SERVER-16856 compact method in SortedDataInterface

Add a compact() method to the SortedDataInterface to allow for compaction if the
indexed record store supports compaction-in-place.

6 files changed, 45 insertions, 2 deletions

diff --git a/src/mongo/db/catalog/collection_compact.cpp b/src/mongo/db/catalog/collection_compact.cpp
index 7d0a9e266f6..b9ea06a2aef 100644
--- a/src/mongo/db/catalog/collection_compact.cpp
+++ b/src/mongo/db/catalog/collection_compact.cpp
@@ -111,13 +111,25 @@ StatusWith<CompactStats> Collection::compact(OperationContext* txn,
                                             << _recordStore->name());
 
     if (_recordStore->compactsInPlace()) {
-        // Since we are compacting in-place, we don't need to touch the indexes.
-        // TODO SERVER-16856 compact indexes
         CompactStats stats;
         Status status = _recordStore->compact(txn, NULL, compactOptions, &stats);
         if (!status.isOK())
             return StatusWith<CompactStats>(status);
 
+        // Compact all indexes (not including unfinished indexes)
+        IndexCatalog::IndexIterator ii(_indexCatalog.getIndexIterator(txn, false));
+        while (ii.more()) {
+            IndexDescriptor* descriptor = ii.next();
+            IndexAccessMethod* index = _indexCatalog.getIndex(descriptor);
+
+            LOG(1) << "compacting index: " << descriptor->toString();
+            Status status = index->compact(txn);
+            if (!status.isOK()) {
+                error() << "failed to compact index: " << descriptor->toString();
+                return status;
+            }
+        }
+
         return StatusWith<CompactStats>(stats);
     }
 
diff --git a/src/mongo/db/index/index_access_method.cpp b/src/mongo/db/index/index_access_method.cpp
index d731f9cbfed..618333b2ea4 100644
--- a/src/mongo/db/index/index_access_method.cpp
+++ b/src/mongo/db/index/index_access_method.cpp
@@ -323,6 +323,10 @@ Status IndexAccessMethod::update(OperationContext* txn,
     return Status::OK();
 }
 
+Status IndexAccessMethod::compact(OperationContext* txn) {
+    return this->_newInterface->compact(txn);
+}
+
 std::unique_ptr<IndexAccessMethod::BulkBuilder> IndexAccessMethod::initiateBulk() {
     return std::unique_ptr<BulkBuilder>(new BulkBuilder(this, _descriptor));
 }
diff --git a/src/mongo/db/index/index_access_method.h b/src/mongo/db/index/index_access_method.h
index ea9ea90c71c..58b1ab40a51 100644
--- a/src/mongo/db/index/index_access_method.h
+++ b/src/mongo/db/index/index_access_method.h
@@ -185,6 +185,12 @@ public:
 
     RecordId findSingle(OperationContext* txn, const BSONObj& key) const;
 
+    /**
+     * Attempt compaction to regain disk space if the indexed record store supports
+     * compaction-in-place.
+     */
+    Status compact(OperationContext* txn);
+
     //
     // Bulk operations support
     //
diff --git a/src/mongo/db/storage/sorted_data_interface.h b/src/mongo/db/storage/sorted_data_interface.h
index 9507339995a..d99f9061f76 100644
--- a/src/mongo/db/storage/sorted_data_interface.h
+++ b/src/mongo/db/storage/sorted_data_interface.h
@@ -121,6 +121,14 @@ public:
      */
     virtual Status dupKeyCheck(OperationContext* txn, const BSONObj& key, const RecordId& loc) = 0;
 
+    /**
+     * Attempt to reduce the storage space used by this index via compaction. Only called if the
+     * indexed record store supports compaction-in-place.
+     */
+    virtual Status compact(OperationContext* txn) {
+        return Status::OK();
+    }
+
     //
     // Information about the tree
     //
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp
index 4cebed3eb61..52fff5ffdd8 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp
@@ -426,6 +426,17 @@ Status WiredTigerIndex::initAsEmpty(OperationContext* txn) {
     return Status::OK();
 }
 
+Status WiredTigerIndex::compact(OperationContext* txn) {
+    WiredTigerSessionCache* cache = WiredTigerRecoveryUnit::get(txn)->getSessionCache();
+    if (!cache->isEphemeral()) {
+        UniqueWiredTigerSession session = cache->getSession();
+        WT_SESSION* s = session->getSession();
+        int ret = s->compact(s, uri().c_str(), "timeout=0");
+        invariantWTOK(ret);
+    }
+    return Status::OK();
+}
+
 /**
  * Base class for WiredTigerIndex bulk builders.
  *
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_index.h b/src/mongo/db/storage/wiredtiger/wiredtiger_index.h
index 4ea5741e7a5..b54f61dc6f4 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_index.h
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_index.h
@@ -108,6 +108,8 @@ public:
 
     virtual Status initAsEmpty(OperationContext* txn);
 
+    virtual Status compact(OperationContext* txn);
+
     const std::string& uri() const {
         return _uri;
     }