anchor.diff:  process_request(TLog, Request) ->
       case Request of
           {read, Key} ->
  -            case transaction_api:read(Key, TLog) of
  -                {{value, Val}, NTLog} ->
  +            case timer:tc(transaction_api, read, [Key, TLog]) of
  +                {Time, {{value, Val}, NTLog}} ->
  +                    ?LOG_CS_API(read_success, Time / 1000.0),
                       {NTLog, {read, Key, {value, Val}}};
  -                {{fail, Reason}, NTLog} ->
  +                {Time, {{fail, Reason}, NTLog}} ->
  +                    ?LOG_CS_API(read_fail, Time / 1000.0),
                       {NTLog, {read, Key, {fail, Reason}}}
               end;
           {write, Key, Value} ->
  -            case transaction_api:write(Key, Value, TLog) of
  -                {ok, NTLog} ->
  +            case timer:tc(transaction_api, write, [Key, Value, TLog]) of
  +                {Time, {ok, NTLog}} ->
  +                    ?LOG_CS_API(write_success, Time / 1000.0),
                       {NTLog, {write, Key, {value, Value}}};
  -                {{fail, Reason}, NTLog} ->
  +                {Time, {{fail, Reason}, NTLog}} ->
  +                    ?LOG_CS_API(write_fail, Time / 1000.0),
                       {NTLog, {write, Key, {fail, Reason}}}
               end;
           {commit} ->
  -            case transaction_api:commit(TLog) of
  -                {ok} ->
  +            case timer:tc(transaction_api, commit, [TLog]) of
  +                {Time, {ok}} ->
  +                    ?LOG_CS_API(commit_success, Time / 1000.0),
                       {TLog, {commit, ok, {value, "ok"}}};
  -                {fail, Reason} ->
  +                {Time, {fail, Reason}} ->
  +                    ?LOG_CS_API(commit_fail, Time / 1000.0),
                       {TLog, {commit, fail, {fail, Reason}}}
               end
       end.
  
positive.code: %% @doc reads the value of a key
  %% @spec read(key()) -> {failure, term()} | value()
  read(Key) ->
      case transaction_api:quorum_read(Key) of
          {fail, Reason} ->
  	       {fail, Reason};
          {Value, _Version} ->
  	       Value
      end.
  
  %% @doc writes the value of a key
  %% @spec write(key(), value()) -> ok | {fail, term()}
  write(Key, Value) ->
      case transaction_api:single_write(Key, Value) of
  	commit ->
  	    ok;
  	{fail, Reason} ->
  	    {fail, Reason}
      end.
  
  
negative.code: -export([process_request_list/2, read/1, write/2, delete/1,
           test_and_set/3, range_read/2]).
  
  -include("../include/scalaris.hrl").
  
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  % Public Interface
  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  