rocksdb/db/version_set_reduce_num_levels.cc
Igor Canadi 65a8a52b54 Decrease reliance on VersionSet::NumberLevels()
Summary:
With column families VersionSet will not have a constant number of levels (each CF can have different options), so we'll need to eliminate call to VersionSet::NumberLevels()

This diff decreases number of callsites, but we're not there yet. It associates number of levels with Version (each version is associated with single CF) instead of VersionSet.

I have also slightly changed how VersionSet keeps track of manifest size.

This diff also modifies constructor of Compaction such that it takes input_version and automatically Ref()s it. Before this was done outside of constructor.

In next diffs I will continue to decrease number of callsites of VersionSet::NumberLevels() and also references to current_

Test Plan: make check

Reviewers: haobo, dhruba, kailiu, sdong

Reviewed By: sdong

Differential Revision: https://reviews.facebook.net/D15171
2014-01-15 16:15:43 -08:00

82 lines
2.4 KiB
C++

// 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.
//
// Copyright (c) 2012 Facebook. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "db/version_set.h"
#include <algorithm>
#include <stdio.h>
#include "db/log_reader.h"
#include "db/log_writer.h"
#include "util/logging.h"
namespace rocksdb {
Status VersionSet::ReduceNumberOfLevels(int new_levels, port::Mutex* mu) {
if(new_levels <= 1) {
return Status::InvalidArgument(
"Number of levels needs to be bigger than 1");
}
Version* current_version = current_;
int current_levels = current_version->NumberLevels();
if (current_levels <= new_levels) {
return Status::OK();
}
// Make sure there are file only on one level from
// (new_levels-1) to (current_levels-1)
int first_nonempty_level = -1;
int first_nonempty_level_filenum = 0;
for (int i = new_levels - 1; i < current_levels; i++) {
int file_num = current_version->NumLevelFiles(i);
if (file_num != 0) {
if (first_nonempty_level < 0) {
first_nonempty_level = i;
first_nonempty_level_filenum = file_num;
} else {
char msg[255];
sprintf(msg, "Found at least two levels containing files: "
"[%d:%d],[%d:%d].\n",
first_nonempty_level, first_nonempty_level_filenum, i, file_num);
return Status::InvalidArgument(msg);
}
}
}
Status st;
std::vector<FileMetaData*>* old_files_list = current_version->files_;
std::vector<FileMetaData*>* new_files_list =
new std::vector<FileMetaData*>[new_levels];
for (int i = 0; i < new_levels - 1; i++) {
new_files_list[i] = old_files_list[i];
}
if (first_nonempty_level > 0) {
new_files_list[new_levels - 1] = old_files_list[first_nonempty_level];
}
delete[] current_version->files_;
current_version->files_ = new_files_list;
current_version->num_levels_ = new_levels;
delete[] compact_pointer_;
delete[] max_file_size_;
delete[] level_max_bytes_;
num_levels_ = new_levels;
compact_pointer_ = new std::string[new_levels];
Init(new_levels);
VersionEdit ve;
st = LogAndApply(&ve, mu, true);
return st;
}
}