sort_r.c Public Domain sort_r() by Isaac Turner

Imported GIT commit 7c60ef94753624291055af0b1eec291f8c4bd5a7
from https://github.com/noporpoise/sort_r

1 files changed, 122 insertions, 0 deletions

diff --git a/src/sort_r.h b/src/sort_r.h
new file mode 100644
index 00000000..5ea05383
--- /dev/null
+++ b/src/sort_r.h
@@ -0,0 +1,122 @@
+/* Isaac Turner 29 April 2014 Public Domain */
+#ifndef SORT_R_H_
+#define SORT_R_H_
+
+#include <stdlib.h>
+
+/*
+sort_r function to be exported.
+
+Parameters:
+  base is the array to be sorted
+  nel is the number of elements in the array
+  width is the size in bytes of each element of the array
+  compar is the comparison function
+  arg is a pointer to be passed to the comparison function
+
+void sort_r(void *base, size_t nel, size_t width,
+            int (*compar)(const void *_a, const void *_b, void *_arg),
+            void *arg);
+*/
+
+#if (defined __APPLE__ || defined __MACH__ || defined __DARWIN__ || \
+     defined __FREEBSD__ || defined __BSD__ || \
+     defined OpenBSD3_1 || defined OpenBSD3_9 || defined __OpenBSD__ || \
+     defined AMIGA)
+#  define _SORT_R_BSD
+#elif (defined _GNU_SOURCE || defined __gnu_hurd__ || defined __GNU__ || \
+       defined __linux__ || defined __MINGW32__ || defined __GLIBC__)
+#  define _SORT_R_LINUX
+#elif (defined _WIN32 || defined _WIN64 || defined __WINDOWS__)
+#  define _SORT_R_WINDOWS
+#else
+#  error Cannot detect operating system
+#endif
+
+#if (defined NESTED_QSORT && NESTED_QSORT == 0)
+#  undef NESTED_QSORT
+#elif (!defined NESTED_QSORT && \
+       defined __GLIBC__ && __GLIBC__ == 2 && __GLIBC_MINOR__ < 8)
+/* no qsort_r in glibc before 2.8 */
+#  define NESTED_QSORT
+#endif
+
+
+#if defined NESTED_QSORT
+
+  static inline void sort_r(void *base, size_t nel, size_t width,
+                            int (*compar)(const void *_a, const void *_b, void *aarg),
+                            void *arg)
+  {
+    int nested_cmp(const void *a, const void *b)
+    {
+      return compar(a, b, arg);
+    }
+
+    qsort(base, nel, width, nested_cmp);
+  }
+
+#else /* !NESTED_QSORT */
+
+  /* Declare structs and functions */
+  #if defined _SORT_R_BSD
+
+    /* BSD requires argument swap */
+    extern void qsort_r(void *base, size_t nel, size_t width, void *thunk,
+                        int (*compar)(void *_thunk, const void *_a, const void *_b));
+
+    struct sort_r_data
+    {
+      void *arg;
+      int (*compar)(const void *_a, const void *_b, void *_arg);
+    };
+
+    static inline int sort_r_arg_swap(void *s, const void *a, const void *b)
+    {
+      struct sort_r_data *ss = (struct sort_r_data*)s;
+      return (ss->compar)(a, b, ss->arg);
+    }
+
+  #elif defined _SORT_R_LINUX
+
+    typedef int(* __compar_d_fn_t)(const void *, const void *, void *);
+    extern void qsort_r(void *base, size_t nel, size_t width,
+                        __compar_d_fn_t __compar, void *arg)
+      __attribute__((nonnull (1, 4)));
+
+  #endif
+
+  /* implementation */
+
+  static inline void sort_r(void *base, size_t nel, size_t width,
+                            int (*compar)(const void *_a, const void *_b, void *_arg),
+                            void *arg)
+  {
+    #if defined _SORT_R_LINUX
+
+      qsort_r(base, nel, width, compar, arg);
+
+    #elif defined _SORT_R_BSD
+
+      struct sort_r_data tmp;
+      tmp.arg = arg;
+      tmp.compar = compar;
+      qsort_r(base, nel, width, &tmp, sort_r_arg_swap);
+
+    #else /* defined _SORT_R_WINDOWS */
+
+      struct sort_r_data tmp;
+      tmp.arg = arg;
+      tmp.compar = compar;
+      qsort_s(base, nel, width, sort_r_arg_swap, &tmp);
+
+    #endif
+  }
+
+#endif /* !NESTED_QSORT */
+
+#undef _SORT_R_WINDOWS
+#undef _SORT_R_LINUX
+#undef _SORT_R_BSD
+
+#endif /* SORT_R_H_ */