jni_instance.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (C) 2003, 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
 */

#include "config.h"
#include "jni_instance.h"

#if ENABLE(MAC_JAVA_BRIDGE)

#include "jni_class.h"
#include "jni_runtime.h"
#include "jni_utility.h"
#include "runtime_object.h"
#include "runtime_root.h"
#include <runtime/ArgList.h>
#include <runtime/Error.h>
#include <runtime/JSLock.h>

#ifdef NDEBUG
#define JS_LOG(formatAndArgs...) ((void)0)
#else
#define JS_LOG(formatAndArgs...) { \
    fprintf (stderr, "%s:%d -- %s:  ", __FILE__, __LINE__, __FUNCTION__); \
    fprintf(stderr, formatAndArgs); \
}
#endif
 
using namespace JSC::Bindings;
using namespace JSC;

JavaInstance::JavaInstance (jobject instance, PassRefPtr<RootObject> rootObject)
    : Instance(rootObject)
{
    _instance = new JObjectWrapper (instance);
    _class = 0;
}

JavaInstance::~JavaInstance () 
{
    delete _class; 
}

#define NUM_LOCAL_REFS 64

void JavaInstance::virtualBegin()
{
    getJNIEnv()->PushLocalFrame (NUM_LOCAL_REFS);
}

void JavaInstance::virtualEnd()
{
    getJNIEnv()->PopLocalFrame (NULL);
}

Class *JavaInstance::getClass() const 
{
    if (_class == 0)
        _class = new JavaClass (_instance->_instance);
    return _class;
}

JSValuePtr JavaInstance::stringValue(ExecState* exec) const
{
    JSLock lock(false);
    
    jstring stringValue = (jstring)callJNIMethod<jobject>(_instance->_instance, "toString", "()Ljava/lang/String;");
    JNIEnv *env = getJNIEnv();
    const jchar *c = getUCharactersFromJStringInEnv(env, stringValue);
    UString u((const UChar *)c, (int)env->GetStringLength(stringValue));
    releaseUCharactersForJStringInEnv(env, stringValue, c);
    return jsString(exec, u);
}

JSValuePtr JavaInstance::numberValue(ExecState* exec) const
{
    jdouble doubleValue = callJNIMethod<jdouble>(_instance->_instance, "doubleValue", "()D");
    return jsNumber(exec, doubleValue);
}

JSValuePtr JavaInstance::booleanValue() const
{
    jboolean booleanValue = callJNIMethod<jboolean>(_instance->_instance, "booleanValue", "()Z");
    return jsBoolean(booleanValue);
}

JSValuePtr JavaInstance::invokeMethod (ExecState *exec, const MethodList &methodList, const ArgList &args)
{
    int i, count = args.size();
    jvalue *jArgs;
    JSValuePtr resultValue;
    Method *method = 0;
    size_t numMethods = methodList.size();
    
    // Try to find a good match for the overloaded method.  The 
    // fundamental problem is that JavaScript doesn have the
    // notion of method overloading and Java does.  We could 
    // get a bit more sophisticated and attempt to does some
    // type checking as we as checking the number of parameters.
    Method *aMethod;
    for (size_t methodIndex = 0; methodIndex < numMethods; methodIndex++) {
        aMethod = methodList[methodIndex];
        if (aMethod->numParameters() == count) {
            method = aMethod;
            break;
        }
    }
    if (method == 0) {
        JS_LOG ("unable to find an appropiate method\n");
        return jsUndefined();
    }
    
    const JavaMethod *jMethod = static_cast<const JavaMethod*>(method);
    JS_LOG ("call %s %s on %p\n", UString(jMethod->name()).UTF8String().c_str(), jMethod->signature(), _instance->_instance);
    
    if (count > 0) {
        jArgs = (jvalue *)malloc (count * sizeof(jvalue));
    }
    else
        jArgs = 0;
        
    for (i = 0; i < count; i++) {
        JavaParameter* aParameter = jMethod->parameterAt(i);
        jArgs[i] = convertValueToJValue(exec, args.at(exec, i), aParameter->getJNIType(), aParameter->type());
        JS_LOG("arg[%d] = %s\n", i, args.at(exec, i).toString(exec).ascii());
    }
        
    jvalue result;

    // Try to use the JNI abstraction first, otherwise fall back to
    // nornmal JNI.  The JNI dispatch abstraction allows the Java plugin
    // to dispatch the call on the appropriate internal VM thread.
    RootObject* rootObject = this->rootObject();
    if (!rootObject)
        return jsUndefined();

    bool handled = false;
    if (rootObject->nativeHandle()) {
        jobject obj = _instance->_instance;
        JSValuePtr exceptionDescription = noValue();
        const char *callingURL = 0;  // FIXME, need to propagate calling URL to Java
        handled = dispatchJNICall(exec, rootObject->nativeHandle(), obj, jMethod->isStatic(), jMethod->JNIReturnType(), jMethod->methodID(obj), jArgs, result, callingURL, exceptionDescription);
        if (exceptionDescription) {
            throwError(exec, GeneralError, exceptionDescription.toString(exec));
            free (jArgs);
            return jsUndefined();
        }
    }
    
    // The following code can be conditionally removed once we have a Tiger update that
    // contains the new Java plugin.  It is needed for builds prior to Tiger.
    if (!handled) {    
        jobject obj = _instance->_instance;
        switch (jMethod->JNIReturnType()){
            case void_type:
                callJNIMethodIDA<void>(obj, jMethod->methodID(obj), jArgs);
                break;            
            case object_type:
                result.l = callJNIMethodIDA<jobject>(obj, jMethod->methodID(obj), jArgs);
                break;
            case boolean_type:
                result.z = callJNIMethodIDA<jboolean>(obj, jMethod->methodID(obj), jArgs);
                break;
            case byte_type:
                result.b = callJNIMethodIDA<jbyte>(obj, jMethod->methodID(obj), jArgs);
                break;
            case char_type:
                result.c = callJNIMethodIDA<jchar>(obj, jMethod->methodID(obj), jArgs);
                break;            
            case short_type:
                result.s = callJNIMethodIDA<jshort>(obj, jMethod->methodID(obj), jArgs);
                break;
            case int_type:
                result.i = callJNIMethodIDA<jint>(obj, jMethod->methodID(obj), jArgs);
                break;
            
            case long_type:
                result.j = callJNIMethodIDA<jlong>(obj, jMethod->methodID(obj), jArgs);
                break;
            case float_type:
                result.f = callJNIMethodIDA<jfloat>(obj, jMethod->methodID(obj), jArgs);
                break;
            case double_type:
                result.d = callJNIMethodIDA<jdouble>(obj, jMethod->methodID(obj), jArgs);
                break;
            case invalid_type:
            default:
                break;
        }
    }
        
    switch (jMethod->JNIReturnType()){
        case void_type: {
            resultValue = jsUndefined();
        }
        break;
        
        case object_type: {
            if (result.l != 0) {
                const char *arrayType = jMethod->returnType();
                if (arrayType[0] == '[') {
                    resultValue = JavaArray::convertJObjectToArray(exec, result.l, arrayType, rootObject);
                }
                else {
                    resultValue = JavaInstance::create(result.l, rootObject)->createRuntimeObject(exec);
                }
            }
            else {
                resultValue = jsUndefined();
            }
        }
        break;
        
        case boolean_type: {
            resultValue = jsBoolean(result.z);
        }
        break;
        
        case byte_type: {
            resultValue = jsNumber(exec, result.b);
        }
        break;
        
        case char_type: {
            resultValue = jsNumber(exec, result.c);
        }
        break;
        
        case short_type: {
            resultValue = jsNumber(exec, result.s);
        }
        break;
        
        case int_type: {
            resultValue = jsNumber(exec, result.i);
        }
        break;
        
        case long_type: {
            resultValue = jsNumber(exec, result.j);
        }
        break;
        
        case float_type: {
            resultValue = jsNumber(exec, result.f);
        }
        break;
        
        case double_type: {
            resultValue = jsNumber(exec, result.d);
        }
        break;

        case invalid_type:
        default: {
            resultValue = jsUndefined();
        }
        break;
    }

    free (jArgs);

    return resultValue;
}

JSValuePtr JavaInstance::defaultValue(ExecState* exec, PreferredPrimitiveType hint) const
{
    if (hint == PreferString)
        return stringValue(exec);
    if (hint == PreferNumber)
        return numberValue(exec);
    JavaClass *aClass = static_cast<JavaClass*>(getClass());
    if (aClass->isStringClass())
        return stringValue(exec);
    if (aClass->isNumberClass())
        return numberValue(exec);
    if (aClass->isBooleanClass())
        return booleanValue();
    return valueOf(exec);
}

JSValuePtr JavaInstance::valueOf(ExecState* exec) const 
{
    return stringValue(exec);
}

JObjectWrapper::JObjectWrapper(jobject instance)
: _refCount(0)
{
    assert (instance != 0);

    // Cache the JNIEnv used to get the global ref for this java instanace.
    // It'll be used to delete the reference.
    _env = getJNIEnv();
        
    _instance = _env->NewGlobalRef (instance);
    
    JS_LOG ("new global ref %p for %p\n", _instance, instance);

    if  (_instance == NULL) {
        fprintf (stderr, "%s:  could not get GlobalRef for %p\n", __PRETTY_FUNCTION__, instance);
    }
}

JObjectWrapper::~JObjectWrapper() {
    JS_LOG ("deleting global ref %p\n", _instance);
    _env->DeleteGlobalRef (_instance);
}

#endif // ENABLE(MAC_JAVA_BRIDGE)