
}
extern "C" bool yql_iterator_has_data(struct yql_table_iterator* iterator) {
if (!iterator || !iterator->Data) {
return false;
}
return iterator->Pos < iterator->Data->size();
}
extern "C" bool yql_iterator_value(struct yql_table_iterator* iterator, int column_index, const char** value) {
if (!iterator || !iterator->Data || !value) {
return false;
}
if (column_index < 0 || column_index >= iterator->NumColumns) {
return false;
}
const auto& cell = (*iterator->Data)[iterator->Pos + iterator->ColumnsRemap[column_index]];
if (!cell) {
*value = nullptr;
return true;
}
*value = cell.GetRef().c_str();
return true;
}
extern "C" void yql_iterator_move(struct yql_table_iterator* iterator) {
if (!iterator || !iterator->Data) {
return;
}
if (iterator->Pos < iterator->Data->size()) {
iterator->Pos += iterator->RowStep;
}
}
extern "C" void yql_iterator_close(struct yql_table_iterator** iterator) {
if (!iterator || !*iterator) {
return;
}
if ((*iterator)->ColumnsRemap) {
pfree((*iterator)->ColumnsRemap);
}
if ((*iterator)->Error) {
pfree((*iterator)->Error);
}
pfree(*iterator);
*iterator = nullptr;
}
extern "C" ui64 TouchReadTableApi() {
return
(ui64)&yql_read_table +
(ui64)&yql_iterator_error +
(ui64)&yql_iterator_has_data +
(ui64)&yql_iterator_value +
(ui64)&yql_iterator_move +
(ui64)&yql_iterator_close;
}
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