From: Marcin Siodelski <marcin@isc.org>
Date: Fri, 17 Feb 2023 07:14:26 +0000 (+0100)
Subject: [#2764] Hashing operator for IOAddress
X-Git-Tag: Kea-2.3.6~92
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=78cc08bd034bcd1b949c823a816ac8c12e2cd045;p=thirdparty%2Fkea.git

[#2764] Hashing operator for IOAddress

To store the addresses in the unordered containers.
---

diff --git a/src/lib/asiolink/io_address.cc b/src/lib/asiolink/io_address.cc
index 7f7134d534..b17ec63acf 100644
--- a/src/lib/asiolink/io_address.cc
+++ b/src/lib/asiolink/io_address.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2010-2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2010-2023 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -28,6 +28,11 @@ using namespace std;
 namespace isc {
 namespace asiolink {
 
+size_t
+IOAddress::Hash::operator()(const IOAddress &io_address) const {
+    return (hash_value(io_address));
+}
+
 // XXX: we cannot simply construct the address in the initialization list,
 // because we'd like to throw our own exception on failure.
 IOAddress::IOAddress(const std::string& address_str) {
diff --git a/src/lib/asiolink/io_address.h b/src/lib/asiolink/io_address.h
index fb1d67b3ea..d08753b5cf 100644
--- a/src/lib/asiolink/io_address.h
+++ b/src/lib/asiolink/io_address.h
@@ -1,4 +1,4 @@
-// Copyright (C) 2010-2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2010-2023 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -44,6 +44,17 @@ namespace asiolink {
 /// This class is a wrapper for the ASIO \c ip::address class.
 class IOAddress {
 public:
+
+    /// \brief An \c IOAddress hash enabling the use in the unordered
+    /// STL containers.
+    struct Hash {
+        /// \brief A hashing operator.
+        ///
+        /// \param io_address an address to be hashed.
+        /// \return a hashing result.
+        size_t operator()(const IOAddress &io_address) const;
+    };
+
     ///
     /// \name Constructors and Destructor
     ///
diff --git a/src/lib/asiolink/tests/io_address_unittest.cc b/src/lib/asiolink/tests/io_address_unittest.cc
index 79888d29a6..b1139402df 100644
--- a/src/lib/asiolink/tests/io_address_unittest.cc
+++ b/src/lib/asiolink/tests/io_address_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (C) 2011-2020 Internet Systems Consortium, Inc. ("ISC")
+// Copyright (C) 2011-2023 Internet Systems Consortium, Inc. ("ISC")
 //
 // This Source Code Form is subject to the terms of the Mozilla Public
 // License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -15,9 +15,38 @@
 #include <cstring>
 #include <vector>
 #include <sstream>
+#include <unordered_set>
 
 using namespace isc::asiolink;
 
+TEST(IOAddressHashTest, hashIPv4) {
+    IOAddress::Hash hash;
+    std::unordered_set<size_t> results;
+    for (uint32_t i = 0; i < 10; i++) {
+        IOAddress address(i);
+        auto result = hash(address);
+        results.insert(result);
+    }
+    // Make sure that the hashing function generated a unique hash for
+    // each address.
+    EXPECT_EQ(10, results.size());
+}
+
+TEST(IOAddressHashTest, hashIPv6) {
+    IOAddress::Hash hash;
+    std::unordered_set<size_t> results;
+    for (auto i = 0; i < 10; i++) {
+        std::ostringstream s;
+        s << "2001:db8:" << i << "::ffff";
+        IOAddress address(s.str());
+        auto result = hash(address);
+        results.insert(result);
+    }
+    // Make sure that the hashing function generated a unique hash for
+    // each address.
+    EXPECT_EQ(10, results.size());
+}
+
 TEST(IOAddressTest, fromText) {
     IOAddress io_address_v4("192.0.2.1");
     EXPECT_EQ("192.0.2.1", io_address_v4.toText());