Merge pull request #1658 from FIWARE/orderBy/id+type

More features for orderBy

CHANGES_NEXT_RELEASE

@@ -1,8 +1,10 @@
 ## Fixed Issues:
 
 ## New Features:
-  * Distributed subscriptions: subordinate subscriptions are DELETED when their "father" is deleted
+  * Distributed subscriptions: subordinate subscriptions are deleted when their "father" is deleted
   * Support for the URL parameter 'csf' in GET /ngsi-ld/v1/csourceRegistrations
   * Support for the URL parameter 'orderBy' (must be an attribute) in GET //ngsi-ld/v1/entities, but only if 'local' is set. (This is not NGSI-LD standard. Yet ...)
+    - Also supporting sorting on entity id, type, and modifiedAt
+    - One more URL parameter '?reverse=true' to reverse the sorting order
 
 ## Notes

src/lib/orionld/common/orionldState.h

@@ -156,6 +156,7 @@ typedef struct OrionldUriParams
   char*     notExists;
   char*     metadata;
   char*     orderBy;
+  bool      reverse;
   bool      collapse;
   bool      reset;
   char*     attributeFormat;

src/lib/orionld/mhd/mhdConnectionInit.cpp

@@ -945,6 +945,16 @@ MHD_Result orionldUriArgumentGet(void* cbDataP, MHD_ValueKind kind, const char*
   {
     orionldState.uriParams.orderBy = (char*) value;
   }
+  else if (strcmp(key, "reverse") == 0)
+  {
+    if (strcmp(value, "true") == 0)
+      orionldState.uriParams.reverse = true;
+    else if (strcmp(key, "false") != 0)
+    {
+      orionldError(OrionldBadRequestData, "Invalid value for uri parameter /reverse/", value, 400);
+      return MHD_YES;
+    }
+  }
   else if (strcmp(key, "collapse") == 0)
   {
     if (strcmp(value, "true") == 0)

src/lib/orionld/mongoc/mongocEntitiesQuery.cpp

@@ -695,30 +695,46 @@ KjNode* mongocEntitiesQuery
     bson_t sortDoc;
     int    limit       = orionldState.uriParams.limit;
     int    offset      = orionldState.uriParams.offset;
+    int    sortOrder   = 1;
+
+    if (orionldState.uriParams.reverse == true)
+      sortOrder = -1;
 
     bson_init(&sortDoc);
 
-    if (orderBy == NULL)
-      bson_append_int32(&sortDoc, "creDate", 7, 1);
+    if ((orderBy == NULL) || (strcmp(orderBy, "createdAt") == 0))
+      bson_append_int32(&sortDoc, "creDate", 7, sortOrder);
     else
     {
-      char* longName = orionldAttributeExpand(orionldState.contextP, orderBy, true, NULL);
-      int   len      = strlen(longName) + 14;
-      char* path     = kaAlloc(&orionldState.kalloc, len);
+      char  pathV[32];
+      char* path = pathV;
+      int   len  = sizeof(pathV);
+
+      if ((strcmp(orderBy, "id") == 0) || (strcmp(orderBy, "type") == 0))
+        len = snprintf(path, len, "_id.%s", orderBy);
+      else if (strcmp(orderBy, "modifiedAt") == 0)
+        len = snprintf(path, len, "%s", "modDate");
+      else
+      {
+        char* longName = orionldAttributeExpand(orionldState.contextP, orderBy, true, NULL);
 
-      len = snprintf(path, len - 1, "attrs.%s.value", longName);
+        len      = strlen(longName) + 14;
+        path     = kaAlloc(&orionldState.kalloc, len);
 
-      // Replacing dots for '=' - including the last one (should not be replaced)
-      dotForEq(&path[6]);
+        len = snprintf(path, len - 1, "attrs.%s.value", longName);
 
-      // Reversing the '=' of ".value" to a dot
-      path[len - 6] = '.';
+        // Replacing dots for '=' - including the last one (should not be replaced)
+        dotForEq(&path[6]);
+
+        // Reversing the '=' of ".value" to a dot
+        path[len - 6] = '.';
+      }
 
       LM_T(LmtMongoc, ("Ordering by '%s' (%d letters)", path, len));
-      bson_append_int32(&sortDoc, path, len, 1);
+      bson_append_int32(&sortDoc, path, len, sortOrder);
     }
 
-    bson_append_int32(&sortDoc, "_id.id", 6, 1);
+    bson_append_int32(&sortDoc, "_id.id", 6, sortOrder);  // Secondary sort on Entity ID
     bson_append_document(&options, "sort", 4, &sortDoc);
     bson_destroy(&sortDoc);
 

src/lib/orionld/service/orionldServiceInit.cpp

@@ -245,6 +245,7 @@ static void restServicePrepare(OrionLdRestService* serviceP, OrionLdRestServiceS
     serviceP->uriParams |= ORIONLD_URIPARAM_ONLYIDS;
     serviceP->uriParams |= ORIONLD_URIPARAM_ENTITYMAP;
     serviceP->uriParams |= ORIONLD_URIPARAM_ORDERBY;
+    serviceP->uriParams |= ORIONLD_URIPARAM_REVERSE;
   }
   else if (serviceP->serviceRoutine == orionldGetEntity)
   {

src/lib/orionld/types/OrionLdRestService.h

@@ -158,6 +158,7 @@ typedef struct OrionLdRestServiceSimplifiedVector
 #define ORIONLD_URIPARAM_EXPAND_VALUES        (UINT64_C(1) << 41)
 #define ORIONLD_URIPARAM_KIND                 (UINT64_C(1) << 42)
 #define ORIONLD_URIPARAM_ORDERBY              (UINT64_C(1) << 43)
+#define ORIONLD_URIPARAM_REVERSE              (UINT64_C(1) << 44)