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#include <cstring>
#include "util/Log.h"
#include "DB.h"
using namespace std;
using namespace crepe;
DB::DB(const string & path) {
dbg_trace();
int ret;
// init database struct
libdb::DB * db;
if ((ret = libdb::db_create(&db, NULL, 0)) != 0)
throw runtime_error(format("db_create: {}", libdb::db_strerror(ret)));
this->db = {db, [](libdb::DB * db) { db->close(db, 0); }};
// load or create database file
ret = this->db->open(this->db.get(), NULL, path.c_str(), NULL, libdb::DB_BTREE, DB_CREATE,
0);
if (ret != 0) throw runtime_error(format("db->open: {}", libdb::db_strerror(ret)));
// create cursor
libdb::DBC * cursor;
ret = this->db->cursor(this->db.get(), NULL, &cursor, 0);
if (ret != 0) throw runtime_error(format("db->cursor: {}", libdb::db_strerror(ret)));
this->cursor = {cursor, [](libdb::DBC * cursor) { cursor->close(cursor); }};
}
libdb::DBT DB::to_thing(const string & thing) const noexcept {
libdb::DBT thang;
memset(&thang, 0, sizeof(libdb::DBT));
thang.data = (void *) thing.data();
thang.size = thing.size();
return thang;
}
string DB::get(const string & key) {
libdb::DBT db_key = this->to_thing(key);
libdb::DBT db_val;
memset(&db_val, 0, sizeof(libdb::DBT));
int ret = this->cursor->get(this->cursor.get(), &db_key, &db_val, DB_FIRST);
if (ret == 0) return {static_cast<char *>(db_val.data), db_val.size};
string err = format("cursor->get: {}", libdb::db_strerror(ret));
if (ret == DB_NOTFOUND) throw out_of_range(err);
else throw runtime_error(err);
}
void DB::set(const string & key, const string & value) {
libdb::DBT db_key = this->to_thing(key);
libdb::DBT db_val = this->to_thing(value);
int ret = this->db->put(this->db.get(), NULL, &db_key, &db_val, 0);
if (ret != 0) throw runtime_error(format("cursor->get: {}", libdb::db_strerror(ret)));
}
bool DB::has(const std::string & key) {
try {
this->get(key);
} catch (std::out_of_range &) {
return false;
}
return true;
}
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