ldb support for range delete

Summary:
Add a subcommand to ldb with which we can delete a range of keys.
Closes https://github.com/facebook/rocksdb/pull/1521

Differential Revision: D4186338

Pulled By: ajkr

fbshipit-source-id: b8e9861

tools/ldb_cmd.cc

@@ -167,6 +167,10 @@ LDBCommand* LDBCommand::SelectCommand(const ParsedParams& parsed_params) {
   } else if (parsed_params.cmd == DeleteCommand::Name()) {
     return new DeleteCommand(parsed_params.cmd_params, parsed_params.option_map,
                              parsed_params.flags);
+  } else if (parsed_params.cmd == DeleteRangeCommand::Name()) {
+    return new DeleteRangeCommand(parsed_params.cmd_params,
+                                  parsed_params.option_map,
+                                  parsed_params.flags);
   } else if (parsed_params.cmd == ApproxSizeCommand::Name()) {
     return new ApproxSizeCommand(parsed_params.cmd_params,
                                  parsed_params.option_map, parsed_params.flags);
@@ -1854,6 +1858,14 @@ class InMemoryHandler : public WriteBatch::Handler {
     return Status::OK();
   }
 
+  virtual Status DeleteRangeCF(uint32_t cf, const Slice& begin_key,
+                               const Slice& end_key) override {
+    row_ << "DELETE_RANGE(" << cf << ") : ";
+    row_ << LDBCommand::StringToHex(begin_key.ToString()) << " ";
+    row_ << LDBCommand::StringToHex(end_key.ToString()) << " ";
+    return Status::OK();
+  }
+
   virtual Status MarkBeginPrepare() override {
     row_ << "BEGIN_PREARE ";
     return Status::OK();
@@ -2346,6 +2358,45 @@ void DeleteCommand::DoCommand() {
   }
 }
 
+DeleteRangeCommand::DeleteRangeCommand(
+    const std::vector<std::string>& params,
+    const std::map<std::string, std::string>& options,
+    const std::vector<std::string>& flags)
+    : LDBCommand(options, flags, false,
+                 BuildCmdLineOptions({ARG_HEX, ARG_KEY_HEX, ARG_VALUE_HEX})) {
+  if (params.size() != 2) {
+    exec_state_ = LDBCommandExecuteResult::Failed(
+        "begin and end keys must be specified for the delete command");
+  } else {
+    begin_key_ = params.at(0);
+    end_key_ = params.at(1);
+    if (is_key_hex_) {
+      begin_key_ = HexToString(begin_key_);
+      end_key_ = HexToString(end_key_);
+    }
+  }
+}
+
+void DeleteRangeCommand::Help(std::string& ret) {
+  ret.append("  ");
+  ret.append(DeleteRangeCommand::Name() + " <begin key> <end key>");
+  ret.append("\n");
+}
+
+void DeleteRangeCommand::DoCommand() {
+  if (!db_) {
+    assert(GetExecuteState().IsFailed());
+    return;
+  }
+  Status st =
+      db_->DeleteRange(WriteOptions(), GetCfHandle(), begin_key_, end_key_);
+  if (st.ok()) {
+    fprintf(stdout, "OK\n");
+  } else {
+    exec_state_ = LDBCommandExecuteResult::Failed(st.ToString());
+  }
+}
+
 PutCommand::PutCommand(const std::vector<std::string>& params,
                        const std::map<std::string, std::string>& options,
                        const std::vector<std::string>& flags)

tools/ldb_cmd_impl.h

@@ -374,6 +374,23 @@ class DeleteCommand : public LDBCommand {
   std::string key_;
 };
 
+class DeleteRangeCommand : public LDBCommand {
+ public:
+  static std::string Name() { return "deleterange"; }
+
+  DeleteRangeCommand(const std::vector<std::string>& params,
+                     const std::map<std::string, std::string>& options,
+                     const std::vector<std::string>& flags);
+
+  virtual void DoCommand() override;
+
+  static void Help(std::string& ret);
+
+ private:
+  std::string begin_key_;
+  std::string end_key_;
+};
+
 class PutCommand : public LDBCommand {
  public:
   static std::string Name() { return "put"; }

tools/ldb_tool.cc

@@ -62,6 +62,7 @@ void LDBCommandRunner::PrintHelp(const char* exec_name) {
   BatchPutCommand::Help(ret);
   ScanCommand::Help(ret);
   DeleteCommand::Help(ret);
+  DeleteRangeCommand::Help(ret);
   DBQuerierCommand::Help(ret);
   ApproxSizeCommand::Help(ret);
   CheckConsistencyCommand::Help(ret);