SERVER-69845: Implement column store size on disk.

4 files changed, 49 insertions, 40 deletions

diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_column_store.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_column_store.cpp
index b3aef5dc0a6..1caf0b67158 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_column_store.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_column_store.cpp
@@ -426,17 +426,22 @@ bool WiredTigerColumnStore::isEmpty(OperationContext* opCtx) {
 }
 
 long long WiredTigerColumnStore::getSpaceUsedBytes(OperationContext* opCtx) const {
-    // TODO: SERVER-65980.
-    // For now we just return  this so that tests can successfully obtain collection-level stats on
-    // a collection with a columnstore index.
-    return 27017;
+    dassert(opCtx->lockState()->isReadLocked());
+    auto ru = WiredTigerRecoveryUnit::get(opCtx);
+    WT_SESSION* s = ru->getSession()->getSession();
+
+    if (ru->getSessionCache()->isEphemeral()) {
+        return static_cast<long long>(WiredTigerUtil::getEphemeralIdentSize(s, _uri));
+    }
+    return static_cast<long long>(WiredTigerUtil::getIdentSize(s, _uri));
 }
 
 long long WiredTigerColumnStore::getFreeStorageBytes(OperationContext* opCtx) const {
-    // TODO: SERVER-65980.
-    // For now we just fake this so that tests can successfully obtain collection-level stats on a
-    // collection with a columnstore index.
-    return 27017;
+    dassert(opCtx->lockState()->isReadLocked());
+    auto ru = WiredTigerRecoveryUnit::get(opCtx);
+    WiredTigerSession* session = ru->getSession();
+
+    return static_cast<long long>(WiredTigerUtil::getIdentReuseSize(session->getSession(), _uri));
 }
 
 Status WiredTigerColumnStore::compact(OperationContext* opCtx) {
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp
index 8e5df7fdf82..ce6f7bb0a84 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_index.cpp
@@ -509,41 +509,12 @@ void WiredTigerIndex::printIndexEntryMetadata(OperationContext* opCtx,
 long long WiredTigerIndex::getSpaceUsedBytes(OperationContext* opCtx) const {
     dassert(opCtx->lockState()->isReadLocked());
     auto ru = WiredTigerRecoveryUnit::get(opCtx);
-    WiredTigerSession* session = ru->getSession();
+    WT_SESSION* s = ru->getSession()->getSession();
 
     if (ru->getSessionCache()->isEphemeral()) {
-        // For ephemeral case, use cursor statistics
-        const auto statsUri = "statistics:" + uri();
-
-        // Helper function to retrieve stats and check for errors
-        auto getStats = [&](int key) -> int64_t {
-            auto result = WiredTigerUtil::getStatisticsValue(
-                session->getSession(), statsUri, "statistics=(fast)", key);
-            if (!result.isOK()) {
-                if (result.getStatus().code() == ErrorCodes::CursorNotFound)
-                    return 0;  // ident gone, so return 0
-
-                uassertStatusOK(result.getStatus());
-            }
-            return result.getValue();
-        };
-
-        auto inserts = getStats(WT_STAT_DSRC_CURSOR_INSERT);
-        auto removes = getStats(WT_STAT_DSRC_CURSOR_REMOVE);
-        auto insertBytes = getStats(WT_STAT_DSRC_CURSOR_INSERT_BYTES);
-
-        if (inserts == 0 || removes >= inserts)
-            return 0;
-
-        // Rough approximation of index size as average entry size times number of entries.
-        // May be off if key sizes change significantly over the life time of the collection,
-        // but is the best we can do currrently with the statistics available.
-        auto bytesPerEntry = (insertBytes + inserts - 1) / inserts;  // round up
-        auto numEntries = inserts - removes;
-        return numEntries * bytesPerEntry;
+        return static_cast<long long>(WiredTigerUtil::getEphemeralIdentSize(s, _uri));
     }
-
-    return static_cast<long long>(WiredTigerUtil::getIdentSize(session->getSession(), _uri));
+    return static_cast<long long>(WiredTigerUtil::getIdentSize(s, _uri));
 }
 
 long long WiredTigerIndex::getFreeStorageBytes(OperationContext* opCtx) const {
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp
index a3a9ec4109d..ab4623f5441 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_util.cpp
@@ -500,6 +500,37 @@ int64_t WiredTigerUtil::getIdentSize(WT_SESSION* s, const std::string& uri) {
     return result.getValue();
 }
 
+int64_t WiredTigerUtil::getEphemeralIdentSize(WT_SESSION* s, const std::string& uri) {
+    // For ephemeral case, use cursor statistics
+    const auto statsUri = "statistics:" + uri;
+
+    // Helper function to retrieve stats and check for errors
+    auto getStats = [&](int key) -> int64_t {
+        auto result = getStatisticsValue(s, statsUri, "statistics=(fast)", key);
+        if (!result.isOK()) {
+            if (result.getStatus().code() == ErrorCodes::CursorNotFound)
+                return 0;  // ident gone, so return 0
+
+            uassertStatusOK(result.getStatus());
+        }
+        return result.getValue();
+    };
+
+    auto inserts = getStats(WT_STAT_DSRC_CURSOR_INSERT);
+    auto removes = getStats(WT_STAT_DSRC_CURSOR_REMOVE);
+    auto insertBytes = getStats(WT_STAT_DSRC_CURSOR_INSERT_BYTES);
+
+    if (inserts == 0 || removes >= inserts)
+        return 0;
+
+    // Rough approximation of index size as average entry size times number of entries.
+    // May be off if key sizes change significantly over the life time of the collection,
+    // but is the best we can do currrently with the statistics available.
+    auto bytesPerEntry = (insertBytes + inserts - 1) / inserts;  // round up
+    auto numEntries = inserts - removes;
+    return numEntries * bytesPerEntry;
+}
+
 int64_t WiredTigerUtil::getIdentReuseSize(WT_SESSION* s, const std::string& uri) {
     auto result = WiredTigerUtil::getStatisticsValue(
         s, "statistics:" + uri, "statistics=(fast)", WT_STAT_DSRC_BLOCK_REUSE_BYTES);
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_util.h b/src/mongo/db/storage/wiredtiger/wiredtiger_util.h
index dbca93e6bc6..b17dfcb6f85 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_util.h
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_util.h
@@ -272,6 +272,8 @@ public:
                                                   const std::string& config,
                                                   int statisticsKey);
 
+    static int64_t getEphemeralIdentSize(WT_SESSION* s, const std::string& uri);
+
     static int64_t getIdentSize(WT_SESSION* s, const std::string& uri);
 
     /**