From dfa1460d88535bf09aaeffdb6d2bdca513b1dbc2 Mon Sep 17 00:00:00 2001
From: Siying Dong <siying.d@fb.com>
Date: Thu, 21 Nov 2013 23:33:45 -0800
Subject: [PATCH] [For Performance Branch] Bloom filter in
 PlainTableIterator::Seek() - Update 1

Summary:
Address @haobo's comments in D14277

Test Plan: ./indexed_table_db_test

Reviewers: haobo

CC:

Task ID: #

Blame Rev:
---
 include/rocksdb/plain_table_factory.h |  4 ++--
 table/plain_table_reader.cc           | 10 +++++-----
 table/table_reader_bench.cc           |  4 +++-
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/rocksdb/plain_table_factory.h b/include/rocksdb/plain_table_factory.h
index 0d843e2c2..3d26c6e4e 100644
--- a/include/rocksdb/plain_table_factory.h
+++ b/include/rocksdb/plain_table_factory.h
@@ -48,8 +48,8 @@ public:
   ~PlainTableFactory() {
   }
   // user_key_size is the length of the user key. key_prefix_len is the
-  // length of the prefix used for im-memory indexes. bloom_num_bits is
-  // number of bits is used for bloom filer per key. hash_table_ratio is
+  // length of the prefix used for in-memory indexes. bloom_num_bits is
+  // number of bits used for bloom filer per key. hash_table_ratio is
   // the desired ultilization of the hash table used for prefix hashing.
   // hash_table_ratio = number of prefixes / #buckets in the hash table
   PlainTableFactory(int user_key_size, int key_prefix_len,
diff --git a/table/plain_table_reader.cc b/table/plain_table_reader.cc
index 657dc031e..9d0283b22 100644
--- a/table/plain_table_reader.cc
+++ b/table/plain_table_reader.cc
@@ -162,10 +162,10 @@ Status PlainTableReader::PopulateIndex(uint64_t file_size) {
   // Make the hash table 3/5 full
   std::vector<Slice> filter_entries(0); // for creating bloom filter;
   if (filter_policy_ != nullptr) {
-    filter_entries.resize(tmp_index.size());
+    filter_entries.reserve(tmp_index.size());
   }
   double hash_table_size_multipier =
-      (hash_table_ratio_ < 1.0) ? 1.0 : 1.0 / hash_table_ratio_;
+      (hash_table_ratio_ > 1.0) ? 1.0 : 1.0 / hash_table_ratio_;
   hash_table_size_ = tmp_index.size() * hash_table_size_multipier + 1;
   hash_table_ = new char[GetHashTableRecordLen() * hash_table_size_];
   for (int i = 0; i < hash_table_size_; i++) {
@@ -173,10 +173,9 @@ Status PlainTableReader::PopulateIndex(uint64_t file_size) {
            kOffsetLen);
   }
 
-  size_t count = 0;
   for (auto it = tmp_index.begin(); it != tmp_index.end(); ++it) {
     if (filter_policy_ != nullptr) {
-      filter_entries[count++] = it->first;
+      filter_entries.push_back(it->first);
     }
 
     int bucket = GetHashTableBucket(it->first);
@@ -194,7 +193,8 @@ Status PlainTableReader::PopulateIndex(uint64_t file_size) {
     memcpy(bucket_ptr + key_prefix_len_, &it->second, kOffsetLen);
   }
   if (filter_policy_ != nullptr) {
-    filter_policy_->CreateFilter(&filter_entries[0], count, &filter_str_);
+    filter_policy_->CreateFilter(&filter_entries[0], filter_entries.size(),
+                                 &filter_str_);
     filter_slice_ = Slice(filter_str_.data(), filter_str_.size());
   }
 
diff --git a/table/table_reader_bench.cc b/table/table_reader_bench.cc
index a8a344434..7e7e6b7da 100644
--- a/table/table_reader_bench.cc
+++ b/table/table_reader_bench.cc
@@ -242,7 +242,9 @@ int main(int argc, char** argv) {
   if (FLAGS_plain_table) {
     options.allow_mmap_reads = true;
     env_options.use_mmap_reads = true;
-    tf = new rocksdb::PlainTableFactory(16, FLAGS_prefix_len, FLAGS_prefix_len);
+    tf = new rocksdb::PlainTableFactory(16, FLAGS_prefix_len,
+                                        (FLAGS_prefix_len == 16) ? 0 : 8,
+                                        0.75);
   } else {
     tf = new rocksdb::BlockBasedTableFactory();
   }