Data structures for communication with network scorer apps.

NetworkKey represents the necessary information to identify a network
to be scored. ScoredNetwork contains the key to identify a network as
well as a score to be used when evaluating that network (as a curve
based on RSSI).

Bug: 13767776
Change-Id: I6bfebd105c9381e615513167b4332b767b43a23a

1 files changed, 129 insertions, 0 deletions

diff --git a/core/java/android/net/RssiCurve.java b/core/java/android/net/RssiCurve.java
new file mode 100644
index 0000000..7af7998
--- /dev/null
+++ b/core/java/android/net/RssiCurve.java
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * 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
+ */
+
+package android.net;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * A curve defining the network score over a range of RSSI values.
+ *
+ * <p>For each RSSI bucket, the score may be any byte. Scores have no absolute meaning and are only
+ * considered relative to other scores assigned by the same scorer. Networks with no score are all
+ * considered equivalent and ranked below any network with a score.
+ *
+ * <p>For example, consider a curve starting at -110 dBm with a bucket width of 10 and the
+ * following buckets: {@code [-20, -10, 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120]}.
+ * This represents a linear curve between -110 dBm and 30 dBm. It scores progressively higher at
+ * stronger signal strengths.
+ *
+ * <p>A network can be assigned a fixed score independent of RSSI by setting
+ * {@link #rssiBuckets} to a one-byte array whose element is the fixed score. {@link #start}
+ * should be set to the lowest RSSI value at which this fixed score should apply, and
+ * {@link #bucketWidth} should be set such that {@code start + bucketWidth} is equal to the
+ * highest RSSI value at which this fixed score should apply.
+ *
+ * <p>Note that RSSI values below -110 dBm or above 30 dBm are unlikely to cause any difference
+ * in connectivity behavior from those endpoints. That is, the connectivity framework will treat
+ * a network with a -120 dBm signal exactly as it would treat one with a -110 dBm signal.
+ * Therefore, graphs which specify scores outside this range may be truncated to this range by
+ * the system.
+ *
+ * @see ScoredNetwork
+ * @hide
+ */
+public class RssiCurve implements Parcelable {
+
+    /** The starting dBm of the curve. */
+    public final int start;
+
+    /** The width of each RSSI bucket, in dBm. */
+    public final int bucketWidth;
+
+    /** The score for each RSSI bucket. */
+    public final byte[] rssiBuckets;
+
+    /**
+     * Construct a new {@link RssiCurve}.
+     *
+     * @param start the starting dBm of the curve.
+     * @param bucketWidth the width of each RSSI bucket, in dBm.
+     * @param rssiBuckets the score for each RSSI bucket.
+     */
+    public RssiCurve(int start, int bucketWidth, byte[] rssiBuckets) {
+        this.start = start;
+        this.bucketWidth = bucketWidth;
+        if (rssiBuckets == null || rssiBuckets.length == 0) {
+            throw new IllegalArgumentException("rssiBuckets must be at least one element large.");
+        }
+        this.rssiBuckets = rssiBuckets;
+    }
+
+    private RssiCurve(Parcel in) {
+        start = in.readInt();
+        bucketWidth = in.readInt();
+        int bucketCount = in.readInt();
+        rssiBuckets = new byte[bucketCount];
+        in.readByteArray(rssiBuckets);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    @Override
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeInt(start);
+        out.writeInt(bucketWidth);
+        out.writeInt(rssiBuckets.length);
+        out.writeByteArray(rssiBuckets);
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        sb.append("RssiCurve[start=")
+                .append(start)
+                .append(",bucketWidth=")
+                .append(bucketWidth);
+
+        sb.append(",buckets=");
+        for (int i = 0; i < rssiBuckets.length; i++) {
+            sb.append(rssiBuckets[i]);
+            if (i < rssiBuckets.length - 1) {
+                sb.append(",");
+            }
+        }
+        sb.append("]");
+
+        return sb.toString();
+    }
+
+    public static final Creator<RssiCurve> CREATOR =
+            new Creator<RssiCurve>() {
+                @Override
+                public RssiCurve createFromParcel(Parcel in) {
+                    return new RssiCurve(in);
+                }
+
+                @Override
+                public RssiCurve[] newArray(int size) {
+                    return new RssiCurve[size];
+                }
+            };
+}