log db path info before open

Summary: 1. write db MANIFEST, CURRENT, IDENTITY, sst files, log files to log before open

Test Plan: run db and check LOG file

Reviewers: ljin, yhchiang, igor, dhruba, sdong

Reviewed By: sdong

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D21459

db/db_impl.cc

@@ -364,6 +364,7 @@ DBImpl::DBImpl(const DBOptions& options, const std::string& dbname)
       new ColumnFamilyMemTablesImpl(versions_->GetColumnFamilySet()));
 
   DumpLeveldbBuildVersion(options_.info_log.get());
+  DumpDBFileSummary(options_, dbname_);
   options_.Dump(options_.info_log.get());
 
   LogFlush(options_.info_log);

db/db_impl.h

@@ -680,4 +680,8 @@ static void ClipToRange(T* ptr, V minvalue, V maxvalue) {
   if (static_cast<V>(*ptr) < minvalue) *ptr = minvalue;
 }
 
+// Dump db file summary, implemented in util/
+extern void DumpDBFileSummary(const DBOptions& options,
+                              const std::string& dbname);
+
 }  // namespace rocksdb

util/db_info_dummper.cc

@@ -0,0 +1,115 @@
+//  Copyright (c) 2013, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+// Must not be included from any .h files to avoid polluting the namespace
+// with macros.
+
+#include <stdio.h>
+#include <string>
+#include <algorithm>
+#include <vector>
+
+#include "rocksdb/options.h"
+#include "rocksdb/env.h"
+#include "db/filename.h"
+
+namespace rocksdb {
+
+void DumpDBFileSummary(const DBOptions& options, const std::string& dbname) {
+  if (options.info_log == nullptr) {
+    return;
+  }
+
+  auto* env = options.env;
+  uint64_t number;
+  FileType type;
+
+  std::vector<std::string> files;
+  uint64_t file_num = 0;
+  uint64_t file_size;
+  std::string file_info, wal_info;
+
+  Log(options.info_log, "DB SUMMARY\n");
+  // Get files in dbname dir
+  if (!env->GetChildren(dbname, &files).ok()) {
+    Log(options.info_log, "Error when reading %s dir\n", dbname.c_str());
+  }
+  std::sort(files.begin(), files.end());
+  for (std::string file : files) {
+    ParseFileName(file, &number, &type);
+    switch (type) {
+      case kCurrentFile:
+        Log(options.info_log, "CURRENT file:  %s\n", file.c_str());
+        break;
+      case kIdentityFile:
+        Log(options.info_log, "IDENTITY file:  %s\n", file.c_str());
+        break;
+      case kDescriptorFile:
+        env->GetFileSize(dbname + "/" + file, &file_size);
+        Log(options.info_log, "MANIFEST file:  %s size: %lu Bytes\n",
+            file.c_str(), file_size);
+        break;
+      case kLogFile:
+        env->GetFileSize(dbname + "/" + file, &file_size);
+        char str[8];
+        snprintf(str, sizeof(str), "%lu", file_size);
+        wal_info.append(file).append(" size: ").
+            append(str, sizeof(str)).append(" ;");
+        break;
+      case kTableFile:
+        if (++file_num < 10) {
+          file_info.append(file).append(" ");
+        }
+        break;
+      default:
+        break;
+    }
+  }
+
+  // Get sst files in db_path dir
+  for (auto& db_path : options.db_paths) {
+    if (dbname.compare(db_path.path) != 0) {
+      if (!env->GetChildren(db_path.path, &files).ok()) {
+        Log(options.info_log, "Error when reading %s dir\n",
+            db_path.path.c_str());
+        continue;
+      }
+      std::sort(files.begin(), files.end());
+      for (std::string file : files) {
+        ParseFileName(file, &number, &type);
+        if (type == kTableFile && ++file_num < 10) {
+          file_info.append(file).append(" ");
+        }
+      }
+    }
+    Log(options.info_log, "SST files in %s dir, Total Num: %lu, files: %s\n",
+        db_path.path.c_str(), file_num, file_info.c_str());
+    file_num = 0;
+    file_info.clear();
+  }
+
+  // Get wal file in wal_dir
+  if (dbname.compare(options.wal_dir) != 0) {
+    if (!env->GetChildren(options.wal_dir, &files).ok()) {
+      Log(options.info_log, "Error when reading %s dir\n",
+          options.wal_dir.c_str());
+      return;
+    }
+    wal_info.clear();
+    for (std::string file : files) {
+      ParseFileName(file, &number, &type);
+      if (type == kLogFile) {
+        env->GetFileSize(options.wal_dir + "/" + file, &file_size);
+        char str[8];
+        snprintf(str, sizeof(str), "%lu", file_size);
+        wal_info.append(file).append(" size: ").
+            append(str, sizeof(str)).append(" ;");
+      }
+    }
+  }
+  Log(options.info_log, "Write Ahead Log file in %s: %s\n",
+      options.wal_dir.c_str(), wal_info.c_str());
+}
+}  // namespace rocksdb