api-v3: First draft

This commit introduces the bindings v3 API for bindings.

The documentation has still to be improved and will come
very soon.

Change-Id: I8f9007370e29f671fdfd1da87fff7372a17db7af
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 39 insertions, 0 deletions

diff --git a/src/pearson.c b/src/pearson.c
new file mode 100644
index 00000000..a39c8952
--- /dev/null
+++ b/src/pearson.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2018 "IoT.bzh"
+ * Author: José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdint.h>
+
+/*
+ * Returns a tiny hash value for the 'text'.
+ *
+ * Tiny hash function inspired from pearson
+ */
+uint8_t pearson4(const char *text)
+{
+	static uint8_t T[16] = {
+		 4,  1,  6,  0,  9, 14, 11,  5,
+		 2,  3, 12, 15, 10,  7,  8, 13
+	};
+	uint8_t r, c;
+
+	for (r = 0; (c = (uint8_t)*text) ; text++) {
+		r = T[r ^ (15 & c)];
+		r = T[r ^ (c >> 4)];
+	}
+	return r; // % HEADCOUNT;
+}
+