Merge #17398: build: Update leveldb to 1.22+

677fb8e92380d4deb6a3753047c01f7cf7b5af91 test: Add ubsan surpression for crc32c (Wladimir J. van der Laan)
8e68bb1ddeca504bedd40aee8492b5478a88c1e5 build: Disable msvc warning 4722 for leveldb build (Aaron Clauson)
be23949765e1b2e050574c6c2a136658a89dee5d build: MSVC changes for leveldb update (Aaron Clauson)
9ebdf047578f0da7e6578d0c51c32f55e84ac157 build: CRC32C build system integration (Wladimir J. van der Laan)
402252a8081e25f22aa1a5c60708714cf1d84ec4 build: Add LCOV exception for crc32c (Wladimir J. van der Laan)
3a037d0067c2c12a1c2c800fb85613a0a2911253 test: Add crc32c exception to various linters and generation scripts (Wladimir J. van der Laan)
84ff1b2076ef91ce688930d0aa0a7f4078ef3e1d test: Add crc32c to subtree check linter (Wladimir J. van der Laan)
7cf13a513409c18d18dff2f6203b3630937b487d doc: Add crc32c subtree to developer notes (Wladimir J. van der Laan)
24d02a9ac00a82d172b171f73554a882df264c80 build: Update build system for new leveldb (Wladimir J. van der Laan)
2e1819311a59fb5cb26e3ca50a510bfe01358350 Squashed 'src/crc32c/' content from commit 224988680f7673cd7c769963d4035cb315aa3388 (Wladimir J. van der Laan)
66480821b36c839ab7615cb9309850015bceadb0 Squashed 'src/leveldb/' changes from f545dfabff4c2e9836efed094dba99a34fbc6b88..f8ae182c1e5176d12e816fb2217ae33a5472fdd7 (Wladimir J. van der Laan)

Pull request description:

  This updates leveldb to currently newest upstream commit https://github.com/bitcoin-core/leveldb/commit/0c40829872a9f00f38e11dc370ff8adb3e19f25b:

  - CRC32C hardware acceleration is now an external library [crc32c](https://github.com/google/crc32c). This adds acceleration on ARM, and should be faster on x86 because of using prefetch. It also makes it easy to support similar instruction sets on other platforms in the future.
  - Thread handling uses C++11, instead of platform specific code.
  - Native windows environment was added. No need to maintain our own hacky one, anymore.
  - Upstream now builds using CMake. This doesn't mean we need to use that (phew), but internal configuration changed to a a series of checks, instead of OS profiles. This means the blanket error "Cannot build leveldb for $host. Please file a bug report' is removed.

  All changes: https://github.com/google/leveldb/compare/a53934a3ae1244679f812d998a4f16f2c7f309a6...0c40829872a9f00f38e11dc370ff8adb3e19f25b

  Pretty much all our changes have been subsumed by upstream, so we figured it was cleaner to start over with a new branch from upstream with the still-relevant patches applied: https://github.com/bitcoin-core/leveldb/tree/bitcoin-fork-new

  There's quite some testing to be done (see below). See https://github.com/bitcoin-core/leveldb/issues/25 and https://github.com/bitcoin-core/leveldb/pull/26 for more history and context.

  TODO:
  - [x] Subtree `crc32c`
  - [x] Make linters happy about crc32 subtree
  - [x] Integrate `crc32c` library into build system
  - [x] MSVC build system

ACKs for top commit:
  sipa:
    ACK 677fb8e92380d4deb6a3753047c01f7cf7b5af91

Tree-SHA512: 37ee92a750e053e924bc4626b12bb3fd81faa9f8c5ebaa343931fee810c45ba05aa6051fdea82535fa351bf2be7297801b98af9469865fc5ead771650a5d6240

1 files changed, 76 insertions, 70 deletions

diff --git a/src/leveldb/db/db_impl.h b/src/leveldb/db/db_impl.h
index 8ff323e728..685735c733 100644
--- a/src/leveldb/db/db_impl.h
+++ b/src/leveldb/db/db_impl.h
@@ -5,8 +5,11 @@
 #ifndef STORAGE_LEVELDB_DB_DB_IMPL_H_
 #define STORAGE_LEVELDB_DB_DB_IMPL_H_
 
+#include <atomic>
 #include <deque>
 #include <set>
+#include <string>
+
 #include "db/dbformat.h"
 #include "db/log_writer.h"
 #include "db/snapshot.h"
@@ -26,21 +29,25 @@ class VersionSet;
 class DBImpl : public DB {
  public:
   DBImpl(const Options& options, const std::string& dbname);
-  virtual ~DBImpl();
+
+  DBImpl(const DBImpl&) = delete;
+  DBImpl& operator=(const DBImpl&) = delete;
+
+  ~DBImpl() override;
 
   // Implementations of the DB interface
-  virtual Status Put(const WriteOptions&, const Slice& key, const Slice& value);
-  virtual Status Delete(const WriteOptions&, const Slice& key);
-  virtual Status Write(const WriteOptions& options, WriteBatch* updates);
-  virtual Status Get(const ReadOptions& options,
-                     const Slice& key,
-                     std::string* value);
-  virtual Iterator* NewIterator(const ReadOptions&);
-  virtual const Snapshot* GetSnapshot();
-  virtual void ReleaseSnapshot(const Snapshot* snapshot);
-  virtual bool GetProperty(const Slice& property, std::string* value);
-  virtual void GetApproximateSizes(const Range* range, int n, uint64_t* sizes);
-  virtual void CompactRange(const Slice* begin, const Slice* end);
+  Status Put(const WriteOptions&, const Slice& key,
+             const Slice& value) override;
+  Status Delete(const WriteOptions&, const Slice& key) override;
+  Status Write(const WriteOptions& options, WriteBatch* updates) override;
+  Status Get(const ReadOptions& options, const Slice& key,
+             std::string* value) override;
+  Iterator* NewIterator(const ReadOptions&) override;
+  const Snapshot* GetSnapshot() override;
+  void ReleaseSnapshot(const Snapshot* snapshot) override;
+  bool GetProperty(const Slice& property, std::string* value) override;
+  void GetApproximateSizes(const Range* range, int n, uint64_t* sizes) override;
+  void CompactRange(const Slice* begin, const Slice* end) override;
 
   // Extra methods (for testing) that are not in the public DB interface
 
@@ -69,6 +76,31 @@ class DBImpl : public DB {
   struct CompactionState;
   struct Writer;
 
+  // Information for a manual compaction
+  struct ManualCompaction {
+    int level;
+    bool done;
+    const InternalKey* begin;  // null means beginning of key range
+    const InternalKey* end;    // null means end of key range
+    InternalKey tmp_storage;   // Used to keep track of compaction progress
+  };
+
+  // Per level compaction stats.  stats_[level] stores the stats for
+  // compactions that produced data for the specified "level".
+  struct CompactionStats {
+    CompactionStats() : micros(0), bytes_read(0), bytes_written(0) {}
+
+    void Add(const CompactionStats& c) {
+      this->micros += c.micros;
+      this->bytes_read += c.bytes_read;
+      this->bytes_written += c.bytes_written;
+    }
+
+    int64_t micros;
+    int64_t bytes_read;
+    int64_t bytes_written;
+  };
+
   Iterator* NewInternalIterator(const ReadOptions&,
                                 SequenceNumber* latest_snapshot,
                                 uint32_t* seed);
@@ -84,7 +116,7 @@ class DBImpl : public DB {
   void MaybeIgnoreError(Status* s) const;
 
   // Delete any unneeded files and stale in-memory entries.
-  void DeleteObsoleteFiles();
+  void DeleteObsoleteFiles() EXCLUSIVE_LOCKS_REQUIRED(mutex_);
 
   // Compact the in-memory write buffer to disk.  Switches to a new
   // log-file/memtable and writes a new descriptor iff successful.
@@ -100,14 +132,15 @@ class DBImpl : public DB {
 
   Status MakeRoomForWrite(bool force /* compact even if there is room? */)
       EXCLUSIVE_LOCKS_REQUIRED(mutex_);
-  WriteBatch* BuildBatchGroup(Writer** last_writer);
+  WriteBatch* BuildBatchGroup(Writer** last_writer)
+      EXCLUSIVE_LOCKS_REQUIRED(mutex_);
 
   void RecordBackgroundError(const Status& s);
 
   void MaybeScheduleCompaction() EXCLUSIVE_LOCKS_REQUIRED(mutex_);
   static void BGWork(void* db);
   void BackgroundCall();
-  void  BackgroundCompaction() EXCLUSIVE_LOCKS_REQUIRED(mutex_);
+  void BackgroundCompaction() EXCLUSIVE_LOCKS_REQUIRED(mutex_);
   void CleanupCompaction(CompactionState* compact)
       EXCLUSIVE_LOCKS_REQUIRED(mutex_);
   Status DoCompactionWork(CompactionState* compact)
@@ -118,93 +151,66 @@ class DBImpl : public DB {
   Status InstallCompactionResults(CompactionState* compact)
       EXCLUSIVE_LOCKS_REQUIRED(mutex_);
 
+  const Comparator* user_comparator() const {
+    return internal_comparator_.user_comparator();
+  }
+
   // Constant after construction
   Env* const env_;
   const InternalKeyComparator internal_comparator_;
   const InternalFilterPolicy internal_filter_policy_;
   const Options options_;  // options_.comparator == &internal_comparator_
-  bool owns_info_log_;
-  bool owns_cache_;
+  const bool owns_info_log_;
+  const bool owns_cache_;
   const std::string dbname_;
 
   // table_cache_ provides its own synchronization
-  TableCache* table_cache_;
+  TableCache* const table_cache_;
 
-  // Lock over the persistent DB state.  Non-NULL iff successfully acquired.
+  // Lock over the persistent DB state.  Non-null iff successfully acquired.
   FileLock* db_lock_;
 
   // State below is protected by mutex_
   port::Mutex mutex_;
-  port::AtomicPointer shutting_down_;
-  port::CondVar bg_cv_;          // Signalled when background work finishes
+  std::atomic<bool> shutting_down_;
+  port::CondVar background_work_finished_signal_ GUARDED_BY(mutex_);
   MemTable* mem_;
-  MemTable* imm_;                // Memtable being compacted
-  port::AtomicPointer has_imm_;  // So bg thread can detect non-NULL imm_
+  MemTable* imm_ GUARDED_BY(mutex_);  // Memtable being compacted
+  std::atomic<bool> has_imm_;         // So bg thread can detect non-null imm_
   WritableFile* logfile_;
-  uint64_t logfile_number_;
+  uint64_t logfile_number_ GUARDED_BY(mutex_);
   log::Writer* log_;
-  uint32_t seed_;                // For sampling.
+  uint32_t seed_ GUARDED_BY(mutex_);  // For sampling.
 
   // Queue of writers.
-  std::deque<Writer*> writers_;
-  WriteBatch* tmp_batch_;
+  std::deque<Writer*> writers_ GUARDED_BY(mutex_);
+  WriteBatch* tmp_batch_ GUARDED_BY(mutex_);
 
-  SnapshotList snapshots_;
+  SnapshotList snapshots_ GUARDED_BY(mutex_);
 
   // Set of table files to protect from deletion because they are
   // part of ongoing compactions.
-  std::set<uint64_t> pending_outputs_;
+  std::set<uint64_t> pending_outputs_ GUARDED_BY(mutex_);
 
   // Has a background compaction been scheduled or is running?
-  bool bg_compaction_scheduled_;
+  bool background_compaction_scheduled_ GUARDED_BY(mutex_);
 
-  // Information for a manual compaction
-  struct ManualCompaction {
-    int level;
-    bool done;
-    const InternalKey* begin;   // NULL means beginning of key range
-    const InternalKey* end;     // NULL means end of key range
-    InternalKey tmp_storage;    // Used to keep track of compaction progress
-  };
-  ManualCompaction* manual_compaction_;
+  ManualCompaction* manual_compaction_ GUARDED_BY(mutex_);
 
-  VersionSet* versions_;
+  VersionSet* const versions_ GUARDED_BY(mutex_);
 
   // Have we encountered a background error in paranoid mode?
-  Status bg_error_;
-
-  // Per level compaction stats.  stats_[level] stores the stats for
-  // compactions that produced data for the specified "level".
-  struct CompactionStats {
-    int64_t micros;
-    int64_t bytes_read;
-    int64_t bytes_written;
-
-    CompactionStats() : micros(0), bytes_read(0), bytes_written(0) { }
+  Status bg_error_ GUARDED_BY(mutex_);
 
-    void Add(const CompactionStats& c) {
-      this->micros += c.micros;
-      this->bytes_read += c.bytes_read;
-      this->bytes_written += c.bytes_written;
-    }
-  };
-  CompactionStats stats_[config::kNumLevels];
-
-  // No copying allowed
-  DBImpl(const DBImpl&);
-  void operator=(const DBImpl&);
-
-  const Comparator* user_comparator() const {
-    return internal_comparator_.user_comparator();
-  }
+  CompactionStats stats_[config::kNumLevels] GUARDED_BY(mutex_);
 };
 
 // Sanitize db options.  The caller should delete result.info_log if
 // it is not equal to src.info_log.
-extern Options SanitizeOptions(const std::string& db,
-                               const InternalKeyComparator* icmp,
-                               const InternalFilterPolicy* ipolicy,
-                               const Options& src);
+Options SanitizeOptions(const std::string& db,
+                        const InternalKeyComparator* icmp,
+                        const InternalFilterPolicy* ipolicy,
+                        const Options& src);
 
 }  // namespace leveldb