[column families] Implement DB::OpenWithColumnFamilies()

Summary:
In addition to implementing OpenWithColumnFamilies, this diff also includes some minor changes:
* Changed all column family names from Slice() to std::string. The performance of column family name handling is not critical, and it's more convenient and cleaner to have names as std::strings
* Implemented ColumnFamilyOptions(const Options&) and DBOptions(const Options&)
* Added ColumnFamilyOptions to VersionSet::ColumnFamilyData. ColumnFamilyOptions are specified on OpenWithColumnFamilies() and CreateColumnFamily()

I will keep the diff in the Phabricator for a day or two and will push to the branch then. Feel free to comment even after the diff has been pushed.

Test Plan: Added a simple unit test

Reviewers: dhruba, haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D15033

db/column_family_test.cc

@@ -33,8 +33,15 @@ class ColumnFamilyTest {
     db_ = nullptr;
   }
 
-  void Open() {
-    ASSERT_OK(DB::Open(options_, dbname_, &db_));
+  Status Open(vector<string> cf) {
+    vector<ColumnFamilyDescriptor> column_families;
+    for (auto x : cf) {
+      column_families.push_back(
+          ColumnFamilyDescriptor(x, ColumnFamilyOptions()));
+    }
+    vector <ColumnFamilyHandle> handles;
+    return DB::OpenWithColumnFamilies(db_options_, dbname_, column_families,
+                                      &handles, &db_);
   }
 
   Options options_;
@@ -45,25 +52,26 @@ class ColumnFamilyTest {
 };
 
 TEST(ColumnFamilyTest, AddDrop) {
-  Open();
+  ASSERT_OK(Open({"default"}));
   ColumnFamilyHandle handles[4];
-  ASSERT_OK(db_->CreateColumnFamily(column_family_options_, Slice("one"),
-                                    &handles[0]));
-  ASSERT_OK(db_->CreateColumnFamily(column_family_options_, Slice("two"),
-                                    &handles[1]));
-  ASSERT_OK(db_->CreateColumnFamily(column_family_options_, Slice("three"),
-                                    &handles[2]));
+  ASSERT_OK(
+      db_->CreateColumnFamily(column_family_options_, "one", &handles[0]));
+  ASSERT_OK(
+      db_->CreateColumnFamily(column_family_options_, "two", &handles[1]));
+  ASSERT_OK(
+      db_->CreateColumnFamily(column_family_options_, "three", &handles[2]));
   ASSERT_OK(db_->DropColumnFamily(handles[1]));
-  ASSERT_OK(db_->CreateColumnFamily(column_family_options_, Slice("four"),
-                                    &handles[3]));
+  ASSERT_OK(
+      db_->CreateColumnFamily(column_family_options_, "four", &handles[3]));
   Close();
-  Open(); // this will roll the manifest, column families should stay consistent
+  ASSERT_TRUE(Open({"default"}).IsInvalidArgument());
+  ASSERT_OK(Open({"default", "one", "three", "four"}));
   Close();
 
   vector<string> families;
   DB::ListColumnFamilies(db_options_, dbname_, &families);
   sort(families.begin(), families.end());
-  ASSERT_TRUE(families == vector<string>({"four", "one", "three"}));
+  ASSERT_TRUE(families == vector<string>({"default", "four", "one", "three"}));
 }
 
 }  // namespace rocksdb

db/db_impl.cc

@@ -60,7 +60,7 @@
 
 namespace rocksdb {
 
-const Slice& default_column_family_name("default");
+const std::string default_column_family_name("default");
 
 void dumpLeveldbBuildVersion(Logger * log);
 
@@ -843,8 +843,10 @@ void DBImpl::PurgeObsoleteWALFiles() {
 
 // If externalTable is set, then apply recovered transactions
 // to that table. This is used for readonly mode.
-Status DBImpl::Recover(VersionEdit* edit, MemTable* external_table,
-    bool error_if_log_file_exist) {
+Status DBImpl::Recover(
+    VersionEdit* edit,
+    const std::vector<ColumnFamilyDescriptor>& column_families,
+    MemTable* external_table, bool error_if_log_file_exist) {
   mutex_.AssertHeld();
 
   assert(db_lock_ == nullptr);
@@ -894,6 +896,19 @@ Status DBImpl::Recover(VersionEdit* edit, MemTable* external_table,
 
   Status s = versions_->Recover();
   if (s.ok()) {
+    if (column_families.size() != versions_->column_families_.size()) {
+      return Status::InvalidArgument("Column family specifications mismatch");
+    }
+    for (auto cf : column_families) {
+      auto cf_iter = versions_->column_families_.find(cf.name);
+      if (cf_iter == versions_->column_families_.end()) {
+        return Status::InvalidArgument("Column family specifications mismatch");
+      }
+      auto cf_data_iter = versions_->column_family_data_.find(cf_iter->second);
+      assert(cf_data_iter != versions_->column_family_data_.end());
+      cf_data_iter->second.options = cf.options;
+    }
+
     SequenceNumber max_sequence(0);
 
     // Recover from all newer log files than the ones named in the
@@ -2862,15 +2877,23 @@ std::vector<Status> DBImpl::MultiGet(
 }
 
 Status DBImpl::CreateColumnFamily(const ColumnFamilyOptions& options,
-                                  const Slice& column_family,
+                                  const std::string& column_family_name,
                                   ColumnFamilyHandle* handle) {
   VersionEdit edit(0);
-  edit.AddColumnFamily(column_family.ToString());
+  edit.AddColumnFamily(column_family_name);
   MutexLock l(&mutex_);
   ++versions_->max_column_family_;
   handle->id = versions_->max_column_family_;
   edit.SetColumnFamily(handle->id);
-  return versions_->LogAndApply(&edit, &mutex_);
+  Status s = versions_->LogAndApply(&edit, &mutex_);
+  if (s.ok()) {
+    // add to internal data structures
+    versions_->column_families_[column_family_name] = handle->id;
+    versions_->column_family_data_.insert(
+        {handle->id,
+         VersionSet::ColumnFamilyData(column_family_name, options)});
+  }
+  return s;
 }
 
 Status DBImpl::DropColumnFamily(const ColumnFamilyHandle& column_family) {
@@ -2878,7 +2901,19 @@ Status DBImpl::DropColumnFamily(const ColumnFamilyHandle& column_family) {
   edit.DropColumnFamily();
   edit.SetColumnFamily(column_family.id);
   MutexLock l(&mutex_);
-  return versions_->LogAndApply(&edit, &mutex_);
+  auto data_iter = versions_->column_family_data_.find(column_family.id);
+  if (data_iter == versions_->column_family_data_.end()) {
+    return Status::NotFound("Column family not found");
+  }
+  Status s = versions_->LogAndApply(&edit, &mutex_);
+  if (s.ok()) {
+    // remove from internal data structures
+    auto cf_iter = versions_->column_families_.find(data_iter->second.name);
+    assert(cf_iter != versions_->column_families_.end());
+    versions_->column_families_.erase(cf_iter);
+    versions_->column_family_data_.erase(data_iter);
+  }
+  return s;
 }
 
 bool DBImpl::KeyMayExist(const ReadOptions& options,
@@ -3803,7 +3838,7 @@ Status DB::Merge(const WriteOptions& opt,
 
 // Default implementation -- returns not supported status
 Status DB::CreateColumnFamily(const ColumnFamilyOptions& options,
-                              const Slice& column_family,
+                              const std::string& column_family_name,
                               ColumnFamilyHandle* handle) {
   return Status::NotSupported("");
 }
@@ -3814,8 +3849,33 @@ Status DB::DropColumnFamily(const ColumnFamilyHandle& column_family) {
 DB::~DB() { }
 
 Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) {
+  DBOptions db_options(options);
+  ColumnFamilyOptions cf_options(options);
+  std::vector<ColumnFamilyDescriptor> column_families;
+  column_families.push_back(
+      ColumnFamilyDescriptor(default_column_family_name, cf_options));
+  std::vector<ColumnFamilyHandle> handles;
+  return DB::OpenWithColumnFamilies(db_options, dbname, column_families,
+                                    &handles, dbptr);
+}
+
+Status DB::OpenWithColumnFamilies(
+    const DBOptions& db_options, const std::string& dbname,
+    const std::vector<ColumnFamilyDescriptor>& column_families,
+    std::vector<ColumnFamilyHandle>* handles, DB** dbptr) {
   *dbptr = nullptr;
   EnvOptions soptions;
+  // TODO temporary until we change DBImpl to accept
+  // DBOptions instead of Options
+  ColumnFamilyOptions default_column_family_options;
+  for (auto cfd : column_families) {
+    if (cfd.name == default_column_family_name) {
+      default_column_family_options = cfd.options;
+      break;
+    }
+  }
+  // default options
+  Options options(db_options, default_column_family_options);
 
   if (options.block_cache != nullptr && options.no_block_cache) {
     return Status::InvalidArgument(
@@ -3836,7 +3896,8 @@ Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) {
   }
   impl->mutex_.Lock();
   VersionEdit edit(impl->NumberLevels());
-  s = impl->Recover(&edit); // Handles create_if_missing, error_if_exists
+  // Handles create_if_missing, error_if_exists
+  s = impl->Recover(&edit, column_families);
   if (s.ok()) {
     uint64_t new_log_number = impl->versions_->NewFileNumber();
     unique_ptr<WritableFile> lfile;
@@ -3854,6 +3915,13 @@ Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) {
       s = impl->versions_->LogAndApply(&edit, &impl->mutex_);
     }
     if (s.ok()) {
+      // set column family handles
+      handles->clear();
+      for (auto cf : column_families) {
+        auto cf_iter = impl->versions_->column_families_.find(cf.name);
+        assert(cf_iter != impl->versions_->column_families_.end());
+        handles->push_back(ColumnFamilyHandle(cf_iter->second));
+      }
       delete impl->InstallSuperVersion(new DBImpl::SuperVersion());
       impl->mem_->SetLogNumber(impl->logfile_number_);
       impl->DeleteObsoleteFiles();
@@ -3878,19 +3946,12 @@ Status DB::Open(const Options& options, const std::string& dbname, DB** dbptr) {
   if (s.ok()) {
     *dbptr = impl;
   } else {
+    handles->clear();
     delete impl;
   }
   return s;
 }
 
-Status DB::OpenWithColumnFamilies(
-    const DBOptions& db_options, const std::string& name,
-    const std::vector<ColumnFamilyDescriptor>& column_families,
-    std::vector<ColumnFamilyHandle>* handles, DB** dbptr) {
-  // TODO
-  return Status::NotSupported("Working on it");
-}
-
 Status DB::ListColumnFamilies(const DBOptions& db_options,
                               const std::string& name,
                               std::vector<std::string>* column_families) {

db/db_impl.h

@@ -62,7 +62,7 @@ class DBImpl : public DB {
       const std::vector<Slice>& keys, std::vector<std::string>* values);
 
   virtual Status CreateColumnFamily(const ColumnFamilyOptions& options,
-                                    const Slice& column_family,
+                                    const std::string& column_family,
                                     ColumnFamilyHandle* handle);
   virtual Status DropColumnFamily(const ColumnFamilyHandle& column_family);
 
@@ -293,7 +293,9 @@ class DBImpl : public DB {
   // Recover the descriptor from persistent storage.  May do a significant
   // amount of work to recover recently logged updates.  Any changes to
   // be made to the descriptor are added to *edit.
-  Status Recover(VersionEdit* edit, MemTable* external_table = nullptr,
+  Status Recover(VersionEdit* edit,
+                 const std::vector<ColumnFamilyDescriptor>& column_families,
+                 MemTable* external_table = nullptr,
                  bool error_if_log_file_exist = false);
 
   void MaybeIgnoreError(Status* s) const;

db/db_impl_readonly.cc

@@ -86,7 +86,12 @@ Status DB::OpenForReadOnly(const Options& options, const std::string& dbname,
   DBImplReadOnly* impl = new DBImplReadOnly(options, dbname);
   impl->mutex_.Lock();
   VersionEdit edit(impl->NumberLevels());
-  Status s = impl->Recover(&edit, impl->GetMemTable(),
+  DBOptions db_options(options);
+  ColumnFamilyOptions cf_options(options);
+  std::vector<ColumnFamilyDescriptor> column_families;
+  column_families.push_back(
+      ColumnFamilyDescriptor(default_column_family_name, cf_options));
+  Status s = impl->Recover(&edit, column_families, impl->GetMemTable(),
                            error_if_log_file_exist);
   impl->mutex_.Unlock();
   if (s.ok()) {

db/version_set.cc

@@ -1443,6 +1443,11 @@ Status VersionSet::Recover() {
   uint64_t prev_log_number = 0;
   Builder builder(this, current_);
 
+  // add default column family
+  column_families_.insert({default_column_family_name, 0});
+  column_family_data_.insert(
+      {0, ColumnFamilyData(default_column_family_name)});
+
   {
     LogReporter reporter;
     reporter.status = &s;
@@ -1847,6 +1852,11 @@ Status VersionSet::WriteSnapshot(log::Writer* log) {
   // Save column families
   for (auto cf : column_families_) {
     VersionEdit edit(0);
+    if (cf.second == 0) {
+      // default column family is always there,
+      // no need to explicitly write it
+      continue;
+    }
     edit.AddColumnFamily(cf.first);
     edit.SetColumnFamily(cf.second);
     std::string record;

db/version_set.h

@@ -439,7 +439,11 @@ class VersionSet {
   // column family metadata
   struct ColumnFamilyData {
     std::string name;
+    ColumnFamilyOptions options;
     explicit ColumnFamilyData(const std::string& name) : name(name) {}
+    ColumnFamilyData(const std::string& name,
+                     const ColumnFamilyOptions& options)
+        : name(name), options(options) {}
   };
   std::unordered_map<std::string, uint32_t> column_families_;
   std::unordered_map<uint32_t, ColumnFamilyData> column_family_data_;

include/rocksdb/column_family.h

@@ -26,6 +26,6 @@ struct ColumnFamilyHandle {
 };
 
 const ColumnFamilyHandle default_column_family = ColumnFamilyHandle();
-extern const Slice& default_column_family_name;
+extern const std::string default_column_family_name;
 
 }

include/rocksdb/db.h

@@ -13,6 +13,7 @@
 #include <stdio.h>
 #include <memory>
 #include <vector>
+#include <string>
 #include "rocksdb/iterator.h"
 #include "rocksdb/options.h"
 #include "rocksdb/types.h"
@@ -26,8 +27,11 @@ struct ColumnFamilyHandle;
 extern const ColumnFamilyHandle default_column_family;
 
 struct ColumnFamilyDescriptor {
-  Slice name;
+  std::string name;
   ColumnFamilyOptions options;
+  ColumnFamilyDescriptor(const std::string& name,
+                         const ColumnFamilyOptions& options)
+      : name(name), options(options) {}
 };
 
 // Update Makefile if you change these
@@ -117,7 +121,7 @@ class DB {
   // Create a column_family and return the handle of column family
   // through the argument handle.
   virtual Status CreateColumnFamily(const ColumnFamilyOptions& options,
-                                    const Slice& column_family,
+                                    const std::string& column_family_name,
                                     ColumnFamilyHandle* handle);
 
   // Drop a column family specified by column_family handle.

include/rocksdb/options.h

@@ -68,6 +68,8 @@ struct CompressionOptions {
                                                        strategy(strategy){}
 };
 
+struct Options;
+
 struct ColumnFamilyOptions {
   // -------------------
   // Parameters that affect behavior
@@ -426,6 +428,8 @@ struct ColumnFamilyOptions {
 
   // Create ColumnFamilyOptions with default values for all fields
   ColumnFamilyOptions();
+  // Create ColumnFamilyOptions from Options
+  explicit ColumnFamilyOptions(const Options& options);
 };
 
 struct DBOptions {
@@ -627,6 +631,8 @@ struct DBOptions {
 
   // Create DBOptions with default values for all fields
   DBOptions();
+  // Create DBOptions from Options
+  explicit DBOptions(const Options& options);
 };
 
 // Options to control the behavior of a database (passed to DB::Open)

util/options.cc

@@ -73,6 +73,65 @@ ColumnFamilyOptions::ColumnFamilyOptions()
   assert(memtable_factory.get() != nullptr);
 }
 
+ColumnFamilyOptions::ColumnFamilyOptions(const Options& options)
+    : comparator(options.comparator),
+      merge_operator(options.merge_operator),
+      compaction_filter(options.compaction_filter),
+      compaction_filter_factory(options.compaction_filter_factory),
+      write_buffer_size(options.write_buffer_size),
+      max_write_buffer_number(options.max_write_buffer_number),
+      min_write_buffer_number_to_merge(
+          options.min_write_buffer_number_to_merge),
+      block_cache(options.block_cache),
+      block_cache_compressed(options.block_cache_compressed),
+      block_size(options.block_size),
+      block_restart_interval(options.block_restart_interval),
+      compression(options.compression),
+      compression_per_level(options.compression_per_level),
+      compression_opts(options.compression_opts),
+      filter_policy(options.filter_policy),
+      prefix_extractor(options.prefix_extractor),
+      whole_key_filtering(options.whole_key_filtering),
+      num_levels(options.num_levels),
+      level0_file_num_compaction_trigger(
+          options.level0_file_num_compaction_trigger),
+      level0_slowdown_writes_trigger(options.level0_slowdown_writes_trigger),
+      level0_stop_writes_trigger(options.level0_stop_writes_trigger),
+      max_mem_compaction_level(options.max_mem_compaction_level),
+      target_file_size_base(options.target_file_size_base),
+      target_file_size_multiplier(options.target_file_size_multiplier),
+      max_bytes_for_level_base(options.max_bytes_for_level_base),
+      max_bytes_for_level_multiplier(options.max_bytes_for_level_multiplier),
+      max_bytes_for_level_multiplier_additional(
+          options.max_bytes_for_level_multiplier_additional),
+      expanded_compaction_factor(options.expanded_compaction_factor),
+      source_compaction_factor(options.source_compaction_factor),
+      max_grandparent_overlap_factor(options.max_grandparent_overlap_factor),
+      disable_seek_compaction(options.disable_seek_compaction),
+      soft_rate_limit(options.soft_rate_limit),
+      hard_rate_limit(options.hard_rate_limit),
+      rate_limit_delay_max_milliseconds(
+          options.rate_limit_delay_max_milliseconds),
+      no_block_cache(options.no_block_cache),
+      table_cache_numshardbits(options.table_cache_numshardbits),
+      table_cache_remove_scan_count_limit(
+          options.table_cache_remove_scan_count_limit),
+      disable_auto_compactions(options.disable_auto_compactions),
+      purge_redundant_kvs_while_flush(options.purge_redundant_kvs_while_flush),
+      block_size_deviation(options.block_size_deviation),
+      compaction_style(options.compaction_style),
+      compaction_options_universal(options.compaction_options_universal),
+      filter_deletes(options.filter_deletes),
+      max_sequential_skip_in_iterations(
+          options.max_sequential_skip_in_iterations),
+      memtable_factory(options.memtable_factory),
+      table_factory(options.table_factory),
+      table_properties_collectors(options.table_properties_collectors),
+      inplace_update_support(options.inplace_update_support),
+      inplace_update_num_locks(options.inplace_update_num_locks) {
+  assert(memtable_factory.get() != nullptr);
+}
+
 DBOptions::DBOptions()
     : create_if_missing(false),
       error_if_exists(false),
@@ -107,6 +166,42 @@ DBOptions::DBOptions()
       use_adaptive_mutex(false),
       bytes_per_sync(0) { }
 
+DBOptions::DBOptions(const Options& options)
+    : create_if_missing(options.create_if_missing),
+      error_if_exists(options.error_if_exists),
+      paranoid_checks(options.paranoid_checks),
+      env(options.env),
+      info_log(options.info_log),
+      max_open_files(options.max_open_files),
+      statistics(options.statistics),
+      disableDataSync(options.disableDataSync),
+      use_fsync(options.use_fsync),
+      db_stats_log_interval(options.db_stats_log_interval),
+      db_log_dir(options.db_log_dir),
+      wal_dir(options.wal_dir),
+      delete_obsolete_files_period_micros(
+          options.delete_obsolete_files_period_micros),
+      max_background_compactions(options.max_background_compactions),
+      max_background_flushes(options.max_background_flushes),
+      max_log_file_size(options.max_log_file_size),
+      log_file_time_to_roll(options.log_file_time_to_roll),
+      keep_log_file_num(options.keep_log_file_num),
+      max_manifest_file_size(options.max_manifest_file_size),
+      arena_block_size(options.arena_block_size),
+      WAL_ttl_seconds(options.WAL_ttl_seconds),
+      WAL_size_limit_MB(options.WAL_size_limit_MB),
+      manifest_preallocation_size(options.manifest_preallocation_size),
+      allow_os_buffer(options.allow_os_buffer),
+      allow_mmap_reads(options.allow_mmap_reads),
+      allow_mmap_writes(options.allow_mmap_writes),
+      is_fd_close_on_exec(options.is_fd_close_on_exec),
+      skip_log_error_on_recovery(options.skip_log_error_on_recovery),
+      stats_dump_period_sec(options.stats_dump_period_sec),
+      advise_random_on_open(options.advise_random_on_open),
+      access_hint_on_compaction_start(options.access_hint_on_compaction_start),
+      use_adaptive_mutex(options.use_adaptive_mutex),
+      bytes_per_sync(options.bytes_per_sync) {}
+
 static const char* const access_hints[] = {
   "NONE", "NORMAL", "SEQUENTIAL", "WILLNEED"
 };