SERVER-60494 Add size estimate field to ChunkType

2 files changed, 15 insertions, 0 deletions

diff --git a/src/mongo/s/catalog/type_chunk.cpp b/src/mongo/s/catalog/type_chunk.cpp
index 85615320d18..bae8a9fc02b 100644
--- a/src/mongo/s/catalog/type_chunk.cpp
+++ b/src/mongo/s/catalog/type_chunk.cpp
@@ -58,6 +58,7 @@ const BSONField<Date_t> ChunkType::lastmod("lastmod");
 const BSONField<OID> ChunkType::epoch("lastmodEpoch");
 const BSONField<Timestamp> ChunkType::timestamp("lastmodTimestamp");
 const BSONField<BSONObj> ChunkType::history("history");
+const BSONField<long long> ChunkType::estimatedSize("estSize");
 
 namespace {
 
@@ -334,6 +335,11 @@ StatusWith<ChunkType> ChunkType::fromConfigBSON(const BSONObj& source,
     chunk.setVersion(
         ChunkVersion(version.majorVersion(), version.minorVersion(), epoch, timestamp));
 
+    auto elem = source.getField(estimatedSize.name());
+    if (!elem.eoo()) {
+        chunk._estimatedSizeBytes = elem.safeNumberLong();
+    }
+
     return chunk;
 }
 
@@ -352,6 +358,8 @@ BSONObj ChunkType::toConfigBSON() const {
     if (_version) {
         builder.appendTimestamp(lastmod.name(), _version->toLong());
     }
+    if (_estimatedSizeBytes)
+        builder.appendNumber(estimatedSize.name(), *_estimatedSizeBytes);
     if (_jumbo)
         builder.append(jumbo.name(), getJumbo());
     addHistoryToBSON(builder);
diff --git a/src/mongo/s/catalog/type_chunk.h b/src/mongo/s/catalog/type_chunk.h
index 925bb7075fe..02c702e1db4 100644
--- a/src/mongo/s/catalog/type_chunk.h
+++ b/src/mongo/s/catalog/type_chunk.h
@@ -210,6 +210,7 @@ public:
     static const BSONField<OID> epoch;
     static const BSONField<Timestamp> timestamp;
     static const BSONField<BSONObj> history;
+    static const BSONField<long long> estimatedSize;
 
     ChunkType();
     ChunkType(CollectionUUID collectionUUID,
@@ -291,6 +292,10 @@ public:
     }
     void setShard(const ShardId& shard);
 
+    boost::optional<long long> getEstimatedSizeBytes() const {
+        return _estimatedSizeBytes;
+    }
+
     bool getJumbo() const {
         return _jumbo.get_value_or(false);
     }
@@ -334,6 +339,8 @@ private:
     boost::optional<ChunkVersion> _version;
     // (M)(C)(S)  shard this chunk lives in
     boost::optional<ShardId> _shard;
+    // (O)(C)     chunk size used for chunk merging operation
+    boost::optional<long long> _estimatedSizeBytes;
     // (O)(C)     too big to move?
     boost::optional<bool> _jumbo;
     // history of the chunk