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

db/table_properties_collector_test.cc

@@ -12,7 +12,9 @@
 #include "db/table_properties_collector.h"
 #include "rocksdb/table_properties.h"
 #include "rocksdb/table.h"
+#include "rocksdb/plain_table_factory.h"
 #include "table/block_based_table_factory.h"
+#include "table/meta_blocks.h"
 #include "util/coding.h"
 #include "util/testharness.h"
 #include "util/testutil.h"
@@ -20,8 +22,6 @@
 namespace rocksdb {
 
 class TablePropertiesTest {
- private:
-  unique_ptr<TableReader> table_reader_;
 };
 
 // TODO(kailiu) the following classes should be moved to some more general
@@ -93,22 +93,6 @@ void MakeBuilder(
                                              options.compression));
 }
 
-void OpenTable(
-    const Options& options,
-    const std::string& contents,
-    std::unique_ptr<TableReader>* table_reader) {
-
-  std::unique_ptr<RandomAccessFile> file(new FakeRandomeAccessFile(contents));
-  auto s = options.table_factory->GetTableReader(
-      options,
-      EnvOptions(),
-      std::move(file),
-      contents.size(),
-      table_reader
-  );
-  ASSERT_OK(s);
-}
-
 // Collects keys that starts with "A" in a table.
 class RegularKeysStartWithA: public TablePropertiesCollector {
  public:
@@ -141,9 +125,12 @@ class RegularKeysStartWithA: public TablePropertiesCollector {
   uint32_t count_ = 0;
 };
 
-TEST(TablePropertiesTest, CustomizedTablePropertiesCollector) {
+extern uint64_t kBlockBasedTableMagicNumber;
-  Options options;
+extern uint64_t kPlainTableMagicNumber;
-
+void TestCustomizedTablePropertiesCollector(
+    uint64_t magic_number,
+    bool encode_as_internal,
+    const Options& options) {
   // make sure the entries will be inserted with order.
   std::map<std::string, std::string> kvs = {
     {"About   ", "val5"},  // starts with 'A'
@@ -155,18 +142,7 @@ TEST(TablePropertiesTest, CustomizedTablePropertiesCollector) {
     {"Find    ", "val6"},
   };
 
-  // Test properties collectors with internal keys or regular keys
-  for (bool encode_as_internal : { true, false }) {
   // -- Step 1: build table
-    auto collector = new RegularKeysStartWithA();
-    if (encode_as_internal) {
-      options.table_properties_collectors = {
-        std::make_shared<UserKeyTablePropertiesCollector>(collector)
-      };
-    } else {
-      options.table_properties_collectors.resize(1);
-      options.table_properties_collectors[0].reset(collector);
-    }
   std::unique_ptr<TableBuilder> builder;
   std::unique_ptr<FakeWritableFile> writable;
   MakeBuilder(options, &writable, &builder);
@@ -181,22 +157,65 @@ TEST(TablePropertiesTest, CustomizedTablePropertiesCollector) {
   }
   ASSERT_OK(builder->Finish());
 
-    // -- Step 2: Open table
+  // -- Step 2: Read properties
-    std::unique_ptr<TableReader> table_reader;
+  FakeRandomeAccessFile readable(writable->contents());
-    OpenTable(options, writable->contents(), &table_reader);
+  TableProperties props;
-    const auto& properties =
+  Status s = ReadTableProperties(
-      table_reader->GetTableProperties().user_collected_properties;
+      &readable,
+      writable->contents().size(),
+      magic_number,
+      Env::Default(),
+      nullptr,
+      &props
+  );
+  ASSERT_OK(s);
+
+  auto user_collected = props.user_collected_properties;
 
-    ASSERT_EQ("Rocksdb", properties.at("TablePropertiesTest"));
+  ASSERT_EQ("Rocksdb", user_collected.at("TablePropertiesTest"));
 
   uint32_t starts_with_A = 0;
-    Slice key(properties.at("Count"));
+  Slice key(user_collected.at("Count"));
   ASSERT_TRUE(GetVarint32(&key, &starts_with_A));
   ASSERT_EQ(3u, starts_with_A);
 }
+
+TEST(TablePropertiesTest, CustomizedTablePropertiesCollector) {
+  // Test properties collectors with internal keys or regular keys
+  // for block based table
+  for (bool encode_as_internal : { true, false }) {
+    Options options;
+    auto collector = new RegularKeysStartWithA();
+    if (encode_as_internal) {
+      options.table_properties_collectors = {
+        std::make_shared<UserKeyTablePropertiesCollector>(collector)
+      };
+    } else {
+      options.table_properties_collectors.resize(1);
+      options.table_properties_collectors[0].reset(collector);
+    }
+    TestCustomizedTablePropertiesCollector(
+        kBlockBasedTableMagicNumber,
+        encode_as_internal,
+        options
+    );
   }
 
-TEST(TablePropertiesTest, InternalKeyPropertiesCollector) {
+  // test plain table
+  Options options;
+  options.table_properties_collectors.push_back(
+      std::make_shared<RegularKeysStartWithA>()
+  );
+  options.table_factory = std::make_shared<PlainTableFactory>(8, 8, 0);
+  TestCustomizedTablePropertiesCollector(
+      kPlainTableMagicNumber, true, options
+  );
+}
+
+void TestInternalKeyPropertiesCollector(
+    uint64_t magic_number,
+    bool sanitized,
+    std::shared_ptr<TableFactory> table_factory) {
   InternalKey keys[] = {
     InternalKey("A       ", 0, ValueType::kTypeValue),
     InternalKey("B       ", 0, ValueType::kTypeValue),
@@ -207,10 +226,10 @@ TEST(TablePropertiesTest, InternalKeyPropertiesCollector) {
     InternalKey("Z       ", 0, ValueType::kTypeDeletion),
   };
 
-  for (bool sanitized : { false, true }) {
   std::unique_ptr<TableBuilder> builder;
   std::unique_ptr<FakeWritableFile> writable;
   Options options;
+  options.table_factory = table_factory;
   if (sanitized) {
     options.table_properties_collectors = {
       std::make_shared<RegularKeysStartWithA>()
@@ -241,21 +260,46 @@ TEST(TablePropertiesTest, InternalKeyPropertiesCollector) {
 
   ASSERT_OK(builder->Finish());
 
-    std::unique_ptr<TableReader> table_reader;
+  FakeRandomeAccessFile readable(writable->contents());
-    OpenTable(options, writable->contents(), &table_reader);
+  TableProperties props;
-    const auto& properties =
+  Status s = ReadTableProperties(
-      table_reader->GetTableProperties().user_collected_properties;
+      &readable,
+      writable->contents().size(),
+      magic_number,
+      Env::Default(),
+      nullptr,
+      &props
+  );
+  ASSERT_OK(s);
 
-    uint64_t deleted = GetDeletedKeys(properties);
+  auto user_collected = props.user_collected_properties;
+  uint64_t deleted = GetDeletedKeys(user_collected);
   ASSERT_EQ(4u, deleted);
 
   if (sanitized) {
     uint32_t starts_with_A = 0;
-      Slice key(properties.at("Count"));
+    Slice key(user_collected.at("Count"));
     ASSERT_TRUE(GetVarint32(&key, &starts_with_A));
     ASSERT_EQ(1u, starts_with_A);
   }
 }
+
+TEST(TablePropertiesTest, InternalKeyPropertiesCollector) {
+  TestInternalKeyPropertiesCollector(
+      kBlockBasedTableMagicNumber,
+      true /* sanitize */,
+      std::make_shared<BlockBasedTableFactory>()
+  );
+  TestInternalKeyPropertiesCollector(
+      kBlockBasedTableMagicNumber,
+      true /* not sanitize */,
+      std::make_shared<BlockBasedTableFactory>()
+  );
+  TestInternalKeyPropertiesCollector(
+      kPlainTableMagicNumber,
+      false /* not sanitize */,
+      std::make_shared<PlainTableFactory>(8, 8, 0)
+  );
 }
 
 }  // namespace rocksdb

include/rocksdb/table_properties.h

@@ -64,6 +64,7 @@ struct TablePropertiesNames {
   static const std::string kFilterPolicy;
 };
 
+extern const std::string kPropertiesBlock;
 
 // `TablePropertiesCollector` provides the mechanism for users to collect
 // their own interested properties. This class is essentially a collection

table/block_based_table_builder.cc

@@ -387,7 +387,7 @@ Status BlockBasedTableBuilder::Finish() {
           &properties_block_handle
       );
 
-      meta_index_builer.Add(BlockBasedTable::kPropertiesBlock,
+      meta_index_builer.Add(kPropertiesBlock,
                             properties_block_handle);
     }  // end of properties block writing
 
@@ -459,7 +459,5 @@ uint64_t BlockBasedTableBuilder::FileSize() const {
 
 const std::string BlockBasedTable::kFilterBlockPrefix =
     "filter.";
-const std::string BlockBasedTable::kPropertiesBlock =
-    "rocksdb.properties";
 
 }  // namespace rocksdb

table/block_based_table_reader.cc

@@ -21,6 +21,7 @@
 #include "table/block.h"
 #include "table/filter_block.h"
 #include "table/format.h"
+#include "table/meta_blocks.h"
 #include "table/two_level_iterator.h"
 
 #include "util/coding.h"
@@ -250,10 +251,16 @@ Status BlockBasedTable::Open(const Options& options,
 
   // Read the properties
   meta_iter->Seek(kPropertiesBlock);
-  if (meta_iter->Valid() && meta_iter->key() == Slice(kPropertiesBlock)) {
+  if (meta_iter->Valid() && meta_iter->key() == kPropertiesBlock) {
     s = meta_iter->status();
     if (s.ok()) {
-      s = ReadProperties(meta_iter->value(), rep, &rep->table_properties);
+      s = ReadProperties(
+          meta_iter->value(),
+          rep->file.get(),
+          rep->options.env,
+          rep->options.info_log.get(),
+          &rep->table_properties
+      );
     }
 
     if (!s.ok()) {
@@ -401,96 +408,6 @@ FilterBlockReader* BlockBasedTable::ReadFilter (
        rep->options, block.data, block.heap_allocated);
 }
 
-Status BlockBasedTable::ReadProperties(
-    const Slice& handle_value, Rep* rep, TableProperties* table_properties) {
-  assert(table_properties);
-
-  Slice v = handle_value;
-  BlockHandle handle;
-  if (!handle.DecodeFrom(&v).ok()) {
-    return Status::InvalidArgument("Failed to decode properties block handle");
-  }
-
-  BlockContents block_contents;
-  Status s = ReadBlockContents(
-      rep->file.get(),
-      ReadOptions(),
-      handle,
-      &block_contents,
-      rep->options.env,
-      false
-  );
-
-  if (!s.ok()) {
-    return s;
-  }
-
-  Block properties_block(block_contents);
-  std::unique_ptr<Iterator> iter(
-      properties_block.NewIterator(BytewiseComparator())
-  );
-
-  // All pre-defined properties of type uint64_t
-  std::unordered_map<std::string, uint64_t*> predefined_uint64_properties = {
-    { TablePropertiesNames::kDataSize,
-      &table_properties->data_size },
-    { TablePropertiesNames::kIndexSize,
-      &table_properties->index_size },
-    { TablePropertiesNames::kFilterSize,
-      &table_properties->filter_size },
-    { TablePropertiesNames::kRawKeySize,
-      &table_properties->raw_key_size },
-    { TablePropertiesNames::kRawValueSize,
-      &table_properties->raw_value_size },
-    { TablePropertiesNames::kNumDataBlocks,
-      &table_properties->num_data_blocks },
-    { TablePropertiesNames::kNumEntries,
-      &table_properties->num_entries },
-  };
-
-  std::string last_key;
-  for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
-    s = iter->status();
-    if (!s.ok()) {
-      break;
-    }
-
-    auto key = iter->key().ToString();
-    // properties block is strictly sorted with no duplicate key.
-    assert(
-        last_key.empty() ||
-        BytewiseComparator()->Compare(key, last_key) > 0
-    );
-    last_key = key;
-
-    auto raw_val = iter->value();
-    auto pos = predefined_uint64_properties.find(key);
-
-    if (pos != predefined_uint64_properties.end()) {
-      // handle predefined rocksdb properties
-      uint64_t val;
-      if (!GetVarint64(&raw_val, &val)) {
-        // skip malformed value
-        auto error_msg =
-          "[Warning] detect malformed value in properties meta-block:"
-          "\tkey: " + key + "\tval: " + raw_val.ToString();
-        Log(rep->options.info_log, "%s", error_msg.c_str());
-        continue;
-      }
-      *(pos->second) = val;
-    } else if (key == TablePropertiesNames::kFilterPolicy) {
-      table_properties->filter_policy_name = raw_val.ToString();
-    } else {
-      // handle user-collected
-      table_properties->user_collected_properties.insert(
-          std::make_pair(key, raw_val.ToString())
-      );
-    }
-  }
-
-  return s;
-}
-
 Status BlockBasedTable::GetBlock(
     const BlockBasedTable* table,
     const BlockHandle& handle,

table/block_based_table_reader.h

@@ -38,7 +38,6 @@ using std::unique_ptr;
 class BlockBasedTable : public TableReader {
  public:
   static const std::string kFilterBlockPrefix;
-  static const std::string kPropertiesBlock;
 
   // Attempt to open the table that is stored in bytes [0..file_size)
   // of "file", and read the metadata entries necessary to allow
@@ -142,7 +141,6 @@ class BlockBasedTable : public TableReader {
 
   void ReadMeta(const Footer& footer);
   void ReadFilter(const Slice& filter_handle_value);
-  static Status ReadProperties(const Slice& handle_value, Rep* rep);
 
   // Read the meta block from sst.
   static Status ReadMetaBlock(
@@ -156,10 +154,6 @@ class BlockBasedTable : public TableReader {
       Rep* rep,
       size_t* filter_size = nullptr);
 
-  // Read the table properties from properties block.
-  static Status ReadProperties(
-      const Slice& handle_value, Rep* rep, TableProperties* properties);
-
   static void SetupCacheKeyPrefix(Rep* rep);
 
   explicit BlockBasedTable(Rep* rep) :

table/meta_blocks.cc

@@ -8,6 +8,7 @@
 #include <map>
 
 #include "rocksdb/table_properties.h"
+#include "table/block.h"
 #include "table/format.h"
 #include "util/coding.h"
 
@@ -131,4 +132,147 @@ bool NotifyCollectTableCollectorsOnFinish(
   return all_succeeded;
 }
 
+Status ReadProperties(
+    const Slice& handle_value,
+    RandomAccessFile* file,
+    Env* env,
+    Logger* logger,
+    TableProperties* table_properties) {
+  assert(table_properties);
+
+  Slice v = handle_value;
+  BlockHandle handle;
+  if (!handle.DecodeFrom(&v).ok()) {
+    return Status::InvalidArgument("Failed to decode properties block handle");
+  }
+
+  BlockContents block_contents;
+  Status s = ReadBlockContents(
+      file,
+      ReadOptions(),
+      handle,
+      &block_contents,
+      env,
+      false
+  );
+
+  if (!s.ok()) {
+    return s;
+  }
+
+  Block properties_block(block_contents);
+  std::unique_ptr<Iterator> iter(
+      properties_block.NewIterator(BytewiseComparator())
+  );
+
+  // All pre-defined properties of type uint64_t
+  std::unordered_map<std::string, uint64_t*> predefined_uint64_properties = {
+    { TablePropertiesNames::kDataSize, &table_properties->data_size },
+    { TablePropertiesNames::kIndexSize, &table_properties->index_size },
+    { TablePropertiesNames::kFilterSize, &table_properties->filter_size },
+    { TablePropertiesNames::kRawKeySize, &table_properties->raw_key_size },
+    { TablePropertiesNames::kRawValueSize, &table_properties->raw_value_size },
+    { TablePropertiesNames::kNumDataBlocks,
+      &table_properties->num_data_blocks },
+    { TablePropertiesNames::kNumEntries, &table_properties->num_entries },
+  };
+
+  std::string last_key;
+  for (iter->SeekToFirst(); iter->Valid(); iter->Next()) {
+    s = iter->status();
+    if (!s.ok()) {
+      break;
+    }
+
+    auto key = iter->key().ToString();
+    // properties block is strictly sorted with no duplicate key.
+    assert(
+        last_key.empty() ||
+        BytewiseComparator()->Compare(key, last_key) > 0
+    );
+    last_key = key;
+
+    auto raw_val = iter->value();
+    auto pos = predefined_uint64_properties.find(key);
+
+    if (pos != predefined_uint64_properties.end()) {
+      // handle predefined rocksdb properties
+      uint64_t val;
+      if (!GetVarint64(&raw_val, &val)) {
+        // skip malformed value
+        auto error_msg =
+          "[Warning] detect malformed value in properties meta-block:"
+          "\tkey: " + key + "\tval: " + raw_val.ToString();
+        Log(logger, "%s", error_msg.c_str());
+        continue;
+      }
+      *(pos->second) = val;
+    } else if (key == TablePropertiesNames::kFilterPolicy) {
+      table_properties->filter_policy_name = raw_val.ToString();
+    } else {
+      // handle user-collected properties
+      table_properties->user_collected_properties.insert(
+          std::make_pair(key, raw_val.ToString())
+      );
+    }
+  }
+
+  return s;
+}
+
+Status ReadTableProperties(
+    RandomAccessFile* file,
+    uint64_t file_size,
+    uint64_t table_magic_number,
+    Env* env,
+    Logger* info_log,
+    TableProperties* properties) {
+  // -- Read metaindex block
+  Footer footer(table_magic_number);
+  auto s = ReadFooterFromFile(file, file_size, &footer);
+  if (!s.ok()) {
+    return s;
+  }
+
+  auto metaindex_handle = footer.metaindex_handle();
+  BlockContents metaindex_contents;
+  s = ReadBlockContents(
+      file,
+      ReadOptions(),
+      metaindex_handle,
+      &metaindex_contents,
+      env,
+      false
+  );
+  if (!s.ok()) {
+    return s;
+  }
+  Block metaindex_block(metaindex_contents);
+  std::unique_ptr<Iterator> meta_iter(
+      metaindex_block.NewIterator(BytewiseComparator())
+  );
+
+  // -- Read property block
+  meta_iter->Seek(kPropertiesBlock);
+  TableProperties table_properties;
+  if (meta_iter->Valid() &&
+      meta_iter->key() == kPropertiesBlock &&
+      meta_iter->status().ok()) {
+    s = ReadProperties(
+        meta_iter->value(),
+        file,
+        env,
+        info_log,
+        properties
+    );
+  } else {
+    s = Status::Corruption(
+        "Unable to read the property block from the plain table"
+    );
+  }
+
+  return s;
+}
+
+
 }  // namespace rocksdb

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

table/plain_table_builder.cc

@@ -14,12 +14,40 @@
 #include "table/block_builder.h"
 #include "table/filter_block.h"
 #include "table/format.h"
+#include "table/meta_blocks.h"
 #include "util/coding.h"
 #include "util/crc32c.h"
 #include "util/stop_watch.h"
 
 namespace rocksdb {
 
+namespace {
+
+// a utility that helps writing block content to the file
+//   @offset will advance if @block_contents was successfully written.
+//   @block_handle the block handle this particular block.
+Status WriteBlock(
+    const Slice& block_contents,
+    WritableFile* file,
+    uint64_t* offset,
+    BlockHandle* block_handle) {
+  block_handle->set_offset(*offset);
+  block_handle->set_size(block_contents.size());
+  Status s = file->Append(block_contents);
+
+  if (s.ok()) {
+    *offset += block_contents.size();
+  }
+  return s;
+}
+
+}  // namespace
+
+// kPlainTableMagicNumber was picked by running
+//    echo rocksdb.plain.table | sha1sum
+// and taking the leading 64 bits.
+extern const uint64_t kPlainTableMagicNumber = 0x4f3418eb7a8f13b8ull;
+
 PlainTableBuilder::PlainTableBuilder(const Options& options,
                                      WritableFile* file,
                                      int user_key_size, int key_prefix_len) :
@@ -28,13 +56,16 @@ PlainTableBuilder::PlainTableBuilder(const Options& options,
   PutFixed32(&version, 1 | 0x80000000);
   file_->Append(Slice(version));
   offset_ = 4;
-}
 
-PlainTableBuilder::~PlainTableBuilder() {
+  // for plain table, we put all the data in a big chuck.
+  properties_.num_data_blocks = 1;
+  // emphasize that currently plain table doesn't have persistent index or
+  // filter block.
+  properties_.index_size = 0;
+  properties_.filter_size = 0;
 }
 
-Status PlainTableBuilder::ChangeOptions(const Options& options) {
+PlainTableBuilder::~PlainTableBuilder() {
-  return Status::OK();
 }
 
 void PlainTableBuilder::Add(const Slice& key, const Slice& value) {
@@ -52,7 +83,17 @@ void PlainTableBuilder::Add(const Slice& key, const Slice& value) {
   file_->Append(value);
   offset_ += value_size + size.length();
 
-  num_entries_++;
+  properties_.num_entries++;
+  properties_.raw_key_size += key.size();
+  properties_.raw_value_size += value.size();
+
+  // notify property collectors
+  NotifyCollectTableCollectorsOnAdd(
+      key,
+      value,
+      options_.table_properties_collectors,
+      options_.info_log.get()
+  );
 }
 
 Status PlainTableBuilder::status() const {
@@ -62,7 +103,63 @@ Status PlainTableBuilder::status() const {
 Status PlainTableBuilder::Finish() {
   assert(!closed_);
   closed_ = true;
-  return Status::OK();
+
+  properties_.data_size = offset_;
+
+  // Write the following blocks
+  //  1. [meta block: properties]
+  //  2. [metaindex block]
+  //  3. [footer]
+  MetaIndexBuilder meta_index_builer;
+
+  PropertyBlockBuilder property_block_builder;
+  // -- Add basic properties
+  property_block_builder.AddTableProperty(properties_);
+
+  // -- Add user collected properties
+  NotifyCollectTableCollectorsOnFinish(
+      options_.table_properties_collectors,
+      options_.info_log.get(),
+      &property_block_builder
+  );
+
+  // -- Write property block
+  BlockHandle property_block_handle;
+  auto s = WriteBlock(
+      property_block_builder.Finish(),
+      file_,
+      &offset_,
+      &property_block_handle
+  );
+  if (!s.ok()) {
+    return s;
+  }
+  meta_index_builer.Add(kPropertiesBlock, property_block_handle);
+
+  // -- write metaindex block
+  BlockHandle metaindex_block_handle;
+  s = WriteBlock(
+      meta_index_builer.Finish(),
+      file_,
+      &offset_,
+      &metaindex_block_handle
+  );
+  if (!s.ok()) {
+    return s;
+  }
+
+  // Write Footer
+  Footer footer(kPlainTableMagicNumber);
+  footer.set_metaindex_handle(metaindex_block_handle);
+  footer.set_index_handle(BlockHandle::NullBlockHandle());
+  std::string footer_encoding;
+  footer.EncodeTo(&footer_encoding);
+  s = file_->Append(footer_encoding);
+  if (s.ok()) {
+    offset_ += footer_encoding.size();
+  }
+
+  return s;
 }
 
 void PlainTableBuilder::Abandon() {
@@ -70,7 +167,7 @@ void PlainTableBuilder::Abandon() {
 }
 
 uint64_t PlainTableBuilder::NumEntries() const {
-  return num_entries_;
+  return properties_.num_entries;
 }
 
 uint64_t PlainTableBuilder::FileSize() const {

table/plain_table_builder.h

@@ -32,14 +32,6 @@ public:
   // REQUIRES: Either Finish() or Abandon() has been called.
   ~PlainTableBuilder();
 
-  // Change the options used by this builder.  Note: only some of the
-  // option fields can be changed after construction.  If a field is
-  // not allowed to change dynamically and its value in the structure
-  // passed to the constructor is different from its value in the
-  // structure passed to this method, this method will return an error
-  // without changing any fields.
-  Status ChangeOptions(const Options& options);
-
   // Add key,value to the table being constructed.
   // REQUIRES: key is after any previously added key according to comparator.
   // REQUIRES: Finish(), Abandon() have not been called
@@ -72,7 +64,7 @@ private:
   WritableFile* file_;
   uint64_t offset_ = 0;
   Status status_;
-  uint64_t num_entries_ = 0;
+  TableProperties properties_;
 
   const size_t user_key_size_;
   bool closed_ = false;  // Either Finish() or Abandon() has been called.

table/plain_table_reader.cc

@@ -19,6 +19,7 @@
 #include "table/block.h"
 #include "table/filter_block.h"
 #include "table/format.h"
+#include "table/meta_blocks.h"
 #include "table/two_level_iterator.h"
 
 #include "util/coding.h"
@@ -41,6 +42,7 @@ public:
 
 namespace rocksdb {
 
+extern const uint64_t kPlainTableMagicNumber;
 static uint32_t getBucketId(Slice const& s, size_t prefix_len,
                             uint32_t num_buckets) {
   return MurmurHash(s.data(), prefix_len, 397) % num_buckets;
@@ -49,18 +51,16 @@ static uint32_t getBucketId(Slice const& s, size_t prefix_len,
 PlainTableReader::PlainTableReader(const EnvOptions& storage_options,
                                    uint64_t file_size, int user_key_size,
                                    int key_prefix_len, int bloom_bits_per_key,
-                                   double hash_table_ratio) :
+                                   double hash_table_ratio,
+                                   const TableProperties& table_properties) :
     hash_table_size_(0), soptions_(storage_options), file_size_(file_size),
     user_key_size_(user_key_size), key_prefix_len_(key_prefix_len),
-    hash_table_ratio_(hash_table_ratio) {
+    hash_table_ratio_(hash_table_ratio),
-  if (bloom_bits_per_key > 0) {
+    filter_policy_(bloom_bits_per_key > 0 ?
-    filter_policy_ = NewBloomFilterPolicy(bloom_bits_per_key);
+                     NewBloomFilterPolicy(bloom_bits_per_key) : nullptr),
-  } else {
+    table_properties_(table_properties),
-    filter_policy_ = nullptr;
+    data_start_offset_(0),
-  }
+    data_end_offset_(table_properties_.data_size) {
-  hash_table_ = nullptr;
-  data_start_offset_ = 0;
-  data_end_offset_ = file_size;
 }
 
 PlainTableReader::~PlainTableReader() {
@@ -87,19 +87,38 @@ Status PlainTableReader::Open(const Options& options,
     return Status::NotSupported("File is too large for PlainTableReader!");
   }
 
-  PlainTableReader* t = new PlainTableReader(soptions, file_size,
+  TableProperties table_properties;
+  auto s = ReadTableProperties(
+      file.get(),
+      file_size,
+      kPlainTableMagicNumber,
+      options.env,
+      options.info_log.get(),
+      &table_properties
+  );
+  if (!s.ok()) {
+    return s;
+  }
+
+  std::unique_ptr<PlainTableReader> new_reader(new PlainTableReader(
+      soptions,
+      file_size,
       user_key_size,
       key_prefix_len,
       bloom_num_bits,
-                                             hash_table_ratio);
+      hash_table_ratio,
-  t->file_ = std::move(file);
+      table_properties
-  t->options_ = options;
+  ));
-  Status s = t->PopulateIndex(file_size);
+  new_reader->file_ = std::move(file);
+  new_reader->options_ = options;
+
+  // -- Populate Index
+  s = new_reader->PopulateIndex();
   if (!s.ok()) {
-    delete t;
     return s;
   }
-  table_reader->reset(t);
+
+  *table_reader = std::move(new_reader);
   return s;
 }
 
@@ -114,7 +133,7 @@ Iterator* PlainTableReader::NewIterator(const ReadOptions& options) {
   return new PlainTableIterator(this);
 }
 
-Status PlainTableReader::PopulateIndex(uint64_t file_size) {
+Status PlainTableReader::PopulateIndex() {
   // Get mmapped memory to file_data_.
   Status s = file_->Read(0, file_size_, &file_data_, nullptr);
   if (!s.ok()) {
@@ -124,7 +143,6 @@ Status PlainTableReader::PopulateIndex(uint64_t file_size) {
   version_ ^= 0x80000000;
   assert(version_ == 1);
   data_start_offset_ = 4;
-  data_end_offset_ = file_size;
 
   Slice key_slice;
   Slice key_prefix_slice;
@@ -140,7 +158,7 @@ Status PlainTableReader::PopulateIndex(uint64_t file_size) {
   // are in order.
   std::vector<std::pair<Slice, std::string>> prefix_index_pairs;
   std::string current_prefix_index;
-  while (pos < file_size) {
+  while (pos < data_end_offset_) {
     uint32_t key_offset = pos;
     status_ = Next(pos, &key_slice, &value_slice, pos);
     key_prefix_slice = Slice(key_slice.data(), key_prefix_len_);

table/plain_table_reader.h

@@ -78,16 +78,21 @@ public:
   void SetupForCompaction();
 
   TableProperties& GetTableProperties() {
-    return tbl_props;
+    return table_properties_;
   }
 
-  PlainTableReader(const EnvOptions& storage_options, uint64_t file_size,
+  PlainTableReader(
-                   int user_key_size, int key_prefix_len, int bloom_num_bits,
+      const EnvOptions& storage_options,
-                   double hash_table_ratio);
+      uint64_t file_size,
+      int user_key_size,
+      int key_prefix_len,
+      int bloom_num_bits,
+      double hash_table_ratio,
+      const TableProperties& table_properties);
   ~PlainTableReader();
 
 private:
-  uint32_t* hash_table_;
+  uint32_t* hash_table_ = nullptr;
   int hash_table_size_;
   std::string sub_index_;
 
@@ -99,8 +104,6 @@ private:
   Slice file_data_;
   uint32_t version_;
   uint32_t file_size_;
-  uint32_t data_start_offset_;
-  uint32_t data_end_offset_;
   const size_t user_key_size_;
   const size_t key_prefix_len_;
   const double hash_table_ratio_;
@@ -108,7 +111,9 @@ private:
   std::string filter_str_;
   Slice filter_slice_;
 
-  TableProperties tbl_props;
+  TableProperties table_properties_;
+  uint32_t data_start_offset_;
+  uint32_t data_end_offset_;
 
   static const size_t kNumInternalBytes = 8;
   static const uint32_t kSubIndexMask = 0x80000000;
@@ -125,7 +130,7 @@ private:
   // any query to the table.
   // This query will populate the hash table hash_table_, the second
   // level of indexes sub_index_ and bloom filter filter_slice_ if enabled.
-  Status PopulateIndex(uint64_t file_size);
+  Status PopulateIndex();
 
   // Check bloom filter to see whether it might contain this prefix
   bool MayHavePrefix(const Slice& target_prefix);

table/table_properties.cc

@@ -105,4 +105,6 @@ const std::string TablePropertiesNames::kNumEntries =
 const std::string TablePropertiesNames::kFilterPolicy =
     "rocksdb.filter.policy";
 
+extern const std::string kPropertiesBlock = "rocksdb.properties";
+
 }  // namespace rocksdb

table/table_test.cc

@@ -15,17 +15,22 @@
 #include "db/db_statistics.h"
 #include "db/memtable.h"
 #include "db/write_batch_internal.h"
+
 #include "rocksdb/cache.h"
 #include "rocksdb/db.h"
+#include "rocksdb/plain_table_factory.h"
 #include "rocksdb/env.h"
 #include "rocksdb/iterator.h"
 #include "rocksdb/memtablerep.h"
+
+#include "table/meta_blocks.h"
 #include "table/block_based_table_builder.h"
 #include "table/block_based_table_factory.h"
 #include "table/block_based_table_reader.h"
 #include "table/block_builder.h"
 #include "table/block.h"
 #include "table/format.h"
+
 #include "util/random.h"
 #include "util/testharness.h"
 #include "util/testutil.h"
@@ -743,49 +748,6 @@ class Harness {
   Constructor* constructor_;
 };
 
-// Test the empty key
-TEST(Harness, SimpleEmptyKey) {
-  std::vector<TestArgs> args = GenerateArgList();
-  for (unsigned int i = 0; i < args.size(); i++) {
-    Init(args[i]);
-    Random rnd(test::RandomSeed() + 1);
-    Add("", "v");
-    Test(&rnd);
-  }
-}
-
-TEST(Harness, SimpleSingle) {
-  std::vector<TestArgs> args = GenerateArgList();
-  for (unsigned int i = 0; i < args.size(); i++) {
-    Init(args[i]);
-    Random rnd(test::RandomSeed() + 2);
-    Add("abc", "v");
-    Test(&rnd);
-  }
-}
-
-TEST(Harness, SimpleMulti) {
-  std::vector<TestArgs> args = GenerateArgList();
-  for (unsigned int i = 0; i < args.size(); i++) {
-    Init(args[i]);
-    Random rnd(test::RandomSeed() + 3);
-    Add("abc", "v");
-    Add("abcd", "v");
-    Add("ac", "v2");
-    Test(&rnd);
-  }
-}
-
-TEST(Harness, SimpleSpecialKey) {
-  std::vector<TestArgs> args = GenerateArgList();
-  for (unsigned int i = 0; i < args.size(); i++) {
-    Init(args[i]);
-    Random rnd(test::RandomSeed() + 4);
-    Add("\xff\xff", "v3");
-    Test(&rnd);
-  }
-}
-
 static bool Between(uint64_t val, uint64_t low, uint64_t high) {
   bool result = (val >= low) && (val <= high);
   if (!result) {
@@ -801,7 +763,7 @@ class TableTest { };
 
 // This test include all the basic checks except those for index size and block
 // size, which will be conducted in separated unit tests.
-TEST(TableTest, BasicTableProperties) {
+TEST(TableTest, BasicBlockedBasedTableProperties) {
   BlockBasedTableConstructor c(BytewiseComparator());
 
   c.Add("a1", "val1");
@@ -845,6 +807,47 @@ TEST(TableTest, BasicTableProperties) {
   );
 }
 
+extern const uint64_t kPlainTableMagicNumber;
+TEST(TableTest, BasicPlainTableProperties) {
+  PlainTableFactory factory(8, 8, 0);
+  StringSink sink;
+  std::unique_ptr<TableBuilder> builder(factory.GetTableBuilder(
+      Options(),
+      &sink,
+      kNoCompression
+  ));
+
+  for (char c = 'a'; c <= 'z'; ++c) {
+    std::string key(16, c);
+    std::string value(28, c + 42);
+    builder->Add(key, value);
+  }
+  ASSERT_OK(builder->Finish());
+
+  StringSource source(sink.contents(), 72242);
+
+  TableProperties props;
+  auto s = ReadTableProperties(
+      &source,
+      sink.contents().size(),
+      kPlainTableMagicNumber,
+      Env::Default(),
+      nullptr,
+      &props
+  );
+  ASSERT_OK(s);
+
+  ASSERT_EQ(0ul, props.index_size);
+  ASSERT_EQ(0ul, props.filter_size);
+  ASSERT_EQ(16ul * 26, props.raw_key_size);
+  ASSERT_EQ(28ul * 26, props.raw_value_size);
+  ASSERT_EQ(26ul, props.num_entries);
+  ASSERT_EQ(1ul, props.num_data_blocks);
+
+  // User collected keys
+  // internal keys
+}
+
 TEST(TableTest, FilterPolicyNameProperties) {
   BlockBasedTableConstructor c(BytewiseComparator());
   c.Add("a1", "val1");
@@ -1292,6 +1295,48 @@ TEST(MemTableTest, Simple) {
   delete memtable->Unref();
 }
 
+// Test the empty key
+TEST(Harness, SimpleEmptyKey) {
+  std::vector<TestArgs> args = GenerateArgList();
+  for (unsigned int i = 0; i < args.size(); i++) {
+    Init(args[i]);
+    Random rnd(test::RandomSeed() + 1);
+    Add("", "v");
+    Test(&rnd);
+  }
+}
+
+TEST(Harness, SimpleSingle) {
+  std::vector<TestArgs> args = GenerateArgList();
+  for (unsigned int i = 0; i < args.size(); i++) {
+    Init(args[i]);
+    Random rnd(test::RandomSeed() + 2);
+    Add("abc", "v");
+    Test(&rnd);
+  }
+}
+
+TEST(Harness, SimpleMulti) {
+  std::vector<TestArgs> args = GenerateArgList();
+  for (unsigned int i = 0; i < args.size(); i++) {
+    Init(args[i]);
+    Random rnd(test::RandomSeed() + 3);
+    Add("abc", "v");
+    Add("abcd", "v");
+    Add("ac", "v2");
+    Test(&rnd);
+  }
+}
+
+TEST(Harness, SimpleSpecialKey) {
+  std::vector<TestArgs> args = GenerateArgList();
+  for (unsigned int i = 0; i < args.size(); i++) {
+    Init(args[i]);
+    Random rnd(test::RandomSeed() + 4);
+    Add("\xff\xff", "v3");
+    Test(&rnd);
+  }
+}
 
 }  // namespace rocksdb