http11: Remove qsort code paths [changelog skip] (#2073)

* http11: Remove unused qsort/bsearch code paths

[changelog skip]

* Explicitly include ctype.h to fix compilation warning

[changelog skip]

Had the following warning during compilation without the include:
warning: implicitly declaring library function 'isspace' with type 'int (int)'

ext/puma_http11/puma_http11.c

@@ -10,6 +10,7 @@
 #include "ext_help.h"
 #include <assert.h>
 #include <string.h>
+#include <ctype.h>
 #include "http11_parser.h"
 
 #ifndef MANAGED_STRINGS
@@ -111,21 +112,6 @@ static struct common_field common_http_fields[] = {
 # undef f
 };
 
-/*
- * qsort(3) and bsearch(3) improve average performance slightly, but may
- * not be worth it for lack of portability to certain platforms...
- */
-#if defined(HAVE_QSORT_BSEARCH)
-/* sort by length, then by name if there's a tie */
-static int common_field_cmp(const void *a, const void *b)
-{
-  struct common_field *cfa = (struct common_field *)a;
-  struct common_field *cfb = (struct common_field *)b;
-  signed long diff = cfa->len - cfb->len;
-  return diff ? diff : memcmp(cfa->name, cfb->name, cfa->len);
-}
-#endif /* HAVE_QSORT_BSEARCH */
-
 static void init_common_fields(void)
 {
   unsigned i;
@@ -142,36 +128,17 @@ static void init_common_fields(void)
     }
     rb_global_variable(&cf->value);
   }
-
-#if defined(HAVE_QSORT_BSEARCH)
-  qsort(common_http_fields,
-        ARRAY_SIZE(common_http_fields),
-        sizeof(struct common_field),
-        common_field_cmp);
-#endif /* HAVE_QSORT_BSEARCH */
 }
 
 static VALUE find_common_field_value(const char *field, size_t flen)
 {
-#if defined(HAVE_QSORT_BSEARCH)
-  struct common_field key;
-  struct common_field *found;
-  key.name = field;
-  key.len = (signed long)flen;
-  found = (struct common_field *)bsearch(&key, common_http_fields,
-                                         ARRAY_SIZE(common_http_fields),
-                                         sizeof(struct common_field),
-                                         common_field_cmp);
-  return found ? found->value : Qnil;
-#else /* !HAVE_QSORT_BSEARCH */
   unsigned i;
   struct common_field *cf = common_http_fields;
   for(i = 0; i < ARRAY_SIZE(common_http_fields); i++, cf++) {
     if (cf->len == flen && !memcmp(cf->name, field, flen))
       return cf->value;
   }
   return Qnil;
-#endif /* !HAVE_QSORT_BSEARCH */
 }
 
 void http_field(puma_parser* hp, const char *field, size_t flen,