add socks_decoder, stratum_decoder and session_flags

decoders/session_flags/onlinemean.h

@@ -0,0 +1,30 @@
+#ifndef ONLINEMEAN_H_
+#define ONLINEMEAN_H_
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/* Set to 1 to return unbiased (sample) variance
+ * rather than a population variance */
+#define UNBIASED_ESTIMATOR  0
+
+#include <stdint.h>
+
+typedef struct OnlineMean {
+	float mean;
+	float varsum;  // variance sum
+	uint32_t count;
+} OnlineMean_t;
+
+void OnlineMean_Init(OnlineMean_t *oMean);
+void OnlineMean_Update(OnlineMean_t *oMean, float newValue);
+float OnlineMean_GetMean(OnlineMean_t *oMean);
+float OnlineMean_GetStd(OnlineMean_t *oMean);
+void OnlineMean_Reset(OnlineMean_t *oMean);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ONLINEMEAN_H_ */