hotspot2: simplify ANQP cache management

This makes the AnqpCache just a simple data cache, all the logic
related to the ANQP query (e.g. pending query, backoff timeout) will
be handled elsewhere (e.g. PasspointManager).

Also simplify the cache entry expiration timeout (entries with ANQP
domain ID vs entries without ANQP domain ID) by using one timeout
for all entries, since this is already factored in the ANQP entry key.
Entries without ANQP domain ID will be keyed per AP (SSID + BSSID)
and entries with ANQP domain ID will be keyed per ESS (either SSID or
HESSID).

TODO: update unit tests once the cleanup for ANQP elements are completed,
so that we can easily construct an ANQPElement objects (without constructing
a raw byte buffer).

Bug: 31348912
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Change-Id: I6d85f69181755afa7845f9f742c2dfb762c3194c

1 files changed, 105 insertions, 0 deletions

diff --git a/service/java/com/android/server/wifi/hotspot2/ANQPNetworkKey.java b/service/java/com/android/server/wifi/hotspot2/ANQPNetworkKey.java
new file mode 100644
index 000000000..aaaedb37d
--- /dev/null
+++ b/service/java/com/android/server/wifi/hotspot2/ANQPNetworkKey.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2016 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 com.android.server.wifi.hotspot2;
+
+import android.text.TextUtils;
+
+/**
+ * Unique key for identifying APs that will contain the same ANQP information.
+ *
+ * APs in the same ESS (SSID or HESSID) with the same ANQP domain ID will have the same ANQP
+ * information. Thus, those APs will be keyed by the ESS identifier (SSID or HESSID) and the
+ * ANQP domain ID.
+ *
+ * APs without ANQP domain ID set will assumed to have unique ANQP information. Thus, those
+ * APs will be keyed by SSID and BSSID.
+ */
+public class ANQPNetworkKey {
+    private final String mSSID;
+    private final long mBSSID;
+    private final long mHESSID;
+    private final int mAnqpDomainID;
+
+    public ANQPNetworkKey(String ssid, long bssid, long hessid, int anqpDomainID) {
+        mSSID = ssid;
+        mBSSID = bssid;
+        mHESSID = hessid;
+        mAnqpDomainID = anqpDomainID;
+    }
+
+    /**
+     * Build an ANQP network key suitable for the granularity of the key space as follows:
+     *
+     * HESSID   domainID    Key content       Rationale
+     * -------- ----------- -----------       --------------------
+     * n/a      zero        SSID/BSSID        Domain ID indicates unique AP info
+     * not set  set         SSID/domainID     Standard definition of an ESS
+     * set      set         HESSID/domainID   The ESS is defined by the HESSID
+     *
+     * @param ssid The SSID of the AP
+     * @param bssid The BSSID of the AP
+     * @param hessid The HESSID of the AP
+     * @param anqpDomainId The ANQP Domain ID of the AP
+     * @return {@link ANQPNetworkKey}
+     */
+    public static ANQPNetworkKey buildKey(String ssid, long bssid, long hessid, int anqpDomainId) {
+        if (anqpDomainId == 0) {
+            return new ANQPNetworkKey(ssid, bssid, 0, 0);
+        } else if (hessid != 0L) {
+            return new ANQPNetworkKey(null, 0, hessid, anqpDomainId);
+        }
+        return new ANQPNetworkKey(ssid, 0, 0, anqpDomainId);
+    }
+
+    @Override
+    public int hashCode() {
+        if (mHESSID != 0) {
+            return (int) (((mHESSID >>> 32) * 31 + mHESSID) * 31 + mAnqpDomainID);
+        } else if (mBSSID != 0) {
+            return (int) ((mSSID.hashCode() * 31 + (mBSSID >>> 32)) * 31 + mBSSID);
+        } else {
+            return mSSID.hashCode() * 31 + mAnqpDomainID;
+        }
+    }
+
+    @Override
+    public boolean equals(Object thatObject) {
+        if (thatObject == this) {
+            return true;
+        }
+        if (!(thatObject instanceof ANQPNetworkKey)) {
+            return false;
+        }
+        ANQPNetworkKey that = (ANQPNetworkKey) thatObject;
+        return TextUtils.equals(that.mSSID, mSSID)
+                && that.mBSSID == mBSSID
+                && that.mHESSID == mHESSID
+                && that.mAnqpDomainID == mAnqpDomainID;
+    }
+
+    @Override
+    public String toString() {
+        if (mHESSID != 0L) {
+            return Utils.macToString(mHESSID) + ":" + mAnqpDomainID;
+        } else if (mBSSID != 0L) {
+            return Utils.macToString(mBSSID)
+                    + ":<" + Utils.toUnicodeEscapedString(mSSID) + ">";
+        } else {
+            return "<" + Utils.toUnicodeEscapedString(mSSID) + ">:" + mAnqpDomainID;
+        }
+    }
+}