lmdb-safe/examples/view.cc

#include "../lmdb-safe.hh"

#include <c++utilities/application/global.h>

#include <iostream>

using namespace std;
using namespace LMDBSafe;

void countDB(MDBEnv &env, MDBROTransaction &txn, const std::string &dbname)
{
    CPP_UTILITIES_UNUSED(env)
    auto db = txn->openDB(dbname, 0);
    auto cursor = txn->getCursor(db);
    std::uint32_t count = 0;
    MDBOutVal key, val;
    while (!cursor.get(key, val, count ? MDB_NEXT : MDB_FIRST)) {
        cout << key.get<std::string>();
        if (key.d_mdbval.mv_size == 4)
            cout << " " << key.get<std::uint32_t>();
        cout << ": " << val.get<std::string>();
        cout << "\n";
        ++count;
    }
    cout << count << endl;
}

int main(int argc, char **argv)
{
    if (argc < 2) {
        cout << "No database file specified.\n";
        return 0;
    }
    MDBEnv env(argv[1], MDB_RDONLY | MDB_NOSUBDIR, 0600);
    auto main = env.openDB("", 0);
    auto txn = env.getROTransaction();

    auto cursor = txn->getCursor(main);

    MDBOutVal key, val;
    if (cursor.get(key, val, MDB_FIRST)) {
        cout << "Database is empty" << endl;
    }
    do {
        cout << key.get<string>() << endl;
        countDB(env, txn, key.get<string>());
    } while (!cursor.get(key, val, MDB_NEXT));
}