ceph/src/rocksdb/utilities/table_properties_collectors/compact_on_deletion_collector.cc

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5
   6 #ifndef ROCKSDB_LITE
   7 #include "utilities/table_properties_collectors/compact_on_deletion_collector.h"
   8
   9 #include <memory>
  10 #include "rocksdb/utilities/table_properties_collectors.h"
  11
  12 namespace ROCKSDB_NAMESPACE {
  13
  14 CompactOnDeletionCollector::CompactOnDeletionCollector(
  15     size_t sliding_window_size, size_t deletion_trigger)
  16     : bucket_size_((sliding_window_size + kNumBuckets - 1) / kNumBuckets),
  17       current_bucket_(0),
  18       num_keys_in_current_bucket_(0),
  19       num_deletions_in_observation_window_(0),
  20       deletion_trigger_(deletion_trigger),
  21       need_compaction_(false),
  22       finished_(false) {
  23   memset(num_deletions_in_buckets_, 0, sizeof(size_t) * kNumBuckets);
  24 }
  25
  26 // AddUserKey() will be called when a new key/value pair is inserted into the
  27 // table.
  28 // @params key    the user key that is inserted into the table.
  29 // @params value  the value that is inserted into the table.
  30 // @params file_size  file size up to now
  31 Status CompactOnDeletionCollector::AddUserKey(const Slice& /*key*/,
  32                                               const Slice& /*value*/,
  33                                               EntryType type,
  34                                               SequenceNumber /*seq*/,
  35                                               uint64_t /*file_size*/) {
  36   assert(!finished_);
  37   if (bucket_size_ == 0) {
  38     // This collector is effectively disabled
  39     return Status::OK();
  40   }
  41
  42   if (need_compaction_) {
  43     // If the output file already needs to be compacted, skip the check.
  44     return Status::OK();
  45   }
  46
  47   if (num_keys_in_current_bucket_ == bucket_size_) {
  48     // When the current bucket is full, advance the cursor of the
  49     // ring buffer to the next bucket.
  50     current_bucket_ = (current_bucket_ + 1) % kNumBuckets;
  51
  52     // Update the current count of observed deletion keys by excluding
  53     // the number of deletion keys in the oldest bucket in the
  54     // observation window.
  55     assert(num_deletions_in_observation_window_ >=
  56         num_deletions_in_buckets_[current_bucket_]);
  57     num_deletions_in_observation_window_ -=
  58         num_deletions_in_buckets_[current_bucket_];
  59     num_deletions_in_buckets_[current_bucket_] = 0;
  60     num_keys_in_current_bucket_ = 0;
  61   }
  62
  63   num_keys_in_current_bucket_++;
  64   if (type == kEntryDelete) {
  65     num_deletions_in_observation_window_++;
  66     num_deletions_in_buckets_[current_bucket_]++;
  67     if (num_deletions_in_observation_window_ >= deletion_trigger_) {
  68       need_compaction_ = true;
  69     }
  70   }
  71   return Status::OK();
  72 }
  73
  74 TablePropertiesCollector*
  75 CompactOnDeletionCollectorFactory::CreateTablePropertiesCollector(
  76     TablePropertiesCollectorFactory::Context /*context*/) {
  77   return new CompactOnDeletionCollector(
  78       sliding_window_size_.load(), deletion_trigger_.load());
  79 }
  80
  81 std::shared_ptr<CompactOnDeletionCollectorFactory>
  82     NewCompactOnDeletionCollectorFactory(
  83         size_t sliding_window_size,
  84         size_t deletion_trigger) {
  85   return std::shared_ptr<CompactOnDeletionCollectorFactory>(
  86       new CompactOnDeletionCollectorFactory(
  87           sliding_window_size, deletion_trigger));
  88 }
  89 }  // namespace ROCKSDB_NAMESPACE
  90 #endif  // !ROCKSDB_LITE