Merge pull request #3994 from Anjali-NEC/issue1492

Fix using limit=0 and details=on to get only the count of elements #1492

CHANGES_NEXT_RELEASE

@@ -1,2 +1,3 @@
+- Fix: allow limit=0 in all paginated operations in the NGSIv2 API (entities, entity types, subscriptions and registrations) (#1492)
 - Add: conditions.alterationTypes subscription fuctionality (#1494)
 - Reference distribution changed RHEL/CentOS 8 to Debian 11

src/lib/mongoBackend/MongoGlobal.cpp

@@ -1560,51 +1560,53 @@ bool entitiesQuery
   int             errType;
   std::string     nextErr;
 
-  while (cursor.next(&r, &errType, &nextErr))
+  if (limit != 0)
   {
-    alarmMgr.dbErrorReset();
-
-    // Build CER from BSON retrieved from DB
-    docs++;
-    LM_T(LmtMongo, ("retrieved document [%d]: '%s'", docs, r.toString().c_str()));
-    ContextElementResponse*  cer = new ContextElementResponse(r, attrL, includeEmpty, apiVersion);
-
-    // Add builtin attributes and metadata (only in NGSIv2)
-    if (apiVersion == V2)
+    while (cursor.next(&r, &errType, &nextErr))
     {
-      addBuiltins(cer);
-    }
+      alarmMgr.dbErrorReset();
 
-    /* All the attributes existing in the request but not found in the response are added with 'found' set to false */
-    for (unsigned int ix = 0; ix < attrL.size(); ++ix)
-    {
-      bool         found     = false;
-      std::string  attrName  = attrL[ix];
+      // Build CER from BSON retrieved from DB
+      docs++;
+      LM_T(LmtMongo, ("retrieved document [%d]: '%s'", docs, r.toString().c_str()));
+      ContextElementResponse*  cer = new ContextElementResponse(r, attrL, includeEmpty, apiVersion);
 
-      /* The special case "*" is not taken into account*/
-      if (attrName == ALL_ATTRS)
+      // Add builtin attributes and metadata (only in NGSIv2)
+      if (apiVersion == V2)
       {
-        continue;
+        addBuiltins(cer);
       }
 
-      for (unsigned int jx = 0; jx < cer->entity.attributeVector.size(); ++jx)
+      /* All the attributes existing in the request but not found in the response are added with 'found' set to false */
+      for (unsigned int ix = 0; ix < attrL.size(); ++ix)
       {
-        if (attrName == cer->entity.attributeVector[jx]->name)
+        bool         found     = false;
+        std::string  attrName  = attrL[ix];
+
+        /* The special case "*" is not taken into account*/
+        if (attrName == ALL_ATTRS)
+        {
+          continue;
+        }
+
+        for (unsigned int jx = 0; jx < cer->entity.attributeVector.size(); ++jx)
         {
-          found = true;
-          break;
+          if (attrName == cer->entity.attributeVector[jx]->name)
+          {
+            found = true;
+            break;
+          }
         }
-      }
 
-      if (!found)
-      {
-        ContextAttribute* caP = new ContextAttribute(attrName, "", "", false);
-        cer->entity.attributeVector.push_back(caP);
+        if (!found)
+        {
+          ContextAttribute* caP = new ContextAttribute(attrName, "", "", false);
+          cer->entity.attributeVector.push_back(caP);
+        }
       }
+      cer->statusCode.fill(SccOk);
+      cerV->push_back(cer);
     }
-
-    cer->statusCode.fill(SccOk);
-    cerV->push_back(cer);
   }
 
   orion::releaseMongoConnection(connection);

src/lib/mongoBackend/mongoGetSubscriptions.cpp

@@ -338,23 +338,25 @@ void mongoListSubscriptions
   /* Process query result */
   unsigned int docs = 0;
 
-  orion::BSONObj  r;
-  while (cursor.next(&r))
+  if (limit != 0)
   {
-    docs++;
-    LM_T(LmtMongo, ("retrieved document [%d]: '%s'", docs, r.toString().c_str()));
+    orion::BSONObj  r;
+    while (cursor.next(&r))
+    {
+      docs++;
+      LM_T(LmtMongo, ("retrieved document [%d]: '%s'", docs, r.toString().c_str()));
 
-    Subscription  s;
+      Subscription  s;
 
-    setNewSubscriptionId(&s, r);
-    setDescription(&s, r);
-    setSubject(&s, r);
-    setStatus(&s, r, tenant);
-    setNotification(&s, r, tenant);
+      setNewSubscriptionId(&s, r);
+      setDescription(&s, r);
+      setSubject(&s, r);
+      setStatus(&s, r, tenant);
+      setNotification(&s, r, tenant);
 
-    subs->push_back(s);
+      subs->push_back(s);
+    }
   }
-
   orion::releaseMongoConnection(connection);
   reqSemGive(__FUNCTION__, "Mongo List Subscriptions", reqSemTaken);
 

src/lib/mongoBackend/mongoQueryContext.cpp

@@ -371,7 +371,6 @@ HttpStatusCode mongoQueryContext
                      countP,
                      sortOrderList,
                      apiVersion);
-
   if (!ok)
   {
     responseP->errorCode.fill(SccReceiverInternalError, err);

src/lib/mongoBackend/mongoQueryTypes.cpp

@@ -627,9 +627,12 @@ HttpStatusCode mongoEntityTypes
         entityType->contextAttributeVector.push_back(caP);
       }
     }
-
-    responseP->entityTypeVector.push_back(entityType);
+    if (limit != 0)
+    {
+      responseP->entityTypeVector.push_back(entityType);
+    }
   }
+
   orion::releaseMongoConnection(connection);
 
   // Get count if user requested (i.e. if totalTypesP is not NULL)

src/lib/mongoBackend/mongoRegistrationGet.cpp

@@ -401,7 +401,10 @@ void mongoRegistrationsGet
     setExpires(&reg, r);
     setStatus(&reg, r);
 
-    regV->push_back(reg);
+    if (limit != 0)
+    {
+      regV->push_back(reg);
+    }
   }
 
   orion::releaseMongoConnection(connection);

src/lib/rest/rest.cpp

@@ -158,7 +158,7 @@ static int uriArgumentGet(void* cbDataP, MHD_ValueKind kind, const char* ckey, c
     {
       if ((*cP < '0') || (*cP > '9'))
       {
-        OrionError error(SccBadRequest, std::string("Bad pagination limit: /") + value + "/ [must be a decimal number]");
+        OrionError error(SccBadRequest, std::string("Bad pagination limit: /") + value + "/ [must be a positive integer number]");
         ciP->httpStatusCode = error.code;
         ciP->answer         = error.smartRender(ciP->apiVersion);
         return MHD_YES;
@@ -175,13 +175,6 @@ static int uriArgumentGet(void* cbDataP, MHD_ValueKind kind, const char* ckey, c
       ciP->answer         = error.smartRender(ciP->apiVersion);
       return MHD_YES;
     }
-    else if (limit == 0)
-    {
-      OrionError error(SccBadRequest, std::string("Bad pagination limit: /") + value + "/ [a value of ZERO is unacceptable]");
-      ciP->httpStatusCode = error.code;
-      ciP->answer         = error.smartRender(ciP->apiVersion);
-      return MHD_YES;
-    }
   }
   else if (key == URI_PARAM_PAGINATION_DETAILS)
   {

test/functionalTest/cases/0000_bad_requests/pagination_error_in_uri_params.test

@@ -62,15 +62,15 @@ echo
 --REGEXPECT--
 +++++ 1. bad characters in URI param 'limit'
 HTTP/1.1 400 Bad Request
-Content-Length: 125
+Content-Length: 134
 Content-Type: application/json
 Fiware-Correlator: REGEX([0-9a-f\-]{36})
 Date: REGEX(.*)
 
 {
     "orionError": {
         "code": "400",
-        "details": "Bad pagination limit: /abc/ [must be a decimal number]",
+        "details": "Bad pagination limit: /abc/ [must be a positive integer number]",
         "reasonPhrase": "Bad Request"
     }
 }
@@ -93,16 +93,16 @@ Date: REGEX(.*)
 
 
 +++++ 3. URI param 'limit' == 0
-HTTP/1.1 400 Bad Request
-Content-Length: 135
+HTTP/1.1 200 OK
+Content-Length: 86
 Content-Type: application/json
 Fiware-Correlator: REGEX([0-9a-f\-]{36})
 Date: REGEX(.*)
 
 {
-    "orionError": {
+    "errorCode": {
         "code": "400",
-        "details": "Bad pagination limit: /000000/ [a value of ZERO is unacceptable]",
+        "details": "JSON Parse Error",
         "reasonPhrase": "Bad Request"
     }
 }

test/functionalTest/cases/1492_limit_zero/limit_zero_entities.test

@@ -0,0 +1,142 @@
+# Copyright 2021 Telefonica Investigacion y Desarrollo, S.A.U
+#
+# This file is part of Orion Context Broker.
+#
+# Orion Context Broker is free software: you can redistribute it and/or
+# modify it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# Orion Context Broker is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero
+# General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with Orion Context Broker. If not, see http://www.gnu.org/licenses/.
+#
+# For those usages not covered by this license please contact with
+# iot_support at tid dot es
+
+# VALGRIND_READY - to mark the test ready for valgrindTestSuite.sh
+
+--NAME--
+limit_zero_entities
+
+--SHELL-INIT--
+dbInit CB
+brokerStart CB
+
+--SHELL--
+
+#
+# 01. GET /v2/entities with 'limit' == 0 and options=count and see no entities and fiware-total-count: 0
+# 02. POST /v2/entities to create E1 entity
+# 03. POST /v2/entities to create E2 entity
+# 04. GET /v2/entities with 'limit' == 0 and options=count and see no entities and fiware-total-count: 2
+# 05. GET /v2/entities with 'limit' == 0 and see no entities
+#
+
+echo "01. GET /v2/entities with 'limit' == 0 and options=count and see no entities and fiware-total-count: 0"
+echo "======================================================================================================"
+orionCurl --url "/v2/entities?limit=0&options=count"
+echo
+echo
+
+
+echo "02. POST /v2/entities to create E1 entity"
+echo "========================================="
+payload='{
+  "id": "E1",
+  "type": "T"
+}'
+orionCurl --url /v2/entities -X POST --payload "$payload"
+echo
+echo
+
+
+echo "03. POST /v2/entities to create E2 entity"
+echo "========================================="
+payload='{
+  "id": "E2",
+  "type": "T"
+}'
+orionCurl --url /v2/entities -X POST --payload "$payload"
+echo
+echo
+
+
+echo "04. GET /v2/entities with 'limit' == 0 and options=count and see no entities and fiware-total-count: 2"
+echo "======================================================================================================"
+orionCurl --url "/v2/entities?limit=0&options=count"
+echo
+echo
+
+
+echo "05. GET /v2/entities with 'limit' == 0 and see no entities"
+echo "=========================================================="
+orionCurl --url "/v2/entities?limit=0"
+echo
+echo
+
+
+
+--REGEXPECT--
+01. GET /v2/entities with 'limit' == 0 and options=count and see no entities and fiware-total-count: 0
+======================================================================================================
+HTTP/1.1 200 OK
+Content-Length: 2
+Content-Type: application/json
+Fiware-Total-Count: 0
+Fiware-Correlator: REGEX([0-9a-f\-]{36})
+Date: REGEX(.*)
+
+[]
+
+
+02. POST /v2/entities to create E1 entity
+=========================================
+HTTP/1.1 201 Created
+Content-Length: 0
+Location: /v2/entities/E1?type=T
+Fiware-Correlator: REGEX([0-9a-f\-]{36})
+Date: REGEX(.*)
+
+
+
+03. POST /v2/entities to create E2 entity
+=========================================
+HTTP/1.1 201 Created
+Content-Length: 0
+Location: /v2/entities/E2?type=T
+Fiware-Correlator: REGEX([0-9a-f\-]{36})
+Date: REGEX(.*)
+
+
+
+04. GET /v2/entities with 'limit' == 0 and options=count and see no entities and fiware-total-count: 2
+======================================================================================================
+HTTP/1.1 200 OK
+Content-Length: 2
+Content-Type: application/json
+Fiware-Total-Count: 2
+Fiware-Correlator: REGEX([0-9a-f\-]{36})
+Date: REGEX(.*)
+
+[]
+
+
+05. GET /v2/entities with 'limit' == 0 and see no entities
+==========================================================
+HTTP/1.1 200 OK
+Content-Length: 2
+Content-Type: application/json
+Fiware-Correlator: REGEX([0-9a-f\-]{36})
+Date: REGEX(.*)
+
+[]
+
+
+--TEARDOWN--
+brokerStop CB
+dbDrop CB