1 files changed, 114 insertions, 0 deletions
diff --git a/src/rocksdb/utilities/options/options_util.cc b/src/rocksdb/utilities/options/options_util.cc
new file mode 100644
index 000000000..0719798e3
--- /dev/null
+++ b/src/rocksdb/utilities/options/options_util.cc
@@ -0,0 +1,114 @@
+// Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#ifndef ROCKSDB_LITE
+
+#include "rocksdb/utilities/options_util.h"
+
+#include "env/composite_env_wrapper.h"
+#include "file/filename.h"
+#include "options/options_parser.h"
+#include "rocksdb/options.h"
+
+namespace ROCKSDB_NAMESPACE {
+Status LoadOptionsFromFile(const std::string& file_name, Env* env,
+                           DBOptions* db_options,
+                           std::vector<ColumnFamilyDescriptor>* cf_descs,
+                           bool ignore_unknown_options,
+                           std::shared_ptr<Cache>* cache) {
+  RocksDBOptionsParser parser;
+  LegacyFileSystemWrapper fs(env);
+  Status s = parser.Parse(file_name, &fs, ignore_unknown_options,
+                          0 /* file_readahead_size */);
+  if (!s.ok()) {
+    return s;
+  }
+  *db_options = *parser.db_opt();
+  const std::vector<std::string>& cf_names = *parser.cf_names();
+  const std::vector<ColumnFamilyOptions>& cf_opts = *parser.cf_opts();
+  cf_descs->clear();
+  for (size_t i = 0; i < cf_opts.size(); ++i) {
+    cf_descs->push_back({cf_names[i], cf_opts[i]});
+    if (cache != nullptr) {
+      TableFactory* tf = cf_opts[i].table_factory.get();
+      if (tf != nullptr && tf->GetOptions() != nullptr &&
+          tf->Name() == BlockBasedTableFactory().Name()) {
+        auto* loaded_bbt_opt =
+            reinterpret_cast<BlockBasedTableOptions*>(tf->GetOptions());
+        loaded_bbt_opt->block_cache = *cache;
+      }
+    }
+  }
+  return Status::OK();
+}
+
+Status GetLatestOptionsFileName(const std::string& dbpath,
+                                Env* env, std::string* options_file_name) {
+  Status s;
+  std::string latest_file_name;
+  uint64_t latest_time_stamp = 0;
+  std::vector<std::string> file_names;
+  s = env->GetChildren(dbpath, &file_names);
+  if (!s.ok()) {
+    return s;
+  }
+  for (auto& file_name : file_names) {
+    uint64_t time_stamp;
+    FileType type;
+    if (ParseFileName(file_name, &time_stamp, &type) && type == kOptionsFile) {
+      if (time_stamp > latest_time_stamp) {
+        latest_time_stamp = time_stamp;
+        latest_file_name = file_name;
+      }
+    }
+  }
+  if (latest_file_name.size() == 0) {
+    return Status::NotFound("No options files found in the DB directory.");
+  }
+  *options_file_name = latest_file_name;
+  return Status::OK();
+}
+
+Status LoadLatestOptions(const std::string& dbpath, Env* env,
+                         DBOptions* db_options,
+                         std::vector<ColumnFamilyDescriptor>* cf_descs,
+                         bool ignore_unknown_options,
+                         std::shared_ptr<Cache>* cache) {
+  std::string options_file_name;
+  Status s = GetLatestOptionsFileName(dbpath, env, &options_file_name);
+  if (!s.ok()) {
+    return s;
+  }
+  return LoadOptionsFromFile(dbpath + "/" + options_file_name, env, db_options,
+                             cf_descs, ignore_unknown_options, cache);
+}
+
+Status CheckOptionsCompatibility(
+    const std::string& dbpath, Env* env, const DBOptions& db_options,
+    const std::vector<ColumnFamilyDescriptor>& cf_descs,
+    bool ignore_unknown_options) {
+  std::string options_file_name;
+  Status s = GetLatestOptionsFileName(dbpath, env, &options_file_name);
+  if (!s.ok()) {
+    return s;
+  }
+
+  std::vector<std::string> cf_names;
+  std::vector<ColumnFamilyOptions> cf_opts;
+  for (const auto& cf_desc : cf_descs) {
+    cf_names.push_back(cf_desc.name);
+    cf_opts.push_back(cf_desc.options);
+  }
+
+  const OptionsSanityCheckLevel kDefaultLevel = kSanityLevelLooselyCompatible;
+  LegacyFileSystemWrapper fs(env);
+
+  return RocksDBOptionsParser::VerifyRocksDBOptionsFromFile(
+      db_options, cf_names, cf_opts, dbpath + "/" + options_file_name, &fs,
+      kDefaultLevel, ignore_unknown_options);
+}
+
+}  // namespace ROCKSDB_NAMESPACE
+#endif  // !ROCKSDB_LITE