From 9984962b98cae0464983e0b0eb896e0dfb0b8429 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Thu, 21 Jan 2016 13:17:13 +0100
Subject: [PATCH] added Matcher and Meanbuf files

---
 matcher.c | 28 ++++++++++++++++++++++++++++
 matcher.h | 21 +++++++++++++++++++++
 meanbuf.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 meanbuf.h | 21 +++++++++++++++++++++
 4 files changed, 118 insertions(+)
 create mode 100644 matcher.c
 create mode 100644 matcher.h
 create mode 100644 meanbuf.c
 create mode 100644 meanbuf.h

diff --git a/matcher.c b/matcher.c
new file mode 100644
index 0000000..312a644
--- /dev/null
+++ b/matcher.c
@@ -0,0 +1,28 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "matcher.h"
+
+
+/** Handle incoming char. Returns true if this char completed the match. */
+bool matcher_test(matcher_t * m, uint8_t b)
+{
+	// If mismatch, rewind (and check at 0)
+	if (m->pattern[m->cursor] != b) {
+		m->cursor = 0;
+	}
+
+	// Check for match
+	if (m->pattern[m->cursor] == b) {
+		// Good char
+		m->cursor++;
+		if (m->pattern[m->cursor] == 0) { // end of pattern
+			m->cursor = 0; // rewind
+			return true; // indicate success
+		}
+	}
+
+	return false;
+}
diff --git a/matcher.h b/matcher.h
new file mode 100644
index 0000000..6aedcb7
--- /dev/null
+++ b/matcher.h
@@ -0,0 +1,21 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+typedef struct {
+	const char *pattern;
+	size_t cursor;
+} matcher_t;
+
+
+/**
+ * Consume an incoming character.
+ * If this char was the last char of the pattern, returns true and rewinds.
+ *
+ * If the char is not in the pattern, resets match state.
+ *
+ * @returns true if the char concluded the expected pattern.
+ */
+bool matcher_test(matcher_t * mb, uint8_t b);
diff --git a/meanbuf.c b/meanbuf.c
new file mode 100644
index 0000000..65ccfa4
--- /dev/null
+++ b/meanbuf.c
@@ -0,0 +1,48 @@
+#include <stdint.h>
+#include <malloc.h>
+
+#include "meanbuf.h"
+
+
+/** Init a buffer */
+void meanbuf_init(meanbuf_t *mb, size_t size)
+{
+	if (size < 1) size = 1;
+
+	mb->buf = calloc(size, sizeof(float)); // calloc, so it starts with zeros.
+	mb->cap = size;
+	mb->nw = 0;
+	mb->mean = 0;
+
+	// clean buffer
+	for (uint16_t i = 0; i < size; i++) {
+		mb->buf[i] = 0;
+	}
+}
+
+
+void meanbuf_deinit(meanbuf_t *mb)
+{
+	if (mb->buf != NULL) {
+		free(mb->buf);
+	}
+}
+
+
+/** Add a value to the buffer. Returns current mean. */
+float meanbuf_add(meanbuf_t *mb, float f)
+{
+	// add sample
+	mb->buf[mb->nw++] = f;
+	if (mb->nw == mb->cap) mb->nw = 0;
+
+	// calculate average
+	float acc = 0;
+	for (size_t i = 0; i < mb->cap; i++) {
+		acc += mb->buf[i];
+	}
+
+	acc /= mb->cap;
+
+	return mb->mean = acc;
+}
diff --git a/meanbuf.h b/meanbuf.h
new file mode 100644
index 0000000..4e655d9
--- /dev/null
+++ b/meanbuf.h
@@ -0,0 +1,21 @@
+#pragma once
+#include <stdlib.h>
+#include <stdint.h>
+
+
+typedef struct {
+	float * buf; // buffer (allocated at init)
+	size_t cap; // capacity
+	size_t nw; // next write index
+	float mean; // updated on write
+} meanbuf_t;
+
+
+/** Init a buffer */
+void meanbuf_init(meanbuf_t *mb, size_t size);
+
+/** Deinit a buffer (free buffer array) */
+void meanbuf_deinit(meanbuf_t *mb);
+
+/** Add a value to the buffer. Returns current mean. */
+float meanbuf_add(meanbuf_t *mb, float f);