cppdataloader is a batching and caching library for C++17.
cppdataloader is a generic utility to be used as part of your application's data fetching layer to provide a simplified and consistent API over various remote data sources such as databases or web services via batching and caching.
- Batching
- Caching
- Direct dispatch
- Timeout dispatch
- Empty values
cppq is a header-only library with no dependencies.
Just include the header: #include "cppdataloader.h".
#include "cppdataloader.hpp"
#include <iostream>
class User {
public:
User(long _id): id(_id) {}
long id;
};
class UserBatchLoader : public BatchLoader<long, User> {
public:
std::vector<User> load(std::vector<long> userIds) const override {
auto result = std::vector<User>();
// Make a DB call here or something and pass in userIds to SELECT and return
for (auto userId : userIds)
result.push_back(User(userId));
// Results should be in the same order as passed-in IDs
return result;
}
};
int main(int argc, char *argv[]) {
UserBatchLoader userBatchLoader = UserBatchLoader();
DataLoader<long, User> userLoader = DataLoader(userBatchLoader);
std::future<User> load1 = userLoader.load(1);
std::future<User> load2 = userLoader.load(2);
// Since this fetches the same ID of `1`, it will return the cached value
std::future<User> load3 = userLoader.load(1);
// Both calls to `load` will be batched and executed with this call
userLoader.dispatch();
std::cout << load1.get().id << " " << load2.get().id << " " << load3.get().id << std::endl;
}cppdataloader is MIT-licensed.