MakeHttpRequest from lua

[cartuchogl]

MakeHttpRequest from lua

[cadaver]

Anything that returns a SharedPtr would require correct reference counting between C++ and the script language. This is natural to AngelScript but to my knowledge tolua++ does not support it. Therefore anything that can't return just a raw pointer has not been exposed to Lua as of now.

@aster2013 may have further insight on the matter.

[cartuchogl]

Thanks for the quick answer.

I will try to watch syntax for AngelScript.

[Canardian]

I thought you can pass a raw pointer as int between C++ and tolua++?

[cadaver]

Raw pointers are being passed OK, that's not the problem. The problem is that MakeHttpRequest expects the receiver of the SharedPtr to properly reference count the object and release it when done. As far as I understand, unmodified tolua++ has no facility for this. You could cheat and increment the reference count, let the original SharedPtr expire, and return the raw pointer to Lua, but this would leak memory for the remainder of the program.

[friesencr]

there is __gc method on lua metatables that gets called on destruction.

[aster2013]

Tolua++ can bind template to lua, But I have not test is fully.

[aster2013]

Sorry, as I know tolua++ can not support shared pointer, you'd better use raw pointer with it.

[cadaver]

I just realized that MakeHttpRequest() is pretty much only a redundant wrapper. In Lua one could just simply create a new HttpRequest object, as it is self-sufficient. It doesn't even need a Context pointer.

[aster2013]

I have add SharedPtr support in Lua, Please checkout the code for test.

[cadaver]

Nice! I'll test; the solution seems good at least for this case. What we're missing is a general robust solution that would understand the relationship between RefCounted subclasses and their SharedPtr's or WeakPtr's, but that's a lot harder to encode into the bindings.

[cartuchogl]

Hello,

I pull last code in master and I try to use MakeHttpRequest from lua, but I don't know how to read the response. The example I tried are:

require "LuaScripts/Utilities/Sample"

local http

function Start()
    -- Execute the common startup for samples
    SampleStart()

    SubscribeToEvents()

    http = GetNetwork():MakeHttpRequest('http://google.com','GET',{},"")
end

function SubscribeToEvents()
    -- Subscribe HandleUpdate() function for processing update events
    SubscribeToEvent("Update", "HandleUpdate")
end

function HandleUpdate(eventType, eventData)
    print(http:GetState(),http:GetAvailableSize(),"\n")
    if http:GetAvailableSize()>0 then
        -- how read?
    end
end

thanks in advance

[cadaver]

The bulk read function ie. plain Read() is not exposed to Lua (yet) but you can use the rest of the Deserializer API, like ReadUByte() to read one byte at a time, or ReadLine() for text.

[aster2013]

Now SharedPtr may have problem to convert to Deserializer.

[cartuchogl]

I tried with ReadUByte() at previous sample

-- same as previous sample
function HandleUpdate(eventType, eventData)
    if http:GetAvailableSize()>0 then
        print(http:ReadUByte())
    end
end

This sample crash with Bus error: 10 on OSX 10.8.5.

With ReadLine()

function HandleUpdate(eventType, eventData)
    if http:GetAvailableSize()>0 then
        print(http:ReadLine())
    end
end

Nothing is readed

For last, I try to add a function ReadByteP() that use Read() and It works

diff --git a/Source/Engine/Network/HttpRequest.cpp b/Source/Engine/Network/HttpRequest.cpp
--- a/Source/Engine/Network/HttpRequest.cpp
+++ b/Source/Engine/Network/HttpRequest.cpp
@@ -193,6 +193,13 @@ void HttpRequest::ThreadFunction()
     }
 }

+unsigned char HttpRequest::ReadByteP()
+{
+    unsigned char b;
+    this->Read(&b,1);
+    return b;
+}
+
 unsigned HttpRequest::Read(void* dest, unsigned size)
 {
     mutex_.Acquire();
diff --git a/Source/Engine/Network/HttpRequest.h b/Source/Engine/Network/HttpRequest.h
--- a/Source/Engine/Network/HttpRequest.h
+++ b/Source/Engine/Network/HttpRequest.h
@@ -56,6 +56,8 @@ public:
     virtual unsigned Read(void* dest, unsigned size);
     /// Set position from the beginning of the stream. Not supported.
     virtual unsigned Seek(unsigned position) { return position_; }
+
+    unsigned char ReadByteP();

     /// Return URL used in the request.
     const String& GetURL() const { return url_; }
diff --git a/Source/Extras/LuaScript/pkgs/Network/HttpRequest.pkg b/Source/Extras/LuaScript/pkgs/Network/HttpRequest.pkg
--- a/Source/Extras/LuaScript/pkgs/Network/HttpRequest.pkg
+++ b/Source/Extras/LuaScript/pkgs/Network/HttpRequest.pkg
@@ -16,6 +16,8 @@ class HttpRequest : public Deserializer
     HttpRequestState GetState() const;
     unsigned GetAvailableSize() const;
     bool IsOpen() const;
+
+    unsigned char ReadByteP();

     tolua_readonly tolua_property__get_set String URL;
     tolua_readonly tolua_property__get_set String verb;

And the modified handle

-- ...
local str = ""

function HandleUpdate(eventType, eventData)
    while http:GetAvailableSize()>0 do
        str = str .. string.char(http:ReadByteP())
    end
    print(str)
end

Thanks for your support.