network: Modernize Address class to use std::array and spaceship operator

Author: Dhiraj03

AUTHORS

@@ -279,6 +279,7 @@ Alberto Gallegos Ramonet ([email protected])
 Manoj Kumar Rana ([email protected])
 Andrea Ranieri ([email protected])
 Ashish Reddy ([email protected])
+Dhiraj Lokesh ([email protected])
 Bruno Ranieri ([email protected])
 Deepti Rajagopal ([email protected])
 Satyarth Ratnani ([email protected])

CHANGES.md

@@ -28,6 +28,7 @@ This file is a best-effort approach to solving this issue; we will do our best b
 * Initializing a Ipv[4,6]Address from a string using the constructor or the `Set` function will result in a crash if the string can not be parsed as an IPv4 or IPv6 address.
 * The `Ipv[4,6]Address::IsInitialized()` function has been deprecated and returns always `true`. The default value of Ipv4Address created with the constructor that takes no arguments is 0.0.0.0 (previously, it was 102.102.102.102), and an Ipv4Address instance can be checked against that unspecified address value (or use std::optional to denote an address that has not been set yet).
 * A new static function `Ipv[4,6]Address::CheckCompatible()` has been added to safely check if a string can be parsed as an IPv4 or IPv6 address.
+* (network): The address class comparison is now based on std::strong_ordering operator<=> comparison operator.
 
 ### Changes to build system
 

src/internet/model/icmpv6-l4-protocol.cc

@@ -600,7 +600,6 @@ Icmpv6L4Protocol::HandleRS(Ptr<Packet> packet,
     Ptr<Ipv6L3Protocol> ipv6 = m_node->GetObject<Ipv6L3Protocol>();
     Icmpv6RS rsHeader;
     packet->RemoveHeader(rsHeader);
-    Address hardwareAddress;
     Icmpv6OptionLinkLayerAddress lla(true);
     NdiscCache::Entry* entry = nullptr;
     Ptr<NdiscCache> cache = FindCache(interface->GetDevice());

src/network/CMakeLists.txt

@@ -158,6 +158,7 @@ build_lib(
   HEADER_FILES ${header_files}
   LIBRARIES_TO_LINK ${libstats}
   TEST_SOURCES
+    test/address-test.cc
     test/bit-serializer-test.cc
     test/buffer-test.cc
     test/drop-tail-queue-test-suite.cc

src/network/model/address.cc

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: GPL-2.0-only
  *
  * Author: Mathieu Lacage <[email protected]>
+ * Modified by: Dhiraj Lokesh <[email protected]>
  */
 
 #include "address.h"
@@ -22,41 +23,14 @@ NS_LOG_COMPONENT_DEFINE("Address");
 
 Address::KindTypeRegistry Address::m_typeRegistry;
 
-Address::Address()
-    : m_type(UNASSIGNED_TYPE),
-      m_len(0)
-{
-    // Buffer left uninitialized
-    NS_LOG_FUNCTION(this);
-}
-
 Address::Address(uint8_t type, const uint8_t* buffer, uint8_t len)
     : m_type(type),
       m_len(len)
 {
     NS_LOG_FUNCTION(this << static_cast<uint32_t>(type) << &buffer << static_cast<uint32_t>(len));
     NS_ASSERT_MSG(m_len <= MAX_SIZE, "Address length too large");
     NS_ASSERT_MSG(type != UNASSIGNED_TYPE, "Type 0 is reserved for uninitialized addresses.");
-    std::memcpy(m_data, buffer, m_len);
-}
-
-Address::Address(const Address& address)
-    : m_type(address.m_type),
-      m_len(address.m_len)
-{
-    NS_ASSERT(m_len <= MAX_SIZE);
-    std::memcpy(m_data, address.m_data, m_len);
-}
-
-Address&
-Address::operator=(const Address& address)
-{
-    NS_ASSERT(m_len <= MAX_SIZE);
-    m_type = address.m_type;
-    m_len = address.m_len;
-    NS_ASSERT(m_len <= MAX_SIZE);
-    std::memcpy(m_data, address.m_data, m_len);
-    return *this;
+    std::copy(buffer, buffer + len, m_data.begin());
 }
 
 void
@@ -97,7 +71,7 @@ Address::CopyTo(uint8_t buffer[MAX_SIZE]) const
 {
     NS_LOG_FUNCTION(this << &buffer);
     NS_ASSERT(m_len <= MAX_SIZE);
-    std::memcpy(buffer, m_data, m_len);
+    std::copy(m_data.begin(), m_data.begin() + m_len, buffer);
     return m_len;
 }
 
@@ -108,7 +82,7 @@ Address::CopyAllTo(uint8_t* buffer, uint8_t len) const
     NS_ASSERT(len - m_len > 1);
     buffer[0] = m_type;
     buffer[1] = m_len;
-    std::memcpy(buffer + 2, m_data, m_len);
+    std::copy(m_data.begin(), m_data.begin() + m_len, buffer + 2);
     return m_len + 2;
 }
 
@@ -119,7 +93,7 @@ Address::CopyFrom(const uint8_t* buffer, uint8_t len)
     NS_ASSERT_MSG(m_len <= MAX_SIZE, "Address length too large");
     NS_ASSERT_MSG(m_type != UNASSIGNED_TYPE,
                   "Type-0 addresses are reserved. Please use SetType before using CopyFrom.");
-    std::memcpy(m_data, buffer, len);
+    std::copy(buffer, buffer + len, m_data.begin());
     m_len = len;
     return m_len;
 }
@@ -133,7 +107,7 @@ Address::CopyAllFrom(const uint8_t* buffer, uint8_t len)
     m_len = buffer[1];
 
     NS_ASSERT(len - m_len > 1);
-    std::memcpy(m_data, buffer + 2, m_len);
+    std::copy(buffer + 2, buffer + 2 + m_len, m_data.begin());
     return m_len + 2;
 }
 
@@ -177,7 +151,7 @@ Address::Serialize(TagBuffer buffer) const
     NS_LOG_FUNCTION(this << &buffer);
     buffer.WriteU8(m_type);
     buffer.WriteU8(m_len);
-    buffer.Write(m_data, m_len);
+    buffer.Write(m_data.data(), m_len);
 }
 
 void
@@ -187,65 +161,11 @@ Address::Deserialize(TagBuffer buffer)
     m_type = buffer.ReadU8();
     m_len = buffer.ReadU8();
     NS_ASSERT(m_len <= MAX_SIZE);
-    buffer.Read(m_data, m_len);
+    buffer.Read(m_data.data(), m_len);
 }
 
 ATTRIBUTE_HELPER_CPP(Address);
 
-bool
-operator==(const Address& a, const Address& b)
-{
-    if (a.m_type != b.m_type)
-    {
-        return false;
-    }
-    if (a.m_len != b.m_len)
-    {
-        return false;
-    }
-    return std::memcmp(a.m_data, b.m_data, a.m_len) == 0;
-}
-
-bool
-operator!=(const Address& a, const Address& b)
-{
-    return !(a == b);
-}
-
-bool
-operator<(const Address& a, const Address& b)
-{
-    if (a.m_type < b.m_type)
-    {
-        return true;
-    }
-    else if (a.m_type > b.m_type)
-    {
-        return false;
-    }
-    if (a.m_len < b.m_len)
-    {
-        return true;
-    }
-    else if (a.m_len > b.m_len)
-    {
-        return false;
-    }
-    NS_ASSERT(a.GetLength() == b.GetLength());
-    for (uint8_t i = 0; i < a.GetLength(); i++)
-    {
-        if (a.m_data[i] < b.m_data[i])
-        {
-            return true;
-        }
-        else if (a.m_data[i] > b.m_data[i])
-        {
-            return false;
-        }
-    }
-    return false;
-}
-
 std::ostream&
 operator<<(std::ostream& os, const Address& address)
 {

src/network/model/address.h

@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: GPL-2.0-only
  *
  * Author: Mathieu Lacage <[email protected]>
+ * Modified by: Dhiraj Lokesh <[email protected]>
  */
 
 #ifndef ADDRESS_H
@@ -14,6 +15,8 @@
 #include "ns3/attribute-helper.h"
 #include "ns3/attribute.h"
 
+#include <array>
+#include <compare>
 #include <ostream>
 #include <stdint.h>
 #include <unordered_map>
@@ -156,7 +159,7 @@ class Address
     /**
      * Create an invalid address
      */
-    Address();
+    Address() = default;
     /**
      * @brief Create an address from a type and a buffer.
      *
@@ -171,26 +174,14 @@ class Address
      * @param len the length of the buffer.
      */
     Address(uint8_t type, const uint8_t* buffer, uint8_t len);
-    /**
-     * @brief Create an address from another address.
-     * @param address the address to copy
-     */
-    Address(const Address& address);
-    /**
-     * @brief Basic assignment operator.
-     * @param address the address to copy
-     * @return the address
-     */
-    Address& operator=(const Address& address);
-
     /**
      * Set the address type.
      *
      * Works only if the type is not yet set.
      * @see Register()
      *
-     * @param length address length
      * @param kind address kind
+     * @param length address length
      */
     void SetType(const std::string& kind, uint8_t length);
     /**
@@ -278,8 +269,8 @@ class Address
      * It is not allowed to have two different addresses with the same
      * kind and length.
      *
-     * @param length address length
      * @param kind address kind, such as "MacAddress"
+     * @param length address length
      * @return a new type id.
      */
     static uint8_t Register(const std::string& kind, uint8_t length);
@@ -303,34 +294,15 @@ class Address
      */
     void Deserialize(TagBuffer buffer);
 
-  private:
     /**
-     * @brief Equal to operator.
+     * @brief Three-way comparison operator.
      *
-     * @param a the first operand
-     * @param b the first operand
-     * @return true if the operands are equal
+     * @param other the other address to compare with
+     * @return comparison result
      */
-    friend bool operator==(const Address& a, const Address& b);
-
-    /**
-     * @brief Not equal to operator.
-     *
-     * @param a the first operand
-     * @param b the first operand
-     * @return true if the operands are not equal
-     */
-    friend bool operator!=(const Address& a, const Address& b);
-
-    /**
-     * @brief Less than operator.
-     *
-     * @param a the first operand
-     * @param b the first operand
-     * @return true if the operand a is less than operand b
-     */
-    friend bool operator<(const Address& a, const Address& b);
+    constexpr std::strong_ordering operator<=>(const Address& other) const = default;
 
+  private:
     /**
      * @brief Stream insertion operator.
      *
@@ -349,16 +321,13 @@ class Address
      */
     friend std::istream& operator>>(std::istream& is, Address& address);
 
-    uint8_t m_type;           //!< Type of the address
-    uint8_t m_len;            //!< Length of the address
-    uint8_t m_data[MAX_SIZE]; //!< The address value
+    uint8_t m_type{UNASSIGNED_TYPE};        //!< Type of the address
+    uint8_t m_len{0};                       //!< Length of the address
+    std::array<uint8_t, MAX_SIZE> m_data{}; //!< The address value
 };
 
 ATTRIBUTE_HELPER_HEADER(Address);
 
-bool operator==(const Address& a, const Address& b);
-bool operator!=(const Address& a, const Address& b);
-bool operator<(const Address& a, const Address& b);
 std::ostream& operator<<(std::ostream& os, const Address& address);
 std::istream& operator>>(std::istream& is, Address& address);