Revert "Digest ZSTD compression dictionary once per SST file (#4251)" (#4347)

Summary:
Reverting is needed to unblock a user building against master, who is blocked for multiple days due to a thread-safety issue in `GetEmptyDict`. We haven't been able to fix it quickly, so reverting.

Simply ran `git revert 6c40806e51a89386d2b066fddf73d3fd03a36f65`. There were no merge conflicts.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/4347

Differential Revision: D9668365

Pulled By: ajkr

fbshipit-source-id: 0c56334f0a23cf5ee0233d4e4679eae6709739cd

table/block_based_table_builder.cc

@@ -103,19 +103,19 @@ bool GoodCompressionRatio(size_t compressed_size, size_t raw_size) {
 }  // namespace
 
 // format_version is the block format as defined in include/rocksdb/table.h
-Slice CompressBlock(const Slice& raw, const CompressionInfo& compression_info,
+Slice CompressBlock(const Slice& raw, const CompressionContext& compression_ctx,
                     CompressionType* type, uint32_t format_version,
                     std::string* compressed_output) {
-  *type = compression_info.type();
-  if (compression_info.type() == kNoCompression) {
+  *type = compression_ctx.type();
+  if (compression_ctx.type() == kNoCompression) {
     return raw;
   }
 
   // Will return compressed block contents if (1) the compression method is
   // supported in this platform and (2) the compression rate is "good enough".
-  switch (compression_info.type()) {
+  switch (compression_ctx.type()) {
     case kSnappyCompression:
-      if (Snappy_Compress(compression_info, raw.data(), raw.size(),
+      if (Snappy_Compress(compression_ctx, raw.data(), raw.size(),
                           compressed_output) &&
           GoodCompressionRatio(compressed_output->size(), raw.size())) {
         return *compressed_output;
@@ -123,7 +123,7 @@ Slice CompressBlock(const Slice& raw, const CompressionInfo& compression_info,
       break;  // fall back to no compression.
     case kZlibCompression:
       if (Zlib_Compress(
-              compression_info,
+              compression_ctx,
               GetCompressFormatForVersion(kZlibCompression, format_version),
               raw.data(), raw.size(), compressed_output) &&
           GoodCompressionRatio(compressed_output->size(), raw.size())) {
@@ -132,7 +132,7 @@ Slice CompressBlock(const Slice& raw, const CompressionInfo& compression_info,
       break;  // fall back to no compression.
     case kBZip2Compression:
       if (BZip2_Compress(
-              compression_info,
+              compression_ctx,
               GetCompressFormatForVersion(kBZip2Compression, format_version),
               raw.data(), raw.size(), compressed_output) &&
           GoodCompressionRatio(compressed_output->size(), raw.size())) {
@@ -141,7 +141,7 @@ Slice CompressBlock(const Slice& raw, const CompressionInfo& compression_info,
       break;  // fall back to no compression.
     case kLZ4Compression:
       if (LZ4_Compress(
-              compression_info,
+              compression_ctx,
               GetCompressFormatForVersion(kLZ4Compression, format_version),
               raw.data(), raw.size(), compressed_output) &&
           GoodCompressionRatio(compressed_output->size(), raw.size())) {
@@ -150,7 +150,7 @@ Slice CompressBlock(const Slice& raw, const CompressionInfo& compression_info,
       break;  // fall back to no compression.
     case kLZ4HCCompression:
       if (LZ4HC_Compress(
-              compression_info,
+              compression_ctx,
               GetCompressFormatForVersion(kLZ4HCCompression, format_version),
               raw.data(), raw.size(), compressed_output) &&
           GoodCompressionRatio(compressed_output->size(), raw.size())) {
@@ -166,7 +166,7 @@ Slice CompressBlock(const Slice& raw, const CompressionInfo& compression_info,
       break;
     case kZSTD:
     case kZSTDNotFinalCompression:
-      if (ZSTD_Compress(compression_info, raw.data(), raw.size(),
+      if (ZSTD_Compress(compression_ctx, raw.data(), raw.size(),
                         compressed_output) &&
           GoodCompressionRatio(compressed_output->size(), raw.size())) {
         return *compressed_output;
@@ -260,9 +260,8 @@ struct BlockBasedTableBuilder::Rep {
   PartitionedIndexBuilder* p_index_builder_ = nullptr;
 
   std::string last_key;
-  CompressionType compression_type;
-  CompressionOptions compression_opts;
-  CompressionDict compression_dict;
+  // Compression dictionary or nullptr
+  const std::string* compression_dict;
   CompressionContext compression_ctx;
   std::unique_ptr<UncompressionContext> verify_ctx;
   TableProperties props;
@@ -313,9 +312,8 @@ struct BlockBasedTableBuilder::Rep {
                    table_options.data_block_hash_table_util_ratio),
         range_del_block(1 /* block_restart_interval */),
         internal_prefix_transform(_moptions.prefix_extractor.get()),
-        compression_type(_compression_type),
-        compression_opts(_compression_opts),
-        compression_ctx(_compression_type),
+        compression_dict(_compression_dict),
+        compression_ctx(_compression_type, _compression_opts),
         use_delta_encoding_for_index_values(table_opt.format_version >= 4 &&
                                             !table_opt.block_align),
         compressed_cache_key_prefix_size(0),
@@ -326,15 +324,6 @@ struct BlockBasedTableBuilder::Rep {
         column_family_name(_column_family_name),
         creation_time(_creation_time),
         oldest_key_time(_oldest_key_time) {
-    if (_compression_dict != nullptr) {
-      compression_dict.Init(*_compression_dict,
-                            CompressionDict::Mode::kCompression,
-                            _compression_type, _compression_opts.level);
-    } else {
-      compression_dict.Init(Slice() /* dict */,
-                            CompressionDict::Mode::kEmpty,
-                            _compression_type, _compression_opts.level);
-    }
     if (table_options.index_type ==
         BlockBasedTableOptions::kTwoLevelIndexSearch) {
       p_index_builder_ = PartitionedIndexBuilder::CreateIndexBuilder(
@@ -365,7 +354,7 @@ struct BlockBasedTableBuilder::Rep {
             _moptions.prefix_extractor != nullptr));
     if (table_options.verify_compression) {
       verify_ctx.reset(new UncompressionContext(UncompressionContext::NoCache(),
-                                                compression_type));
+                                                compression_ctx.type()));
     }
   }
 
@@ -509,7 +498,7 @@ void BlockBasedTableBuilder::WriteBlock(const Slice& raw_block_contents,
   assert(ok());
   Rep* r = rep_;
 
-  auto type = r->compression_type;
+  auto type = r->compression_ctx.type();
   Slice block_contents;
   bool abort_compression = false;
 
@@ -517,12 +506,24 @@ void BlockBasedTableBuilder::WriteBlock(const Slice& raw_block_contents,
     ShouldReportDetailedTime(r->ioptions.env, r->ioptions.statistics));
 
   if (raw_block_contents.size() < kCompressionSizeLimit) {
-    CompressionInfo compression_info(
-        r->compression_opts, r->compression_ctx,
-        is_data_block ? r->compression_dict : CompressionDict::GetEmptyDict(),
-        r->compression_type);
+    Slice compression_dict;
+    if (is_data_block && r->compression_dict && r->compression_dict->size()) {
+      r->compression_ctx.dict() = *r->compression_dict;
+      if (r->table_options.verify_compression) {
+        assert(r->verify_ctx != nullptr);
+        r->verify_ctx->dict() = *r->compression_dict;
+      }
+    } else {
+      // Clear dictionary
+      r->compression_ctx.dict() = Slice();
+      if (r->table_options.verify_compression) {
+        assert(r->verify_ctx != nullptr);
+        r->verify_ctx->dict() = Slice();
+      }
+    }
+
     block_contents =
-        CompressBlock(raw_block_contents, compression_info, &type,
+        CompressBlock(raw_block_contents, r->compression_ctx, &type,
                       r->table_options.format_version, &r->compressed_output);
 
     // Some of the compression algorithms are known to be unreliable. If
@@ -531,12 +532,8 @@ void BlockBasedTableBuilder::WriteBlock(const Slice& raw_block_contents,
     if (type != kNoCompression && r->table_options.verify_compression) {
       // Retrieve the uncompressed contents into a new buffer
       BlockContents contents;
-      UncompressionInfo uncompression_info(
-          *r->verify_ctx,
-          is_data_block ? r->compression_dict : CompressionDict::GetEmptyDict(),
-          r->compression_type);
       Status stat = UncompressBlockContentsForCompressionType(
-          uncompression_info, block_contents.data(), block_contents.size(),
+          *r->verify_ctx, block_contents.data(), block_contents.size(),
           &contents, r->table_options.format_version, r->ioptions);
 
       if (stat.ok()) {
@@ -783,7 +780,7 @@ void BlockBasedTableBuilder::WritePropertiesBlock(
             ? rep_->ioptions.merge_operator->Name()
             : "nullptr";
     rep_->props.compression_name =
-        CompressionTypeToString(rep_->compression_type);
+        CompressionTypeToString(rep_->compression_ctx.type());
     rep_->props.prefix_extractor_name =
         rep_->moptions.prefix_extractor != nullptr
             ? rep_->moptions.prefix_extractor->Name()
@@ -832,10 +829,10 @@ void BlockBasedTableBuilder::WritePropertiesBlock(
 
 void BlockBasedTableBuilder::WriteCompressionDictBlock(
     MetaIndexBuilder* meta_index_builder) {
-  if (rep_->compression_dict.GetRawDict().size()) {
+  if (rep_->compression_dict && rep_->compression_dict->size()) {
     BlockHandle compression_dict_block_handle;
     if (ok()) {
-      WriteRawBlock(rep_->compression_dict.GetRawDict(), kNoCompression,
+      WriteRawBlock(*rep_->compression_dict, kNoCompression,
                     &compression_dict_block_handle);
     }
     if (ok()) {

table/block_based_table_builder.h

@@ -131,7 +131,7 @@ class BlockBasedTableBuilder : public TableBuilder {
   const uint64_t kCompressionSizeLimit = std::numeric_limits<int>::max();
 };
 
-Slice CompressBlock(const Slice& raw, const CompressionInfo& info,
+Slice CompressBlock(const Slice& raw, const CompressionContext& compression_ctx,
                     CompressionType* type, uint32_t format_version,
                     std::string* compressed_output);
 

table/block_based_table_reader.cc

@@ -1226,12 +1226,9 @@ Status BlockBasedTable::GetDataBlockFromCache(
 
   // Retrieve the uncompressed contents into a new buffer
   BlockContents contents;
-  UncompressionContext context(compressed_block->compression_type());
-  CompressionDict dict;
-  dict.Init(compression_dict, CompressionDict::Mode::kUncompression,
-            compressed_block->compression_type());
-  UncompressionInfo info(context, dict, compressed_block->compression_type());
-  s = UncompressBlockContents(info, compressed_block->data(),
+  UncompressionContext uncompresssion_ctx(compressed_block->compression_type(),
+                                          compression_dict);
+  s = UncompressBlockContents(uncompresssion_ctx, compressed_block->data(),
                               compressed_block->size(), &contents,
                               format_version, ioptions);
 
@@ -1304,13 +1301,11 @@ Status BlockBasedTable::PutDataBlockToCache(
   BlockContents contents;
   Statistics* statistics = ioptions.statistics;
   if (raw_block->compression_type() != kNoCompression) {
-    UncompressionContext context(raw_block->compression_type());
-    CompressionDict dict;
-    dict.Init(compression_dict, CompressionDict::Mode::kUncompression,
-              raw_block->compression_type());
-    UncompressionInfo info(context, dict, raw_block->compression_type());
-    s = UncompressBlockContents(info, raw_block->data(), raw_block->size(),
-                                &contents, format_version, ioptions);
+    UncompressionContext uncompression_ctx(raw_block->compression_type(),
+                                           compression_dict);
+    s = UncompressBlockContents(uncompression_ctx, raw_block->data(),
+                                raw_block->size(), &contents, format_version,
+                                ioptions);
   }
   if (!s.ok()) {
     delete raw_block;

table/block_fetcher.cc

@@ -227,12 +227,9 @@ Status BlockFetcher::ReadBlockContents() {
 
   if (do_uncompress_ && compression_type != kNoCompression) {
     // compressed page, uncompress, update cache
-    UncompressionContext context(compression_type);
-    CompressionDict dict;
-    dict.Init(compression_dict_, CompressionDict::Mode::kUncompression,
-              compression_type);
-    UncompressionInfo info(context, dict, compression_type);
-    status_ = UncompressBlockContents(info, slice_.data(), block_size_,
+    UncompressionContext uncompression_ctx(compression_type, compression_dict_);
+    status_ =
+        UncompressBlockContents(uncompression_ctx, slice_.data(), block_size_,
                                 contents_, footer_.version(), ioptions_);
   } else {
     GetBlockContents();

table/format.cc

@@ -284,18 +284,18 @@ Status ReadFooterFromFile(RandomAccessFileReader* file,
 }
 
 Status UncompressBlockContentsForCompressionType(
-    const UncompressionInfo& uncompression_info, const char* data, size_t n,
+    const UncompressionContext& uncompression_ctx, const char* data, size_t n,
     BlockContents* contents, uint32_t format_version,
     const ImmutableCFOptions& ioptions) {
   std::unique_ptr<char[]> ubuf;
 
-  assert(uncompression_info.type() != kNoCompression &&
+  assert(uncompression_ctx.type() != kNoCompression &&
          "Invalid compression type");
 
   StopWatchNano timer(ioptions.env,
     ShouldReportDetailedTime(ioptions.env, ioptions.statistics));
   int decompress_size = 0;
-  switch (uncompression_info.type()) {
+  switch (uncompression_ctx.type()) {
     case kSnappyCompression: {
       size_t ulength = 0;
       static char snappy_corrupt_msg[] =
@@ -312,7 +312,7 @@ Status UncompressBlockContentsForCompressionType(
     }
     case kZlibCompression:
       ubuf.reset(Zlib_Uncompress(
-          uncompression_info, data, n, &decompress_size,
+          uncompression_ctx, data, n, &decompress_size,
           GetCompressFormatForVersion(kZlibCompression, format_version)));
       if (!ubuf) {
         static char zlib_corrupt_msg[] =
@@ -336,7 +336,7 @@ Status UncompressBlockContentsForCompressionType(
       break;
     case kLZ4Compression:
       ubuf.reset(LZ4_Uncompress(
-          uncompression_info, data, n, &decompress_size,
+          uncompression_ctx, data, n, &decompress_size,
           GetCompressFormatForVersion(kLZ4Compression, format_version)));
       if (!ubuf) {
         static char lz4_corrupt_msg[] =
@@ -348,7 +348,7 @@ Status UncompressBlockContentsForCompressionType(
       break;
     case kLZ4HCCompression:
       ubuf.reset(LZ4_Uncompress(
-          uncompression_info, data, n, &decompress_size,
+          uncompression_ctx, data, n, &decompress_size,
           GetCompressFormatForVersion(kLZ4HCCompression, format_version)));
       if (!ubuf) {
         static char lz4hc_corrupt_msg[] =
@@ -370,8 +370,7 @@ Status UncompressBlockContentsForCompressionType(
       break;
     case kZSTD:
     case kZSTDNotFinalCompression:
-      ubuf.reset(
-          ZSTD_Uncompress(uncompression_info, data, n, &decompress_size));
+      ubuf.reset(ZSTD_Uncompress(uncompression_ctx, data, n, &decompress_size));
       if (!ubuf) {
         static char zstd_corrupt_msg[] =
             "ZSTD not supported or corrupted ZSTD compressed block contents";
@@ -401,14 +400,14 @@ Status UncompressBlockContentsForCompressionType(
 // buffer is returned via 'result' and it is upto the caller to
 // free this buffer.
 // format_version is the block format as defined in include/rocksdb/table.h
-Status UncompressBlockContents(const UncompressionInfo& uncompression_info,
+Status UncompressBlockContents(const UncompressionContext& uncompression_ctx,
                                const char* data, size_t n,
                                BlockContents* contents, uint32_t format_version,
                                const ImmutableCFOptions& ioptions) {
   assert(data[n] != kNoCompression);
-  assert(data[n] == uncompression_info.type());
+  assert(data[n] == uncompression_ctx.type());
   return UncompressBlockContentsForCompressionType(
-      uncompression_info, data, n, contents, format_version, ioptions);
+      uncompression_ctx, data, n, contents, format_version, ioptions);
 }
 
 }  // namespace rocksdb

table/format.h

@@ -250,17 +250,16 @@ extern Status ReadBlockContents(
 // free this buffer.
 // For description of compress_format_version and possible values, see
 // util/compression.h
-extern Status UncompressBlockContents(const UncompressionInfo& info,
-                                      const char* data, size_t n,
-                                      BlockContents* contents,
-                                      uint32_t compress_format_version,
+extern Status UncompressBlockContents(
+    const UncompressionContext& uncompression_ctx, const char* data, size_t n,
+    BlockContents* contents, uint32_t compress_format_version,
     const ImmutableCFOptions& ioptions);
 
 // This is an extension to UncompressBlockContents that accepts
 // a specific compression type. This is used by un-wrapped blocks
 // with no compression header.
 extern Status UncompressBlockContentsForCompressionType(
-    const UncompressionInfo& info, const char* data, size_t n,
+    const UncompressionContext& uncompression_ctx, const char* data, size_t n,
     BlockContents* contents, uint32_t compress_format_version,
     const ImmutableCFOptions& ioptions);
 

tools/db_bench_tool.cc

@@ -1991,28 +1991,28 @@ class Benchmark {
     return true;
   }
 
-  inline bool CompressSlice(const CompressionInfo& compression_info,
+  inline bool CompressSlice(const CompressionContext& compression_ctx,
                             const Slice& input, std::string* compressed) {
     bool ok = true;
     switch (FLAGS_compression_type_e) {
       case rocksdb::kSnappyCompression:
-        ok = Snappy_Compress(compression_info, input.data(), input.size(),
+        ok = Snappy_Compress(compression_ctx, input.data(), input.size(),
                              compressed);
         break;
       case rocksdb::kZlibCompression:
-        ok = Zlib_Compress(compression_info, 2, input.data(), input.size(),
+        ok = Zlib_Compress(compression_ctx, 2, input.data(), input.size(),
                            compressed);
         break;
       case rocksdb::kBZip2Compression:
-        ok = BZip2_Compress(compression_info, 2, input.data(), input.size(),
+        ok = BZip2_Compress(compression_ctx, 2, input.data(), input.size(),
                             compressed);
         break;
       case rocksdb::kLZ4Compression:
-        ok = LZ4_Compress(compression_info, 2, input.data(), input.size(),
+        ok = LZ4_Compress(compression_ctx, 2, input.data(), input.size(),
                           compressed);
         break;
       case rocksdb::kLZ4HCCompression:
-        ok = LZ4HC_Compress(compression_info, 2, input.data(), input.size(),
+        ok = LZ4HC_Compress(compression_ctx, 2, input.data(), input.size(),
                             compressed);
         break;
       case rocksdb::kXpressCompression:
@@ -2020,7 +2020,7 @@ class Benchmark {
           input.size(), compressed);
         break;
       case rocksdb::kZSTD:
-        ok = ZSTD_Compress(compression_info, input.data(), input.size(),
+        ok = ZSTD_Compress(compression_ctx, input.data(), input.size(),
                            compressed);
         break;
       default:
@@ -2103,11 +2103,10 @@ class Benchmark {
       const int len = FLAGS_block_size;
       std::string input_str(len, 'y');
       std::string compressed;
-      CompressionOptions opts;
-      CompressionContext context(FLAGS_compression_type_e);
-      CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(),
-                           FLAGS_compression_type_e);
-      bool result = CompressSlice(info, Slice(input_str), &compressed);
+      CompressionContext compression_ctx(FLAGS_compression_type_e,
+                                         Options().compression_opts);
+      bool result =
+          CompressSlice(compression_ctx, Slice(input_str), &compressed);
 
       if (!result) {
         fprintf(stdout, "WARNING: %s compression is not enabled\n",
@@ -2957,14 +2956,13 @@ void VerifyDBFromDB(std::string& truth_db_name) {
     int64_t produced = 0;
     bool ok = true;
     std::string compressed;
-    CompressionOptions opts;
-    CompressionContext context(FLAGS_compression_type_e);
-    CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(),
-                         FLAGS_compression_type_e);
+    CompressionContext compression_ctx(FLAGS_compression_type_e,
+                                       Options().compression_opts);
+
     // Compress 1G
     while (ok && bytes < int64_t(1) << 30) {
       compressed.clear();
-      ok = CompressSlice(info, input, &compressed);
+      ok = CompressSlice(compression_ctx, input, &compressed);
       produced += compressed.size();
       bytes += input.size();
       thread->stats.FinishedOps(nullptr, nullptr, 1, kCompress);
@@ -2986,17 +2984,11 @@ void VerifyDBFromDB(std::string& truth_db_name) {
     Slice input = gen.Generate(FLAGS_block_size);
     std::string compressed;
 
-    CompressionContext compression_ctx(FLAGS_compression_type_e);
-    CompressionOptions compression_opts;
-    CompressionInfo compression_info(compression_opts, compression_ctx,
-                                     CompressionDict::GetEmptyDict(),
-                                     FLAGS_compression_type_e);
     UncompressionContext uncompression_ctx(FLAGS_compression_type_e);
-    UncompressionInfo uncompression_info(uncompression_ctx,
-                                         CompressionDict::GetEmptyDict(),
-                                         FLAGS_compression_type_e);
+    CompressionContext compression_ctx(FLAGS_compression_type_e,
+                                       Options().compression_opts);
 
-    bool ok = CompressSlice(compression_info, input, &compressed);
+    bool ok = CompressSlice(compression_ctx, input, &compressed);
     int64_t bytes = 0;
     int decompress_size;
     while (ok && bytes < 1024 * 1048576) {
@@ -3016,7 +3008,7 @@ void VerifyDBFromDB(std::string& truth_db_name) {
           break;
         }
       case rocksdb::kZlibCompression:
-        uncompressed = Zlib_Uncompress(uncompression_info, compressed.data(),
+        uncompressed = Zlib_Uncompress(uncompression_ctx, compressed.data(),
                                        compressed.size(), &decompress_size, 2);
         ok = uncompressed != nullptr;
         break;
@@ -3026,12 +3018,12 @@ void VerifyDBFromDB(std::string& truth_db_name) {
         ok = uncompressed != nullptr;
         break;
       case rocksdb::kLZ4Compression:
-        uncompressed = LZ4_Uncompress(uncompression_info, compressed.data(),
+        uncompressed = LZ4_Uncompress(uncompression_ctx, compressed.data(),
                                       compressed.size(), &decompress_size, 2);
         ok = uncompressed != nullptr;
         break;
       case rocksdb::kLZ4HCCompression:
-        uncompressed = LZ4_Uncompress(uncompression_info, compressed.data(),
+        uncompressed = LZ4_Uncompress(uncompression_ctx, compressed.data(),
                                       compressed.size(), &decompress_size, 2);
         ok = uncompressed != nullptr;
         break;
@@ -3041,7 +3033,7 @@ void VerifyDBFromDB(std::string& truth_db_name) {
         ok = uncompressed != nullptr;
         break;
       case rocksdb::kZSTD:
-        uncompressed = ZSTD_Uncompress(uncompression_info, compressed.data(),
+        uncompressed = ZSTD_Uncompress(uncompression_ctx, compressed.data(),
                                        compressed.size(), &decompress_size);
         ok = uncompressed != nullptr;
         break;

util/compression.h

@@ -133,147 +133,13 @@ class ZSTDUncompressCachedData {
 
 namespace rocksdb {
 
-// Holds dictionary and related data, like ZSTD's digested dictionary.
-struct CompressionDict {
-  enum class Mode {
-    kUninit,
-    kEmpty,  // An empty one can be used for both compression and uncompression
-    kCompression,
-    kUncompression,
-  };
-#if ZSTD_VERSION_NUMBER >= 700
-  union {
-    ZSTD_CDict* zstd_cdict_;
-    ZSTD_DDict* zstd_ddict_;
-  };
-#endif  // ZSTD_VERSION_NUMBER >= 700
-  Mode mode_ = Mode::kUninit;
-  Slice dict_;
-
- public:
-  static const CompressionDict& GetEmptyDict() {
-    static CompressionDict empty_dict{};
-    static bool init = false;
-    if (!init) {
-      empty_dict.Init(Slice() /* dict */, Mode::kEmpty,
-                      false /* use_zstd_trainer */);
-      init = true;
-    }
-    return empty_dict;
-  }
-
-  void Init(Slice dict, Mode mode, CompressionType type, int level = -1) {
-    return Init(dict, mode, type == kZSTD || type == kZSTDNotFinalCompression,
-                level);
-  }
-
- private:
-#if ZSTD_VERSION_NUMBER >= 700
-  void Init(Slice dict, Mode mode, bool use_zstd_trainer, int level = -1) {
-#else   // ZSTD_VERSION_NUMBER >= 700
-  void Init(Slice dict, Mode mode, bool /* use_zstd_trainer */,
-            int /*level*/ = -1) {
-#endif  // ZSTD_VERSION_NUMBER >= 700
-    assert(mode_ == Mode::kUninit);
-    dict_ = std::move(dict);
-    mode_ = mode;
-    switch (mode) {
-      case Mode::kUninit:
-        assert(false);
-        break;
-      case Mode::kEmpty:
-        break;
-      case Mode::kCompression:
-#if ZSTD_VERSION_NUMBER >= 700
-        zstd_cdict_ = nullptr;
-        if (!dict_.empty() && use_zstd_trainer) {
-          if (level == CompressionOptions::kDefaultCompressionLevel) {
-            // 3 is the value of ZSTD_CLEVEL_DEFAULT (not exposed publicly), see
-            // https://github.com/facebook/zstd/issues/1148
-            level = 3;
-          }
-          // Should be safe (but slower) if below call fails as we'll use the
-          // raw dictionary to compress.
-          zstd_cdict_ = ZSTD_createCDict(dict_.data(), dict_.size(), level);
-          assert(zstd_cdict_ != nullptr);
-        }
-#endif  // ZSTD_VERSION_NUMBER >= 700
-        break;
-      case Mode::kUncompression:
-#if ZSTD_VERSION_NUMBER >= 700
-        zstd_ddict_ = nullptr;
-        if (!dict_.empty() && use_zstd_trainer) {
-          zstd_ddict_ = ZSTD_createDDict(dict_.data(), dict_.size());
-          assert(zstd_ddict_ != nullptr);
-        }
-#endif  // ZSTD_VERSION_NUMBER >= 700
-        break;
-    }
-  }
-
- public:
-  ~CompressionDict() {
-#if ZSTD_VERSION_NUMBER >= 700
-    size_t res = 0;
-    switch (mode_) {
-      case Mode::kUninit:
-        break;
-      case Mode::kEmpty:
-        break;
-      case Mode::kCompression:
-        if (zstd_cdict_ != nullptr) {
-          res = ZSTD_freeCDict(zstd_cdict_);
-        }
-        break;
-      case Mode::kUncompression:
-        if (zstd_ddict_ != nullptr) {
-          res = ZSTD_freeDDict(zstd_ddict_);
-        }
-        break;
-    }
-    assert(res == 0);  // Last I checked they can't fail
-    (void)res;         // prevent unused var warning
-#endif                 // ZSTD_VERSION_NUMBER >= 700
-  }
-
-#if ZSTD_VERSION_NUMBER >= 700
-  const ZSTD_CDict* GetDigestedZstdCDict() const {
-    assert(mode_ != Mode::kUninit);
-    if (mode_ == Mode::kEmpty) {
-      return nullptr;
-    }
-    assert(mode_ == Mode::kCompression);
-    return zstd_cdict_;
-  }
-
-  const ZSTD_DDict* GetDigestedZstdDDict() const {
-    assert(mode_ != Mode::kUninit);
-    if (mode_ == Mode::kEmpty) {
-      return nullptr;
-    }
-    assert(mode_ == Mode::kUncompression);
-    return zstd_ddict_;
-  }
-#endif  // ZSTD_VERSION_NUMBER >= 700
-
-  Slice GetRawDict() const {
-    assert(mode_ != Mode::kUninit);
-    assert(mode_ != Mode::kEmpty || dict_.empty());
-    return dict_;
-  }
-
-  CompressionDict() = default;
-  // Disable copy/move
-  CompressionDict(const CompressionDict&) = delete;
-  CompressionDict& operator=(const CompressionDict&) = delete;
-  CompressionDict(CompressionDict&&) = delete;
-  CompressionDict& operator=(CompressionDict&&) = delete;
-};
-
+// Instantiate this class and pass it to the uncompression API below
 class CompressionContext {
-#if defined(ZSTD) && (ZSTD_VERSION_NUMBER >= 500)
  private:
   const CompressionType type_;
+  const CompressionOptions opts_;
+  Slice dict_;
+#if defined(ZSTD) && (ZSTD_VERSION_NUMBER >= 500)
   ZSTD_CCtx* zstd_ctx_ = nullptr;
   void CreateNativeContext() {
     if (type_ == kZSTD || type_ == kZSTDNotFinalCompression) {
@@ -297,45 +163,35 @@ class CompressionContext {
     assert(type_ == kZSTD || type_ == kZSTDNotFinalCompression);
     return zstd_ctx_;
   }
-
-  explicit CompressionContext(CompressionType comp_type) : type_(comp_type) {
-    CreateNativeContext();
-  }
-
 #else   // ZSTD && (ZSTD_VERSION_NUMBER >= 500)
- public:
-  explicit CompressionContext(CompressionType /* comp_type */) {}
  private:
   void CreateNativeContext() {}
   void DestroyNativeContext() {}
 #endif  // ZSTD && (ZSTD_VERSION_NUMBER >= 500)
  public:
+  explicit CompressionContext(CompressionType comp_type) : type_(comp_type) {
+    CreateNativeContext();
+  }
+  CompressionContext(CompressionType comp_type, const CompressionOptions& opts,
+                     const Slice& comp_dict = Slice())
+      : type_(comp_type), opts_(opts), dict_(comp_dict) {
+    CreateNativeContext();
+  }
   ~CompressionContext() { DestroyNativeContext(); }
   CompressionContext(const CompressionContext&) = delete;
   CompressionContext& operator=(const CompressionContext&) = delete;
-};
-
-class CompressionInfo {
-  const CompressionOptions& opts_;
-  const CompressionContext& context_;
-  const CompressionDict& dict_;
-  const CompressionType type_;
-
- public:
-  CompressionInfo(const CompressionOptions& _opts,
-                  const CompressionContext& _context,
-                  const CompressionDict& _dict, CompressionType _type)
-      : opts_(_opts), context_(_context), dict_(_dict), type_(_type) {}
 
   const CompressionOptions& options() const { return opts_; }
-  const CompressionContext& context() const { return context_; }
-  const CompressionDict& dict() const { return dict_; }
   CompressionType type() const { return type_; }
+  const Slice& dict() const { return dict_; }
+  Slice& dict() { return dict_; }
 };
 
+// Instantiate this class and pass it to the uncompression API below
 class UncompressionContext {
  private:
-  const CompressionType type_;
+  CompressionType type_;
+  Slice dict_;
   CompressionContextCache* ctx_cache_ = nullptr;
   ZSTDUncompressCachedData uncomp_cached_data_;
 
@@ -343,8 +199,10 @@ class UncompressionContext {
   struct NoCache {};
   // Do not use context cache, used by TableBuilder
   UncompressionContext(NoCache, CompressionType comp_type) : type_(comp_type) {}
-
-  explicit UncompressionContext(CompressionType comp_type) : type_(comp_type) {
+  explicit UncompressionContext(CompressionType comp_type)
+      : UncompressionContext(comp_type, Slice()) {}
+  UncompressionContext(CompressionType comp_type, const Slice& comp_dict)
+      : type_(comp_type), dict_(comp_dict) {
     if (type_ == kZSTD || type_ == kZSTDNotFinalCompression) {
       ctx_cache_ = CompressionContextCache::Instance();
       uncomp_cached_data_ = ctx_cache_->GetCachedZSTDUncompressData();
@@ -364,21 +222,9 @@ class UncompressionContext {
   ZSTDUncompressCachedData::ZSTDNativeContext GetZSTDContext() const {
     return uncomp_cached_data_.Get();
   }
-};
-
-class UncompressionInfo {
-  const UncompressionContext& context_;
-  const CompressionDict& dict_;
-  const CompressionType type_;
-
- public:
-  UncompressionInfo(const UncompressionContext& _context,
-                    const CompressionDict& _dict, CompressionType _type)
-      : context_(_context), dict_(_dict), type_(_type) {}
-
-  const UncompressionContext& context() const { return context_; }
-  const CompressionDict& dict() const { return dict_; }
   CompressionType type() const { return type_; }
+  const Slice& dict() const { return dict_; }
+  Slice& dict() { return dict_; }
 };
 
 inline bool Snappy_Supported() {
@@ -497,8 +343,9 @@ inline std::string CompressionTypeToString(CompressionType compression_type) {
 // 2 -- Zlib, BZip2 and LZ4 encode decompressed size as Varint32 just before the
 // start of compressed block. Snappy format is the same as version 1.
 
-inline bool Snappy_Compress(const CompressionInfo& /*info*/, const char* input,
-                            size_t length, ::std::string* output) {
+inline bool Snappy_Compress(const CompressionContext& /*ctx*/,
+                            const char* input, size_t length,
+                            ::std::string* output) {
 #ifdef SNAPPY
   output->resize(snappy::MaxCompressedLength(length));
   size_t outlen;
@@ -563,7 +410,7 @@ inline bool GetDecompressedSizeInfo(const char** input_data,
 // header in varint32 format
 // @param compression_dict Data for presetting the compression library's
 //    dictionary.
-inline bool Zlib_Compress(const CompressionInfo& info,
+inline bool Zlib_Compress(const CompressionContext& ctx,
                           uint32_t compress_format_version, const char* input,
                           size_t length, ::std::string* output) {
 #ifdef ZLIB
@@ -588,25 +435,24 @@ inline bool Zlib_Compress(const CompressionInfo& info,
   // The default value is 8. See zconf.h for more details.
   static const int memLevel = 8;
   int level;
-  if (info.options().level == CompressionOptions::kDefaultCompressionLevel) {
+  if (ctx.options().level == CompressionOptions::kDefaultCompressionLevel) {
     level = Z_DEFAULT_COMPRESSION;
   } else {
-    level = info.options().level;
+    level = ctx.options().level;
   }
   z_stream _stream;
   memset(&_stream, 0, sizeof(z_stream));
-  int st = deflateInit2(&_stream, level, Z_DEFLATED, info.options().window_bits,
-                        memLevel, info.options().strategy);
+  int st = deflateInit2(&_stream, level, Z_DEFLATED, ctx.options().window_bits,
+                        memLevel, ctx.options().strategy);
   if (st != Z_OK) {
     return false;
   }
 
-  Slice compression_dict = info.dict().GetRawDict();
-  if (compression_dict.size()) {
+  if (ctx.dict().size()) {
     // Initialize the compression library's dictionary
-    st = deflateSetDictionary(
-        &_stream, reinterpret_cast<const Bytef*>(compression_dict.data()),
-        static_cast<unsigned int>(compression_dict.size()));
+    st = deflateSetDictionary(&_stream,
+                              reinterpret_cast<const Bytef*>(ctx.dict().data()),
+                              static_cast<unsigned int>(ctx.dict().size()));
     if (st != Z_OK) {
       deflateEnd(&_stream);
       return false;
@@ -634,7 +480,7 @@ inline bool Zlib_Compress(const CompressionInfo& info,
   deflateEnd(&_stream);
   return compressed;
 #else
-  (void)info;
+  (void)ctx;
   (void)compress_format_version;
   (void)input;
   (void)length;
@@ -649,7 +495,7 @@ inline bool Zlib_Compress(const CompressionInfo& info,
 // header in varint32 format
 // @param compression_dict Data for presetting the compression library's
 //    dictionary.
-inline char* Zlib_Uncompress(const UncompressionInfo& info,
+inline char* Zlib_Uncompress(const UncompressionContext& ctx,
                              const char* input_data, size_t input_length,
                              int* decompress_size,
                              uint32_t compress_format_version,
@@ -682,12 +528,11 @@ inline char* Zlib_Uncompress(const UncompressionInfo& info,
     return nullptr;
   }
 
-  Slice compression_dict = info.dict().GetRawDict();
-  if (compression_dict.size()) {
+  if (ctx.dict().size()) {
     // Initialize the compression library's dictionary
-    st = inflateSetDictionary(
-        &_stream, reinterpret_cast<const Bytef*>(compression_dict.data()),
-        static_cast<unsigned int>(compression_dict.size()));
+    st = inflateSetDictionary(&_stream,
+                              reinterpret_cast<const Bytef*>(ctx.dict().data()),
+                              static_cast<unsigned int>(ctx.dict().size()));
     if (st != Z_OK) {
       return nullptr;
     }
@@ -740,7 +585,7 @@ inline char* Zlib_Uncompress(const UncompressionInfo& info,
   inflateEnd(&_stream);
   return output;
 #else
-  (void)info;
+  (void)ctx;
   (void)input_data;
   (void)input_length;
   (void)decompress_size;
@@ -754,7 +599,7 @@ inline char* Zlib_Uncompress(const UncompressionInfo& info,
 // block header
 // compress_format_version == 2 -- decompressed size is included in the block
 // header in varint32 format
-inline bool BZip2_Compress(const CompressionInfo& /*info*/,
+inline bool BZip2_Compress(const CompressionContext& /*ctx*/,
                            uint32_t compress_format_version, const char* input,
                            size_t length, ::std::string* output) {
 #ifdef BZIP2
@@ -901,7 +746,7 @@ inline char* BZip2_Uncompress(const char* input_data, size_t input_length,
 // header in varint32 format
 // @param compression_dict Data for presetting the compression library's
 //    dictionary.
-inline bool LZ4_Compress(const CompressionInfo& info,
+inline bool LZ4_Compress(const CompressionContext& ctx,
                          uint32_t compress_format_version, const char* input,
                          size_t length, ::std::string* output) {
 #ifdef LZ4
@@ -929,10 +774,9 @@ inline bool LZ4_Compress(const CompressionInfo& info,
   int outlen;
 #if LZ4_VERSION_NUMBER >= 10400  // r124+
   LZ4_stream_t* stream = LZ4_createStream();
-  Slice compression_dict = info.dict().GetRawDict();
-  if (compression_dict.size()) {
-    LZ4_loadDict(stream, compression_dict.data(),
-                 static_cast<int>(compression_dict.size()));
+  if (ctx.dict().size()) {
+    LZ4_loadDict(stream, ctx.dict().data(),
+                 static_cast<int>(ctx.dict().size()));
   }
 #if LZ4_VERSION_NUMBER >= 10700  // r129+
   outlen =
@@ -955,7 +799,7 @@ inline bool LZ4_Compress(const CompressionInfo& info,
   output->resize(static_cast<size_t>(output_header_len + outlen));
   return true;
 #else  // LZ4
-  (void)info;
+  (void)ctx;
   (void)compress_format_version;
   (void)input;
   (void)length;
@@ -970,7 +814,7 @@ inline bool LZ4_Compress(const CompressionInfo& info,
 // header in varint32 format
 // @param compression_dict Data for presetting the compression library's
 //    dictionary.
-inline char* LZ4_Uncompress(const UncompressionInfo& info,
+inline char* LZ4_Uncompress(const UncompressionContext& ctx,
                             const char* input_data, size_t input_length,
                             int* decompress_size,
                             uint32_t compress_format_version) {
@@ -996,10 +840,9 @@ inline char* LZ4_Uncompress(const UncompressionInfo& info,
   char* output = new char[output_len];
 #if LZ4_VERSION_NUMBER >= 10400  // r124+
   LZ4_streamDecode_t* stream = LZ4_createStreamDecode();
-  Slice compression_dict = info.dict().GetRawDict();
-  if (compression_dict.size()) {
-    LZ4_setStreamDecode(stream, compression_dict.data(),
-                        static_cast<int>(compression_dict.size()));
+  if (ctx.dict().size()) {
+    LZ4_setStreamDecode(stream, ctx.dict().data(),
+                        static_cast<int>(ctx.dict().size()));
   }
   *decompress_size = LZ4_decompress_safe_continue(
       stream, input_data, output, static_cast<int>(input_length),
@@ -1018,7 +861,7 @@ inline char* LZ4_Uncompress(const UncompressionInfo& info,
   assert(*decompress_size == static_cast<int>(output_len));
   return output;
 #else  // LZ4
-  (void)info;
+  (void)ctx;
   (void)input_data;
   (void)input_length;
   (void)decompress_size;
@@ -1033,7 +876,7 @@ inline char* LZ4_Uncompress(const UncompressionInfo& info,
 // header in varint32 format
 // @param compression_dict Data for presetting the compression library's
 //    dictionary.
-inline bool LZ4HC_Compress(const CompressionInfo& info,
+inline bool LZ4HC_Compress(const CompressionContext& ctx,
                            uint32_t compress_format_version, const char* input,
                            size_t length, ::std::string* output) {
 #ifdef LZ4
@@ -1060,18 +903,17 @@ inline bool LZ4HC_Compress(const CompressionInfo& info,
 
   int outlen;
   int level;
-  if (info.options().level == CompressionOptions::kDefaultCompressionLevel) {
+  if (ctx.options().level == CompressionOptions::kDefaultCompressionLevel) {
     level = 0;  // lz4hc.h says any value < 1 will be sanitized to default
   } else {
-    level = info.options().level;
+    level = ctx.options().level;
   }
 #if LZ4_VERSION_NUMBER >= 10400  // r124+
   LZ4_streamHC_t* stream = LZ4_createStreamHC();
   LZ4_resetStreamHC(stream, level);
-  Slice compression_dict = info.dict().GetRawDict();
   const char* compression_dict_data =
-      compression_dict.size() > 0 ? compression_dict.data() : nullptr;
-  size_t compression_dict_size = compression_dict.size();
+      ctx.dict().size() > 0 ? ctx.dict().data() : nullptr;
+  size_t compression_dict_size = ctx.dict().size();
   LZ4_loadDictHC(stream, compression_dict_data,
                  static_cast<int>(compression_dict_size));
 
@@ -1102,7 +944,7 @@ inline bool LZ4HC_Compress(const CompressionInfo& info,
   output->resize(static_cast<size_t>(output_header_len + outlen));
   return true;
 #else  // LZ4
-  (void)info;
+  (void)ctx;
   (void)compress_format_version;
   (void)input;
   (void)length;
@@ -1136,7 +978,9 @@ inline char* XPRESS_Uncompress(const char* /*input_data*/,
 }
 #endif
 
-inline bool ZSTD_Compress(const CompressionInfo& info, const char* input,
+// @param compression_dict Data for presetting the compression library's
+//    dictionary.
+inline bool ZSTD_Compress(const CompressionContext& ctx, const char* input,
                           size_t length, ::std::string* output) {
 #ifdef ZSTD
   if (length > std::numeric_limits<uint32_t>::max()) {
@@ -1151,29 +995,19 @@ inline bool ZSTD_Compress(const CompressionInfo& info, const char* input,
   output->resize(static_cast<size_t>(output_header_len + compressBound));
   size_t outlen = 0;
   int level;
-  if (info.options().level == CompressionOptions::kDefaultCompressionLevel) {
+  if (ctx.options().level == CompressionOptions::kDefaultCompressionLevel) {
     // 3 is the value of ZSTD_CLEVEL_DEFAULT (not exposed publicly), see
     // https://github.com/facebook/zstd/issues/1148
     level = 3;
   } else {
-    level = info.options().level;
+    level = ctx.options().level;
   }
 #if ZSTD_VERSION_NUMBER >= 500  // v0.5.0+
-  ZSTD_CCtx* context = info.context().ZSTDPreallocCtx();
+  ZSTD_CCtx* context = ctx.ZSTDPreallocCtx();
   assert(context != nullptr);
-#if ZSTD_VERSION_NUMBER >= 700  // v0.7.0+
-  if (info.dict().GetDigestedZstdCDict() != nullptr) {
-    outlen = ZSTD_compress_usingCDict(context, &(*output)[output_header_len],
-                                      compressBound, input, length,
-                                      info.dict().GetDigestedZstdCDict());
-  }
-#endif  // ZSTD_VERSION_NUMBER >= 700
-  if (outlen == 0) {
   outlen = ZSTD_compress_usingDict(context, &(*output)[output_header_len],
                                    compressBound, input, length,
-                                     info.dict().GetRawDict().data(),
-                                     info.dict().GetRawDict().size(), level);
-  }
+                                   ctx.dict().data(), ctx.dict().size(), level);
 #else   // up to v0.4.x
   outlen = ZSTD_compress(&(*output)[output_header_len], compressBound, input,
                          length, level);
@@ -1184,7 +1018,7 @@ inline bool ZSTD_Compress(const CompressionInfo& info, const char* input,
   output->resize(output_header_len + outlen);
   return true;
 #else  // ZSTD
-  (void)info;
+  (void)ctx;
   (void)input;
   (void)length;
   (void)output;
@@ -1194,7 +1028,7 @@ inline bool ZSTD_Compress(const CompressionInfo& info, const char* input,
 
 // @param compression_dict Data for presetting the compression library's
 //    dictionary.
-inline char* ZSTD_Uncompress(const UncompressionInfo& info,
+inline char* ZSTD_Uncompress(const UncompressionContext& ctx,
                              const char* input_data, size_t input_length,
                              int* decompress_size) {
 #ifdef ZSTD
@@ -1205,24 +1039,14 @@ inline char* ZSTD_Uncompress(const UncompressionInfo& info,
   }
 
   char* output = new char[output_len];
-  size_t actual_output_length = 0;
+  size_t actual_output_length;
 #if ZSTD_VERSION_NUMBER >= 500  // v0.5.0+
-  ZSTD_DCtx* context = info.context().GetZSTDContext();
+  ZSTD_DCtx* context = ctx.GetZSTDContext();
   assert(context != nullptr);
-#if ZSTD_VERSION_NUMBER >= 700  // v0.7.0+
-  if (info.dict().GetDigestedZstdDDict() != nullptr) {
-    actual_output_length = ZSTD_decompress_usingDDict(
-        context, output, output_len, input_data, input_length,
-        info.dict().GetDigestedZstdDDict());
-  }
-#endif  // ZSTD_VERSION_NUMBER >= 700
-  if (actual_output_length == 0) {
   actual_output_length = ZSTD_decompress_usingDict(
-        context, output, output_len, input_data, input_length,
-        info.dict().GetRawDict().data(), info.dict().GetRawDict().size());
-  }
+      context, output, output_len, input_data, input_length, ctx.dict().data(),
+      ctx.dict().size());
 #else   // up to v0.4.x
-  (void) info;
   actual_output_length =
       ZSTD_decompress(output, output_len, input_data, input_length);
 #endif  // ZSTD_VERSION_NUMBER >= 500
@@ -1230,7 +1054,7 @@ inline char* ZSTD_Uncompress(const UncompressionInfo& info,
   *decompress_size = static_cast<int>(actual_output_length);
   return output;
 #else  // ZSTD
-  (void)info;
+  (void)ctx;
   (void)input_data;
   (void)input_length;
   (void)decompress_size;
@@ -1245,10 +1069,6 @@ inline std::string ZSTD_TrainDictionary(const std::string& samples,
   // available for dynamic linking until v1.1.3. For now we enable the feature
   // in v1.1.3+ only.
 #if ZSTD_VERSION_NUMBER >= 10103  // v1.1.3+
-  assert(samples.empty() == sample_lens.empty());
-  if (samples.empty()) {
-    return "";
-  }
   std::string dict_data(max_dict_bytes, '\0');
   size_t dict_len = ZDICT_trainFromBuffer(
       &dict_data[0], max_dict_bytes, &samples[0], &sample_lens[0],

utilities/blob_db/blob_db_impl.cc

@@ -738,11 +738,9 @@ Slice BlobDBImpl::GetCompressedSlice(const Slice& raw,
     return raw;
   }
   StopWatch compression_sw(env_, statistics_, BLOB_DB_COMPRESSION_MICROS);
-  CompressionType type = bdb_options_.compression;
-  CompressionOptions opts;
-  CompressionContext context(type);
-  CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(), type);
-  CompressBlock(raw, info, &type, kBlockBasedTableVersionFormat,
+  CompressionType ct = bdb_options_.compression;
+  CompressionContext compression_ctx(ct);
+  CompressBlock(raw, compression_ctx, &ct, kBlockBasedTableVersionFormat,
                 compression_output);
   return *compression_output;
 }
@@ -1075,11 +1073,9 @@ Status BlobDBImpl::GetBlobValue(const Slice& key, const Slice& index_entry,
     {
       StopWatch decompression_sw(env_, statistics_,
                                  BLOB_DB_DECOMPRESSION_MICROS);
-      UncompressionContext context(bfile->compression());
-      UncompressionInfo info(context, CompressionDict::GetEmptyDict(),
-                             bfile->compression());
+      UncompressionContext uncompression_ctx(bfile->compression());
       s = UncompressBlockContentsForCompressionType(
-          info, blob_value.data(), blob_value.size(), &contents,
+          uncompression_ctx, blob_value.data(), blob_value.size(), &contents,
           kBlockBasedTableVersionFormat, *(cfh->cfd()->ioptions()));
     }
     value->PinSelf(contents.data);

utilities/blob_db/blob_dump_tool.cc

@@ -208,12 +208,10 @@ Status BlobDumpTool::DumpRecord(DisplayType show_key, DisplayType show_blob,
   if (compression != kNoCompression &&
       (show_uncompressed_blob != DisplayType::kNone || show_summary)) {
     BlockContents contents;
-    UncompressionContext context(compression);
-    UncompressionInfo info(context, CompressionDict::GetEmptyDict(),
-                           compression);
+    UncompressionContext uncompression_ctx(compression);
     s = UncompressBlockContentsForCompressionType(
-        info, slice.data() + key_size, static_cast<size_t>(value_size), &contents,
-        2 /*compress_format_version*/, ImmutableCFOptions(Options()));
+        uncompression_ctx, slice.data() + key_size, static_cast<size_t>(value_size),
+        &contents, 2 /*compress_format_version*/, ImmutableCFOptions(Options()));
     if (!s.ok()) {
       return s;
     }

utilities/column_aware_encoding_util.cc

@@ -89,9 +89,8 @@ void ColumnAwareEncodingReader::DecodeBlocks(
     CompressionType type =
         (CompressionType)slice_final_with_bit[slice_final_with_bit.size() - 1];
     if (type != kNoCompression) {
-      UncompressionContext context(type);
-      UncompressionInfo info(context, CompressionDict::GetEmptyDict(), type);
-      UncompressBlockContents(info, slice_final_with_bit.c_str(),
+      UncompressionContext uncompression_ctx(type);
+      UncompressBlockContents(uncompression_ctx, slice_final_with_bit.c_str(),
                               slice_final_with_bit.size() - 1, &contents,
                               format_version, ioptions);
       content_ptr = contents.data.data();
@@ -172,9 +171,8 @@ void ColumnAwareEncodingReader::DecodeBlocksFromRowFormat(
     CompressionType type =
         (CompressionType)slice_final_with_bit[slice_final_with_bit.size() - 1];
     if (type != kNoCompression) {
-      UncompressionContext context(type);
-      UncompressionInfo info(context, CompressionDict::GetEmptyDict(), type);
-      UncompressBlockContents(info, slice_final_with_bit.c_str(),
+      UncompressionContext uncompression_ctx(type);
+      UncompressBlockContents(uncompression_ctx, slice_final_with_bit.c_str(),
                               slice_final_with_bit.size() - 1, &contents,
                               format_version, ioptions);
       decoded_content = std::string(contents.data.data(), contents.data.size());
@@ -245,12 +243,10 @@ namespace {
 
 void CompressDataBlock(const std::string& output_content, Slice* slice_final,
                        CompressionType* type, std::string* compressed_output) {
-  CompressionContext context(*type);
-  CompressionOptions opts;
-  CompressionInfo info(opts, context, CompressionDict::GetEmptyDict(), *type);
+  CompressionContext compression_ctx(*type);
   uint32_t format_version = 2;  // hard-coded version
-  *slice_final = CompressBlock(output_content, info, type, format_version,
-                               compressed_output);
+  *slice_final = CompressBlock(output_content, compression_ctx, type,
+                               format_version, compressed_output);
 }
 
 }  // namespace