update ceph source to reef 18.1.2

[ceph.git] / ceph / src / rocksdb / include / rocksdb / utilities / checkpoint.h

diff --git a/ceph/src/rocksdb/include/rocksdb/utilities/checkpoint.h b/ceph/src/rocksdb/include/rocksdb/utilities/checkpoint.h
index 1b6a7407ff111f0843fe097e44a0ba536c1b974f..ecf92061629fac69ea18788005d2a1f5ed9a8792 100644 (file)
--- a/ceph/src/rocksdb/include/rocksdb/utilities/checkpoint.h
+++ b/ceph/src/rocksdb/include/rocksdb/utilities/checkpoint.h
@@ -8,8 +8,10 @@
 #pragma once
 #ifndef ROCKSDB_LITE
 
+#include <cstdint>
 #include <string>
 #include <vector>
+
 #include "rocksdb/status.h"
 
 namespace ROCKSDB_NAMESPACE {
@@ -24,13 +26,13 @@ class Checkpoint {
   // Creates a Checkpoint object to be used for creating openable snapshots
   static Status Create(DB* db, Checkpoint** checkpoint_ptr);
 
-  // Builds an openable snapshot of RocksDB on the same disk, which
-  // accepts an output directory on the same disk, and under the directory
-  // (1) hard-linked SST files pointing to existing live SST files
-  // SST files will be copied if output directory is on a different filesystem
-  // (2) a copied manifest files and other files
-  // The directory should not already exist and will be created by this API.
-  // The directory will be an absolute path
+  // Builds an openable snapshot of RocksDB. checkpoint_dir should contain an
+  // absolute path. The specified directory should not exist, since it will be
+  // created by the API.
+  // When a checkpoint is created,
+  // (1) SST and blob files are hard linked if the output directory is on the
+  // same filesystem as the database, and copied otherwise.
+  // (2) other required files (like MANIFEST) are always copied.
   // log_size_for_flush: if the total log file size is equal or larger than
   // this value, then a flush is triggered for all the column families. The
   // default value is 0, which means flush is always triggered. If you move
@@ -38,8 +40,11 @@ class Checkpoint {
   // if WAL writing is not always enabled.
   // Flush will always trigger if it is 2PC.
   // sequence_number_ptr: if it is not nullptr, the value it points to will be
-  // set to the DB's sequence number. The default value of this parameter is
-  // nullptr.
+  // set to a sequence number guaranteed to be part of the DB, not necessarily
+  // the latest. The default value of this parameter is nullptr.
+  // NOTE: db_paths and cf_paths are not supported for creating checkpoints
+  // and NotSupported will be returned when the DB (without WALs) uses more
+  // than one directory.
   virtual Status CreateCheckpoint(const std::string& checkpoint_dir,
                                   uint64_t log_size_for_flush = 0,
                                   uint64_t* sequence_number_ptr = nullptr);