SERVER-63387 Reverse return order of backup cursors in StreamingCursor

10 files changed, 23 insertions, 24 deletions

diff --git a/src/mongo/db/storage/backup_cursor_state.h b/src/mongo/db/storage/backup_cursor_state.h
index 317dd3ff05f..2d8083eab11 100644
--- a/src/mongo/db/storage/backup_cursor_state.h
+++ b/src/mongo/db/storage/backup_cursor_state.h
@@ -30,8 +30,8 @@
 #pragma once
 
 #include <boost/optional.hpp>
+#include <deque>
 #include <string>
-#include <vector>
 
 #include "mongo/db/exec/document_value/document.h"
 #include "mongo/db/storage/storage_engine.h"
@@ -44,11 +44,11 @@ struct BackupCursorState {
     std::unique_ptr<StorageEngine::StreamingCursor> streamingCursor;
     // 'otherBackupBlocks' includes the backup blocks for the encrypted storage engine in the
     // enterprise module.
-    std::vector<StorageEngine::BackupBlock> otherBackupBlocks;
+    std::deque<StorageEngine::BackupBlock> otherBackupBlocks;
 };
 
 struct BackupCursorExtendState {
-    std::vector<std::string> filenames;
+    std::deque<std::string> filenames;
 };
 
 }  // namespace mongo
diff --git a/src/mongo/db/storage/devnull/devnull_kv_engine.cpp b/src/mongo/db/storage/devnull/devnull_kv_engine.cpp
index 413dee06859..dc87e97a661 100644
--- a/src/mongo/db/storage/devnull/devnull_kv_engine.cpp
+++ b/src/mongo/db/storage/devnull/devnull_kv_engine.cpp
@@ -273,9 +273,9 @@ public:
         return BSONObj();
     }
 
-    StatusWith<std::vector<StorageEngine::BackupBlock>> getNextBatch(const std::size_t batchSize) {
+    StatusWith<std::deque<StorageEngine::BackupBlock>> getNextBatch(const std::size_t batchSize) {
         if (_exhaustCursor) {
-            std::vector<StorageEngine::BackupBlock> emptyVector;
+            std::deque<StorageEngine::BackupBlock> emptyVector;
             return emptyVector;
         }
         _exhaustCursor = true;
@@ -283,7 +283,7 @@ public:
     }
 
 private:
-    std::vector<StorageEngine::BackupBlock> _backupBlocks;
+    std::deque<StorageEngine::BackupBlock> _backupBlocks;
     bool _exhaustCursor;
 };
 
@@ -294,8 +294,8 @@ StatusWith<std::unique_ptr<StorageEngine::StreamingCursor>> DevNullKVEngine::beg
     return std::make_unique<StreamingCursorImpl>(options);
 }
 
-StatusWith<std::vector<std::string>> DevNullKVEngine::extendBackupCursor(OperationContext* opCtx) {
-    std::vector<std::string> filesToCopy = {"journal/WiredTigerLog.999"};
+StatusWith<std::deque<std::string>> DevNullKVEngine::extendBackupCursor(OperationContext* opCtx) {
+    std::deque<std::string> filesToCopy = {"journal/WiredTigerLog.999"};
     return filesToCopy;
 }
 
diff --git a/src/mongo/db/storage/devnull/devnull_kv_engine.h b/src/mongo/db/storage/devnull/devnull_kv_engine.h
index 97e414852ea..39d990097f4 100644
--- a/src/mongo/db/storage/devnull/devnull_kv_engine.h
+++ b/src/mongo/db/storage/devnull/devnull_kv_engine.h
@@ -143,7 +143,7 @@ public:
 
     virtual void endNonBlockingBackup(OperationContext* opCtx) override {}
 
-    virtual StatusWith<std::vector<std::string>> extendBackupCursor(
+    virtual StatusWith<std::deque<std::string>> extendBackupCursor(
         OperationContext* opCtx) override;
 
     virtual boost::optional<Timestamp> getLastStableRecoveryTimestamp() const override {
diff --git a/src/mongo/db/storage/kv/kv_engine.h b/src/mongo/db/storage/kv/kv_engine.h
index 07a8887f884..89faafe5fd0 100644
--- a/src/mongo/db/storage/kv/kv_engine.h
+++ b/src/mongo/db/storage/kv/kv_engine.h
@@ -208,7 +208,7 @@ public:
         MONGO_UNREACHABLE;
     }
 
-    virtual StatusWith<std::vector<std::string>> extendBackupCursor(OperationContext* opCtx) {
+    virtual StatusWith<std::deque<std::string>> extendBackupCursor(OperationContext* opCtx) {
         return Status(ErrorCodes::CommandNotSupported,
                       "The current storage engine doesn't support backup mode");
     }
diff --git a/src/mongo/db/storage/storage_engine.h b/src/mongo/db/storage/storage_engine.h
index aed7c3978d4..4d4fb703539 100644
--- a/src/mongo/db/storage/storage_engine.h
+++ b/src/mongo/db/storage/storage_engine.h
@@ -349,7 +349,7 @@ public:
 
         virtual ~StreamingCursor() = default;
 
-        virtual StatusWith<std::vector<BackupBlock>> getNextBatch(const std::size_t batchSize) = 0;
+        virtual StatusWith<std::deque<BackupBlock>> getNextBatch(const std::size_t batchSize) = 0;
 
     protected:
         BackupOptions options;
@@ -360,7 +360,7 @@ public:
 
     virtual void endNonBlockingBackup(OperationContext* opCtx) = 0;
 
-    virtual StatusWith<std::vector<std::string>> extendBackupCursor(OperationContext* opCtx) = 0;
+    virtual StatusWith<std::deque<std::string>> extendBackupCursor(OperationContext* opCtx) = 0;
 
     /**
      * Recover as much data as possible from a potentially corrupt RecordStore.
diff --git a/src/mongo/db/storage/storage_engine_impl.cpp b/src/mongo/db/storage/storage_engine_impl.cpp
index 6af5185e793..6f4d99c6dfc 100644
--- a/src/mongo/db/storage/storage_engine_impl.cpp
+++ b/src/mongo/db/storage/storage_engine_impl.cpp
@@ -878,8 +878,7 @@ void StorageEngineImpl::endNonBlockingBackup(OperationContext* opCtx) {
     return _engine->endNonBlockingBackup(opCtx);
 }
 
-StatusWith<std::vector<std::string>> StorageEngineImpl::extendBackupCursor(
-    OperationContext* opCtx) {
+StatusWith<std::deque<std::string>> StorageEngineImpl::extendBackupCursor(OperationContext* opCtx) {
     return _engine->extendBackupCursor(opCtx);
 }
 
diff --git a/src/mongo/db/storage/storage_engine_impl.h b/src/mongo/db/storage/storage_engine_impl.h
index 119de49c4bf..5731d3c934d 100644
--- a/src/mongo/db/storage/storage_engine_impl.h
+++ b/src/mongo/db/storage/storage_engine_impl.h
@@ -98,7 +98,7 @@ public:
 
     virtual void endNonBlockingBackup(OperationContext* opCtx) override;
 
-    virtual StatusWith<std::vector<std::string>> extendBackupCursor(
+    virtual StatusWith<std::deque<std::string>> extendBackupCursor(
         OperationContext* opCtx) override;
 
     virtual bool isDurable() const override;
diff --git a/src/mongo/db/storage/storage_engine_mock.h b/src/mongo/db/storage/storage_engine_mock.h
index 3d69c854a5b..cdeb564a004 100644
--- a/src/mongo/db/storage/storage_engine_mock.h
+++ b/src/mongo/db/storage/storage_engine_mock.h
@@ -78,7 +78,7 @@ public:
                       "The current storage engine doesn't support backup mode");
     }
     void endNonBlockingBackup(OperationContext* opCtx) final {}
-    StatusWith<std::vector<std::string>> extendBackupCursor(OperationContext* opCtx) final {
+    StatusWith<std::deque<std::string>> extendBackupCursor(OperationContext* opCtx) final {
         return Status(ErrorCodes::CommandNotSupported,
                       "The current storage engine doesn't support backup mode");
     }
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp
index e0dc11b2bf1..63e679ac7ec 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.cpp
@@ -1013,9 +1013,9 @@ const boost::filesystem::path constructFilePath(std::string path, std::string fi
     return filePath;
 }
 
-std::vector<std::string> getUniqueFiles(const std::vector<std::string>& files,
-                                        const std::set<std::string>& referenceFiles) {
-    std::vector<std::string> result;
+std::deque<std::string> getUniqueFiles(const std::vector<std::string>& files,
+                                       const std::set<std::string>& referenceFiles) {
+    std::deque<std::string> result;
     for (auto& file : files) {
         if (referenceFiles.find(file) == referenceFiles.end()) {
             result.push_back(file);
@@ -1038,9 +1038,9 @@ public:
 
     ~StreamingCursorImpl() = default;
 
-    StatusWith<std::vector<StorageEngine::BackupBlock>> getNextBatch(const std::size_t batchSize) {
+    StatusWith<std::deque<StorageEngine::BackupBlock>> getNextBatch(const std::size_t batchSize) {
         int wtRet;
-        std::vector<StorageEngine::BackupBlock> backupBlocks;
+        std::deque<StorageEngine::BackupBlock> backupBlocks;
 
         stdx::lock_guard<Latch> backupCursorLk(_wtBackup->wtBackupCursorMutex);
         while (backupBlocks.size() < batchSize) {
@@ -1113,7 +1113,7 @@ private:
                                            boost::filesystem::path filePath,
                                            const std::uint64_t fileSize,
                                            const std::size_t batchSize,
-                                           std::vector<StorageEngine::BackupBlock>* backupBlocks) {
+                                           std::deque<StorageEngine::BackupBlock>* backupBlocks) {
         // For each file listed, open a duplicate backup cursor and get the blocks to copy.
         std::stringstream ss;
         ss << "incremental=(file=" << filename << ")";
@@ -1251,7 +1251,7 @@ void WiredTigerKVEngine::endNonBlockingBackup(OperationContext* opCtx) {
     _wtBackup.logFilePathsSeenByGetNextBatch = {};
 }
 
-StatusWith<std::vector<std::string>> WiredTigerKVEngine::extendBackupCursor(
+StatusWith<std::deque<std::string>> WiredTigerKVEngine::extendBackupCursor(
     OperationContext* opCtx) {
     uassert(51033, "Cannot extend backup cursor with in-memory mode.", !isEphemeral());
     invariant(_wtBackup.cursor);
diff --git a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.h b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.h
index 70c0a217bda..11766b6a80a 100644
--- a/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.h
+++ b/src/mongo/db/storage/wiredtiger/wiredtiger_kv_engine.h
@@ -182,7 +182,7 @@ public:
 
     void endNonBlockingBackup(OperationContext* opCtx) override;
 
-    virtual StatusWith<std::vector<std::string>> extendBackupCursor(
+    virtual StatusWith<std::deque<std::string>> extendBackupCursor(
         OperationContext* opCtx) override;
 
     int64_t getIdentSize(OperationContext* opCtx, StringData ident) override;