#include <Cmm.h>
#include "Errors.h"

STRING(debugval, "debugval %d")

stg_tryPack (gcptr original, gcptr buffer)
{
    // args: closure (graph root to serialize)
    //       buffer (MutableByteArray to pack into)
    W_ errCode;
    W_ size;

    MAYBE_GC_PP(stg_tryPack, original, buffer);

    // assign something to keep cmm reg.allocator happy
    errCode = P_SUCCESS;

    // call packing function (without giving the TSO, no blocking)
    (size) = ccall pmtryPackToBuffer(original "ptr", buffer "ptr");
    // small values indicate failure (size biased with P_ERRCODEMAX,
    // see Errors.h and Pack.c
    // NB seems Cmm always compares unsigned (wanted to use negative values here)
    if (size < P_ERRCODEMAX ) {
        errCode = size;
        size = 0;
    } else {
        size = size - P_ERRCODEMAX;
    }
    
    return (errCode, size);
}

stg_unpack (gcptr buff)
{
    // args: R1 ByteArray# containing a serialized subgraph
    W_ new;
    W_ errCode;

    // assign something to keep cmm reg.allocator happy
    new = ghczmprim_GHCziTypes_False_closure;
    errCode = P_SUCCESS;

    MAYBE_GC_P(stg_unpack, buff);

    // call packing function
    ("ptr" new) = ccall pmUnpackGraphWrapper(buff "ptr", MyCapability() "ptr");

    if (new <= P_ERRCODEMAX) {
        errCode = new;
        new = ghczmprim_GHCziTypes_False_closure;
    }

    return (errCode, new);
}