crimson/osd: create the collected push ops use shared_ptr

do_with() uses a unique_ptr for keeping the captured variables alive. so
it is practically the same thing in concept. but `do_with()` is more
distracting and difficult to reason about, it increases the indent level
also.

so use a lw_shared_ptr() for collecting the push ops map.

Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/src/crimson/osd/replicated_recovery_backend.cc b/src/crimson/osd/replicated_recovery_backend.cc
index da32ee8b7b4de9e72a92ba682a39c8b50c4f78b8..8173489055d2e4a819b7814a1c4b8208a2e681e0 100644 (file)
--- a/src/crimson/osd/replicated_recovery_backend.cc
+++ b/src/crimson/osd/replicated_recovery_backend.cc
@@ -288,59 +288,52 @@ ReplicatedRecoveryBackend::prep_push(
 {
   logger().debug("{}: {}, {}", __func__, soid, need);
 
-  return seastar::do_with(std::map<pg_shard_t, PushOp>(),
-                         std::map<pg_shard_t, interval_set<uint64_t>>(),
-    [this, soid, &shards](auto& pops,
-                          auto& data_subsets) {
-    return seastar::parallel_for_each(shards,
-      [this, soid, pops, &data_subsets](auto pg_shard) mutable {
-      pops.emplace(pg_shard, PushOp());
-      auto& recovery_waiter = recovering.at(soid);
-      auto& obc = recovery_waiter.obc;
-      auto& data_subset = data_subsets[pg_shard];
-
-      if (obc->obs.oi.size) {
-       data_subset.insert(0, obc->obs.oi.size);
-      }
-      const auto& missing = pg.get_shard_missing().find(pg_shard)->second;
-      if (HAVE_FEATURE(pg.min_peer_features(), SERVER_OCTOPUS)) {
-       const auto it = missing.get_items().find(soid);
-       assert(it != missing.get_items().end());
-       data_subset.intersection_of(it->second.clean_regions.get_dirty_regions());
-       logger().debug("calc_head_subsets {} data_subset {}", soid, data_subset);
-      }
+  auto pops = seastar::make_lw_shared<std::map<pg_shard_t, PushOp>>();
+  return seastar::parallel_for_each(shards,
+    [this, soid, pops](auto pg_shard) mutable {
+    auto& recovery_waiter = recovering.at(soid);
+    auto& obc = recovery_waiter.obc;
+    interval_set<uint64_t> data_subset;
+    if (obc->obs.oi.size) {
+      data_subset.insert(0, obc->obs.oi.size);
+    }
+    const auto& missing = pg.get_shard_missing().find(pg_shard)->second;
+    if (HAVE_FEATURE(pg.min_peer_features(), SERVER_OCTOPUS)) {
+      const auto it = missing.get_items().find(soid);
+      assert(it != missing.get_items().end());
+      data_subset.intersection_of(it->second.clean_regions.get_dirty_regions());
+      logger().debug("prep_push: {} data_subset {}", soid, data_subset);
+    }
 
-      logger().debug("prep_push: {} to {}", soid, pg_shard);
-      auto& pi = recovery_waiter.pushing[pg_shard];
-      pg.begin_peer_recover(pg_shard, soid);
-      const auto pmissing_iter = pg.get_shard_missing().find(pg_shard);
-      const auto missing_iter = pmissing_iter->second.get_items().find(soid);
-      assert(missing_iter != pmissing_iter->second.get_items().end());
+    logger().debug("prep_push: {} to {}", soid, pg_shard);
+    auto& pi = recovery_waiter.pushing[pg_shard];
+    pg.begin_peer_recover(pg_shard, soid);
+    const auto pmissing_iter = pg.get_shard_missing().find(pg_shard);
+    const auto missing_iter = pmissing_iter->second.get_items().find(soid);
+    assert(missing_iter != pmissing_iter->second.get_items().end());
 
-      pi.obc = obc;
-      pi.recovery_info.size = obc->obs.oi.size;
-      pi.recovery_info.copy_subset = data_subset;
-      pi.recovery_info.soid = soid;
-      pi.recovery_info.oi = obc->obs.oi;
-      pi.recovery_info.version = obc->obs.oi.version;
-      pi.recovery_info.object_exist =
-       missing_iter->second.clean_regions.object_is_exist();
-      pi.recovery_progress.omap_complete =
-       !missing_iter->second.clean_regions.omap_is_dirty() &&
-       HAVE_FEATURE(pg.min_peer_features(), SERVER_OCTOPUS);
+    pi.obc = obc;
+    pi.recovery_info.size = obc->obs.oi.size;
+    pi.recovery_info.copy_subset = data_subset;
+    pi.recovery_info.soid = soid;
+    pi.recovery_info.oi = obc->obs.oi;
+    pi.recovery_info.version = obc->obs.oi.version;
+    pi.recovery_info.object_exist =
+      missing_iter->second.clean_regions.object_is_exist();
+    pi.recovery_progress.omap_complete =
+      (!missing_iter->second.clean_regions.omap_is_dirty() &&
+       HAVE_FEATURE(pg.min_peer_features(), SERVER_OCTOPUS));
 
-      return build_push_op(pi.recovery_info, pi.recovery_progress,
-                           &pi.stat).then(
-        [this, soid, pg_shard, &pops](auto pop) {
-       auto& recovery_waiter = recovering.at(soid);
-       auto& pi = recovery_waiter.pushing[pg_shard];
-       pi.recovery_progress = pop.after_progress;
-       pops[pg_shard] = std::move(pop);
-       return seastar::make_ready_future<>();
-      });
-    }).then([&pops]() mutable {
-      return seastar::make_ready_future<std::map<pg_shard_t, PushOp>>(std::move(pops));
+    return build_push_op(pi.recovery_info, pi.recovery_progress,
+                        &pi.stat).then(
+      [this, soid, pg_shard, pops](auto pop) {
+      auto& recovery_waiter = recovering.at(soid);
+      auto& pi = recovery_waiter.pushing[pg_shard];
+      pi.recovery_progress = pop.after_progress;
+      pops->emplace(pg_shard, std::move(pop));
     });
+  }).then([pops]() mutable {
+    return seastar::make_ready_future<std::map<pg_shard_t, PushOp>>(std::move(*pops));
   });
 }