Binary data-structure serialization

[Robert Jacques]

On Fri, 04 Jun 2010 08:43:11 -0400, Robert M. Münch  
<robert.muench at robertmuench.de> wrote:

> On 2010-06-04 02:27:56 +0200, Robert Jacques said:
>
>> I've written a JSON serializer/de-serializer which uses compile time  
>> type reflection. Doesn't handle cycles or polymorphism yet, but I'd  
>> gladly share it if you (or others) are interested.
>
> Thanks for the offer. AFAIK JSON is focused for wire-transfer, what I'm  
> looking for is a way to efficiently write such structures into a file in  
> binary form and re-create the run-time structure fast.
>
> What I need is directed to a database / transactional system where  
> millions of in/out operations happen.
>

Pretty much all serialization methods have some amount of verification  
overhead, which it sounds like you neither want nor need. I'd recommend  
directly using .tupleof for structs/classes. Here's some simplified code  
snippets from my JSON library:

         // From toJson(T)(T value)
         static if(is(T == struct) || is(T == class)) {
             foreach(i,v;value.tupleof) {
                 result[getVariableName!(T,i)] = toJson(v);
             }
         }


         // From fromJson(T)(ref T dst)
         static if(is(T == struct) || is(T == class)) {
             static if(__traits(compiles, dst = new T() ))
                    if(dst is null)       dst = new T();
             static if(is(T == class)) enforce(dst !is null);
             foreach(i,v;dst.tupleof) { // Warning V is read-only because  
ref v doesn't compile
                 auto pJson = getVariableName!(T,i) in obj;
                 if(!pJson)   continue;
                 static if( is(typeof(v)==ulong) ) {
                     dst.tupleof[i] = roundTo!(long)(pJson.number);         
// Hack around bug 3418
                 } else {
                     pJson.fromJson( dst.tupleof[i] );
                 }
             }
         }