Add the property block for the plain table

Summary:
This is the last diff that adds the property block to plain table.
The format resembles that of the block-based table: https://github.com/facebook/rocksdb/wiki/Rocksdb-table-format

  [data block]
  [meta block 1: stats block]
  [meta block 2: future extended block]
  ...
  [meta block K: future extended block]  (we may add more meta blocks in the future)
  [metaindex block]
  [index block: we only have the placeholder here, we can add persistent index block in the future]
  [Footer: contains magic number, handle to metaindex block and index block]
  <end_of_file>

Test Plan: extended existing property block test.

Reviewers: haobo, sdong, dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D14523

table/meta_blocks.h

@@ -15,9 +15,11 @@
 
 namespace rocksdb {
 
-class BlockHandle;
 class BlockBuilder;
+class BlockHandle;
+class Env;
 class Logger;
+class RandomAccessFile;
 struct TableProperties;
 
 // An STL style comparator that does the bytewise comparator comparasion
@@ -49,11 +51,6 @@ class MetaIndexBuilder {
   Slice Finish();
 
  private:
-  //   * Key: meta block name
-  //   * Value: block handle to that meta block
-  struct Rep;
-  Rep* rep_;
-
   // store the sorted key/handle of the metablocks.
   BytewiseSortedMap meta_block_handles_;
   std::unique_ptr<BlockBuilder> meta_index_block_;
@@ -103,4 +100,21 @@ bool NotifyCollectTableCollectorsOnFinish(
     Logger* info_log,
     PropertyBlockBuilder* builder);
 
+// Read the properties from the table.
+Status ReadProperties(
+    const Slice& handle_value,
+    RandomAccessFile* file,
+    Env* env,
+    Logger* logger,
+    TableProperties* table_properties);
+
+// Directly read the properties from the properties block of a plain table.
+Status ReadTableProperties(
+    RandomAccessFile* file,
+    uint64_t file_size,
+    uint64_t table_magic_number,
+    Env* env,
+    Logger* info_log,
+    TableProperties* properties);
+
 }  // namespace rocksdb