Key-Value Store API Reference

Insert a value for the given key.

If the key is already present, the operation will fail.

• Go
• C++
• Python

def insert(key, value):
  store.Insert(kvs.InsertRequest(key = key, value = value.encode('utf-8')))

func insert(store kvs.KeyValueStoreClient, key string, value string) error {
  _, err := store.Insert(context.Background(), &kvs.InsertRequest{Key: key, Value: []byte(value)})
  return err
}

void
insert(std::string const& key, std::string const& value)
{
  InsertResponse res;
  {
    grpc::ClientContext ctx;
    InsertRequest req;
    req.set_key(key);
    req.set_value(value);
    auto status = store->Insert(&ctx, req, &res);
    if (!status.ok())
      throw std::runtime_error(status.error_message());
  }
}

Update the value for the given key.

If the key is not already present, the operation will fail.

• Go
• C++
• Python

def update(key, value):
  store.Update(kvs.UpdateRequest(key = key, value = value.encode('utf-8')))

func update(store kvs.KeyValueStoreClient, key string, value string) error {
  _, err := store.Update(context.Background(), &kvs.UpdateRequest{Key: key, Value: []byte(value)})
  return err
}

void
update(std::string const& key, std::string const& value)
{
  UpdateResponse res;
  {
    grpc::ClientContext ctx;
    UpdateRequest req;
    req.set_key(key);
    req.set_value(value);
    auto status = store->Update(&ctx, req, &res);
    if (!status.ok())
      throw std::runtime_error(status.error_message());
  }
}

Update (or insert if not present) a value for the given key.

• Go
• C++
• Python

def upsert(key, value):
  store.Upsert(kvs.UpsertRequest(key = key, value = value.encode('utf-8')))

func upsert(store kvs.KeyValueStoreClient, key string, value string) error {
  _, err := store.Upsert(context.Background(), &kvs.UpsertRequest{Key: key, Value: []byte(value)})
  return err
}

void
upsert(std::string const& key, std::string const& value)
{
  UpsertResponse res;
  {
    grpc::ClientContext ctx;
    UpsertRequest req;
    req.set_key(key);
    req.set_value(value);
    auto status = store->Upsert(&ctx, req, &res);
    if (!status.ok())
      throw std::runtime_error(status.error_message());
  }
}

Retrieve the value for the given key.

If the key doesn't exist, the operation will fail.

• Go
• C++
• Python

def fetch(key):
  return store.Fetch(kvs.FetchRequest(key = key)).value.decode('utf-8')

func fetch(store kvs.KeyValueStoreClient, key string) (string, error) {
  res, err := store.Fetch(context.Background(), &kvs.FetchRequest{Key: key})
  if err != nil {
    return "", err
  }
  return string(res.Value), nil
}

std::string
fetch(std::string const& key)
{
  FetchResponse res;
  {
    grpc::ClientContext ctx;
    FetchRequest req;
    req.set_key(key);
    auto status = store->Fetch(&ctx, req, &res);
    check_status(status);
  }
  return res.value();
}

Delete the value for the given key.

If the key doesn't exist, the operation will fail.

• Go
• C++
• Python

def delete(key):
  store.Delete(kvs.DeleteRequest(key = key))

func delete_(store kvs.KeyValueStoreClient, key string) error {
  _, err := store.Delete(context.Background(), &kvs.DeleteRequest{Key: key})
  return err
}

void
delete_(std::string const& key)
{
  DeleteResponse res;
  {
    grpc::ClientContext ctx;
    DeleteRequest req;
    req.set_key(key);
    auto status = store->Delete(&ctx, req, &res);
    if (!status.ok())
      throw std::runtime_error(status.error_message());
  }
}

Return the list of keys.

• Go
• C++
• Python

def list_():
  return list(map(lambda i: i.key, store.List(kvs.ListRequest()).items))

func list(store kvs.KeyValueStoreClient) ([]string, error) {
  res, err := store.List(context.Background(), &kvs.ListRequest{})
  if err != nil {
    return nil, err
  }
  result := []string{}
  for _, i := range res.Items {
    result = append(result, i.Key)
  }
  return result, nil
}

std::vector
list()
{
  ListResponse res;
  {
    grpc::ClientContext ctx;
    ListRequest req;
    auto status = store->List(&ctx, req, &res);
  }
  std::vector list;
  for (int i = 0; i < res.items_size(); i++)
    list.push_back(res.items(i).key());
  return list;
}