/*
 * Copyright (C) 2013 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 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 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"

#import "JavaScriptCore.h"

#if JSC_OBJC_API_ENABLED

#import "APICast.h"
#import "JSVirtualMachineInternal.h"

static NSMapTable *globalWrapperCache = 0;

static Mutex& wrapperCacheLock()
{
    DEFINE_STATIC_LOCAL(Mutex, mutex, ());
    return mutex;
}

static void initWrapperCache()
{
    ASSERT(!globalWrapperCache);
    NSPointerFunctionsOptions keyOptions = NSPointerFunctionsOpaqueMemory | NSPointerFunctionsOpaquePersonality;
    NSPointerFunctionsOptions valueOptions = NSPointerFunctionsWeakMemory | NSPointerFunctionsObjectPersonality;
    globalWrapperCache = [[NSMapTable alloc] initWithKeyOptions:keyOptions valueOptions:valueOptions capacity:0];
}

static NSMapTable *wrapperCache()
{
    if (!globalWrapperCache)
        initWrapperCache();
    return globalWrapperCache;
}

@interface JSVMWrapperCache : NSObject
+ (void)addWrapper:(JSVirtualMachine *)wrapper forJSContextGroupRef:(JSContextGroupRef)group;
+ (JSVirtualMachine *)wrapperForJSContextGroupRef:(JSContextGroupRef)group;
@end

@implementation JSVMWrapperCache

+ (void)addWrapper:(JSVirtualMachine *)wrapper forJSContextGroupRef:(JSContextGroupRef)group
{
    MutexLocker locker(wrapperCacheLock());
    NSMapInsert(wrapperCache(), group, wrapper);
}

+ (JSVirtualMachine *)wrapperForJSContextGroupRef:(JSContextGroupRef)group
{
    MutexLocker locker(wrapperCacheLock());
    return static_cast<JSVirtualMachine *>(NSMapGet(wrapperCache(), group));
}

@end

@implementation JSVirtualMachine {
    JSContextGroupRef m_group;
    NSMapTable *m_contextCache;
}

- (id)init
{
    JSContextGroupRef group = JSContextGroupCreate();
    self = [self initWithContextGroupRef:group];
    // The extra JSContextGroupRetain is balanced here.
    JSContextGroupRelease(group);
    return self;
}

- (id)initWithContextGroupRef:(JSContextGroupRef)group
{
    self = [super init];
    if (!self)
        return nil;
    
    m_group = JSContextGroupRetain(group);
    
    NSPointerFunctionsOptions keyOptions = NSPointerFunctionsOpaqueMemory | NSPointerFunctionsOpaquePersonality;
    NSPointerFunctionsOptions valueOptions = NSPointerFunctionsWeakMemory | NSPointerFunctionsObjectPersonality;
    m_contextCache = [[NSMapTable alloc] initWithKeyOptions:keyOptions valueOptions:valueOptions capacity:0];
   
    [JSVMWrapperCache addWrapper:self forJSContextGroupRef:group];
 
    return self;
}

@end

@implementation JSVirtualMachine(Internal)

- (void)dealloc
{
    JSContextGroupRelease(m_group);
    [super dealloc];
}

JSContextGroupRef getGroupFromVirtualMachine(JSVirtualMachine *virtualMachine)
{
    return virtualMachine->m_group;
}

+ (JSVirtualMachine *)virtualMachineWithContextGroupRef:(JSContextGroupRef)group
{
    JSVirtualMachine *virtualMachine = [JSVMWrapperCache wrapperForJSContextGroupRef:group];
    if (!virtualMachine)
        virtualMachine = [[[JSVirtualMachine alloc] initWithContextGroupRef:group] autorelease];
    return virtualMachine;
}

- (JSContext *)contextForGlobalContextRef:(JSGlobalContextRef)globalContext
{
    return static_cast<JSContext *>(NSMapGet(m_contextCache, globalContext));
}

- (void)addContext:(JSContext *)wrapper forGlobalContextRef:(JSGlobalContextRef)globalContext
{
    NSMapInsert(m_contextCache, globalContext, wrapper);
}

@end


#endif