feat: GrpcSource for ETL ng (#1745)

For #1596 and #1597

src/etlng/impl/GrpcSource.hpp

@@ -0,0 +1,70 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#pragma once
+
+#include "etlng/InitialLoadObserverInterface.hpp"
+#include "util/log/Logger.hpp"
+
+#include <grpcpp/support/status.h>
+#include <org/xrpl/rpc/v1/get_ledger.pb.h>
+#include <xrpl/proto/org/xrpl/rpc/v1/xrp_ledger.grpc.pb.h>
+
+#include <cstdint>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+namespace etlng::impl {
+
+class GrpcSource {
+    util::Logger log_;
+    std::unique_ptr<org::xrpl::rpc::v1::XRPLedgerAPIService::Stub> stub_;
+
+public:
+    GrpcSource(std::string const& ip, std::string const& grpcPort);
+
+    /**
+     * @brief Fetch data for a specific ledger.
+     *
+     * This function will continuously try to fetch data for the specified ledger until the fetch succeeds, the ledger
+     * is found in the database, or the server is shutting down.
+     *
+     * @param sequence Sequence of the ledger to fetch
+     * @param getObjects Whether to get the account state diff between this ledger and the prior one; defaults to true
+     * @param getObjectNeighbors Whether to request object neighbors; defaults to false
+     * @return A std::pair of the response status and the response itself
+     */
+    std::pair<grpc::Status, org::xrpl::rpc::v1::GetLedgerResponse>
+    fetchLedger(uint32_t sequence, bool getObjects = true, bool getObjectNeighbors = false);
+
+    /**
+     * @brief Download a ledger in full.
+     *
+     * @param sequence Sequence of the ledger to download
+     * @param numMarkers Number of markers to generate for async calls
+     * @param observer InitialLoadObserverInterface implementation
+     * @return A std::pair of the data and a bool indicating whether the download was successful
+     */
+    std::pair<std::vector<std::string>, bool>
+    loadInitialLedger(uint32_t sequence, uint32_t numMarkers, etlng::InitialLoadObserverInterface& observer);
+};
+
+}  // namespace etlng::impl