Merge branch 'master' into performance

Conflicts:
	db/db_impl.cc
	util/options.cc

db/c.cc

@@ -502,6 +502,13 @@ void leveldb_options_set_compression(leveldb_options_t* opt, int t) {
   opt->rep.compression = static_cast<CompressionType>(t);
 }
 
+void leveldb_options_set_compression_options(
+    leveldb_options_t* opt, int w_bits, int level, int strategy) {
+  opt->rep.compression_opts.window_bits = w_bits;
+  opt->rep.compression_opts.level = level;
+  opt->rep.compression_opts.strategy = strategy;
+}
+
 void leveldb_options_set_disable_data_sync(
     leveldb_options_t* opt, bool disable_data_sync) {
   opt->rep.disableDataSync = disable_data_sync;

db/c_test.c

@@ -187,6 +187,7 @@ int main(int argc, char** argv) {
   leveldb_options_set_block_size(options, 1024);
   leveldb_options_set_block_restart_interval(options, 8);
   leveldb_options_set_compression(options, leveldb_no_compression);
+  leveldb_options_set_compression_options(options, -14, -1, 0);
 
   roptions = leveldb_readoptions_create();
   leveldb_readoptions_set_verify_checksums(roptions, 1);

db/db_bench.cc

@@ -193,6 +193,8 @@ static enum leveldb::CompressionType FLAGS_compression_type =
 // other levels are compressed
 static int FLAGS_min_level_to_compress = -1;
 
+static int FLAGS_table_cache_numshardbits = 4;
+
 // posix or hdfs environment
 static leveldb::Env* FLAGS_env = leveldb::Env::Default();
 
@@ -518,15 +520,18 @@ class Benchmark {
 
       switch (FLAGS_compression_type) {
         case kSnappyCompression:
-          result = port::Snappy_Compress(text, strlen(text), &compressed);
+          result = port::Snappy_Compress(Options().compression_opts, text,
+                                         strlen(text), &compressed);
           name = "Snappy";
           break;
         case kZlibCompression:
-          result = port::Zlib_Compress(text, strlen(text), &compressed);
+          result = port::Zlib_Compress(Options().compression_opts, text,
+                                       strlen(text), &compressed);
           name = "Zlib";
           break;
         case kBZip2Compression:
-          result = port::BZip2_Compress(text, strlen(text), &compressed);
+          result = port::BZip2_Compress(Options().compression_opts, text,
+                                        strlen(text), &compressed);
           name = "BZip2";
           break;
       }
@@ -864,7 +869,8 @@ class Benchmark {
     bool ok = true;
     std::string compressed;
     while (ok && bytes < 1024 * 1048576) {  // Compress 1G
-      ok = port::Snappy_Compress(input.data(), input.size(), &compressed);
+      ok = port::Snappy_Compress(Options().compression_opts, input.data(),
+                                 input.size(), &compressed);
       produced += compressed.size();
       bytes += input.size();
       thread->stats.FinishedSingleOp(NULL);
@@ -885,7 +891,8 @@ class Benchmark {
     RandomGenerator gen;
     Slice input = gen.Generate(Options().block_size);
     std::string compressed;
-    bool ok = port::Snappy_Compress(input.data(), input.size(), &compressed);
+    bool ok = port::Snappy_Compress(Options().compression_opts, input.data(),
+                                    input.size(), &compressed);
     int64_t bytes = 0;
     char* uncompressed = new char[input.size()];
     while (ok && bytes < 1024 * 1048576) {  // Compress 1G
@@ -908,6 +915,9 @@ class Benchmark {
     Options options;
     options.create_if_missing = !FLAGS_use_existing_db;
     options.block_cache = cache_;
+    if (cache_ == NULL) {
+      options.no_block_cache = true;
+    }
     options.write_buffer_size = FLAGS_write_buffer_size;
     options.max_write_buffer_number = FLAGS_max_write_buffer_number;
     options.max_background_compactions = FLAGS_max_background_compactions;
@@ -945,6 +955,7 @@ class Benchmark {
     options.delete_obsolete_files_period_micros =
       FLAGS_delete_obsolete_files_period_micros;
     options.rate_limit = FLAGS_rate_limit;
+    options.table_cache_numshardbits = FLAGS_table_cache_numshardbits;
     Status s = DB::Open(options, FLAGS_db, &db_);
     if (!s.ok()) {
       fprintf(stderr, "open error: %s\n", s.ToString().c_str());
@@ -1276,6 +1287,13 @@ int main(int argc, char** argv) {
         fprintf(stderr, "The cache cannot be sharded into 2**%d pieces\n", n);
         exit(1);
       }
+    } else if (sscanf(argv[i], "--table_cache_numshardbits=%d%c",
+		      &n, &junk) == 1) {
+      if (n <= 0 || n > 20) {
+        fprintf(stderr, "The cache cannot be sharded into 2**%d pieces\n", n);
+        exit(1);
+      }
+      FLAGS_table_cache_numshardbits = n;
     } else if (sscanf(argv[i], "--bloom_bits=%d%c", &n, &junk) == 1) {
       FLAGS_bloom_bits = n;
     } else if (sscanf(argv[i], "--open_files=%d%c", &n, &junk) == 1) {

db/db_impl.cc

@@ -155,7 +155,7 @@ Options SanitizeOptions(const std::string& dbname,
       result.info_log = NULL;
     }
   }
-  if (result.block_cache == NULL) {
+  if (result.block_cache == NULL && !result.no_block_cache) {
     result.block_cache = NewLRUCache(8 << 20);
   }
   if (src.compression_per_level != NULL) {
@@ -1707,9 +1707,14 @@ Status DBImpl::MakeRoomForWrite(bool force) {
       // this delay hands over some CPU to the compaction thread in
       // case it is sharing the same core as the writer.
       mutex_.Unlock();
+      uint64_t t1 = env_->NowMicros();
       env_->SleepForMicroseconds(1000);
-      stall_level0_slowdown_ += 1000;
+      uint64_t delayed = env_->NowMicros() - t1;
+      stall_level0_slowdown_ += delayed;
       allow_delay = false;  // Do not delay a single write more than once
+      //Log(options_.info_log,
+      //    "delaying write %llu usecs for level0_slowdown_writes_trigger\n",
+      //     delayed);
       mutex_.Lock();
       delayed_writes_++;
     } else if (!force &&
@@ -1741,11 +1746,14 @@ Status DBImpl::MakeRoomForWrite(bool force) {
         (score = versions_->MaxCompactionScore()) > options_.rate_limit) {
       // Delay a write when the compaction score for any level is too large.
       mutex_.Unlock();
+      uint64_t t1 = env_->NowMicros();
       env_->SleepForMicroseconds(1000);
-      stall_leveln_slowdown_ += 1000;
+      uint64_t delayed = env_->NowMicros() - t1;
+      stall_leveln_slowdown_ += delayed;
       allow_delay = false;  // Do not delay a single write more than once
       Log(options_.info_log,
-          "delaying write for rate limits with max score %.2f\n", score);
+          "delaying write %llu usecs for rate limits with max score %.2f\n",
+          delayed, score);
       mutex_.Lock();
     } else {
       // Attempt to switch to a new memtable and trigger compaction of old
@@ -1930,6 +1938,10 @@ Status DB::Open(const Options& options, const std::string& dbname,
                 DB** dbptr) {
   *dbptr = NULL;
 
+  if (options.block_cache != NULL && options.no_block_cache) {
+    return Status::InvalidArgument(
+        "no_block_cache is true while block_cache is not NULL");
+  }
   DBImpl* impl = new DBImpl(options, dbname);
   impl->mutex_.Lock();
   VersionEdit edit(impl->NumberLevels());

db/db_test.cc

@@ -20,22 +20,22 @@
 
 namespace leveldb {
 
-static bool SnappyCompressionSupported() {	
+static bool SnappyCompressionSupported(const CompressionOptions& options) {
   std::string out;
   Slice in = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
-  return port::Snappy_Compress(in.data(), in.size(), &out);	
+  return port::Snappy_Compress(options, in.data(), in.size(), &out);
 }
 
-static bool ZlibCompressionSupported() {	
+static bool ZlibCompressionSupported(const CompressionOptions& options) {
   std::string out;
   Slice in = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
-  return port::Zlib_Compress(in.data(), in.size(), &out);	
+  return port::Zlib_Compress(options, in.data(), in.size(), &out);
 }
 
-static bool BZip2CompressionSupported() {	
+static bool BZip2CompressionSupported(const CompressionOptions& options) {
   std::string out;
   Slice in = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
-  return port::BZip2_Compress(in.data(), in.size(), &out);	
+  return port::BZip2_Compress(options, in.data(), in.size(), &out);
 }
 
 static std::string RandomString(Random* rnd, int len) {
@@ -1105,22 +1105,24 @@ void MinLevelHelper(DBTest* self, Options& options) {
   ASSERT_EQ(self->NumTableFilesAtLevel(1), 1);
 }
 
-TEST(DBTest, MinLevelToCompress) {	
-  Options options = CurrentOptions();	
+void MinLevelToCompress(CompressionType& type, Options& options, int wbits,
+                        int lev, int strategy) {
+  fprintf(stderr, "Test with compression options : window_bits = %d, level =  %d, strategy = %d}\n", wbits, lev, strategy);
   options.write_buffer_size = 100<<10; //100KB
   options.num_levels = 3;
   options.max_mem_compaction_level = 0;
   options.level0_file_num_compaction_trigger = 3;
   options.create_if_missing = true;
-  CompressionType type;
 
-  if (SnappyCompressionSupported()) {	
+  if (SnappyCompressionSupported(CompressionOptions(wbits, lev, strategy))) {
     type = kSnappyCompression;
     fprintf(stderr, "using snappy\n");
-  } else if (ZlibCompressionSupported()) {	
+  } else if (ZlibCompressionSupported(
+               CompressionOptions(wbits, lev, strategy))) {
     type = kZlibCompression;
     fprintf(stderr, "using zlib\n");
-  } else if (BZip2CompressionSupported()) {	
+  } else if (BZip2CompressionSupported(
+               CompressionOptions(wbits, lev, strategy))) {
     type = kBZip2Compression;
     fprintf(stderr, "using bzip2\n");
   } else {
@@ -1136,6 +1138,29 @@ TEST(DBTest, MinLevelToCompress) {
   for (int i = 1; i < options.num_levels; i++) {
     options.compression_per_level[i] = type;
   }
+}
+TEST(DBTest, MinLevelToCompress1) {
+  Options options = CurrentOptions();
+  CompressionType type;
+  MinLevelToCompress(type, options, -14, -1, 0);
+  Reopen(&options);
+  MinLevelHelper(this, options);
+
+  // do not compress L0 and L1
+  for (int i = 0; i < 2; i++) {
+    options.compression_per_level[i] = kNoCompression;
+  }
+  for (int i = 2; i < options.num_levels; i++) {
+    options.compression_per_level[i] = type;
+  }
+  DestroyAndReopen(&options);
+  MinLevelHelper(this, options);
+}
+
+TEST(DBTest, MinLevelToCompress2) {
+  Options options = CurrentOptions();
+  CompressionType type;
+  MinLevelToCompress(type, options, 15, -1, 0);
   Reopen(&options);
   MinLevelHelper(this, options);
 
@@ -1682,6 +1707,29 @@ TEST(DBTest, DBOpen_Options) {
   db = NULL;
 }
 
+TEST(DBTest, DBOpen_Change_NumLevels) {
+  std::string dbname = test::TmpDir() + "/db_change_num_levels";
+  DestroyDB(dbname, Options());
+  Options opts;
+  Status s;
+  DB* db = NULL;
+  opts.create_if_missing = true;
+  s = DB::Open(opts, dbname, &db);
+  ASSERT_OK(s);
+  ASSERT_TRUE(db != NULL);
+  db->Put(WriteOptions(), "a", "123");
+  db->Put(WriteOptions(), "b", "234");
+  db->CompactRange(NULL, NULL);
+  delete db;
+  db = NULL;
+
+  opts.create_if_missing = false;
+  opts.num_levels = 2;
+  s = DB::Open(opts, dbname, &db);
+  ASSERT_TRUE(strstr(s.ToString().c_str(), "Corruption") != NULL);
+  ASSERT_TRUE(db == NULL);
+}
+
 // Check that number of files does not grow when we are out of space
 TEST(DBTest, NoSpace) {
   Options options = CurrentOptions();

db/table_cache.cc

@@ -39,7 +39,7 @@ TableCache::TableCache(const std::string& dbname,
     : env_(options->env),
       dbname_(dbname),
       options_(options),
-      cache_(NewLRUCache(entries)) {
+      cache_(NewLRUCache(entries, options->table_cache_numshardbits)) {
   dbstatistics = (DBStatistics*)options->statistics;
 }
 

include/leveldb/options.h

@@ -32,6 +32,19 @@ enum CompressionType {
   kBZip2Compression = 0x3
 };
 
+// Compression options for different compression algorithms like Zlib
+struct CompressionOptions {
+  int window_bits;
+  int level;
+  int strategy;
+  CompressionOptions():window_bits(-14),
+                       level(-1),
+                       strategy(0){}
+  CompressionOptions(int wbits, int lev, int strategy):window_bits(wbits),
+                                                       level(lev),
+                                                       strategy(strategy){}
+};
+
 // Options to control the behavior of a database (passed to DB::Open)
 struct Options {
   // -------------------
@@ -155,6 +168,9 @@ struct Options {
   // java/C api hard to construct.
   CompressionType* compression_per_level;
 
+  //different options for compression algorithms
+  CompressionOptions compression_opts;
+
   // If non-NULL, use the specified filter policy to reduce disk reads.
   // Many applications will benefit from passing the result of
   // NewBloomFilterPolicy() here.
@@ -282,6 +298,14 @@ struct Options {
   // exceeds rate_limit. This is ignored when <= 1.0.
   double rate_limit;
 
+  // Disable block cache. If this is set to false,
+  // then no block cache should be used, and the block_cache should
+  // point to a NULL object.
+  bool no_block_cache;
+
+  // Number of shards used for table cache.
+  int table_cache_numshardbits;
+
   // Create an Options object with default values for all fields.
   Options();
 

port/port_posix.h

@@ -44,6 +44,7 @@
 #include <stdint.h>
 #include <string>
 #include <string.h>
+#include "leveldb/options.h"
 #include "port/atomic_pointer.h"
 
 #ifndef PLATFORM_IS_LITTLE_ENDIAN
@@ -131,8 +132,8 @@ typedef pthread_once_t OnceType;
 #define LEVELDB_ONCE_INIT PTHREAD_ONCE_INIT
 extern void InitOnce(OnceType* once, void (*initializer)());
 
-inline bool Snappy_Compress(const char* input, size_t length,
-                            ::std::string* output) {
+inline bool Snappy_Compress(const CompressionOptions& opts, const char* input,
+                            size_t length, ::std::string* output) {
 #ifdef SNAPPY
   output->resize(snappy::MaxCompressedLength(length));
   size_t outlen;
@@ -162,9 +163,8 @@ inline bool Snappy_Uncompress(const char* input, size_t length,
 #endif
 }
 
-inline bool Zlib_Compress(const char* input, size_t length,
-    ::std::string* output, int windowBits = -14, int level = -1,
-     int strategy = 0) {
+inline bool Zlib_Compress(const CompressionOptions& opts, const char* input,
+                          size_t length, ::std::string* output) {
 #ifdef ZLIB
   // The memLevel parameter specifies how much memory should be allocated for
   // the internal compression state.
@@ -174,8 +174,8 @@ inline bool Zlib_Compress(const char* input, size_t length,
   static const int memLevel = 8;
   z_stream _stream;
   memset(&_stream, 0, sizeof(z_stream));
-  int st = deflateInit2(&_stream, level, Z_DEFLATED, windowBits,
-                        memLevel, strategy);
+  int st = deflateInit2(&_stream, opts.level, Z_DEFLATED, opts.window_bits,
+                        memLevel, opts.strategy);
   if (st != Z_OK) {
     return false;
   }
@@ -284,8 +284,8 @@ inline char* Zlib_Uncompress(const char* input_data, size_t input_length,
   return NULL;
 }
 
-inline bool BZip2_Compress(const char* input, size_t length,
-    ::std::string* output) {
+inline bool BZip2_Compress(const CompressionOptions& opts, const char* input,
+                           size_t length, ::std::string* output) {
 #ifdef BZIP2
   bz_stream _stream;
   memset(&_stream, 0, sizeof(bz_stream));

table/table_builder.cc

@@ -175,7 +175,8 @@ void TableBuilder::WriteBlock(BlockBuilder* block, BlockHandle* handle) {
 
     case kSnappyCompression: {
       std::string* compressed = &r->compressed_output;
-      if (port::Snappy_Compress(raw.data(), raw.size(), compressed) &&
+      if (port::Snappy_Compress(r->options.compression_opts, raw.data(),
+                                raw.size(), compressed) &&
           GoodCompressionRatio(compressed->size(), raw.size())) {
         block_contents = *compressed;
       } else {
@@ -187,7 +188,8 @@ void TableBuilder::WriteBlock(BlockBuilder* block, BlockHandle* handle) {
       break;
     }
     case kZlibCompression:
-      if (port::Zlib_Compress(raw.data(), raw.size(), compressed) &&
+      if (port::Zlib_Compress(r->options.compression_opts, raw.data(),
+                              raw.size(), compressed) &&
           GoodCompressionRatio(compressed->size(), raw.size())) {
         block_contents = *compressed;
       } else {
@@ -198,7 +200,8 @@ void TableBuilder::WriteBlock(BlockBuilder* block, BlockHandle* handle) {
       }
       break;
     case kBZip2Compression:
-      if (port::BZip2_Compress(raw.data(), raw.size(), compressed) &&
+      if (port::BZip2_Compress(r->options.compression_opts, raw.data(),
+                               raw.size(), compressed) &&
           GoodCompressionRatio(compressed->size(), raw.size())) {
         block_contents = *compressed;
       } else {

table/table_test.cc

@@ -247,6 +247,7 @@ class TableConstructor: public Constructor {
     source_ = new StringSource(sink.contents());
     Options table_options;
     table_options.comparator = options.comparator;
+    table_options.compression_opts = options.compression_opts;
     return Table::Open(table_options, source_, sink.contents().size(), &table_);
   }
 
@@ -399,19 +400,22 @@ class DBConstructor: public Constructor {
 static bool SnappyCompressionSupported() {
   std::string out;
   Slice in = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
-  return port::Snappy_Compress(in.data(), in.size(), &out);
+  return port::Snappy_Compress(Options().compression_opts, in.data(), in.size(),
+                               &out);
 }
 
 static bool ZlibCompressionSupported() {
   std::string out;
   Slice in = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
-  return port::Zlib_Compress(in.data(), in.size(), &out);
+  return port::Zlib_Compress(Options().compression_opts, in.data(), in.size(),
+                             &out);
 }
 
 static bool BZip2CompressionSupported() {
   std::string out;
   Slice in = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
-  return port::BZip2_Compress(in.data(), in.size(), &out);
+  return port::BZip2_Compress(Options().compression_opts, in.data(), in.size(),
+                              &out);
 }
 
 enum TestType {

util/options.cc

@@ -44,10 +44,12 @@ Options::Options()
       db_stats_log_interval(1800),
       db_log_dir(""),
       disable_seek_compaction(false),
-      delete_obsolete_files_period_micros(0),
-      max_background_compactions(1),
+      no_block_cache(false),
+      table_cache_numshardbits(4),
       max_log_file_size(0),
-      rate_limit(0.0) {
+      delete_obsolete_files_period_micros(0),
+      rate_limit(0.0),
+      max_background_compactions(1) {
 }
 
 void
@@ -64,15 +66,12 @@ Options::Dump(
     Log(log," Options.max_write_buffer_number: %zd", max_write_buffer_number);
     Log(log,"          Options.max_open_files: %d", max_open_files);
     Log(log,"             Options.block_cache: %p", block_cache);
-    Log(log,"        Options.block_cache_size: %zd", block_cache->GetCapacity());
+    if (block_cache) {
+      Log(log,"      Options.block_cache_size: %zd",
+          block_cache->GetCapacity());
+    }
     Log(log,"              Options.block_size: %zd", block_size);
     Log(log,"  Options.block_restart_interval: %d", block_restart_interval);
-    Log(log,"             Options.compression: %d", compression);
-    Log(log,"           Options.filter_policy: %s",
-        filter_policy == NULL ? "NULL" : filter_policy->Name());
-    Log(log,"              Options.num_levels: %d", num_levels);
-    Log(log,"         Options.disableDataSync: %d", disableDataSync);
-    Log(log,"               Options.use_fsync: %d", use_fsync);
     if (compression_per_level != NULL) {
        for (unsigned int i = 0; i < num_levels; i++){
           Log(log,"       Options.compression[%d]: %d",
@@ -89,6 +88,12 @@ Options::Dump(
     Log(log,"     Options.max_log_file_size: %d", max_log_file_size);
     Log(log," Options.db_stats_log_interval: %d", 
         db_stats_log_interval);
+    Log(log,"           Options.compression_opts.window_bits: %d",
+        compression_opts.window_bits);
+    Log(log,"                 Options.compression_opts.level: %d",
+        compression_opts.level);
+    Log(log,"              Options.compression_opts.strategy: %d",
+        compression_opts.strategy);
     Log(log,"     Options.level0_file_num_compaction_trigger: %d",
         level0_file_num_compaction_trigger);
     Log(log,"         Options.level0_slowdown_writes_trigger: %d",
@@ -113,6 +118,10 @@ Options::Dump(
         db_log_dir.c_str());
     Log(log,"                Options.disable_seek_compaction: %d",
         disable_seek_compaction);
+    Log(log,"                         Options.no_block_cache: %d",
+        no_block_cache);
+    Log(log,"               Options.table_cache_numshardbits: %d",
+	table_cache_numshardbits);
     Log(log,"    Options.delete_obsolete_files_period_micros: %ld",
         delete_obsolete_files_period_micros);
     Log(log,"             Options.max_background_compactions: %d",
@@ -121,5 +130,4 @@ Options::Dump(
         rate_limit);
 }   // Options::Dump
 
-
 }  // namespace leveldb