Compare all percentage fields with compareRealNumbers()

The SPACESHIP_NUMBER() macro does not work well with floating point
values that are possible to be NaNs. Change the compare logic of all
percentage fields of Process entries to use compareRealNumbers().

Signed-off-by: Kang-Che Sung <explorer09@gmail.com>

Process.c

@@ -1184,7 +1184,7 @@ int Process_compareByKey_Base(const Process* p1, const Process* p2, ProcessField
    switch (key) {
    case PERCENT_CPU:
    case PERCENT_NORM_CPU:
-      return SPACESHIP_NUMBER(p1->percent_cpu, p2->percent_cpu);
+      return compareRealNumbers(p1->percent_cpu, p2->percent_cpu);
    case PERCENT_MEM:
       return SPACESHIP_NUMBER(p1->m_resident, p2->m_resident);
    case COMM:

XUtils.c

@@ -12,6 +12,7 @@ in the source distribution for its full text.
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <math.h>
 #include <stdarg.h>
 #include <stdint.h>
 #include <stdlib.h>
@@ -339,6 +340,16 @@ ssize_t full_write(int fd, const void* buf, size_t count) {
    return written;
 }
 
+/* Compares floating point values for ordering data entries. In this function,
+   NaN is considered "less than" any other floating point value (regardless of
+   sign), and two NaNs are considered "equal" regardless of payload. */
+int compareRealNumbers(double a, double b) {
+   int result = (int)isgreater(a, b) - isgreater(b, a);
+   if (result)
+      return result;
+   return (int)!isNaN(a) - !isNaN(b);
+}
+
 /* Computes the sum of all positive floating point values in an array.
    NaN values in the array are skipped. The returned sum will always be
    nonnegative. */

XUtils.h

@@ -82,6 +82,11 @@ ssize_t xReadfileat(openat_arg_t dirfd, const char* pathname, void* buffer, size
 ATTR_ACCESS3_R(2, 3)
 ssize_t full_write(int fd, const void* buf, size_t count);
 
+/* Compares floating point values for ordering data entries. In this function,
+   NaN is considered "less than" any other floating point value (regardless of
+   sign), and two NaNs are considered "equal" regardless of payload. */
+int compareRealNumbers(double a, double b);
+
 /* Computes the sum of all positive floating point values in an array.
    NaN values in the array are skipped. The returned sum will always be
    nonnegative. */

linux/LinuxProcess.c

@@ -310,16 +310,6 @@ static void LinuxProcess_writeField(const Process* this, RichString* str, Proces
    RichString_appendAscii(str, attr, buffer);
 }
 
-/* Compares floating point values for ordering data entries. In this function,
-   NaN is considered "less than" any other floating point value (regardless of
-   sign), and two NaNs are considered "equal" regardless of payload. */
-static int compareRealNumbers(double a, double b) {
-   int result = (int)isgreater(a, b) - isgreater(b, a);
-   if (result)
-      return result;
-   return (int)!isNaN(a) - !isNaN(b);
-}
-
 static int LinuxProcess_compareByKey(const Process* v1, const Process* v2, ProcessField key) {
    const LinuxProcess* p1 = (const LinuxProcess*)v1;
    const LinuxProcess* p2 = (const LinuxProcess*)v2;
@@ -385,11 +375,11 @@ static int LinuxProcess_compareByKey(const Process* v1, const Process* v2, Proce
       return SPACESHIP_NUMBER(p1->oom, p2->oom);
    #ifdef HAVE_DELAYACCT
    case PERCENT_CPU_DELAY:
-      return SPACESHIP_NUMBER(p1->cpu_delay_percent, p2->cpu_delay_percent);
+      return compareRealNumbers(p1->cpu_delay_percent, p2->cpu_delay_percent);
    case PERCENT_IO_DELAY:
-      return SPACESHIP_NUMBER(p1->blkio_delay_percent, p2->blkio_delay_percent);
+      return compareRealNumbers(p1->blkio_delay_percent, p2->blkio_delay_percent);
    case PERCENT_SWAP_DELAY:
-      return SPACESHIP_NUMBER(p1->swapin_delay_percent, p2->swapin_delay_percent);
+      return compareRealNumbers(p1->swapin_delay_percent, p2->swapin_delay_percent);
    #endif
    case IO_PRIORITY:
       return SPACESHIP_NUMBER(LinuxProcess_effectiveIOPriority(p1), LinuxProcess_effectiveIOPriority(p2));

pcp/PCPProcess.c

@@ -199,16 +199,6 @@ static void PCPProcess_writeField(const Process* this, RichString* str, ProcessF
    RichString_appendWide(str, attr, buffer);
 }
 
-/* Compares floating point values for ordering data entries. In this function,
-   NaN is considered "less than" any other floating point value (regardless of
-   sign), and two NaNs are considered "equal" regardless of payload. */
-static int compareRealNumbers(double a, double b) {
-   int result = (int)isgreater(a, b) - isgreater(b, a);
-   if (result)
-      return result;
-   return (int)!isNaN(a) - !isNaN(b);
-}
-
 static int PCPProcess_compareByKey(const Process* v1, const Process* v2, ProcessField key) {
    const PCPProcess* p1 = (const PCPProcess*)v1;
    const PCPProcess* p2 = (const PCPProcess*)v2;
@@ -263,11 +253,11 @@ static int PCPProcess_compareByKey(const Process* v1, const Process* v2, Process
    case OOM:
       return SPACESHIP_NUMBER(p1->oom, p2->oom);
    case PERCENT_CPU_DELAY:
-      return SPACESHIP_NUMBER(p1->cpu_delay_percent, p2->cpu_delay_percent);
+      return compareRealNumbers(p1->cpu_delay_percent, p2->cpu_delay_percent);
    case PERCENT_IO_DELAY:
-      return SPACESHIP_NUMBER(p1->blkio_delay_percent, p2->blkio_delay_percent);
+      return compareRealNumbers(p1->blkio_delay_percent, p2->blkio_delay_percent);
    case PERCENT_SWAP_DELAY:
-      return SPACESHIP_NUMBER(p1->swapin_delay_percent, p2->swapin_delay_percent);
+      return compareRealNumbers(p1->swapin_delay_percent, p2->swapin_delay_percent);
    case CTXT:
       return SPACESHIP_NUMBER(p1->ctxt_diff, p2->ctxt_diff);
    case SECATTR: