jtie_tconv_refbybb_impl.hpp

/*
 Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; version 2 of the License.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/
/*
 * jtie_tconv_refbybb_impl.hpp
 */

#ifndef jtie_tconv_refbybb_impl_hpp
#define jtie_tconv_refbybb_impl_hpp

#include <assert.h> // not using namespaces yet
#include <jni.h>

#include "jtie_tconv_refbybb.hpp"
#include "jtie_tconv_impl.hpp"
#include "jtie_tconv_ptrbybb_impl.hpp"
#include "jtie_tconv_utils_impl.hpp"
#include "helpers.hpp"

// ---------------------------------------------------------------------------
// ByteBufferRefParam, ByteBufferRefResult
// ---------------------------------------------------------------------------

// XXX document, cleanup

// implements the mapping of ByteBuffers to reference parameters
template< typename J, typename C > struct ByteBufferRefParam;

// implements the mapping of ByteBuffers to reference results
template< typename J, typename C > struct ByteBufferRefResult;

inline cstatus
ensureNonNullBuffer(jtie_j_n_ByteBuffer jbb, JNIEnv * env) {
    // init return value to error
    cstatus s = -1;
    
    if (jbb == NULL) {
        const char * c = "java/lang/IllegalArgumentException";
        const char * m = ("JTie: java.nio.ByteBuffer cannot be null"
                          " when mapped to an object reference type"
                          " (file: " __FILE__ ")");
        registerException(env, c, m);
    } else {
        // ok
        s = 0;
    }
    return s;
}

template< typename J, typename C >
struct ByteBufferRefParam {

    static C &
    convert(cstatus & s, jtie_j_n_ByteBuffer j, JNIEnv * env) {
        TRACE("C & ByteBufferRefParam.convert(cstatus &, jtie_j_n_ByteBuffer, JNIEnv *)");

        // init return value and status to error
        s = -1;
        C * c = NULL;

        if (ensureNonNullBuffer(j, env) != 0) {
            // exception pending
        } else {
            c = ByteBufferPtrParam< J, C >::convert(s, j, env);
            assert(s != 0 || c != NULL);
        }
        return *c;
    }

    static void
    release(C & c, jtie_j_n_ByteBuffer j, JNIEnv * env) {
        TRACE("void ByteBufferRefParam.release(C &, jtie_j_n_ByteBuffer, JNIEnv *)");
        ByteBufferPtrParam< J, C >::release(&c, j, env);
    }
};

template< typename J, typename C >
struct ByteBufferRefResult {
    static J *
    convert(C & c, JNIEnv * env) {
        TRACE("J * ByteBufferRefResult.convert(C &, JNIEnv *)");
        // technically, C++ references can be null, hence, no asserts here
        //assert(&c != NULL);
        J * j = ByteBufferPtrResult< J, C >::convert(&c, env);
        //assert(j != NULL);
        return j;
    }
};

// ---------------------------------------------------------------------------
// Specializations for ByteBuffer type conversions
// ---------------------------------------------------------------------------

// specialize ByteBuffers mapped to references:
// - params: require a minimum buffer capacity of the size of the base type
// - results: allocate buffer with a capacity of the size of the base type
template< typename C >
struct Param< jtie_j_n_ByteBuffer, C & >
    : ByteBufferRefParam< _jtie_j_n_BoundedByteBuffer< sizeof(C) >, C > {};
template< typename C >
struct Result< jtie_j_n_ByteBuffer, C & >
    : ByteBufferRefResult< _jtie_j_n_BoundedByteBuffer< sizeof(C) >, C > {};

// ---------------------------------------------------------------------------

#endif // jtie_tconv_refbybb_impl_hpp