JsonLogTask: fix value comparisons

- fix string comparison (was comparing pointers) (fixes #43)
- improve value comparison code
- REF improve name of compare function

Author: ralphlange

caPutLogApp/caPutJsonLogTask.cpp

@@ -458,7 +458,7 @@ caPutJsonLogStatus CaPutJsonLogTask::buildJsonMsg(const VALUE *pold_value, const
 
     // Dont log duplicate values if configured so
     if (this->config == caPutJsonLogOnChange && !burst) {
-        if (this->compareValues(pLogData))
+        if (this->valuesAreEqual(pLogData))
             return caPutJsonLogSuccess;
     }
 
@@ -794,46 +794,22 @@ void CaPutJsonLogTask::calculateMax(VALUE *pres, const VALUE *pa, const VALUE *p
     }
 }
 
-#define SINGLE_TYPE_COMPARE(_t, _s)                            \
-    if (pLogData->is_array)                                    \
-        return memcmp(pa->a_##_t, pb->a_##_t, size * _s) == 0; \
-    return pa->v_##_t == pb->v_##_t;
-
-bool CaPutJsonLogTask::compareValues(const LOGDATA *pLogData) {
+bool CaPutJsonLogTask::valuesAreEqual(const LOGDATA *pLogData) {
     const VALUE *pa = &pLogData->old_value;
     const VALUE *pb = &pLogData->new_value.value;
-    const int size = pLogData->old_log_size;
+    size_t size = pLogData->is_array ? pLogData->old_log_size : 1;
 
-    if (pLogData->is_array && pLogData->old_log_size != pLogData->new_log_size)
+    if (pLogData->old_log_size != pLogData->new_log_size)
         return false;
 
-    switch (pLogData->type)
-    {
-    case DBR_CHAR:
-        SINGLE_TYPE_COMPARE(int8, sizeof(epicsInt8));
-    case DBR_UCHAR:
-        SINGLE_TYPE_COMPARE(uint8, sizeof(epicsUInt8));
-    case DBR_SHORT:
-        SINGLE_TYPE_COMPARE(int16, sizeof(epicsInt16));
-    case DBR_USHORT:
-    case DBR_ENUM:
-        SINGLE_TYPE_COMPARE(uint16, sizeof(epicsUInt16));
-    case DBR_LONG:
-        SINGLE_TYPE_COMPARE(int32, sizeof(epicsInt32));
-    case DBR_ULONG:
-        SINGLE_TYPE_COMPARE(uint32, sizeof(epicsUInt32));
-    case DBR_INT64:
-        SINGLE_TYPE_COMPARE(int64, sizeof(epicsInt64));
-    case DBR_UINT64:
-        SINGLE_TYPE_COMPARE(uint64, sizeof(epicsUInt64));
-    case DBR_FLOAT:
-        SINGLE_TYPE_COMPARE(float, sizeof(epicsFloat32));
-    case DBR_DOUBLE:
-        SINGLE_TYPE_COMPARE(double, sizeof(epicsFloat64));
-    case DBR_STRING:
-        SINGLE_TYPE_COMPARE(string, MAX_STRING_SIZE);
-    default:
-        return 0;
+    if (pLogData->type == DBR_STRING) {
+        for (size_t i = 0; i < size; i++) {
+            if (strncmp(pa->a_string[i], pb->a_string[i], MAX_STRING_SIZE) != 0)
+                return false;
+        }
+        return true;
+    } else {
+        return memcmp(pa, pb, size*dbValueSize(pLogData->type)) == 0;
     }
 }
 

caPutLogApp/caPutJsonLogTask.h

@@ -300,7 +300,7 @@ class epicsShareClass CaPutJsonLogTask {
      * @return true If values are the same.
      * @return false  If values are not the same.
      */
-    bool compareValues(const LOGDATA *pLogData);
+    bool valuesAreEqual(const LOGDATA *pLogData);
 
     /**
      * @brief Get a string representation of the value stored in the ::VALUE.