update ceph source to reef 18.1.2

[ceph.git] / ceph / src / rocksdb / db / merge_context.h

diff --git a/ceph/src/rocksdb/db/merge_context.h b/ceph/src/rocksdb/db/merge_context.h
index e1869a341b06acefc453babd634c8d31f377ed6b..8a7b0729020808eb3937a314b33a967f45242c0b 100644 (file)
--- a/ceph/src/rocksdb/db/merge_context.h
+++ b/ceph/src/rocksdb/db/merge_context.h
@@ -8,6 +8,7 @@
 #include <memory>
 #include <string>
 #include <vector>
+
 #include "rocksdb/slice.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -68,7 +69,7 @@ class MergeContext {
   }
 
   // Get the operand at the index.
-  Slice GetOperand(int index) {
+  Slice GetOperand(int index) const {
     assert(operand_list_);
 
     SetDirectionForward();
@@ -76,13 +77,21 @@ class MergeContext {
   }
 
   // Same as GetOperandsDirectionForward
-  const std::vector<Slice>& GetOperands() {
+  //
+  // Note that the returned reference is only good until another call
+  // to this MergeContext.  If the returned value is needed for longer,
+  // a copy must be made.
+  const std::vector<Slice>& GetOperands() const {
     return GetOperandsDirectionForward();
   }
 
   // Return all the operands in the order as they were merged (passed to
   // FullMerge or FullMergeV2)
-  const std::vector<Slice>& GetOperandsDirectionForward() {
+  //
+  // Note that the returned reference is only good until another call
+  // to this MergeContext.  If the returned value is needed for longer,
+  // a copy must be made.
+  const std::vector<Slice>& GetOperandsDirectionForward() const {
     if (!operand_list_) {
       return empty_operand_list;
     }
@@ -93,7 +102,11 @@ class MergeContext {
 
   // Return all the operands in the reversed order relative to how they were
   // merged (passed to FullMerge or FullMergeV2)
-  const std::vector<Slice>& GetOperandsDirectionBackward() {
+  //
+  // Note that the returned reference is only good until another call
+  // to this MergeContext.  If the returned value is needed for longer,
+  // a copy must be made.
+  const std::vector<Slice>& GetOperandsDirectionBackward() const {
     if (!operand_list_) {
       return empty_operand_list;
     }
@@ -110,14 +123,14 @@ class MergeContext {
     }
   }
 
-  void SetDirectionForward() {
+  void SetDirectionForward() const {
     if (operands_reversed_ == true) {
       std::reverse(operand_list_->begin(), operand_list_->end());
       operands_reversed_ = false;
     }
   }
 
-  void SetDirectionBackward() {
+  void SetDirectionBackward() const {
     if (operands_reversed_ == false) {
       std::reverse(operand_list_->begin(), operand_list_->end());
       operands_reversed_ = true;
@@ -125,10 +138,10 @@ class MergeContext {
   }
 
   // List of operands
-  std::unique_ptr<std::vector<Slice>> operand_list_;
+  mutable std::unique_ptr<std::vector<Slice>> operand_list_;
   // Copy of operands that are not pinned.
   std::unique_ptr<std::vector<std::unique_ptr<std::string>>> copied_operands_;
-  bool operands_reversed_ = true;
+  mutable bool operands_reversed_ = true;
 };
 
 }  // namespace ROCKSDB_NAMESPACE