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/*************************************************************************************************
* Example for basic usage of the asynchronous database
*
* Copyright 2020 Google LLC
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of the License at
* https://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software distributed under the
* License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied. See the License for the specific language governing permissions
* and limitations under the License.
*************************************************************************************************/
#include "tkrzw_dbm_async.h"
#include "tkrzw_dbm_poly.h"
// Main routine.
int main(int argc, char** argv) {
// All symbols of Tkrzw are under the namespace "tkrzw".
using namespace tkrzw;
// Opens a new database.
PolyDBM dbm;
dbm.OpenAdvanced("casket.tkt", true, File::OPEN_TRUNCATE).OrDie();
{
// Makes an asynchronouns adapter with 10 worker threads.
// We limit its scope to destroy it bofore the database instance.
AsyncDBM async(&dbm, 10);
// Sets records without checking the results of operations.
async.Set("one", "hop");
async.Set("two", "step");
async.Set("three", "jump");
// Retrieves a record value and evaluates the result.
// The record may or may not be found due to scheduling.
auto get_result = async.Get("three").get();
std::cout << get_result.first << std::endl;
if (get_result.first == Status::SUCCESS) {
std::cout << get_result.second << std::endl;
}
// Prints progression while rebuilding the database.
auto rebuild_future = async.Rebuild();
do {
std::cout << "Rebuilding the database" << std::endl;
} while (rebuild_future.wait_for(
std::chrono::seconds(1)) != std::future_status::ready);
std::cout << rebuild_future.get() << std::endl;
// Scans all records.
std::string last_key = "";
while (true) {
// Retrieve 100 keys which are upper than the last key.
auto [search_status, keys] =
async.SearchModal("upper", last_key, 100).get();
if (!search_status.IsOK() || keys.empty()) {
break;
}
last_key = keys.back();
// Retrieves and prints the values of the keys.
auto [get_status, records] = async.GetMulti(keys).get();
if (get_status.IsOK()) {
for (const auto& record : records) {
std::cout << record.first << ":" << record.second << std::endl;
}
}
}
}
// Closes the database.
dbm.Close().OrDie();
return 0;
}
// END OF FILE
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