OOJSFunction.m

Go to the documentation of this file.

/*
 
OOJSFunction.m
 
 
JavaScript support for Oolite
Copyright (C) 2007-2013 David Taylor and Jens Ayton.
 
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; either version 2
of the License, or (at your option) any later version.
 
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 Street, Fifth Floor, Boston,
MA 02110-1301, USA.
 
*/
 
#import "OOJSFunction.h"
#import "OOJSScript.h"
#import "OOJSEngineTimeManagement.h"
 
 
@implementation OOJSFunction
 
- (id) initWithFunction:(JSFunction *)function context:(JSContext *)context
{
    NSParameterAssert(context != NULL);
    
    if (function == NULL)
    {
        [self release];
        return nil;
    }
    
    if ((self = [super init]))
    {
        _function = function;
        OOJSAddGCObjectRoot(context, (JSObject **)&_function, "OOJSFunction._function");
        _name = [OOStringFromJSString(context, JS_GetFunctionId(function)) retain];
        
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(deleteJSValue)
                                                     name:kOOJavaScriptEngineWillResetNotification
                                                   object:[OOJavaScriptEngine sharedEngine]];
    }
    
    return self;
}
 
 
- (id) initWithName:(NSString *)name
              scope:(JSObject *)scope
               code:(NSString *)code
      argumentCount:(NSUInteger)argCount
      argumentNames:(const char **)argNames
           fileName:(NSString *)fileName
         lineNumber:(NSUInteger)lineNumber
            context:(JSContext *)context
{
    BOOL                        OK = YES;
    BOOL                        releaseContext = NO;
    jschar                      *buffer = NULL;
    size_t                      length = 0;
    JSFunction                  *function;
    
    if (context == NULL)
    {
        context = OOJSAcquireContext();
        releaseContext = YES;
    }
    if (scope == NULL)  scope = [[OOJavaScriptEngine sharedEngine] globalObject];
    
    if (code == nil || (argCount > 0 && argNames == NULL))  OK = NO;
    
    if (OK)
    {
        // jschar and unichar are both defined to be 16-bit elements.
        assert(sizeof(jschar) == sizeof(unichar));
        
        length = [code length];
        buffer = malloc(sizeof(jschar) * length);
        if (buffer == NULL)  OK = NO;
    }
    
    if (OK)
    {
        assert(argCount < UINT32_MAX);
        
        [code getCharacters:buffer];
        
        function = JS_CompileUCFunction(context, scope, [name UTF8String], (uint32_t)argCount, argNames, buffer, length, [fileName UTF8String], (uint32_t)lineNumber);
        if (function == NULL)  OK = NO;
        
        free(buffer);
    }
    
    if (OK)
    {
        self = [self initWithFunction:function context:context];
    }
    else
    {
        DESTROY(self);
    }
    
    if (releaseContext)  OOJSRelinquishContext(context);
    
    return self;
}
 
 
- (void) deleteJSValue
{
    if (_function != NULL)
    {
        JSContext *context = OOJSAcquireContext();
        JS_RemoveObjectRoot(context, (JSObject **)&_function);
        OOJSRelinquishContext(context);
        
        _function = NULL;
        [[NSNotificationCenter defaultCenter] removeObserver:self
                                                        name:kOOJavaScriptEngineWillResetNotification
                                                      object:[OOJavaScriptEngine sharedEngine]];
    }
}
 
 
- (void) dealloc
{
    [self deleteJSValue];
    DESTROY(_name);
    
    [super dealloc];
}
 
 
- (NSString *) descriptionComponents
{
    NSString *name = [self name];
    if (name == nil)  name = @"<anonymous>";
    return [NSString stringWithFormat:@"%@()", name];
}
 
 
- (NSString *) name
{
    return _name;
}
 
 
- (JSFunction *) function
{
    return _function;
}
 
 
- (jsval) functionValue
{
    if (EXPECT(_function != NULL))
    {
        return OBJECT_TO_JSVAL(JS_GetFunctionObject(_function));
    }
    else
    {
        return JSVAL_NULL;
    }
 
}
 
 
- (BOOL) evaluateWithContext:(JSContext *)context
                       scope:(JSObject *)jsThis
                        argc:(uintN)argc
                        argv:(jsval *)argv
                      result:(jsval *)result
{
    [OOJSScript pushScript:nil];
    OOJSStartTimeLimiter();
    BOOL OK = JS_CallFunction(context, jsThis, _function, argc, argv, result);
    OOJSStopTimeLimiter();
    [OOJSScript popScript:nil];
    
    return OK;
}
 
// Semi-raw evaluation shared by convenience methods below.
- (BOOL) evaluateWithContext:(JSContext *)context
                       scope:(id)jsThis
                   arguments:(NSArray *)arguments
                      result:(jsval *)result
{
    NSUInteger i, argc = [arguments count];
    assert(argc < UINT32_MAX);
    jsval argv[argc];
    
    for (i = 0; i < argc; i++)
    {
        argv[i] = [[arguments objectAtIndex:i] oo_jsValueInContext:context];
        OOJSAddGCValueRoot(context, &argv[i], "OOJSFunction argv");
    }
    
    JSObject *scopeObj = NULL;
    BOOL OK = YES;
    if (jsThis != nil)  OK = JS_ValueToObject(context, [jsThis oo_jsValueInContext:context], &scopeObj);
    if (OK)  OK = [self evaluateWithContext:context
                                      scope:scopeObj
                                       argc:(uint32_t)argc
                                       argv:argv
                                     result:result];
    
    for (i = 0; i < argc; i++)
    {
        JS_RemoveValueRoot(context, &argv[i]);
    }
    
    return OK;
}
 
 
- (id) evaluateWithContext:(JSContext *)context
                     scope:(id)jsThis
                 arguments:(NSArray *)arguments
{
    jsval result;
    BOOL OK = [self evaluateWithContext:context
                                  scope:jsThis
                              arguments:arguments
                                 result:&result];
    if (!OK)  return nil;
    
    return OOJSNativeObjectFromJSValue(context, result);
}
               
 
- (BOOL) evaluatePredicateWithContext:(JSContext *)context
                                scope:(id)jsThis
                            arguments:(NSArray *)arguments
{
    jsval result;
    BOOL OK = [self evaluateWithContext:context
                                  scope:jsThis
                              arguments:arguments
                                 result:&result];
    JSBool retval = NO;
    if (OK)  OK = JS_ValueToBoolean(context, result, &retval);
    return OK && retval;
}
 
@end