Merge pull request basicthinker#7 from ldeng-ustc/zeropadding

add zeropadding parameter

core/core_workload.cc

@@ -57,6 +57,9 @@ const string CoreWorkload::REQUEST_DISTRIBUTION_PROPERTY =
     "requestdistribution";
 const string CoreWorkload::REQUEST_DISTRIBUTION_DEFAULT = "uniform";
 
+const string CoreWorkload::ZERO_PADDING_PROPERTY = "zeropadding";
+const string CoreWorkload::ZERO_PADDING_DEFAULT = "1";
+
 const string CoreWorkload::MAX_SCAN_LENGTH_PROPERTY = "maxscanlength";
 const string CoreWorkload::MAX_SCAN_LENGTH_DEFAULT = "1000";
 
@@ -94,6 +97,7 @@ void CoreWorkload::Init(const utils::Properties &p) {
   record_count_ = std::stoi(p.GetProperty(RECORD_COUNT_PROPERTY));
   std::string request_dist = p.GetProperty(REQUEST_DISTRIBUTION_PROPERTY,
                                            REQUEST_DISTRIBUTION_DEFAULT);
+  zero_padding_ = std::stoi(p.GetProperty(ZERO_PADDING_PROPERTY, ZERO_PADDING_DEFAULT));
   int max_scan_len = std::stoi(p.GetProperty(MAX_SCAN_LENGTH_PROPERTY,
                                              MAX_SCAN_LENGTH_DEFAULT));
   std::string scan_len_dist = p.GetProperty(SCAN_LENGTH_DISTRIBUTION_PROPERTY,

core/core_workload.h

@@ -107,6 +107,13 @@ class CoreWorkload {
   static const std::string REQUEST_DISTRIBUTION_PROPERTY;
   static const std::string REQUEST_DISTRIBUTION_DEFAULT;
 
+  ///
+  /// The name of the property for adding zero padding to record numbers in order to match 
+  /// string sort order. Controls the number of 0s to left pad with.
+  ///
+  static const std::string ZERO_PADDING_PROPERTY;
+  static const std::string ZERO_PADDING_DEFAULT;
+
   /// 
   /// The name of the property for the max scan length (number of records).
   ///
@@ -184,6 +191,7 @@ class CoreWorkload {
   CounterGenerator insert_key_sequence_;
   bool ordered_inserts_;
   size_t record_count_;
+  int zero_padding_;
 };
 
 inline std::string CoreWorkload::NextSequenceKey() {
@@ -203,7 +211,10 @@ inline std::string CoreWorkload::BuildKeyName(uint64_t key_num) {
   if (!ordered_inserts_) {
     key_num = utils::Hash(key_num);
   }
-  return std::string("user").append(std::to_string(key_num));
+  std::string key_num_str = std::to_string(key_num);
+  int zeros = zero_padding_ - key_num_str.length();
+  zeros = std::max(0, zeros);
+  return std::string("user").append(zeros, '0').append(key_num_str);
 }
 
 inline std::string CoreWorkload::NextFieldName() {