jtie_tconv_refbyval_impl.hpp

/*
 Copyright 2010 Sun Microsystems, Inc.
 All rights reserved. Use is subject to license terms.

 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_refbyval_impl.hpp
 */

#ifndef jtie_tconv_refbyval_impl_hpp
#define jtie_tconv_refbyval_impl_hpp

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

#include "jtie_tconv_refbyval.hpp"
#include "jtie_tconv_impl.hpp"
#include "jtie_tconv_ptrbyval_impl.hpp"
#include "jtie_tconv_utils_impl.hpp"
#include "helpers.hpp"

// ---------------------------------------------------------------------------
// ArrayRefParam, ArrayRefResult
// ---------------------------------------------------------------------------

// XXX document, cleanup

// implements the mapping of (1-elem) arrays to reference parameters
template< typename J, typename C > struct ArrayRefParam;

// implements the mapping of (1-elem) arrays to reference results
template< typename J, typename C > struct ArrayRefResult;

inline cstatus
ensureNonNullArray(jarray ja, JNIEnv * env) {
    // init return value to error
    cstatus s = -1;

    if (ja == NULL) {
        const char * c = "java/lang/IllegalArgumentException";
        const char * m = ("JNI wrapper: Java array 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 ArrayRefParam {

    static C &
    convert(cstatus & s, typename J::JA_t * j, JNIEnv * env) {
        TRACE("C & ArrayRefParam.convert(cstatus &, typename J::JA_t *, JNIEnv *)");

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

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

    static void
    release(C & c, typename J::JA_t * j, JNIEnv * env) {
        TRACE("void ArrayRefParam.release(C &, typename J::JA_t *, JNIEnv *)");
        ArrayPtrParam< J, C >::release(&c, j, env);
    }
};

// actually, there's not much of a point to map a result reference to an
// 1-element array as a value-copy holder, for we can return the value
// directly, instead; hence, this class is defined for completeness only
template< typename J, typename C >
struct ArrayRefResult {
    static J *
    convert(C & c, JNIEnv * env) {
        TRACE("J * ArrayRefResult.convert(C &, JNIEnv *)");
        // technically, C++ references can be null, hence, no asserts here
        //assert(&c != NULL);
        J * j = ArrayPtrResult< J, C >::convert(&c, env);
        //assert(j != NULL);
        return j;
    }
};

// ---------------------------------------------------------------------------
// Specializations for reference type conversions
// ---------------------------------------------------------------------------

// Avoid mapping types by broad, generic rules, which easily results in
// template instantiation ambiguities for non-primitive types.  Therefore,
// we enumerate all specicializations for primitive type references.

// specialize values/value-holders mapped to references:
// - const params: map as value copy
// - const results: map as value copy
// - non-const params: map as value holder (array of length 1)
// - non-const results:  map as value copy (no use as value holders)
#define JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING( JA, J, C )              \
    template<>                                                          \
    struct Param< J, const C & >                                        \
        : Param< J, C > {};                                             \
    template<>                                                          \
    struct Result< J, const C & >                                       \
        : Result< J, C > {};                                            \
    template<>                                                          \
    struct Param< JA *, C & >                                           \
        : ArrayRefParam< _jtie_j_BoundedArray< JA, 1 >, C > {};         \
    template<>                                                          \
    struct Result< J, C & >                                             \
        : Result< J, C > {};                                            \

// ---------------------------------------------------------------------------
// Specializations for reference to exact-width primitive type conversions
// ---------------------------------------------------------------------------

JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jbooleanArray, jboolean, bool)

JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jbyteArray, jbyte, char)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jbyteArray, jbyte, signed char)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jbyteArray, jbyte, unsigned char)

JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jfloatArray, jfloat, float)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jdoubleArray, jdouble, double)

// ---------------------------------------------------------------------------
// Specializations for reference to variable-width primitive type conversions
// ---------------------------------------------------------------------------

// jshort in LP32, ILP32, LP64, ILP64, LLP64
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jshortArray, jshort, signed short)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jshortArray, jshort, unsigned short)

// jshort in LP32
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jshortArray, jshort, signed int)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jshortArray, jshort, unsigned int)

// jint in ILP32, LP64, LLP64
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jintArray, jint, signed int)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jintArray, jint, unsigned int)

// jint in LP32, ILP32, LLP64
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jintArray, jint, signed long)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jintArray, jint, unsigned long)

// jlong in ILP64
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jlongArray, jlong, signed int)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jlongArray, jlong, unsigned int)

// jlong in LP64, ILP64
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jlongArray, jlong, signed long)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jlongArray, jlong, unsigned long)

// jlong in LLP64
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jlongArray, jlong, signed long long)
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jlongArray, jlong, unsigned long long)

// jdouble
JTIE_SPECIALIZE_REFERENCE_TYPE_MAPPING(_jdoubleArray, jdouble, long double)

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

#endif // jtie_tconv_refbyval_impl_hpp