When Options.max_num_files=-1, non level0 files also by pass table cache

Summary:
This is the part that was not finished when doing the Options.max_num_files=-1 feature. For iterating non level0 SST files (which was done using two level iterator), table cache is not bypassed. With this patch, the leftover feature is done.

Test Plan: make all check; change Options.max_num_files=-1 in one of the tests to cover the codes.

Reviewers: haobo, igor, dhruba, ljin, yhchiang

Reviewed By: haobo

CC: leveldb

Differential Revision: https://reviews.facebook.net/D17001

db/db_test.cc

@@ -3330,6 +3330,7 @@ TEST(DBTest, InPlaceUpdateCallbackNoAction) {
 
 TEST(DBTest, CompactionFilter) {
   Options options = CurrentOptions();
+  options.max_open_files = -1;
   options.num_levels = 3;
   options.max_mem_compaction_level = 0;
   options.compaction_filter_factory = std::make_shared<KeepFilterFactory>();

db/table_cache.cc

@@ -192,17 +192,27 @@ Status TableCache::GetTableProperties(
 
 bool TableCache::PrefixMayMatch(const ReadOptions& options,
                                 const InternalKeyComparator& icomparator,
-                                uint64_t file_number, uint64_t file_size,
+                                const FileMetaData& file_meta,
                                 const Slice& internal_prefix, bool* table_io) {
-  Cache::Handle* handle = nullptr;
-  Status s = FindTable(storage_options_, icomparator, file_number, file_size,
-                       &handle, table_io);
   bool may_match = true;
-  if (s.ok()) {
-    TableReader* t = GetTableReaderFromHandle(handle);
-    may_match = t->PrefixMayMatch(internal_prefix);
-    ReleaseHandle(handle);
+  auto table_handle = file_meta.table_reader_handle;
+  if (table_handle == nullptr) {
+    // Need to get table handle from file number
+    Status s = FindTable(storage_options_, icomparator, file_meta.number,
+                         file_meta.file_size, &table_handle, table_io);
+    if (!s.ok()) {
+      return may_match;
+    }
   }
+
+  auto table = GetTableReaderFromHandle(table_handle);
+  may_match = table->PrefixMayMatch(internal_prefix);
+
+  if (file_meta.table_reader_handle == nullptr) {
+    // Need to release handle if it is generated from here.
+    ReleaseHandle(table_handle);
+  }
+
   return may_match;
 }
 

db/table_cache.h

@@ -58,7 +58,7 @@ class TableCache {
   // the table index or blooms are not in memory, this may cause an I/O
   bool PrefixMayMatch(const ReadOptions& options,
                       const InternalKeyComparator& internal_comparator,
-                      uint64_t file_number, uint64_t file_size,
+                      const FileMetaData& file_meta,
                       const Slice& internal_prefix, bool* table_io);
 
   // Evict any entry for the specified file number

db/version_set.cc

@@ -181,18 +181,14 @@ class Version::LevelFileNumIterator : public Iterator {
   }
   Slice value() const {
     assert(Valid());
-    EncodeFixed64(value_buf_, (*flist_)[index_]->number);
-    EncodeFixed64(value_buf_+8, (*flist_)[index_]->file_size);
-    return Slice(value_buf_, sizeof(value_buf_));
+    return Slice(reinterpret_cast<const char*>((*flist_)[index_]),
+                 sizeof(FileMetaData));
   }
   virtual Status status() const { return Status::OK(); }
  private:
   const InternalKeyComparator icmp_;
   const std::vector<FileMetaData*>* const flist_;
   uint32_t index_;
-
-  // Backing store for value().  Holds the file number and size.
-  mutable char value_buf_[16];
 };
 
 static Iterator* GetFileIterator(void* arg, const ReadOptions& options,
@@ -200,7 +196,7 @@ static Iterator* GetFileIterator(void* arg, const ReadOptions& options,
                                  const InternalKeyComparator& icomparator,
                                  const Slice& file_value, bool for_compaction) {
   TableCache* cache = reinterpret_cast<TableCache*>(arg);
-  if (file_value.size() != 16) {
+  if (file_value.size() != sizeof(FileMetaData)) {
     return NewErrorIterator(
         Status::Corruption("FileReader invoked with unexpected value"));
   } else {
@@ -211,11 +207,12 @@ static Iterator* GetFileIterator(void* arg, const ReadOptions& options,
       options_copy = options;
       options_copy.prefix = nullptr;
     }
-    FileMetaData meta(DecodeFixed64(file_value.data()),
-                      DecodeFixed64(file_value.data() + 8));
+
+    const FileMetaData* meta_file =
+        reinterpret_cast<const FileMetaData*>(file_value.data());
     return cache->NewIterator(
-        options.prefix ? options_copy : options, soptions, icomparator, meta,
-        nullptr /* don't need reference to table*/, for_compaction);
+        options.prefix ? options_copy : options, soptions, icomparator,
+        *meta_file, nullptr /* don't need reference to table*/, for_compaction);
   }
 }
 
@@ -234,10 +231,11 @@ bool Version::PrefixMayMatch(const ReadOptions& options,
     // key() will always be the biggest value for this SST?
     may_match = true;
   } else {
+    const FileMetaData* meta_file =
+        reinterpret_cast<const FileMetaData*>(level_iter->value().data());
+
     may_match = vset_->table_cache_->PrefixMayMatch(
-        options, vset_->icmp_, DecodeFixed64(level_iter->value().data()),
-        DecodeFixed64(level_iter->value().data() + 8), internal_prefix,
-        nullptr);
+        options, vset_->icmp_, *meta_file, internal_prefix, nullptr);
   }
   return may_match;
 }