Squashed 'src/rocksdb/' content from commit 224932d

git-subtree-dir: src/rocksdb
git-subtree-split: 224932d4d0

db/compaction.cc

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+//  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) 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.
+
+#include "db/compaction.h"
+
+#define __STDC_FORMAT_MACROS
+#include <inttypes.h>
+#include <vector>
+
+#include "db/column_family.h"
+#include "util/logging.h"
+
+namespace rocksdb {
+
+uint64_t TotalFileSize(const std::vector<FileMetaData*>& files) {
+  uint64_t sum = 0;
+  for (size_t i = 0; i < files.size() && files[i]; i++) {
+    sum += files[i]->fd.GetFileSize();
+  }
+  return sum;
+}
+
+Compaction::Compaction(Version* input_version, int start_level, int out_level,
+                       uint64_t target_file_size,
+                       uint64_t max_grandparent_overlap_bytes,
+                       uint32_t output_path_id,
+                       CompressionType output_compression, bool seek_compaction,
+                       bool deletion_compaction)
+    : start_level_(start_level),
+      output_level_(out_level),
+      max_output_file_size_(target_file_size),
+      max_grandparent_overlap_bytes_(max_grandparent_overlap_bytes),
+      input_version_(input_version),
+      number_levels_(input_version_->NumberLevels()),
+      cfd_(input_version_->cfd_),
+      output_path_id_(output_path_id),
+      output_compression_(output_compression),
+      seek_compaction_(seek_compaction),
+      deletion_compaction_(deletion_compaction),
+      grandparent_index_(0),
+      seen_key_(false),
+      overlapped_bytes_(0),
+      base_index_(-1),
+      parent_index_(-1),
+      score_(0),
+      bottommost_level_(false),
+      is_full_compaction_(false),
+      is_manual_compaction_(false),
+      level_ptrs_(std::vector<size_t>(number_levels_)) {
+
+  cfd_->Ref();
+  input_version_->Ref();
+  edit_ = new VersionEdit();
+  edit_->SetColumnFamily(cfd_->GetID());
+  for (int i = 0; i < number_levels_; i++) {
+    level_ptrs_[i] = 0;
+  }
+  int num_levels = output_level_ - start_level_ + 1;
+  input_levels_.resize(num_levels);
+  inputs_.resize(num_levels);
+  for (int i = 0; i < num_levels; ++i) {
+    inputs_[i].level = start_level_ + i;
+  }
+}
+
+Compaction::~Compaction() {
+  delete edit_;
+  if (input_version_ != nullptr) {
+    input_version_->Unref();
+  }
+  if (cfd_ != nullptr) {
+    if (cfd_->Unref()) {
+      delete cfd_;
+    }
+  }
+}
+
+void Compaction::GenerateFileLevels() {
+  input_levels_.resize(num_input_levels());
+  for (int which = 0; which < num_input_levels(); which++) {
+    DoGenerateFileLevel(&input_levels_[which], inputs_[which].files, &arena_);
+  }
+}
+
+bool Compaction::IsTrivialMove() const {
+  // Avoid a move if there is lots of overlapping grandparent data.
+  // Otherwise, the move could create a parent file that will require
+  // a very expensive merge later on.
+  // If start_level_== output_level_, the purpose is to force compaction
+  // filter to be applied to that level, and thus cannot be a trivia move.
+  return (start_level_ != output_level_ &&
+          num_input_levels() == 2 &&
+          num_input_files(0) == 1 &&
+          num_input_files(1) == 0 &&
+          TotalFileSize(grandparents_) <= max_grandparent_overlap_bytes_);
+}
+
+void Compaction::AddInputDeletions(VersionEdit* edit) {
+  for (int which = 0; which < num_input_levels(); which++) {
+    for (size_t i = 0; i < inputs_[which].size(); i++) {
+      edit->DeleteFile(level(which), inputs_[which][i]->fd.GetNumber());
+    }
+  }
+}
+
+bool Compaction::KeyNotExistsBeyondOutputLevel(const Slice& user_key) {
+  assert(cfd_->options()->compaction_style != kCompactionStyleFIFO);
+  if (cfd_->options()->compaction_style == kCompactionStyleUniversal) {
+    return bottommost_level_;
+  }
+  // Maybe use binary search to find right entry instead of linear search?
+  const Comparator* user_cmp = cfd_->user_comparator();
+  for (int lvl = output_level_ + 1; lvl < number_levels_; lvl++) {
+    const std::vector<FileMetaData*>& files = input_version_->files_[lvl];
+    for (; level_ptrs_[lvl] < files.size(); ) {
+      FileMetaData* f = files[level_ptrs_[lvl]];
+      if (user_cmp->Compare(user_key, f->largest.user_key()) <= 0) {
+        // We've advanced far enough
+        if (user_cmp->Compare(user_key, f->smallest.user_key()) >= 0) {
+          // Key falls in this file's range, so definitely
+          // exists beyond output level
+          return false;
+        }
+        break;
+      }
+      level_ptrs_[lvl]++;
+    }
+  }
+  return true;
+}
+
+bool Compaction::ShouldStopBefore(const Slice& internal_key) {
+  // Scan to find earliest grandparent file that contains key.
+  const InternalKeyComparator* icmp = &cfd_->internal_comparator();
+  while (grandparent_index_ < grandparents_.size() &&
+      icmp->Compare(internal_key,
+                    grandparents_[grandparent_index_]->largest.Encode()) > 0) {
+    if (seen_key_) {
+      overlapped_bytes_ += grandparents_[grandparent_index_]->fd.GetFileSize();
+    }
+    assert(grandparent_index_ + 1 >= grandparents_.size() ||
+           icmp->Compare(grandparents_[grandparent_index_]->largest.Encode(),
+                         grandparents_[grandparent_index_+1]->smallest.Encode())
+                         < 0);
+    grandparent_index_++;
+  }
+  seen_key_ = true;
+
+  if (overlapped_bytes_ > max_grandparent_overlap_bytes_) {
+    // Too much overlap for current output; start new output
+    overlapped_bytes_ = 0;
+    return true;
+  } else {
+    return false;
+  }
+}
+
+// Mark (or clear) each file that is being compacted
+void Compaction::MarkFilesBeingCompacted(bool mark_as_compacted) {
+  for (int i = 0; i < num_input_levels(); i++) {
+    for (unsigned int j = 0; j < inputs_[i].size(); j++) {
+      assert(mark_as_compacted ? !inputs_[i][j]->being_compacted :
+                                  inputs_[i][j]->being_compacted);
+      inputs_[i][j]->being_compacted = mark_as_compacted;
+    }
+  }
+}
+
+// Is this compaction producing files at the bottommost level?
+void Compaction::SetupBottomMostLevel(bool is_manual) {
+  assert(cfd_->options()->compaction_style != kCompactionStyleFIFO);
+  if (cfd_->options()->compaction_style == kCompactionStyleUniversal) {
+    // If universal compaction style is used and manual
+    // compaction is occuring, then we are guaranteed that
+    // all files will be picked in a single compaction
+    // run. We can safely set bottommost_level_ = true.
+    // If it is not manual compaction, then bottommost_level_
+    // is already set when the Compaction was created.
+    if (is_manual) {
+      bottommost_level_ = true;
+    }
+    return;
+  }
+  bottommost_level_ = true;
+  // checks whether there are files living beyond the output_level.
+  for (int i = output_level_ + 1; i < number_levels_; i++) {
+    if (input_version_->NumLevelFiles(i) > 0) {
+      bottommost_level_ = false;
+      break;
+    }
+  }
+}
+
+void Compaction::ReleaseInputs() {
+  if (input_version_ != nullptr) {
+    input_version_->Unref();
+    input_version_ = nullptr;
+  }
+  if (cfd_ != nullptr) {
+    if (cfd_->Unref()) {
+      delete cfd_;
+    }
+    cfd_ = nullptr;
+  }
+}
+
+void Compaction::ReleaseCompactionFiles(Status status) {
+  cfd_->compaction_picker()->ReleaseCompactionFiles(this, status);
+}
+
+void Compaction::ResetNextCompactionIndex() {
+  input_version_->ResetNextCompactionIndex(start_level_);
+}
+
+namespace {
+int InputSummary(const std::vector<FileMetaData*>& files, char* output,
+                 int len) {
+  *output = '\0';
+  int write = 0;
+  for (unsigned int i = 0; i < files.size(); i++) {
+    int sz = len - write;
+    int ret;
+    char sztxt[16];
+    AppendHumanBytes(files.at(i)->fd.GetFileSize(), sztxt, 16);
+    ret = snprintf(output + write, sz, "%" PRIu64 "(%s) ",
+                   files.at(i)->fd.GetNumber(), sztxt);
+    if (ret < 0 || ret >= sz) break;
+    write += ret;
+  }
+  // if files.size() is non-zero, overwrite the last space
+  return write - !!files.size();
+}
+}  // namespace
+
+void Compaction::Summary(char* output, int len) {
+  int write =
+      snprintf(output, len, "Base version %" PRIu64
+                            " Base level %d, seek compaction:%d, inputs: [",
+               input_version_->GetVersionNumber(),
+               start_level_, seek_compaction_);
+  if (write < 0 || write >= len) {
+    return;
+  }
+
+  for (int level = 0; level < num_input_levels(); ++level) {
+    if (level > 0) {
+      write += snprintf(output + write, len - write, "], [");
+      if (write < 0 || write >= len) {
+        return;
+      }
+    }
+    write += InputSummary(inputs_[level].files, output + write, len - write);
+    if (write < 0 || write >= len) {
+      return;
+    }
+  }
+
+  snprintf(output + write, len - write, "]");
+}
+
+uint64_t Compaction::OutputFilePreallocationSize() {
+  uint64_t preallocation_size = 0;
+
+  if (cfd_->options()->compaction_style == kCompactionStyleLevel) {
+    preallocation_size =
+        cfd_->compaction_picker()->MaxFileSizeForLevel(output_level());
+  } else {
+    for (int level = 0; level < num_input_levels(); ++level) {
+      for (const auto& f : inputs_[level].files) {
+        preallocation_size += f->fd.GetFileSize();
+      }
+    }
+  }
+  // Over-estimate slightly so we don't end up just barely crossing
+  // the threshold
+  return preallocation_size * 1.1;
+}
+
+}  // namespace rocksdb