// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
// vim: ts=8 sw=2 smarttab

#include "librbd/io/ImageDispatch.h"
#include "common/dout.h"
#include "librbd/ImageCtx.h"
#include "librbd/io/AioCompletion.h"
#include "librbd/io/ImageRequest.h"
#include "librbd/io/ObjectDispatcherInterface.h"

#define dout_subsys ceph_subsys_rbd
#undef dout_prefix
#define dout_prefix *_dout << "librbd::io::ImageDispatch: " << this << " " \
                           << __func__ << ": "

namespace librbd {
namespace io {

namespace {

void start_in_flight_io(AioCompletion* aio_comp) {
  // TODO remove AsyncOperation from AioCompletion
  if (!aio_comp->async_op.started()) {
    aio_comp->start_op();
  }
}

} // anonymous namespace

template <typename I>
void ImageDispatch<I>::shut_down(Context* on_finish) {
  on_finish->complete(0);
}

template <typename I>
bool ImageDispatch<I>::read(
    AioCompletion* aio_comp, Extents &&image_extents, ReadResult &&read_result,
    IOContext io_context, int op_flags, int read_flags,
    const ZTracer::Trace &parent_trace, uint64_t tid,
    std::atomic<uint32_t>* image_dispatch_flags,
    DispatchResult* dispatch_result, Context** on_finish,
    Context* on_dispatched) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << "image_extents=" << image_extents << dendl;

  start_in_flight_io(aio_comp);

  *dispatch_result = DISPATCH_RESULT_COMPLETE;
  ImageRequest<I>::aio_read(
    m_image_ctx, aio_comp, std::move(image_extents), std::move(read_result),
    io_context, op_flags, read_flags, parent_trace);
  return true;
}

template <typename I>
bool ImageDispatch<I>::write(
    AioCompletion* aio_comp, Extents &&image_extents, bufferlist &&bl,
    IOContext io_context, int op_flags, const ZTracer::Trace &parent_trace,
    uint64_t tid, std::atomic<uint32_t>* image_dispatch_flags,
    DispatchResult* dispatch_result, Context** on_finish,
    Context* on_dispatched) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << "image_extents=" << image_extents << dendl;

  start_in_flight_io(aio_comp);

  *dispatch_result = DISPATCH_RESULT_COMPLETE;
  ImageRequest<I>::aio_write(
    m_image_ctx, aio_comp, std::move(image_extents), std::move(bl),
    io_context, op_flags, parent_trace);
  return true;
}

template <typename I>
bool ImageDispatch<I>::discard(
    AioCompletion* aio_comp, Extents &&image_extents,
    uint32_t discard_granularity_bytes, IOContext io_context,
    const ZTracer::Trace &parent_trace, uint64_t tid,
    std::atomic<uint32_t>* image_dispatch_flags,
    DispatchResult* dispatch_result, Context** on_finish,
    Context* on_dispatched) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << "image_extents=" << image_extents << dendl;

  start_in_flight_io(aio_comp);

  *dispatch_result = DISPATCH_RESULT_COMPLETE;
  ImageRequest<I>::aio_discard(
    m_image_ctx, aio_comp, std::move(image_extents), discard_granularity_bytes,
    io_context, parent_trace);
  return true;
}

template <typename I>
bool ImageDispatch<I>::write_same(
    AioCompletion* aio_comp, Extents &&image_extents, bufferlist &&bl,
    IOContext io_context, int op_flags, const ZTracer::Trace &parent_trace,
    uint64_t tid, std::atomic<uint32_t>* image_dispatch_flags,
    DispatchResult* dispatch_result, Context** on_finish,
    Context* on_dispatched) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << "image_extents=" << image_extents << dendl;

  start_in_flight_io(aio_comp);

  *dispatch_result = DISPATCH_RESULT_COMPLETE;
  ImageRequest<I>::aio_writesame(
    m_image_ctx, aio_comp, std::move(image_extents), std::move(bl),
    io_context, op_flags, parent_trace);
  return true;
}

template <typename I>
bool ImageDispatch<I>::compare_and_write(
    AioCompletion* aio_comp, Extents &&image_extents, bufferlist &&cmp_bl,
    bufferlist &&bl, uint64_t *mismatch_offset, IOContext io_context,
    int op_flags, const ZTracer::Trace &parent_trace, uint64_t tid,
    std::atomic<uint32_t>* image_dispatch_flags,
    DispatchResult* dispatch_result, Context** on_finish,
    Context* on_dispatched) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << "image_extents=" << image_extents << dendl;

  start_in_flight_io(aio_comp);

  *dispatch_result = DISPATCH_RESULT_COMPLETE;
  ImageRequest<I>::aio_compare_and_write(
    m_image_ctx, aio_comp, std::move(image_extents), std::move(cmp_bl),
    std::move(bl), mismatch_offset, io_context, op_flags, parent_trace);
  return true;
}

template <typename I>
bool ImageDispatch<I>::flush(
    AioCompletion* aio_comp, FlushSource flush_source,
    const ZTracer::Trace &parent_trace, uint64_t tid,
    std::atomic<uint32_t>* image_dispatch_flags,
    DispatchResult* dispatch_result, Context** on_finish,
    Context* on_dispatched) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << dendl;

  start_in_flight_io(aio_comp);

  *dispatch_result = DISPATCH_RESULT_COMPLETE;
  ImageRequest<I>::aio_flush(m_image_ctx, aio_comp, flush_source, parent_trace);
  return true;
}

template <typename I>
bool ImageDispatch<I>::list_snaps(
    AioCompletion* aio_comp, Extents&& image_extents, SnapIds&& snap_ids,
    int list_snaps_flags, SnapshotDelta* snapshot_delta,
    const ZTracer::Trace &parent_trace, uint64_t tid,
    std::atomic<uint32_t>* image_dispatch_flags,
    DispatchResult* dispatch_result, Context** on_finish,
    Context* on_dispatched) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << dendl;

  start_in_flight_io(aio_comp);

  *dispatch_result = DISPATCH_RESULT_COMPLETE;
  ImageListSnapsRequest<I> req(
    *m_image_ctx, aio_comp, std::move(image_extents), std::move(snap_ids),
    list_snaps_flags, snapshot_delta, parent_trace);
  req.send();
  return true;
}

template <typename I>
bool ImageDispatch<I>::invalidate_cache(Context* on_finish) {
  auto cct = m_image_ctx->cct;
  ldout(cct, 20) << dendl;

  std::shared_lock owner_lock{m_image_ctx->owner_lock};
  m_image_ctx->io_object_dispatcher->invalidate_cache(on_finish);
  return true;
}

} // namespace io
} // namespace librbd

template class librbd::io::ImageDispatch<librbd::ImageCtx>;