Merge pull request #13 from vtorri/master

add Windows port of perf.c

source/lexbor/ports/windows_nt/lexbor/perf.c

@@ -0,0 +1,81 @@
+/*
+ * Copyright (C) 2018 Alexander Borisov
+ *
+ * Author: Vincent Torri <vincent.torri@gmail.com>
+ */
+
+#include "lexbor/core/perf.h"
+
+#include <windows.h>
+
+
+typedef struct lexbor_perf {
+    LARGE_INTEGER start;
+    LARGE_INTEGER end;
+    LARGE_INTEGER freq;
+}
+lexbor_perf_t;
+
+
+void *
+lexbor_perf_create(void)
+{
+    lexbor_perf_t *perf = lexbor_calloc(1, sizeof(lexbor_perf_t));
+    if (perf == NULL) {
+        return NULL;
+    }
+
+    /*
+     * According to MSDN, QueryPerformanceFrequency() never fails
+     * on Windows XP or later
+     */
+    QueryPerformanceFrequency(&perf->freq);
+    return perf;
+}
+
+void
+lexbor_perf_clean(void *perf)
+{
+    memset(perf, 0, sizeof(lexbor_perf_t));
+}
+
+void
+lexbor_perf_destroy(void *perf)
+{
+    if (perf != NULL) {
+        lexbor_free(perf);
+    }
+}
+
+lxb_status_t
+lexbor_perf_begin(void *perf)
+{
+    /*
+     * According to MSDN, QueryPerformanceCounter() never fails
+     * on Windows XP or later
+     */
+    QueryPerformanceCounter(&(((lexbor_perf_t *) (perf))->start));
+
+    return LXB_STATUS_OK;
+}
+
+lxb_status_t
+lexbor_perf_end(void *perf)
+{
+    /*
+     * According to MSDN, QueryPerformanceCounter() never fails
+     * on Windows XP or later
+     */
+    QueryPerformanceCounter(&(((lexbor_perf_t *) (perf))->end));
+
+    return LXB_STATUS_OK;
+}
+
+double
+lexbor_perf_in_sec(void *perf)
+{
+    lexbor_perf_t *obj_perf = (lexbor_perf_t *) perf;
+
+    return ((double) (obj_perf->end.QuadPart - obj_perf->start.QuadPart)
+            / (double)obj_perf->freq.QuadPart);
+}