#270 get_worker_count(), lookup_worker_accounts() and list_workers() functions

libraries/app/database_api.cpp

@@ -202,6 +202,8 @@ public:
    // Workers
    vector<optional<worker_object>> get_workers(const vector<worker_id_type> &witness_ids) const;
    fc::optional<worker_object> get_worker_by_account(const std::string account_id_or_name) const;
+   map<string, worker_id_type> lookup_worker_accounts(const string &lower_bound_name, uint32_t limit) const;
+   uint64_t get_worker_count() const;
 
    // Votes
    vector<variant> lookup_vote_ids(const vector<vote_id_type> &votes) const;
@@ -294,6 +296,7 @@ public:
    uint32_t api_limit_lookup_witness_accounts = 1000;
    uint32_t api_limit_lookup_committee_member_accounts = 1000;
    uint32_t api_limit_lookup_son_accounts = 1000;
+   uint32_t api_limit_lookup_worker_accounts = 1000;
    uint32_t api_limit_get_trade_history = 100;
    uint32_t api_limit_get_trade_history_by_sequence = 100;
 
@@ -1944,6 +1947,14 @@ fc::optional<worker_object> database_api::get_worker_by_account(const std::strin
    return my->get_worker_by_account(account_id_or_name);
 }
 
+map<string, worker_id_type> database_api::lookup_worker_accounts(const string &lower_bound_name, uint32_t limit) const {
+   return my->lookup_worker_accounts(lower_bound_name, limit);
+}
+
+uint64_t database_api::get_worker_count() const {
+   return my->get_worker_count();
+}
+
 vector<optional<worker_object>> database_api_impl::get_workers(const vector<worker_id_type> &worker_ids) const {
    vector<optional<worker_object>> result;
    result.reserve(worker_ids.size());
@@ -1965,6 +1976,35 @@ fc::optional<worker_object> database_api_impl::get_worker_by_account(const std::
    return {};
 }
 
+map<string, worker_id_type> database_api_impl::lookup_worker_accounts(const string &lower_bound_name, uint32_t limit) const {
+   FC_ASSERT(limit <= api_limit_lookup_worker_accounts,
+             "Number of querying accounts can not be greater than ${configured_limit}",
+             ("configured_limit", api_limit_lookup_worker_accounts));
+
+   const auto &workers_by_id = _db.get_index_type<worker_index>().indices().get<by_id>();
+
+   // we want to order workers by account name, but that name is in the account object
+   // so the worker_index doesn't have a quick way to access it.
+   // get all the names and look them all up, sort them, then figure out what
+   // records to return.  This could be optimized, but we expect the
+   // number of witnesses to be few and the frequency of calls to be rare
+   std::map<std::string, worker_id_type> workers_by_account_name;
+   for (const worker_object &worker : workers_by_id)
+      if (auto account_iter = _db.find(worker.worker_account))
+         if (account_iter->name >= lower_bound_name) // we can ignore anything below lower_bound_name
+            workers_by_account_name.insert(std::make_pair(account_iter->name, worker.id));
+
+   auto end_iter = workers_by_account_name.begin();
+   while (end_iter != workers_by_account_name.end() && limit--)
+      ++end_iter;
+   workers_by_account_name.erase(end_iter, workers_by_account_name.end());
+   return workers_by_account_name;
+}
+
+uint64_t database_api_impl::get_worker_count() const {
+   return _db.get_index_type<worker_index>().indices().size();
+}
+
 //////////////////////////////////////////////////////////////////////
 //                                                                  //
 // Votes                                                            //

libraries/app/include/graphene/app/database_api.hpp

@@ -732,6 +732,19 @@ public:
     */
    fc::optional<worker_object> get_worker_by_account(const std::string account_id_or_name) const;
 
+   /**
+    * @brief Get names and IDs for registered workers
+    * @param lower_bound_name Lower bound of the first name to return
+    * @param limit Maximum number of results to return -- must not exceed 1000
+    * @return Map of worker names to corresponding IDs
+    */
+   map<string, worker_id_type> lookup_worker_accounts(const string &lower_bound_name, uint32_t limit) const;
+
+   /**
+    * @brief Get the total number of workers registered with the blockchain
+    */
+   uint64_t get_worker_count() const;
+
    ///////////
    // Votes //
    ///////////
@@ -1123,6 +1136,8 @@ FC_API(graphene::app::database_api,
    // Workers
    (get_workers)
    (get_worker_by_account)
+   (lookup_worker_accounts)
+   (get_worker_count)
 
    // Votes
    (lookup_vote_ids)

libraries/wallet/include/graphene/wallet/wallet.hpp

@@ -1346,6 +1346,21 @@ class wallet_api
        */
       map<string, committee_member_id_type>       list_committee_members(const string& lowerbound, uint32_t limit);
 
+      /** Lists all workers in the blockchain.
+       * This returns a list of all account names that own worker, and the associated worker id,
+       * sorted by name.  This lists workers whether they are currently voted in or not.
+       *
+       * Use the \c lowerbound and limit parameters to page through the list.  To retrieve all workers,
+       * start by setting \c lowerbound to the empty string \c "", and then each iteration, pass
+       * the last worker name returned as the \c lowerbound for the next \c list_workers() call.
+       *
+       * @param lowerbound the name of the first worker to return.  If the named worker does not exist,
+       *                   the list will start at the worker that comes after \c lowerbound
+       * @param limit the maximum number of worker to return (max: 1000)
+       * @returns a list of worker mapping worker names to worker ids
+       */
+      map<string, worker_id_type> list_workers(const string& lowerbound, uint32_t limit);
+
       /** Returns information about the given SON.
        * @param owner_account the name or id of the SON account owner, or the id of the SON
        * @returns the information about the SON stored in the block chain
@@ -2660,6 +2675,7 @@ FC_API( graphene::wallet::wallet_api,
         (get_committee_member)
         (list_witnesses)
         (list_committee_members)
+        (list_workers)
         (create_son)
         (try_create_son)
         (update_son)

libraries/wallet/wallet.cpp

@@ -5027,6 +5027,11 @@ map<string,committee_member_id_type> wallet_api::list_committee_members(const st
    return my->_remote_db->lookup_committee_member_accounts(lowerbound, limit);
 }
 
+map<string, worker_id_type> wallet_api::list_workers(const string& lowerbound, uint32_t limit)
+{
+   return my->_remote_db->lookup_worker_accounts(lowerbound, limit);
+}
+
 son_object wallet_api::get_son(string owner_account)
 {
    return my->get_son(owner_account);