Merge branch 'performance' of github.com:facebook/rocksdb into performance

Conflicts:
	db/builder.cc
	db/db_impl.cc
	db/version_set.cc
	include/leveldb/statistics.h

include/leveldb/options.h

@@ -12,6 +12,7 @@
 #include <stdint.h>
 #include "leveldb/slice.h"
 #include "leveldb/statistics.h"
+#include "leveldb/universal_compaction.h"
 #include "leveldb/memtablerep.h"
 
 namespace leveldb {
@@ -40,6 +41,11 @@ enum CompressionType {
   kBZip2Compression = 0x3
 };
 
+enum CompactionStyle {
+  kCompactionStyleLevel       = 0x0, // level based compaction style
+  kCompactionStyleUniversal   = 0x1  // Universal compaction style
+};
+
 // Compression options for different compression algorithms like Zlib
 struct CompressionOptions {
   int window_bits;
@@ -483,6 +489,12 @@ struct Options {
   // Default: 0
   uint64_t bytes_per_sync;
 
+  // The compaction style. Default: kCompactionStyleLevel
+  CompactionStyle compaction_style;
+
+  // The options needed to support Universal Style compactions
+  CompactionOptionsUniversal compaction_options_universal;
+
   // Use KeyMayExist API to filter deletes when this is true.
   // If KeyMayExist returns false, i.e. the key definitely does not exist, then
   // the delete is a noop. KeyMayExist only incurs in-memory look up.
@@ -494,7 +506,6 @@ struct Options {
   // Default: a factory that provides a skip-list-based implementation of
   // MemTableRep.
   std::shared_ptr<MemTableRepFactory> memtable_factory;
-
 };
 
 // Options that control read operations

include/leveldb/statistics.h

@@ -115,7 +115,8 @@ enum Histograms {
   STALL_L0_NUM_FILES_COUNT = 14,
   HARD_RATE_LIMIT_DELAY_COUNT = 15,
   SOFT_RATE_LIMIT_DELAY_COUNT = 16,
-  HISTOGRAM_ENUM_MAX = 17
+  NUM_FILES_IN_SINGLE_COMPACTION = 17,
+  HISTOGRAM_ENUM_MAX = 18
 };
 
 const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
@@ -135,7 +136,8 @@ const std::vector<std::pair<Histograms, std::string>> HistogramsNameMap = {
   { STALL_MEMTABLE_COMPACTION_COUNT, "rocksdb.memtable.compaction.count"},
   { STALL_L0_NUM_FILES_COUNT, "rocksdb.num.files.stall.count"},
   { HARD_RATE_LIMIT_DELAY_COUNT, "rocksdb.hard.rate.limit.delay.count"},
-  { SOFT_RATE_LIMIT_DELAY_COUNT, "rocksdb.soft.rate.limit.delay.count"}
+  { SOFT_RATE_LIMIT_DELAY_COUNT, "rocksdb.soft.rate.limit.delay.count"},
+  { NUM_FILES_IN_SINGLE_COMPACTION, "rocksdb.numfiles.in.singlecompaction" }
 };
 
 struct HistogramData {

include/leveldb/universal_compaction.h

@@ -0,0 +1,57 @@
+// Copyright (c) 2011 The LevelDB Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file. See the AUTHORS file for names of contributors.
+
+#ifndef STORAGE_ROCKSDB_UNIVERSAL_COMPACTION_OPTIONS_H
+#define STORAGE_ROCKSDB_UNIVERSAL_COMPACTION_OPTIONS_H
+
+#include <stddef.h>
+#include <string>
+#include <memory>
+#include <vector>
+#include <stdint.h>
+#include <climits>
+#include "leveldb/slice.h"
+#include "leveldb/statistics.h"
+
+namespace leveldb {
+
+//
+// Algorithm used to make a compaction request stop picking new files
+// into a single compaction run
+//
+enum CompactionStopStyle {
+  kCompactionStopStyleSimilarSize, // pick files of similar size
+  kCompactionStopStyleTotalSize    // total size of picked files > next file
+};
+
+class CompactionOptionsUniversal {
+ public:
+
+  // Percentage flexibilty while comparing file size. If the candidate file(s)
+  // size is 1% smaller than the next file's size, then include next file into
+  // this candidate set. // Default: 1
+  unsigned int size_ratio;
+
+  // The minimum number of files in a single compaction run. Default: 2
+  unsigned int min_merge_width;
+
+  // The maximum number of files in a single compaction run. Default: INT_MAX
+  unsigned int max_merge_width;
+
+  // The algorithm used to stop picking files into a single compaction run
+  // Default: kCompactionStopStyleTotalSize
+  CompactionStopStyle stop_style;
+
+  // Default set of parameters
+  CompactionOptionsUniversal() :
+    size_ratio(1),
+    min_merge_width(2),
+    max_merge_width(UINT_MAX),
+    stop_style(kCompactionStopStyleTotalSize) {
+  }
+};
+
+}  // namespace leveldb
+
+#endif  // STORAGE_ROCKSDB_UNIVERSAL_COMPACTION_OPTIONS_H