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 the BSD-style license found in the
   3 //  LICENSE file in the root directory of this source tree. An additional grant
   4 //  of patent rights can be found in the PATENTS file in the same 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 {
  13
  14 CompactOnDeletionCollector::CompactOnDeletionCollector(
  15     size_t sliding_window_size,
  16     size_t deletion_trigger) {
  17   deletion_trigger_ = deletion_trigger;
  18
  19   // First, compute the number of keys in each bucket.
  20   bucket_size_ =
  21       (sliding_window_size + kNumBuckets - 1) / kNumBuckets;
  22   assert(bucket_size_ > 0U);
  23
  24   Reset();
  25 }
  26
  27 void CompactOnDeletionCollector::Reset() {
  28   for (int i = 0; i < kNumBuckets; ++i) {
  29     num_deletions_in_buckets_[i] = 0;
  30   }
  31   current_bucket_ = 0;
  32   num_keys_in_current_bucket_ = 0;
  33   num_deletions_in_observation_window_ = 0;
  34   need_compaction_ = false;
  35 }
  36
  37 // AddUserKey() will be called when a new key/value pair is inserted into the
  38 // table.
  39 // @params key    the user key that is inserted into the table.
  40 // @params value  the value that is inserted into the table.
  41 // @params file_size  file size up to now
  42 Status CompactOnDeletionCollector::AddUserKey(
  43     const Slice& key, const Slice& value,
  44     EntryType type, SequenceNumber seq,
  45     uint64_t file_size) {
  46   if (need_compaction_) {
  47     // If the output file already needs to be compacted, skip the check.
  48     return Status::OK();
  49   }
  50
  51   if (num_keys_in_current_bucket_ == bucket_size_) {
  52     // When the current bucket is full, advance the cursor of the
  53     // ring buffer to the next bucket.
  54     current_bucket_ = (current_bucket_ + 1) % kNumBuckets;
  55
  56     // Update the current count of observed deletion keys by excluding
  57     // the number of deletion keys in the oldest bucket in the
  58     // observation window.
  59     assert(num_deletions_in_observation_window_ >=
  60         num_deletions_in_buckets_[current_bucket_]);
  61     num_deletions_in_observation_window_ -=
  62         num_deletions_in_buckets_[current_bucket_];
  63     num_deletions_in_buckets_[current_bucket_] = 0;
  64     num_keys_in_current_bucket_ = 0;
  65   }
  66
  67   num_keys_in_current_bucket_++;
  68   if (type == kEntryDelete) {
  69     num_deletions_in_observation_window_++;
  70     num_deletions_in_buckets_[current_bucket_]++;
  71     if (num_deletions_in_observation_window_ >= deletion_trigger_) {
  72       need_compaction_ = true;
  73     }
  74   }
  75   return Status::OK();
  76 }
  77
  78 TablePropertiesCollector*
  79 CompactOnDeletionCollectorFactory::CreateTablePropertiesCollector(
  80     TablePropertiesCollectorFactory::Context context) {
  81   return new CompactOnDeletionCollector(
  82       sliding_window_size_, deletion_trigger_);
  83 }
  84
  85 std::shared_ptr<TablePropertiesCollectorFactory>
  86     NewCompactOnDeletionCollectorFactory(
  87         size_t sliding_window_size,
  88         size_t deletion_trigger) {
  89   return std::shared_ptr<TablePropertiesCollectorFactory>(
  90       new CompactOnDeletionCollectorFactory(
  91           sliding_window_size, deletion_trigger));
  92 }
  93 }  // namespace rocksdb
  94 #endif  // !ROCKSDB_LITE