Cleanup CompactionJob

Summary:
Couple changes:
1. instead of SnapshotList, just take a vector of snapshots
2. don't take a separate parameter is_snapshots_supported. If there are snapshots in the list, that means they are supported. I actually think we should get rid of this notion of snapshots not being supported.
3. don't pass in mutable_cf_options as a parameter. Lifetime of mutable_cf_options is a bit tricky to maintain, so it's better to not pass it in for the whole compaction job. We only really need it when we install the compaction results.

Test Plan: make check

Reviewers: sdong, rven, yhchiang

Reviewed By: yhchiang

Subscribers: dhruba, leveldb

Differential Revision: https://reviews.facebook.net/D36627

db/compaction.cc

@@ -322,12 +322,11 @@ void Compaction::Summary(char* output, int len) {
   snprintf(output + write, len - write, "]");
 }
 
-uint64_t Compaction::OutputFilePreallocationSize(
-    const MutableCFOptions& mutable_options) {
+uint64_t Compaction::OutputFilePreallocationSize() {
   uint64_t preallocation_size = 0;
 
   if (cfd_->ioptions()->compaction_style == kCompactionStyleLevel) {
-    preallocation_size = mutable_options.MaxFileSizeForLevel(output_level());
+    preallocation_size = max_output_file_size_;
   } else {
     for (size_t level_iter = 0; level_iter < num_input_levels(); ++level_iter) {
       for (const auto& f : inputs_[level_iter].files) {

db/compaction.h

@@ -163,7 +163,7 @@ class Compaction {
   // Returns the size in bytes that the output file should be preallocated to.
   // In level compaction, that is max_file_size_. In universal compaction, that
   // is the sum of all input file sizes.
-  uint64_t OutputFilePreallocationSize(const MutableCFOptions& mutable_options);
+  uint64_t OutputFilePreallocationSize();
 
   void SetInputVersion(Version* input_version);
 

db/compaction_job.cc

@@ -58,12 +58,6 @@ namespace rocksdb {
 struct CompactionJob::CompactionState {
   Compaction* const compaction;
 
-  // If there were two snapshots with seq numbers s1 and
-  // s2 and s1 < s2, and if we find two instances of a key k1 then lies
-  // entirely within s1 and s2, then the earlier version of k1 can be safely
-  // deleted because that version is not visible in any snapshot.
-  std::vector<SequenceNumber> existing_snapshots;
-
   // Files produced by compaction
   struct Output {
     uint64_t number;
@@ -204,17 +198,17 @@ struct CompactionJob::CompactionState {
 
 CompactionJob::CompactionJob(
     int job_id, Compaction* compaction, const DBOptions& db_options,
-    const MutableCFOptions& mutable_cf_options, const EnvOptions& env_options,
-    VersionSet* versions, std::atomic<bool>* shutting_down,
-    LogBuffer* log_buffer, Directory* db_directory, Directory* output_directory,
-    Statistics* stats, SnapshotList* snapshots, bool is_snapshot_supported,
+    const EnvOptions& env_options, VersionSet* versions,
+    std::atomic<bool>* shutting_down, LogBuffer* log_buffer,
+    Directory* db_directory, Directory* output_directory, Statistics* stats,
+    std::vector<SequenceNumber> existing_snapshots,
     std::shared_ptr<Cache> table_cache,
-    std::function<uint64_t()> yield_callback, EventLogger* event_logger)
+    std::function<uint64_t()> yield_callback, EventLogger* event_logger,
+    bool paranoid_file_checks)
     : job_id_(job_id),
       compact_(new CompactionState(compaction)),
       compaction_stats_(1),
       db_options_(db_options),
-      mutable_cf_options_(mutable_cf_options),
       env_options_(env_options),
       env_(db_options.env),
       versions_(versions),
@@ -223,13 +217,12 @@ CompactionJob::CompactionJob(
       db_directory_(db_directory),
       output_directory_(output_directory),
       stats_(stats),
-      snapshots_(snapshots),
-      is_snapshot_supported_(is_snapshot_supported),
+      existing_snapshots_(std::move(existing_snapshots)),
       table_cache_(std::move(table_cache)),
       yield_callback_(std::move(yield_callback)),
-      event_logger_(event_logger) {
-  ThreadStatusUtil::SetColumnFamily(
-      compact_->compaction->column_family_data());
+      event_logger_(event_logger),
+      paranoid_file_checks_(paranoid_file_checks) {
+  ThreadStatusUtil::SetColumnFamily(compact_->compaction->column_family_data());
   ThreadStatusUtil::SetThreadOperation(ThreadStatus::OP_COMPACTION);
 }
 
@@ -256,18 +249,16 @@ void CompactionJob::Prepare() {
 
   visible_at_tip_ = 0;
   latest_snapshot_ = 0;
-  // TODO(icanadi) move snapshots_ out of CompactionJob
-  snapshots_->getAll(compact_->existing_snapshots);
-  if (compact_->existing_snapshots.size() == 0) {
+  if (existing_snapshots_.size() == 0) {
     // optimize for fast path if there are no snapshots
     visible_at_tip_ = versions_->LastSequence();
     earliest_snapshot_ = visible_at_tip_;
   } else {
-    latest_snapshot_ = compact_->existing_snapshots.back();
+    latest_snapshot_ = existing_snapshots_.back();
     // Add the current seqno as the 'latest' virtual
     // snapshot to the end of this list.
-    compact_->existing_snapshots.push_back(versions_->LastSequence());
-    earliest_snapshot_ = compact_->existing_snapshots[0];
+    existing_snapshots_.push_back(versions_->LastSequence());
+    earliest_snapshot_ = existing_snapshots_[0];
   }
 
   // Is this compaction producing files at the bottommost level?
@@ -509,7 +500,9 @@ Status CompactionJob::Run() {
   return status;
 }
 
-void CompactionJob::Install(Status* status, InstrumentedMutex* db_mutex) {
+void CompactionJob::Install(Status* status,
+                            const MutableCFOptions& mutable_cf_options,
+                            InstrumentedMutex* db_mutex) {
   AutoThreadOperationStageUpdater stage_updater(
       ThreadStatus::STAGE_COMPACTION_INSTALL);
   db_mutex->AssertHeld();
@@ -518,7 +511,7 @@ void CompactionJob::Install(Status* status, InstrumentedMutex* db_mutex) {
       compact_->compaction->output_level(), compaction_stats_);
 
   if (status->ok()) {
-    *status = InstallCompactionResults(db_mutex);
+    *status = InstallCompactionResults(db_mutex, mutable_cf_options);
   }
   VersionStorageInfo::LevelSummaryStorage tmp;
   auto vstorage = cfd->current()->storage_info();
@@ -716,11 +709,8 @@ Status CompactionJob::ProcessKeyValueCompaction(int64_t* imm_micros,
       SequenceNumber visible =
           visible_at_tip_
               ? visible_at_tip_
-              : is_snapshot_supported_
-                    ? findEarliestVisibleSnapshot(ikey.sequence,
-                                                  compact_->existing_snapshots,
-                                                  &prev_snapshot)
-                    : 0;
+              : findEarliestVisibleSnapshot(ikey.sequence, existing_snapshots_,
+                                            &prev_snapshot);
 
       if (visible_in_snapshot == visible) {
         // If the earliest snapshot is which this key is visible in
@@ -1018,7 +1008,7 @@ Status CompactionJob::FinishCompactionOutputFile(Iterator* input) {
         ReadOptions(), env_options_, cfd->internal_comparator(), fd);
     s = iter->status();
 
-    if (s.ok() && mutable_cf_options_.paranoid_file_checks) {
+    if (s.ok() && paranoid_file_checks_) {
       for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {}
       s = iter->status();
     }
@@ -1039,7 +1029,8 @@ Status CompactionJob::FinishCompactionOutputFile(Iterator* input) {
   return s;
 }
 
-Status CompactionJob::InstallCompactionResults(InstrumentedMutex* db_mutex) {
+Status CompactionJob::InstallCompactionResults(
+    InstrumentedMutex* db_mutex, const MutableCFOptions& mutable_cf_options) {
   db_mutex->AssertHeld();
 
   auto* compaction = compact_->compaction;
@@ -1074,7 +1065,7 @@ Status CompactionJob::InstallCompactionResults(InstrumentedMutex* db_mutex) {
         out.smallest, out.largest, out.smallest_seqno, out.largest_seqno);
   }
   return versions_->LogAndApply(compaction->column_family_data(),
-                                mutable_cf_options_, compaction->edit(),
+                                mutable_cf_options, compaction->edit(),
                                 db_mutex, db_directory_);
 }
 
@@ -1142,8 +1133,8 @@ Status CompactionJob::OpenCompactionOutputFile() {
 
   compact_->outputs.push_back(out);
   compact_->outfile->SetIOPriority(Env::IO_LOW);
-  compact_->outfile->SetPreallocationBlockSize(static_cast<size_t>(
-      compact_->compaction->OutputFilePreallocationSize(mutable_cf_options_)));
+  compact_->outfile->SetPreallocationBlockSize(
+      static_cast<size_t>(compact_->compaction->OutputFilePreallocationSize()));
 
   ColumnFamilyData* cfd = compact_->compaction->column_family_data();
   bool skip_filters = false;

db/compaction_job.h

@@ -19,7 +19,6 @@
 
 #include "db/dbformat.h"
 #include "db/log_writer.h"
-#include "db/snapshot.h"
 #include "db/column_family.h"
 #include "db/version_edit.h"
 #include "db/memtable_list.h"
@@ -51,18 +50,15 @@ class Arena;
 
 class CompactionJob {
  public:
-  // TODO(icanadi) make effort to reduce number of parameters here
-  // IMPORTANT: mutable_cf_options needs to be alive while CompactionJob is
-  // alive
   CompactionJob(int job_id, Compaction* compaction, const DBOptions& db_options,
-                const MutableCFOptions& mutable_cf_options,
                 const EnvOptions& env_options, VersionSet* versions,
                 std::atomic<bool>* shutting_down, LogBuffer* log_buffer,
                 Directory* db_directory, Directory* output_directory,
-                Statistics* stats, SnapshotList* snapshot_list,
-                bool is_snapshot_supported, std::shared_ptr<Cache> table_cache,
+                Statistics* stats,
+                std::vector<SequenceNumber> existing_snapshots,
+                std::shared_ptr<Cache> table_cache,
                 std::function<uint64_t()> yield_callback,
-                EventLogger* event_logger);
+                EventLogger* event_logger, bool paranoid_file_checks);
 
   ~CompactionJob();
 
@@ -77,7 +73,8 @@ class CompactionJob {
   Status Run();
   // REQUIRED: mutex held
   // status is the return of Run()
-  void Install(Status* status, InstrumentedMutex* db_mutex);
+  void Install(Status* status, const MutableCFOptions& mutable_cf_options,
+               InstrumentedMutex* db_mutex);
 
  private:
   void AllocateCompactionOutputFileNumbers();
@@ -89,7 +86,8 @@ class CompactionJob {
   void CallCompactionFilterV2(CompactionFilterV2* compaction_filter_v2,
                               uint64_t* time);
   Status FinishCompactionOutputFile(Iterator* input);
-  Status InstallCompactionResults(InstrumentedMutex* db_mutex);
+  Status InstallCompactionResults(InstrumentedMutex* db_mutex,
+                                  const MutableCFOptions& mutable_cf_options);
   SequenceNumber findEarliestVisibleSnapshot(
       SequenceNumber in, const std::vector<SequenceNumber>& snapshots,
       SequenceNumber* prev_snapshot);
@@ -112,7 +110,6 @@ class CompactionJob {
 
   // DBImpl state
   const DBOptions& db_options_;
-  const MutableCFOptions& mutable_cf_options_;
   const EnvOptions& env_options_;
   Env* env_;
   VersionSet* versions_;
@@ -121,14 +118,19 @@ class CompactionJob {
   Directory* db_directory_;
   Directory* output_directory_;
   Statistics* stats_;
-  SnapshotList* snapshots_;
-  bool is_snapshot_supported_;
+  // If there were two snapshots with seq numbers s1 and
+  // s2 and s1 < s2, and if we find two instances of a key k1 then lies
+  // entirely within s1 and s2, then the earlier version of k1 can be safely
+  // deleted because that version is not visible in any snapshot.
+  std::vector<SequenceNumber> existing_snapshots_;
   std::shared_ptr<Cache> table_cache_;
 
   // yield callback
   std::function<uint64_t()> yield_callback_;
 
   EventLogger* event_logger_;
+
+  bool paranoid_file_checks_;
 };
 
 }  // namespace rocksdb

db/compaction_job_test.cc

@@ -155,7 +155,6 @@ TEST_F(CompactionJobTest, Simple) {
       {compaction_input_files}, 1, 1024 * 1024, 10, 0, kNoCompression, {}));
   compaction->SetInputVersion(cfd->current());
 
-  SnapshotList snapshots;
   int yield_callback_called = 0;
   std::function<uint64_t()> yield_callback = [&]() {
     yield_callback_called++;
@@ -164,17 +163,17 @@ TEST_F(CompactionJobTest, Simple) {
   LogBuffer log_buffer(InfoLogLevel::INFO_LEVEL, db_options_.info_log.get());
   mutex_.Lock();
   EventLogger event_logger(db_options_.info_log.get());
-  CompactionJob compaction_job(
-      0, compaction.get(), db_options_, *cfd->GetLatestMutableCFOptions(),
-      env_options_, versions_.get(), &shutting_down_, &log_buffer, nullptr,
-      nullptr, nullptr, &snapshots, true, table_cache_,
-      std::move(yield_callback), &event_logger);
+  CompactionJob compaction_job(0, compaction.get(), db_options_, env_options_,
+                               versions_.get(), &shutting_down_, &log_buffer,
+                               nullptr, nullptr, nullptr, {}, table_cache_,
+                               std::move(yield_callback), &event_logger, false);
+
   compaction_job.Prepare();
   mutex_.Unlock();
   ASSERT_OK(compaction_job.Run());
   mutex_.Lock();
   Status s;
-  compaction_job.Install(&s, &mutex_);
+  compaction_job.Install(&s, *cfd->GetLatestMutableCFOptions(), &mutex_);
   ASSERT_OK(s);
   mutex_.Unlock();
 

db/db_impl.cc

@@ -1482,18 +1482,19 @@ Status DBImpl::CompactFilesImpl(
         c->column_family_data(), *c->mutable_cf_options(),
         job_context, log_buffer);
   };
+  assert(is_snapshot_supported_ || snapshots_.empty());
   CompactionJob compaction_job(
-      job_context->job_id, c.get(), db_options_, *c->mutable_cf_options(),
-      env_options_, versions_.get(), &shutting_down_, log_buffer,
-      directories_.GetDbDir(), directories_.GetDataDir(c->GetOutputPathId()),
-      stats_, &snapshots_, is_snapshot_supported_, table_cache_,
-      std::move(yield_callback), &event_logger_);
+      job_context->job_id, c.get(), db_options_, env_options_, versions_.get(),
+      &shutting_down_, log_buffer, directories_.GetDbDir(),
+      directories_.GetDataDir(c->GetOutputPathId()), stats_,
+      snapshots_.GetAll(), table_cache_, std::move(yield_callback),
+      &event_logger_, c->mutable_cf_options()->paranoid_file_checks);
   compaction_job.Prepare();
 
   mutex_.Unlock();
   Status status = compaction_job.Run();
   mutex_.Lock();
-  compaction_job.Install(&status, &mutex_);
+  compaction_job.Install(&status, *c->mutable_cf_options(), &mutex_);
   if (status.ok()) {
     InstallSuperVersionBackground(c->column_family_data(), job_context,
                                   *c->mutable_cf_options());
@@ -2357,17 +2358,18 @@ Status DBImpl::BackgroundCompaction(bool* madeProgress, JobContext* job_context,
                                        *c->mutable_cf_options(), job_context,
                                        log_buffer);
     };
+    assert(is_snapshot_supported_ || snapshots_.empty());
     CompactionJob compaction_job(
-        job_context->job_id, c.get(), db_options_, *c->mutable_cf_options(),
-        env_options_, versions_.get(), &shutting_down_, log_buffer,
-        directories_.GetDbDir(), directories_.GetDataDir(c->GetOutputPathId()),
-        stats_, &snapshots_, is_snapshot_supported_, table_cache_,
-        std::move(yield_callback), &event_logger_);
+        job_context->job_id, c.get(), db_options_, env_options_,
+        versions_.get(), &shutting_down_, log_buffer, directories_.GetDbDir(),
+        directories_.GetDataDir(c->GetOutputPathId()), stats_,
+        snapshots_.GetAll(), table_cache_, std::move(yield_callback),
+        &event_logger_, c->mutable_cf_options()->paranoid_file_checks);
     compaction_job.Prepare();
     mutex_.Unlock();
     status = compaction_job.Run();
     mutex_.Lock();
-    compaction_job.Install(&status, &mutex_);
+    compaction_job.Install(&status, *c->mutable_cf_options(), &mutex_);
     if (status.ok()) {
       InstallSuperVersionBackground(c->column_family_data(), job_context,
                                     *c->mutable_cf_options());

db/snapshot.h

@@ -8,6 +8,8 @@
 // found in the LICENSE file. See the AUTHORS file for names of contributors.
 
 #pragma once
+#include <vector>
+
 #include "rocksdb/db.h"
 
 namespace rocksdb {
@@ -69,13 +71,17 @@ class SnapshotList {
   }
 
   // retrieve all snapshot numbers. They are sorted in ascending order.
-  void getAll(std::vector<SequenceNumber>& ret) {
-    if (empty()) return;
+  std::vector<SequenceNumber> GetAll() {
+    std::vector<SequenceNumber> ret;
+    if (empty()) {
+      return ret;
+    }
     SnapshotImpl* s = &list_;
     while (s->next_ != &list_) {
       ret.push_back(s->next_->number_);
-      s = s ->next_;
+      s = s->next_;
     }
+    return ret;
   }
 
   // get the sequence number of the most recent snapshot