ldb: support --block_size=<4096|65536|...> and --auto_compaction=<0|1>

Summary: This allows us to use ldb to do more experiments like block_size changes.

Test Plan: run it by hand.

Reviewers: dhruba, sheki, emayanke

Reviewed By: dhruba

CC: leveldb

Differential Revision: https://reviews.facebook.net/D7431

util/ldb_cmd.cc

@@ -13,13 +13,17 @@ namespace leveldb {
 
 const char* LDBCommand::BLOOM_ARG = "--bloom_bits=";
 const char* LDBCommand::COMPRESSION_TYPE_ARG = "--compression_type=";
+const char* LDBCommand::BLOCK_SIZE = "--block_size=";
+const char* LDBCommand::AUTO_COMPACTION = "--auto_compaction=";
 
 void LDBCommand::parse_open_args(std::vector<std::string>& args) {
   std::vector<std::string> rest_of_args;
   for (unsigned int i = 0; i < args.size(); i++) {
     std::string& arg = args.at(i);
     if (arg.find(BLOOM_ARG) == 0
-        || arg.find(COMPRESSION_TYPE_ARG) == 0) {
+        || arg.find(COMPRESSION_TYPE_ARG) == 0
+        || arg.find(BLOCK_SIZE) == 0
+        || arg.find(AUTO_COMPACTION) == 0) {
       open_args_.push_back(arg);
     } else {
       rest_of_args.push_back(arg);
@@ -42,6 +46,26 @@ leveldb::Options LDBCommand::PrepareOptionsForOpenDB() {
           std::string("Badly-formatted bits: ") + bits_string);
       }
       opt.filter_policy = leveldb::NewBloomFilterPolicy(bits);
+    } else if (arg.find(BLOCK_SIZE) == 0) {
+      std::string block_size_string = arg.substr(strlen(BLOCK_SIZE));
+      int block_size = atoi(block_size_string.c_str());
+      if (block_size == 0) {
+        // Badly-formatted bits.
+        exec_state_ = LDBCommandExecuteResult::FAILED(
+          std::string("Badly-formatted block size: ") + block_size_string);
+      }
+      opt.block_size = block_size;
+    } else if (arg.find(AUTO_COMPACTION) == 0) {
+      std::string value = arg.substr(strlen(AUTO_COMPACTION));
+      if (value == "false") {
+        opt.disable_auto_compactions = true;
+      } else if (value == "true") {
+        opt.disable_auto_compactions = false;
+      } else {
+        // Unknown compression.
+        exec_state_ = LDBCommandExecuteResult::FAILED(
+          "Unknown auto_compaction value: " + value);
+      }
     } else if (arg.find(COMPRESSION_TYPE_ARG) == 0) {
       std::string comp = arg.substr(strlen(COMPRESSION_TYPE_ARG));
       if (comp == "no") {

util/ldb_cmd.h

@@ -123,7 +123,11 @@ public:
     ret.append(LDBCommand::BLOOM_ARG);
     ret.append("<int,e.g.:14>] [");
     ret.append(LDBCommand::COMPRESSION_TYPE_ARG);
-    ret.append("<no|snappy|zlib|bzip2>] ");
+    ret.append("<no|snappy|zlib|bzip2> ");
+    ret.append(LDBCommand::BLOCK_SIZE);
+    ret.append("=<block_size_in_bytes> ");
+    ret.append(LDBCommand::AUTO_COMPACTION);
+    ret.append("=<true|false>]");
   }
 
   /* Run the command, and return the execute result. */
@@ -203,6 +207,8 @@ private:
 
   static const char* BLOOM_ARG;
   static const char* COMPRESSION_TYPE_ARG;
+  static const char* BLOCK_SIZE;
+  static const char* AUTO_COMPACTION;
   std::vector<std::string> open_args_;
   void parse_open_args(std::vector<std::string>& args);
 };