Add memelemscan

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 94 insertions, 0 deletions

diff --git a/memelemscan.c b/memelemscan.c
new file mode 100644
index 0000000..744989b
--- /dev/null
+++ b/memelemscan.c
@@ -0,0 +1,94 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsimple.h"
+#ifndef TEST
+
+
+void *
+libsimple_memelemscan(const void *hay_, size_t hayn, const void *sub_, size_t subn)
+{
+	if (!subn)
+		return (void *)hay_;
+
+	switch (subn) {
+	case 1:
+		return libsimple_memscan(hay_, *(char *)sub_, hayn);
+	case 2:
+		{
+			uint16_t *hay = (void *)hay_;
+			uint16_t sub = *(uint16_t *)sub_;
+			for (; hayn-- && *hay != sub; hay++);
+			return hay;
+		}
+	case 4:
+		{
+			uint32_t *hay = (void *)hay_;
+			uint32_t sub = *(uint32_t *)sub_;
+			for (; hayn-- && *hay != sub; hay++);
+			return hay;
+		}
+	case 8:
+		{
+			uint64_t *hay = (void *)hay_;
+			uint64_t sub = *(uint64_t *)sub_;
+			for (; hayn-- && *hay != sub; hay++);
+			return hay;
+		}
+	default:
+		{
+			char *hay = (void *)hay_;
+			const char *sub = sub_;
+			size_t i;
+			for (; hayn--; hay += subn) {
+				for (i = 0; i < subn; i++)
+					if (hay[i] != sub[i])
+						goto next;
+				return hay;
+			next:;
+			}
+			return hay;
+		}
+	}
+
+	return NULL;
+}
+
+
+#else
+#include "test.h"
+
+int
+main(void)
+{
+	assert(!strcmpnul(libsimple_memelemscan("12345634", 8, "", 0), "12345634"));
+	assert(!strcmpnul(libsimple_memelemscan("12345634", 0, "", 0), "12345634"));
+
+	assert(!strcmpnul(libsimple_memelemscan("12345634", 8, "3", 1), "345634"));
+	assert(!strcmpnul(libsimple_memelemscan("12345634", 8, "x", 1), ""));
+	assert(!strcmpnul(libsimple_memelemscan("13456342", 8, "3", 1), "3456342"));
+	assert(!strcmpnul(libsimple_memelemscan("12345634", 0, "3", 1), "12345634"));
+
+	assert(!strcmpnul(libsimple_memelemscan("12345634", 4, "34", 2), "345634"));
+	assert(!strcmpnul(libsimple_memelemscan("12345634z", 4, "xx", 2), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("13456342z", 4, "34", 2), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("12345634z", 0, "34", 2), "12345634z"));
+
+	assert(!strcmpnul(libsimple_memelemscan("abcd1234abcd1234", 4, "1234", 4), "1234abcd1234"));
+	assert(!strcmpnul(libsimple_memelemscan("abcd1234abcd1234z", 4, "zzzz", 4), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("cd1234abcd1234abz", 4, "1234", 4), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("abcd1234abcd1234z", 0, "1234", 4), "abcd1234abcd1234z"));
+
+	assert(!strcmpnul(libsimple_memelemscan("abcdefgh12345678abcdefgh12345678", 4, "12345678", 8), "12345678abcdefgh12345678"));
+	assert(!strcmpnul(libsimple_memelemscan("abcdefgh12345678abcdefgh12345678z", 4, "zzzzzzzz", 8), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("efgh12345678abcdefgh12345678abcdz", 4, "12345678", 8), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("abcdefgh12345678abcdefgh12345678z", 0, "12345678", 8),
+	                  "abcdefgh12345678abcdefgh12345678z"));
+
+	assert(!strcmpnul(libsimple_memelemscan("abc123abc123", 4, "123", 3), "123abc123"));
+	assert(!strcmpnul(libsimple_memelemscan("abc123abc123z", 4, "zzz", 3), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("bc123abc123az", 4, "123", 3), "z"));
+	assert(!strcmpnul(libsimple_memelemscan("abc123abc123z", 0, "123", 3), "abc123abc123z"));
+
+	return 0;
+}
+
+#endif