Fixing broken Mac build

Summary: Made some small changes to fix the broken mac build

Test Plan: make check all in both linux and mac. All tests pass.

Reviewers: sdong, igor, ljin, yhchiang

Reviewed By: ljin, yhchiang

Subscribers: leveldb

Differential Revision: https://reviews.facebook.net/D20895

table/cuckoo_table_builder.cc

@@ -274,6 +274,16 @@ uint64_t CuckooTableBuilder::FileSize() const {
   }
 }
 
+// This method is invoked when there is no place to insert the target key.
+// It searches for a set of elements that can be moved to accommodate target
+// key. The search is a BFS graph traversal with first level (hash_vals)
+// being all the buckets target key could go to.
+// Then, from each node (curr_node), we find all the buckets that curr_node
+// could go to. They form the children of curr_node in the tree.
+// We continue the traversal until we find an empty bucket, in which case, we
+// move all elements along the path from first level to this empty bucket, to
+// make space for target key which is inserted at first level (*bucket_id).
+// If tree depth exceedes max depth, we return false indicating failure.
 bool CuckooTableBuilder::MakeSpaceForKey(const Slice& key,
     uint64_t *bucket_id, autovector<uint64_t> hash_vals) {
   struct CuckooNode {
@@ -331,23 +341,21 @@ bool CuckooTableBuilder::MakeSpaceForKey(const Slice& key,
   }
 
   if (null_found) {
+    // There is an empty node in tree.back(). Now, traverse the path from this
+    // empty node to top of the tree and at every node in the path, replace
+    // child with the parent. Stop when first level is reached in the tree
+    // (happens when 0 <= bucket_to_replace_pos < num_hash_table_) and return
+    // this location in first level for target key to be inserted.
     uint32_t bucket_to_replace_pos = tree.size()-1;
-    while (bucket_to_replace_pos >= 0) {
+    while (bucket_to_replace_pos >= num_hash_table_) {
       CuckooNode& curr_node = tree[bucket_to_replace_pos];
-      if (bucket_to_replace_pos >= num_hash_table_) {
-        buckets_[curr_node.bucket_id] =
-          buckets_[tree[curr_node.parent_pos].bucket_id];
-        bucket_to_replace_pos = curr_node.parent_pos;
-      } else {
-        *bucket_id = curr_node.bucket_id;
-        return true;
-      }
+      buckets_[curr_node.bucket_id] =
+        buckets_[tree[curr_node.parent_pos].bucket_id];
+      bucket_to_replace_pos = curr_node.parent_pos;
     }
-    assert(false);
-    return true;
-  } else {
-    return false;
+    *bucket_id = tree[bucket_to_replace_pos].bucket_id;
   }
+  return null_found;
 }
 
 }  // namespace rocksdb

table/cuckoo_table_reader.cc

@@ -24,7 +24,6 @@ CuckooTableReader::CuckooTableReader(
     uint64_t file_size,
     uint64_t (*GetSliceHashPtr)(const Slice&, uint32_t, uint64_t))
     : file_(std::move(file)),
-      file_size_(file_size),
       GetSliceHash(GetSliceHashPtr) {
   if (!options.allow_mmap_reads) {
     status_ = Status::InvalidArgument("File is not mmaped");

table/cuckoo_table_reader.h

@@ -53,7 +53,6 @@ class CuckooTableReader: public TableReader {
  private:
   std::unique_ptr<RandomAccessFile> file_;
   Slice file_data_;
-  const uint64_t file_size_;
   bool is_last_level_;
   std::shared_ptr<const TableProperties> table_props_;
   Status status_;

table/cuckoo_table_reader_test.cc

@@ -11,6 +11,8 @@ int main() {
 }
 #else
 
+#define __STDC_FORMAT_MACROS
+#include <inttypes.h>
 #include <gflags/gflags.h>
 #include <vector>
 #include <string>
@@ -304,8 +306,8 @@ void BM_CuckooRead(uint64_t num, uint32_t key_length,
     reader.GetTableProperties()->user_collected_properties;
   const uint32_t num_hash_fun = *reinterpret_cast<const uint32_t*>(
       user_props.at(CuckooTablePropertyNames::kNumHashTable).data());
-  fprintf(stderr, "With %lu items and hash table ratio %f, number of hash"
-      " functions used: %u.\n", num, hash_ratio, num_hash_fun);
+  fprintf(stderr, "With %" PRIu64 " items and hash table ratio %f, number of"
+      " hash functions used: %u.\n", num, hash_ratio, num_hash_fun);
   ReadOptions r_options;
   for (auto& key : keys) {
     int cnt = 0;

util/statistics.cc

@@ -4,6 +4,9 @@
 //  of patent rights can be found in the PATENTS file in the same directory.
 //
 #include "util/statistics.h"
+
+#define __STDC_FORMAT_MACROS
+#include <inttypes.h>
 #include "rocksdb/statistics.h"
 #include "port/likely.h"
 #include <algorithm>
@@ -96,7 +99,7 @@ std::string StatisticsImpl::ToString() const {
   for (const auto& t : TickersNameMap) {
     if (t.first < TICKER_ENUM_MAX || enable_internal_stats_) {
       char buffer[kBufferSize];
-      snprintf(buffer, kBufferSize, "%s COUNT : %ld\n",
+      snprintf(buffer, kBufferSize, "%s COUNT : %" PRIu64 "\n",
                t.second.c_str(), getTickerCount(t.first));
       res.append(buffer);
     }