Change internal storage of PLIST_DATE values from struct timeval to double

This removes the timeval union member from the plist_data_t structure.
Since struct timeval is 2x64bit on 64bit platforms this member unnecessarily
grew the union size to 16 bytes while a size of 8 bytes is sufficient.
Also, on 32bit platforms struct timeval is only 2x32bit of size, limiting the
range of possible time values. In addition the binary property list format
also stores PLIST_DATE nodes as double.

1 files changed, 11 insertions, 22 deletions

diff --git a/src/plist.c b/src/plist.c
index ef1d7a2..af64ed1 100644
--- a/src/plist.c
+++ b/src/plist.c
@@ -27,6 +27,7 @@
 #include "plist.h"
 #include <stdlib.h>
 #include <stdio.h>
+#include <math.h>
 
 #include <node.h>
 #include <node_iterator.h>
@@ -214,9 +215,8 @@ PLIST_API plist_t plist_new_date(int32_t sec, int32_t usec)
 {
     plist_data_t data = plist_new_plist_data();
     data->type = PLIST_DATE;
-    data->timeval.tv_sec = sec;
-    data->timeval.tv_usec = usec;
-    data->length = sizeof(struct timeval);
+    data->realval = (double)sec + (double)usec / 1000000;
+    data->length = sizeof(double);
     return plist_new_node(data);
 }
 
@@ -567,6 +567,7 @@ static void plist_get_type_and_value(plist_t node, plist_type * type, void *valu
         *((uint64_t *) value) = data->intval;
         break;
     case PLIST_REAL:
+    case PLIST_DATE:
         *((double *) value) = data->realval;
         break;
     case PLIST_KEY:
@@ -577,11 +578,6 @@ static void plist_get_type_and_value(plist_t node, plist_type * type, void *valu
         *((uint8_t **) value) = (uint8_t *) malloc(*length * sizeof(uint8_t));
         memcpy(*((uint8_t **) value), data->buff, *length * sizeof(uint8_t));
         break;
-    case PLIST_DATE:
-        //exception : here we use memory on the stack since it is just a temporary buffer
-        ((struct timeval*) value)->tv_sec = data->timeval.tv_sec;
-        ((struct timeval*) value)->tv_usec = data->timeval.tv_usec;
-        break;
     case PLIST_ARRAY:
     case PLIST_DICT:
     default:
@@ -670,12 +666,12 @@ PLIST_API void plist_get_date_val(plist_t node, int32_t * sec, int32_t * usec)
 {
     plist_type type = plist_get_node_type(node);
     uint64_t length = 0;
-    struct timeval val = { 0, 0 };
+    double val = 0;
     if (PLIST_DATE == type)
         plist_get_type_and_value(node, &type, (void *) &val, &length);
-    assert(length == sizeof(struct timeval));
-    *sec = val.tv_sec;
-    *usec = val.tv_usec;
+    assert(length == sizeof(double));
+    *sec = (int32_t)val;
+    *usec = (int32_t)fabs((val - (int64_t)val) * 1000000);
 }
 
 int plist_data_compare(const void *a, const void *b)
@@ -700,6 +696,7 @@ int plist_data_compare(const void *a, const void *b)
     case PLIST_BOOLEAN:
     case PLIST_UINT:
     case PLIST_REAL:
+    case PLIST_DATE:
     case PLIST_UID:
         if (val_a->length != val_b->length)
             return FALSE;
@@ -730,11 +727,6 @@ int plist_data_compare(const void *a, const void *b)
         else
             return FALSE;
         break;
-    case PLIST_DATE:
-        if (!memcmp(&(val_a->timeval), &(val_b->timeval), sizeof(struct timeval)))
-            return TRUE;
-        else
-            return FALSE;
     default:
         break;
     }
@@ -782,6 +774,7 @@ static void plist_set_element_val(plist_t node, plist_type type, const void *val
         data->intval = *((uint64_t *) value);
         break;
     case PLIST_REAL:
+    case PLIST_DATE:
         data->realval = *((double *) value);
         break;
     case PLIST_KEY:
@@ -792,10 +785,6 @@ static void plist_set_element_val(plist_t node, plist_type type, const void *val
         data->buff = (uint8_t *) malloc(length);
         memcpy(data->buff, value, length);
         break;
-    case PLIST_DATE:
-        data->timeval.tv_sec = ((struct timeval*) value)->tv_sec;
-        data->timeval.tv_usec = ((struct timeval*) value)->tv_usec;
-        break;
     case PLIST_ARRAY:
     case PLIST_DICT:
     default:
@@ -840,7 +829,7 @@ PLIST_API void plist_set_data_val(plist_t node, const char *val, uint64_t length
 
 PLIST_API void plist_set_date_val(plist_t node, int32_t sec, int32_t usec)
 {
-    struct timeval val = { sec, usec };
+    double val = (double)sec + (double)usec / 1000000;
     plist_set_element_val(node, PLIST_DATE, &val, sizeof(struct timeval));
 }