From 26e61a02ec4e3a6d92af5ac8b4f1902244dd697f Mon Sep 17 00:00:00 2001
From: Kefu Chai <kchai@redhat.com>
Date: Wed, 4 Nov 2020 13:27:15 +0800
Subject: [PATCH] crimson/osd: extract read_omap_for_push_op()

extract read_omap_for_push_op() out of build_push_op() for better
readability

Signed-off-by: Kefu Chai <kchai@redhat.com>
---
 .../osd/replicated_recovery_backend.cc        | 84 +++++++++++--------
 src/crimson/osd/replicated_recovery_backend.h |  6 ++
 2 files changed, 56 insertions(+), 34 deletions(-)

diff --git a/src/crimson/osd/replicated_recovery_backend.cc b/src/crimson/osd/replicated_recovery_backend.cc
index 9e2707f72cc3b..03ffda209b6e5 100644
--- a/src/crimson/osd/replicated_recovery_backend.cc
+++ b/src/crimson/osd/replicated_recovery_backend.cc
@@ -426,40 +426,11 @@ seastar::future<ObjectRecoveryProgress> ReplicatedRecoveryBackend::build_push_op
 	);
       }
       return seastar::make_ready_future<>();
-    }().then([this, &recovery_info] {
-      return shard_services.get_store().get_omap_iterator(coll,
-		ghobject_t(recovery_info.soid));
-    }).then([&progress, &available, &new_progress, pop](auto iter) {
-      if (!progress.omap_complete) {
-	return iter->lower_bound(progress.omap_recovered_to).then(
-	  [iter, &new_progress, pop, &available](int ret) {
-	  return seastar::repeat([iter, &new_progress, pop, &available] {
-	    if (!iter->valid()) {
-	      new_progress.omap_complete = true;
-	      return seastar::make_ready_future<seastar::stop_iteration>(
-			seastar::stop_iteration::yes);
-	    }
-	    if (!pop->omap_entries.empty()
-		&& ((crimson::common::local_conf()->osd_recovery_max_omap_entries_per_chunk > 0
-		    && pop->omap_entries.size()
-		    >= crimson::common::local_conf()->osd_recovery_max_omap_entries_per_chunk)
-		  || available <= iter->key().size() + iter->value().length())) {
-	      new_progress.omap_recovered_to = iter->key();
-	      return seastar::make_ready_future<seastar::stop_iteration>(
-			seastar::stop_iteration::yes);
-	    }
-	    pop->omap_entries.insert(make_pair(iter->key(), iter->value()));
-	    if ((iter->key().size() + iter->value().length()) <= available)
-	      available -= (iter->key().size() + iter->value().length());
-	    else
-	      available = 0;
-	    return iter->next().then([](int r) {
-	      return seastar::stop_iteration::no;
-	    });
-	  });
-	});
-      }
-      return seastar::make_ready_future<>();
+    }().then([this, &recovery_info, &progress, &new_progress, &available, pop] {
+      return read_omap_for_push_op(recovery_info.soid,
+                                   progress,
+                                   new_progress,
+                                   available, pop);
     }).then([this, &recovery_info, &progress, &available, pop] {
       logger().debug("build_push_op: available: {}, copy_subset: {}",
 		     available, recovery_info.copy_subset);
@@ -544,6 +515,51 @@ ReplicatedRecoveryBackend::read_object_for_push_op(
   }));
 }
 
+seastar::future<>
+ReplicatedRecoveryBackend::read_omap_for_push_op(
+    const hobject_t& oid,
+    const ObjectRecoveryProgress& progress,
+    ObjectRecoveryProgress& new_progress,
+    uint64_t max_len,
+    PushOp* push_op)
+{
+  return shard_services.get_store().get_omap_iterator(coll, ghobject_t{oid})
+    .then([&progress, &new_progress, &max_len, push_op](auto omap_iter) {
+    if (progress.omap_complete) {
+      return seastar::make_ready_future<>();
+    }
+    return omap_iter->lower_bound(progress.omap_recovered_to).then(
+      [omap_iter, &new_progress, &max_len, push_op](int ret) {
+      return seastar::repeat([omap_iter, &new_progress, &max_len, push_op] {
+        if (!omap_iter->valid()) {
+          new_progress.omap_complete = true;
+          return seastar::make_ready_future<seastar::stop_iteration>(
+            seastar::stop_iteration::yes);
+        }
+        unsigned entry_size = omap_iter->key().size() + omap_iter->value().length();
+        if (!push_op->omap_entries.empty() &&
+            ((crimson::common::local_conf()->osd_recovery_max_omap_entries_per_chunk > 0 &&
+              (push_op->omap_entries.size() >=
+               crimson::common::local_conf()->osd_recovery_max_omap_entries_per_chunk)) ||
+             max_len <= entry_size)) {
+          new_progress.omap_recovered_to = omap_iter->key();
+          return seastar::make_ready_future<seastar::stop_iteration>(
+            seastar::stop_iteration::yes);
+        }
+        push_op->omap_entries.emplace(omap_iter->key(), omap_iter->value());
+        if (entry_size >= max_len) {
+          max_len -= entry_size;
+        } else {
+          max_len = 0;
+        }
+        return omap_iter->next().then([](int r) {
+          return seastar::stop_iteration::no;
+        });
+      });
+    });
+  });
+}
+
 std::list<std::map<pg_shard_t, pg_missing_t>::const_iterator>
 ReplicatedRecoveryBackend::get_shards_to_push(const hobject_t& soid)
 {
diff --git a/src/crimson/osd/replicated_recovery_backend.h b/src/crimson/osd/replicated_recovery_backend.h
index a224cb6da3e3b..4bb353c5aa0dc 100644
--- a/src/crimson/osd/replicated_recovery_backend.h
+++ b/src/crimson/osd/replicated_recovery_backend.h
@@ -134,4 +134,10 @@ private:
     uint64_t offset,
     uint64_t max_len,
     PushOp* push_op);
+  seastar::future<> read_omap_for_push_op(
+    const hobject_t& oid,
+    const ObjectRecoveryProgress& progress,
+    ObjectRecoveryProgress& new_progress,
+    uint64_t max_len,
+    PushOp* push_op);
 };
-- 
2.39.5