--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/servlib/routing/LinkScheduleEstimator.h Thu Apr 21 14:57:45 2011 +0100
@@ -0,0 +1,96 @@
+/*
+ * Copyright 2005-2006 Intel Corporation
+ *
+ * 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 <vector>
+#include <oasys/util/IntUtils.h>
+#include <oasys/debug/Log.h>
+
+#define CONTACT(s, d) { s, d }
+#define absdiff(x,y) ((x<y)?((y)-(x)):((x)-(y)))
+
+#define WARPING_WINDOW .02
+#define PERIOD_TOLERANCE .02
+#define MAX_DIST 1<<30
+
+namespace dtn {
+
+/**
+ * Given a log on the form (start1, duration1), ... ,(startN,
+ * durationN), the LinkScheduleEstimator algorithm figures out a
+ * periodic schedule that this log conforms to.
+ *
+ * The schedule computed can then be used to predict future link-up
+ * events, and to inform far-away nodes about the future predicted
+ * availability of the link in question.
+ *
+ * Usage:
+ * Log* find_schedule(Log* log);
+ *
+ * Returns the best schedule for the given log. If there's no
+ * discernible periodicity in the log, the return value will be
+ * NULL.
+ */
+class LinkScheduleEstimator : public oasys::Logger {
+public:
+ typedef struct {
+ unsigned int start;
+ unsigned int duration;
+ } LogEntry;
+
+ typedef std::vector<LogEntry> Log;
+
+ static Log* find_schedule(Log* log);
+
+ LinkScheduleEstimator();
+private:
+ unsigned int entry_dist(Log &a, unsigned int a_index, unsigned int a_offset,
+ Log &b, unsigned int b_index, unsigned int b_offset,
+ unsigned int warping_window);
+
+ unsigned int log_dist_r(Log &a, unsigned int a_index, unsigned int a_offset,
+ Log &b, unsigned int b_index, unsigned int b_offset,
+ unsigned int warping_window);
+
+
+ unsigned int log_dist(Log &a, unsigned int a_offset,
+ Log &b, unsigned int b_offset,
+ unsigned int warping_window, int print_table);
+
+ unsigned int autocorrelation(Log &log, unsigned int phase, int print_table);
+ void print_log(Log &log, int relative_dates);
+
+ Log* generate_samples(Log &schedule,
+ unsigned int log_size,
+ unsigned int start_jitter,
+ double duration_jitter);
+
+ unsigned int estimate_period(Log &log);
+ unsigned int seek_to_before_date(Log &log, unsigned int date);
+ unsigned int closest_entry_to_date(Log &log, unsigned int date);
+ Log* clone_subsequence(Log &log, unsigned int start, unsigned int len);
+
+ unsigned int badness_of_match(Log &pattern,
+ Log &log,
+ unsigned int warping_window,
+ unsigned int period);
+
+ Log* extract_schedule(Log &log, unsigned int period_estimate);
+ unsigned int refine_period(Log &log, unsigned int period_estimate);
+ Log* find_schedule(Log &log);
+};
+
+
+}