Adding upstream version 14.2.21.upstream/14.2.21upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 190 insertions, 0 deletions

diff --git a/src/librados/librados_asio.h b/src/librados/librados_asio.h
new file mode 100644
index 00000000..3ddc1972
--- /dev/null
+++ b/src/librados/librados_asio.h
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+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2017 Red Hat, Inc.
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ */
+
+#ifndef LIBRADOS_ASIO_H
+#define LIBRADOS_ASIO_H
+
+#include "include/rados/librados.hpp"
+#include "common/async/completion.h"
+
+/// Defines asynchronous librados operations that satisfy all of the
+/// "Requirements on asynchronous operations" imposed by the C++ Networking TS
+/// in section 13.2.7. Many of the type and variable names below are taken
+/// directly from those requirements.
+///
+/// The current draft of the Networking TS (as of 2017-11-27) is available here:
+/// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/n4711.pdf
+///
+/// The boost::asio documentation duplicates these requirements here:
+/// http://www.boost.org/doc/libs/1_66_0/doc/html/boost_asio/reference/asynchronous_operations.html
+
+namespace librados {
+
+namespace detail {
+
+/// unique_ptr with custom deleter for AioCompletion
+struct AioCompletionDeleter {
+  void operator()(AioCompletion *c) { c->release(); }
+};
+using unique_aio_completion_ptr =
+    std::unique_ptr<AioCompletion, AioCompletionDeleter>;
+
+/// Invokes the given completion handler. When the type of Result is not void,
+/// storage is provided for it and that result is passed as an additional
+/// argument to the handler.
+template <typename Result>
+struct Invoker {
+  using Signature = void(boost::system::error_code, Result);
+  Result result;
+  template <typename Completion>
+  void dispatch(Completion&& completion, boost::system::error_code ec) {
+    ceph::async::dispatch(std::move(completion), ec, std::move(result));
+  }
+};
+// specialization for Result=void
+template <>
+struct Invoker<void> {
+  using Signature = void(boost::system::error_code);
+  template <typename Completion>
+  void dispatch(Completion&& completion, boost::system::error_code ec) {
+    ceph::async::dispatch(std::move(completion), ec);
+  }
+};
+
+template <typename Result>
+struct AsyncOp : Invoker<Result> {
+  unique_aio_completion_ptr aio_completion;
+
+  using Signature = typename Invoker<Result>::Signature;
+  using Completion = ceph::async::Completion<Signature, AsyncOp<Result>>;
+
+  static void aio_dispatch(completion_t cb, void *arg) {
+    // reclaim ownership of the completion
+    auto p = std::unique_ptr<Completion>{static_cast<Completion*>(arg)};
+    // move result out of Completion memory being freed
+    auto op = std::move(p->user_data);
+    const int ret = op.aio_completion->get_return_value();
+    boost::system::error_code ec;
+    if (ret < 0) {
+      ec.assign(-ret, boost::system::system_category());
+    }
+    op.dispatch(std::move(p), ec);
+  }
+
+  template <typename Executor1, typename CompletionHandler>
+  static auto create(const Executor1& ex1, CompletionHandler&& handler) {
+    auto p = Completion::create(ex1, std::move(handler));
+    p->user_data.aio_completion.reset(
+        Rados::aio_create_completion(p.get(), nullptr, aio_dispatch));
+    return p;
+  }
+};
+
+} // namespace detail
+
+
+/// Calls IoCtx::aio_read() and arranges for the AioCompletion to call a
+/// given handler with signature (boost::system::error_code, bufferlist).
+template <typename ExecutionContext, typename CompletionToken>
+auto async_read(ExecutionContext& ctx, IoCtx& io, const std::string& oid,
+                size_t len, uint64_t off, CompletionToken&& token)
+{
+  using Op = detail::AsyncOp<bufferlist>;
+  using Signature = typename Op::Signature;
+  boost::asio::async_completion<CompletionToken, Signature> init(token);
+  auto p = Op::create(ctx.get_executor(), init.completion_handler);
+  auto& op = p->user_data;
+
+  int ret = io.aio_read(oid, op.aio_completion.get(), &op.result, len, off);
+  if (ret < 0) {
+    auto ec = boost::system::error_code{-ret, boost::system::system_category()};
+    ceph::async::post(std::move(p), ec, bufferlist{});
+  } else {
+    p.release(); // release ownership until completion
+  }
+  return init.result.get();
+}
+
+/// Calls IoCtx::aio_write() and arranges for the AioCompletion to call a
+/// given handler with signature (boost::system::error_code).
+template <typename ExecutionContext, typename CompletionToken>
+auto async_write(ExecutionContext& ctx, IoCtx& io, const std::string& oid,
+                 bufferlist &bl, size_t len, uint64_t off,
+                 CompletionToken&& token)
+{
+  using Op = detail::AsyncOp<void>;
+  using Signature = typename Op::Signature;
+  boost::asio::async_completion<CompletionToken, Signature> init(token);
+  auto p = Op::create(ctx.get_executor(), init.completion_handler);
+  auto& op = p->user_data;
+
+  int ret = io.aio_write(oid, op.aio_completion.get(), bl, len, off);
+  if (ret < 0) {
+    auto ec = boost::system::error_code{-ret, boost::system::system_category()};
+    ceph::async::post(std::move(p), ec);
+  } else {
+    p.release(); // release ownership until completion
+  }
+  return init.result.get();
+}
+
+/// Calls IoCtx::aio_operate() and arranges for the AioCompletion to call a
+/// given handler with signature (boost::system::error_code, bufferlist).
+template <typename ExecutionContext, typename CompletionToken>
+auto async_operate(ExecutionContext& ctx, IoCtx& io, const std::string& oid,
+                   ObjectReadOperation *read_op, int flags,
+                   CompletionToken&& token)
+{
+  using Op = detail::AsyncOp<bufferlist>;
+  using Signature = typename Op::Signature;
+  boost::asio::async_completion<CompletionToken, Signature> init(token);
+  auto p = Op::create(ctx.get_executor(), init.completion_handler);
+  auto& op = p->user_data;
+
+  int ret = io.aio_operate(oid, op.aio_completion.get(), read_op,
+                           flags, &op.result);
+  if (ret < 0) {
+    auto ec = boost::system::error_code{-ret, boost::system::system_category()};
+    ceph::async::post(std::move(p), ec, bufferlist{});
+  } else {
+    p.release(); // release ownership until completion
+  }
+  return init.result.get();
+}
+
+/// Calls IoCtx::aio_operate() and arranges for the AioCompletion to call a
+/// given handler with signature (boost::system::error_code).
+template <typename ExecutionContext, typename CompletionToken>
+auto async_operate(ExecutionContext& ctx, IoCtx& io, const std::string& oid,
+                   ObjectWriteOperation *write_op, int flags,
+                   CompletionToken &&token)
+{
+  using Op = detail::AsyncOp<void>;
+  using Signature = typename Op::Signature;
+  boost::asio::async_completion<CompletionToken, Signature> init(token);
+  auto p = Op::create(ctx.get_executor(), init.completion_handler);
+  auto& op = p->user_data;
+
+  int ret = io.aio_operate(oid, op.aio_completion.get(), write_op, flags);
+  if (ret < 0) {
+    auto ec = boost::system::error_code{-ret, boost::system::system_category()};
+    ceph::async::post(std::move(p), ec);
+  } else {
+    p.release(); // release ownership until completion
+  }
+  return init.result.get();
+}
+
+} // namespace librados
+
+#endif // LIBRADOS_ASIO_H