Implement command alias.

module/Core/Command.cpp

@@ -39,7 +39,10 @@ Command::Command(std::size_t hash, String name, Listener * ptr, CtrPtr  ctr)
 {
     if (mPtr)
     {
-        mPtr->m_Controller = mCtr; // Create controller association
+        // Create controller association
+        mPtr->m_Controller = mCtr;
+        // Increment alias count
+        mPtr->AddAliases(1);
     }
 }
 // ------------------------------------------------------------------------------------------------
@@ -48,7 +51,10 @@ Command::Command(std::size_t hash, String name, const Object & obj, CtrPtr  ctr)
 {
     if (mPtr)
     {
-        mPtr->m_Controller = mCtr; // Create controller association
+        // Create controller association
+        mPtr->m_Controller = mCtr;
+        // Increment alias count
+        mPtr->AddAliases(1);
     }
 }
 
@@ -58,7 +64,10 @@ Command::Command(std::size_t hash, String name, Object && obj, CtrPtr  ctr)
 {
     if (mPtr)
     {
-        mPtr->m_Controller = mCtr; // Create controller association
+        // Create controller association
+        mPtr->m_Controller = mCtr;
+        // Increment alias count
+        mPtr->AddAliases(1);
     }
 }
 
@@ -68,7 +77,10 @@ Command::Command(std::size_t hash, String name, Listener * ptr, const Object & o
 {
     if (mPtr)
     {
-        mPtr->m_Controller = mCtr; // Create controller association
+        // Create controller association
+        mPtr->m_Controller = mCtr;
+        // Increment alias count
+        mPtr->AddAliases(1);
     }
 }
 
@@ -78,7 +90,10 @@ Command::Command(std::size_t hash, String name, Listener * ptr, Object && obj, C
 {
     if (mPtr)
     {
-        mPtr->m_Controller = mCtr; // Create controller association
+        // Create controller association
+        mPtr->m_Controller = mCtr;
+        // Increment alias count
+        mPtr->AddAliases(1);
     }
 }
 
@@ -87,7 +102,12 @@ Command::~Command()
 {
     if (mPtr)
     {
-        mPtr->m_Controller.Reset(); // Break controller association
+        // The listener will continue to be associated with the controller as long as an alias points to it
+        if (mPtr->SubAliases(1) == 0)
+        {
+            // Break controller association
+            mPtr->m_Controller.Reset();
+        }
     }
 }
 
@@ -150,6 +170,63 @@ Object & Controller::Attach(Object && obj, Listener * ptr)
     return m_Commands.back().mObj;
 }
 
+// ------------------------------------------------------------------------------------------------
+Object & Controller::Attach(Object && obj, Listener * ptr, String name)
+{
+    // Is there anything that we can attach
+    if (obj.IsNull() && ptr == nullptr)
+    {
+        STHROWF("Cannot attach invalid command listener");
+    }
+    // Are we supposed to grab the object?
+    else if (obj.IsNull())
+    {
+        // Obtain the initial stack size
+        const StackGuard sg;
+        // Push the instance on the stack
+        ClassType< Listener >::PushInstance(SqVM(), ptr);
+        // Grab the instance from the stack
+        obj = Var< Object >(SqVM(), -1).value;
+    }
+    // Are we supposed to grab the instance?
+    else if (ptr == nullptr)
+    {
+        // Obtain the initial stack size
+        const StackGuard sg(obj.GetVM());
+        // Push the object on the stack
+        Var< Object & >::push(obj.GetVM(), obj);
+        // Grab the instance from the stack
+        ptr = Var< Listener * >(obj.GetVM(), -1).value;
+    }
+    // At this point we should have both the instance and the object
+    if (obj.IsNull() || ptr == nullptr)
+    {
+        STHROWF("Unable to obtain the command listener");
+    }
+    // Validate the command name
+    if (name.empty())
+    {
+        STHROWF("Cannot attach command without a name");
+    }
+    // Obtain the unique identifier of the specified name
+    const std::size_t hash = std::hash< String >()(name);
+    // Make sure the command doesn't already exist
+    for (const auto & cmd : m_Commands)
+    {
+        // Are the hashes identical?
+        if (cmd.mHash == hash)
+        {
+            // Include information necessary to help identify hash collisions!
+            STHROWF("Command '{}' already exists as '{}' for hash ({})",
+                        name.c_str(), cmd.mName.c_str(), hash);
+        }
+    }
+    // Attempt to insert the command
+    m_Commands.emplace_back(hash, std::move(name), ptr, std::move(obj), m_Manager->GetCtr());
+    // Return the script object of the listener
+    return m_Commands.back().mObj;
+}
+
 // ------------------------------------------------------------------------------------------------
 Object Manager::Create(StackStrF & name, StackStrF & spec, Array & tags, uint8_t min, uint8_t max, SQInteger auth, bool prot, bool assoc)
 {
@@ -933,6 +1010,19 @@ void Listener::GenerateInfo(bool full)
     }
 }
 
+// ------------------------------------------------------------------------------------------------
+Listener & Listener::Rebind(StackStrF & name)
+{
+    if (m_Controller.Expired())
+    {
+        STHROWF("Command must be attached to a manager before having an alias.");
+    }
+    // Create an alias for this command listener
+    m_Controller.Lock()->Attach(Object{}, this, name.ToStr());
+    // Allow chaining
+    return *this;
+}
+
 // ------------------------------------------------------------------------------------------------
 void Listener::ProcSpec(const SQChar * str)
 {
@@ -1136,6 +1226,7 @@ void Register(HSQUIRRELVM vm)
         .Prop(_SC("Associate"), &Listener::GetAssociate, &Listener::SetAssociate)
         .Prop(_SC("MinArgs"), &Listener::GetMinArgC, &Listener::SetMinArgC)
         .Prop(_SC("MaxArgs"), &Listener::GetMaxArgC, &Listener::SetMaxArgC)
+        .Prop(_SC("AliasCount"), &Listener::GetAliases)
         .Prop(_SC("OnExec"), &Listener::GetOnExec)
         .Prop(_SC("OnAuth"), &Listener::GetOnAuth)
         .Prop(_SC("OnAudit"), &Listener::GetOnAudit)
@@ -1159,6 +1250,7 @@ void Register(HSQUIRRELVM vm)
         .Func(_SC("ArgCheck"), &Listener::ArgCheck)
         .Func(_SC("AuthCheck"), &Listener::AuthCheck)
         .Func(_SC("GenerateInfo"), &Listener::GenerateInfo)
+        .FmtFunc(_SC("Rebind"), &Listener::Rebind)
     );
 
     RootTable(vm).Bind(_SC("SqCmd"), cmdns);

module/Core/Command.hpp

@@ -255,11 +255,11 @@ public:
 struct Command
 {
     // --------------------------------------------------------------------------------------------
-    std::size_t     mHash; // The unique hash that identifies this command.
+    std::size_t     mHash{0}; // The unique hash that identifies this command.
-    String          mName; // The unique name that identifies this command.
+    String          mName{}; // The unique name that identifies this command.
-    Listener*       mPtr; // The listener that reacts to this command.
+    Listener*       mPtr{nullptr}; // The listener that reacts to this command.
-    Object          mObj; // A strong reference to the script object.
+    Object          mObj{}; // A strong reference to the script object.
-    CtrPtr          mCtr; // The associated controller.
+    CtrPtr          mCtr{}; // The associated controller.
 
     /* --------------------------------------------------------------------------------------------
      * Construct a command and the also create a script object from the specified listener.
@@ -418,7 +418,7 @@ protected:
     bool Parse(Context & ctx);
 
     /* --------------------------------------------------------------------------------------------
-     * Attach a command listener to a certain name.
+     * Attach a command listener to the associated name.
     */
     Object & Attach(Object & obj, Listener * ptr)
     {
@@ -426,7 +426,7 @@ protected:
     }
 
     /* --------------------------------------------------------------------------------------------
-     * Attach a command listener to a certain name.
+     * Attach a command listener to the associated name.
     */
     Object & Attach(const Object & obj, Listener * ptr)
     {
@@ -434,10 +434,31 @@ protected:
     }
 
     /* --------------------------------------------------------------------------------------------
-     * Attach a command listener to a certain name.
+     * Attach a command listener to the associated name.
     */
     Object & Attach(Object && obj, Listener * ptr);
 
+    /* --------------------------------------------------------------------------------------------
+     * Attach a command listener to a certain name.
+    */
+    Object & Attach(Object & obj, Listener * ptr, String name)
+    {
+        return Attach(Object(obj), ptr, std::move(name));
+    }
+
+    /* --------------------------------------------------------------------------------------------
+     * Attach a command listener to a certain name.
+    */
+    Object & Attach(const Object & obj, Listener * ptr, String name)
+    {
+        return Attach(Object(obj), ptr, std::move(name));
+    }
+
+    /* --------------------------------------------------------------------------------------------
+     * Attach a command listener to a certain name.
+    */
+    Object & Attach(Object && obj, Listener * ptr, String name);
+
     /* --------------------------------------------------------------------------------------------
      * Detach a command listener from a certain name.
     */
@@ -445,17 +466,10 @@ protected:
     {
         // Obtain the unique identifier of the specified name
         const std::size_t hash = std::hash< String >()(name);
-        // Iterator to the found command, if any
-        auto itr = m_Commands.cbegin();
         // Attempt to find the specified command
-        for (; itr != m_Commands.cend(); ++itr)
+        auto itr = std::find_if(m_Commands.cbegin(), m_Commands.cend(), [=](Commands::const_reference c) {
-        {
+            return (c.mHash == hash);
-            // Are the hashes identical?
+        });
-            if (itr->mHash == hash)
-            {
-                break; // We found our command!
-            }
-        }
         // Make sure the command exist before attempting to remove it
         if (itr != m_Commands.end())
         {
@@ -468,17 +482,10 @@ protected:
     */
     void Detach(Listener * ptr)
     {
-        // Iterator to the found command, if any
-        auto itr = m_Commands.cbegin();
         // Attempt to find the specified command
-        for (; itr != m_Commands.cend(); ++itr)
+        auto itr = std::find_if(m_Commands.cbegin(), m_Commands.cend(), [=](Commands::const_reference c) {
-        {
+            return (c.mPtr == ptr);
-            // Are the instances identical?
+        });
-            if (itr->mPtr == ptr)
-            {
-                break; // We found our command!
-            }
-        }
         // Make sure the command exists before attempting to remove it
         if (itr != m_Commands.end())
         {
@@ -1200,6 +1207,7 @@ public:
         , m_ArgTags()
         , m_MinArgc(0)
         , m_MaxArgc(SQMOD_MAX_CMD_ARGS-1)
+        , m_Aliases(0)
         , m_Spec()
         , m_Help()
         , m_Info()
@@ -1336,6 +1344,42 @@ public:
         return m_Name;
     }
 
+    /* --------------------------------------------------------------------------------------------
+     * Increment the number of names that point to this command.
+    */
+    uint16_t AddAliases(uint16_t n)
+    {
+        m_Aliases += n;
+        // Return new alias count
+        return m_Aliases;
+    }
+
+    /* --------------------------------------------------------------------------------------------
+     * Decrement the number of names that point to this command.
+    */
+    uint16_t SubAliases(uint16_t n)
+    {
+        m_Aliases -= n;
+        // Return new alias count
+        return m_Aliases;
+    }
+
+    /* --------------------------------------------------------------------------------------------
+     * Retrieve the number of names that point to this command.
+    */
+    SQMOD_NODISCARD uint16_t GetAliases() const
+    {
+        return m_Aliases;
+    }
+
+    /* --------------------------------------------------------------------------------------------
+     * Modify the number of names that point to this command.
+    */
+    void SetAliases(uint16_t n)
+    {
+        m_Aliases = n;
+    }
+
     /* --------------------------------------------------------------------------------------------
      * Retrieve the number of weak references to the managed controller.
     */
@@ -1906,6 +1950,11 @@ public:
     */
     void GenerateInfo(bool full);
 
+    /* --------------------------------------------------------------------------------------------
+     * Create an alias for this command listener.
+    */
+    Listener & Rebind(StackStrF & name);
+
 protected:
 
     // --------------------------------------------------------------------------------------------
@@ -1955,6 +2004,7 @@ private:
     // --------------------------------------------------------------------------------------------
     uint8_t     m_MinArgc; // Minimum number of arguments supported by this listener.
     uint8_t     m_MaxArgc; // Maximum number of arguments supported by this listener.
+    uint16_t    m_Aliases; // Number of aliases that point to this command.
 
     // --------------------------------------------------------------------------------------------
     String      m_Spec; // String used to generate the argument type specification list.