table: Fix coverity issues

Summary:
table/block.cc:
420  }

CID 1396127 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
7. uninit_member: Non-static class member restart_offset_ is not initialized in this constructor nor in any functions that it calls.
421}

table/block_based_table_builder.cc:

CID 1418259 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
7. uninit_member: Non-static class member compressed_cache_key_prefix_size is not initialized in this constructor nor in any functions that it calls.

table/block_based_table_reader.h:
   	3. uninit_member: Non-static class member index_type is not initialized in this constructor nor in any functions that it calls.

CID 1396147 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
5. uninit_member: Non-static class member hash_index_allow_collision is not initialized in this constructor nor in any functions that it calls.
413        global_seqno(kDisableGlobalSequenceNumber) {}
414

table/cuckoo_table_reader.cc:
 55  if (hash_funs == user_props.end()) {
 56    status_ = Status::Corruption("Number of hash functions not found");
   	5. uninit_member: Non-static class member is_last_level_ is not initialized in this constructor nor in any functions that it calls.
   	7. uninit_member: Non-static class member identity_as_first_hash_ is not initialized in this constructor nor in any functions that it calls.
   	9. uninit_member: Non-static class member use_module_hash_ is not initialized in this constructor nor in any functions that it calls.
   	11. uninit_member: Non-static class member num_hash_func_ is not initialized in this constructor nor in any functions that it calls.
   	13. uninit_member: Non-static class member key_length_ is not initialized in this constructor nor in any functions that it calls.
   	15. uninit_member: Non-static class member user_key_length_ is not initialized in this constructor nor in any functions that it calls.
   	17. uninit_member: Non-static class member value_length_ is not initialized in this constructor nor in any functions that it calls.
   	19. uninit_member: Non-static class member bucket_length_ is not initialized in this constructor nor in any functions that it calls.
   	21. uninit_member: Non-static class member cuckoo_block_size_ is not initialized in this constructor nor in any functions that it calls.
   	23. uninit_member: Non-static class member cuckoo_block_bytes_minus_one_ is not initialized in this constructor nor in any functions that it calls.

CID 1322785 (#2 of 2): Uninitialized scalar field (UNINIT_CTOR)
25. uninit_member: Non-static class member table_size_ is not initialized in this constructor nor in any functions that it calls.
 57    return;

table/plain_table_index.h:
   	2. uninit_member: Non-static class member index_size_ is not initialized in this constructor nor in any functions that it calls.

CID 1322801 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
4. uninit_member: Non-static class member sub_index_size_ is not initialized in this constructor nor in any functions that it calls.
128        huge_page_tlb_size_(huge_page_tlb_size) {}
129
Closes https://github.com/facebook/rocksdb/pull/3113

Differential Revision: D6505719

Pulled By: yiwu-arbug

fbshipit-source-id: 38f44d8f9dfefb4c2e25d83b8df25a5201c75618

table/block.cc

@@ -402,6 +402,7 @@ Block::Block(BlockContents&& contents, SequenceNumber _global_seqno,
     : contents_(std::move(contents)),
       data_(contents_.data.data()),
       size_(contents_.data.size()),
+      restart_offset_(0),
       global_seqno_(_global_seqno) {
   if (size_ < sizeof(uint32_t)) {
     size_ = 0;  // Error marker

table/block_based_table_builder.cc

@@ -301,6 +301,7 @@ struct BlockBasedTableBuilder::Rep {
         compression_type(_compression_type),
         compression_opts(_compression_opts),
         compression_dict(_compression_dict),
+        compressed_cache_key_prefix_size(0),
         flush_block_policy(
             table_options.flush_block_policy_factory->NewFlushBlockPolicy(
                 table_options, data_block)),

table/block_based_table_reader.h

@@ -407,6 +407,8 @@ struct BlockBasedTable::Rep {
         filter_policy(skip_filters ? nullptr : _table_opt.filter_policy.get()),
         internal_comparator(_internal_comparator),
         filter_type(FilterType::kNoFilter),
+        index_type(BlockBasedTableOptions::IndexType::kBinarySearch),
+        hash_index_allow_collision(false),
         whole_key_filtering(_table_opt.whole_key_filtering),
         prefix_filtering(true),
         range_del_handle(BlockHandle::NullBlockHandle()),

table/cuckoo_table_reader.cc

@@ -38,6 +38,18 @@ CuckooTableReader::CuckooTableReader(
     const Comparator* comparator,
     uint64_t (*get_slice_hash)(const Slice&, uint32_t, uint64_t))
     : file_(std::move(file)),
+      is_last_level_(false),
+      identity_as_first_hash_(false),
+      use_module_hash_(false),
+      num_hash_func_(0),
+      unused_key_(""),
+      key_length_(0),
+      user_key_length_(0),
+      value_length_(0),
+      bucket_length_(0),
+      cuckoo_block_size_(0),
+      cuckoo_block_bytes_minus_one_(0),
+      table_size_(0),
       ucomp_(comparator),
       get_slice_hash_(get_slice_hash) {
   if (!ioptions.allow_mmap_reads) {

table/plain_table_index.h

@@ -123,6 +123,8 @@ class PlainTableIndexBuilder {
         num_keys_per_prefix_(0),
         prev_key_prefix_hash_(0),
         index_sparseness_(index_sparseness),
+        index_size_(0),
+        sub_index_size_(0),
         prefix_extractor_(ioptions.prefix_extractor),
         hash_table_ratio_(hash_table_ratio),
         huge_page_tlb_size_(huge_page_tlb_size) {}