// included by json_value.cpp
// everything is within Json namespace
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// class ValueInternalMap
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////
/** \internal MUST be safely initialized using memset( this, 0, sizeof(ValueInternalLink) );
* This optimization is used by the fast allocator.
*/
ValueInternalLink::ValueInternalLink()
: previous_( 0 )
, next_( 0 )
{
}
ValueInternalLink::~ValueInternalLink()
{
for ( int index =0; index < itemPerLink; ++index )
{
if ( !items_[index].isItemAvailable() )
{
if ( !items_[index].isMemberNameStatic() )
free( keys_[index] );
}
else
break;
}
}
ValueMapAllocator::~ValueMapAllocator()
{
}
#ifdef JSON_USE_SIMPLE_INTERNAL_ALLOCATOR
class DefaultValueMapAllocator : public ValueMapAllocator
{
public: // overridden from ValueMapAllocator
virtual ValueInternalMap *newMap()
{
return new ValueInternalMap();
}
virtual ValueInternalMap *newMapCopy( const ValueInternalMap &other )
{
return new ValueInternalMap( other );
}
virtual void destructMap( ValueInternalMap *map )
{
delete map;
}
virtual ValueInternalLink *allocateMapBuckets( unsigned int size )
{
return new ValueInternalLink[size];
}
virtual void releaseMapBuckets( ValueInternalLink *links )
{
delete [] links;
}
virtual ValueInternalLink *allocateMapLink()
{
return new ValueInternalLink();
}
virtual void releaseMapLink( ValueInternalLink *link )
{
delete link;
}
};
#else
/// @todo make this thread-safe (lock when accessign batch allocator)
class DefaultValueMapAllocator : public ValueMapAllocator
{
public: // overridden from ValueMapAllocator
virtual ValueInternalMap *newMap()
{
ValueInternalMap *map = mapsAllocator_.allocate();
new (map) ValueInternalMap(); // placement new
return map;
}
virtual ValueInternalMap *newMapCopy( const ValueInternalMap &other )
{
ValueInternalMap *map = mapsAllocator_.allocate();
new (map) ValueInternalMap( other ); // placement new
return map;
}
virtual void destructMap( ValueInternalMap *map )
{
if ( map )
{
map->~ValueInternalMap();
mapsAllocator_.release( map );
}
}
virtual ValueInternalLink *allocateMapBuckets( unsigned int size )
{
return new ValueInternalLink[size];
}
virtual void releaseMapBuckets( ValueInternalLink *links )
{
delete [] links;
}
virtual ValueInternalLink *allocateMapLink()
{
ValueInternalLink *link = linksAllocator_.allocate();
memset( link, 0, sizeof(ValueInternalLink) );
return link;
}
virtual void releaseMapLink( ValueInternalLink *link )
{
link->~ValueInternalLink();
linksAllocator_.release( link );
}
private:
BatchAllocator<ValueInternalMap,1> mapsAllocator_;
BatchAllocator<ValueInternalLink,1> linksAllocator_;
};
#endif
static ValueMapAllocator *&mapAllocator()
{
static DefaultValueMapAllocator defaultAllocator;
static ValueMapAllocator *mapAllocator = &defaultAllocator;
return mapAllocator;
}
static struct DummyMapAllocatorInitializer {
DummyMapAllocatorInitializer()
{
mapAllocator(); // ensure mapAllocator() statics are initialized before main().
}
} dummyMapAllocatorInitializer;
// h(K) = value * K >> w ; with w = 32 & K prime w.r.t. 2^32.
/*
use linked list hash map.
buckets array is a container.
linked list element contains 6 key/values. (memory = (16+4) * 6 + 4 = 124)
value have extra state: valid, available, deleted
*/
ValueInternalMap::ValueInternalMap()
: buckets_( 0 )
, tailLink_( 0 )
, bucketsSize_( 0 )
, itemCount_( 0 )
{
}
ValueInternalMap::ValueInternalMap( const ValueInternalMap &other )
: buckets_( 0 )
, tailLink_( 0 )
, bucketsSize_( 0 )
, itemCount_( 0 )
{
reserve( other.itemCount_ );
IteratorState it;
IteratorState itEnd;
other.makeBeginIterator( it );
other.makeEndIterator( itEnd );
for ( ; !equals(it,itEnd); increment(it) )
{
bool isStatic;
const char *memberName = key( it, isStatic );
const Value &aValue = value( it );
resolveReference(memberName, isStatic) = aValue;
}
}
ValueInternalMap &
ValueInternalMap::operator =( const ValueInternalMap &other )
{
ValueInternalMap dummy( other );
swap( dummy );
return *this;
}
ValueInternalMap::~ValueInternalMap()
{
if ( buckets_ )
{
for ( BucketIndex bucketIndex =0; bucketIndex < bucketsSize_; ++bucketIndex )
{
ValueInternalLink *link = buckets_[bucketIndex].next_;
while ( link )
{
ValueInternalLink *linkToRelease = link;
link = link->next_;
mapAllocator()->releaseMapLink( linkToRelease );
}
}
mapAllocator()->releaseMapBuckets( buckets_ );
}
}
void
ValueInternalMap::swap( ValueInternalMap &other )
{
ValueInternalLink *tempBuckets = buckets_;
buckets_ = other.buckets_;
other.buckets_ = tempBuckets;
ValueInternalLink *tempTailLink = tailLink_;
tailLink_ = other.tailLink_;
other.tailLink_ = tempTailLink;
BucketIndex tempBucketsSize = bucketsSize_;
bucketsSize_ = other.bucketsSize_;
other.bucketsSize_ = tempBucketsSize;
BucketIndex tempItemCount = itemCount_;
itemCount_ = other.itemCount_;
other.itemCount_ = tempItemCount;
}
void
ValueInternalMap::clear()
{
ValueInternalMap dummy;
swap( dummy );
}
ValueInternalMap::BucketIndex
ValueInternalMap::size() const
{
return itemCount_;
}
bool
ValueInternalMap::reserveDelta( BucketIndex growth )
{
return reserve( itemCount_ + growth );
}
bool
ValueInternalMap::reserve( BucketIndex newItemCount )
{
if ( !buckets_ && newItemCount > 0 )
{
buckets_ = mapAllocator()->allocateMapBuckets( 1 );
bucketsSize_ = 1;
tailLink_ = &buckets_[0];
}
// BucketIndex idealBucketCount = (newItemCount + ValueInternalLink::itemPerLink) / ValueInternalLink::itemPerLink;
return true;
}
const Value *
ValueInternalMap::find( const char *key ) const
{
if ( !bucketsSize_ )
return 0;
HashKey hashedKey = hash( key );
BucketIndex bucketIndex = hashedKey % bucketsSize_;
for ( const ValueInternalLink *current = &buckets_[bucketIndex];
current != 0;
current = current->next_ )
{
for ( BucketIndex index=0; index < ValueInternalLink::itemPerLink; ++index )
{
if ( current->items_[index].isItemAvailable() )
return 0;
if ( strcmp( key, current->keys_[index] ) == 0 )
return ¤t->items_[index];
}
}
return 0;
}
Value *
ValueInternalMap::find( const char *key )
{
const ValueInternalMap *constThis = this;
return const_cast<Value *>( constThis->find( key ) );
}
Value &
ValueInternalMap::resolveReference( const char *key,
bool isStatic )
{
HashKey hashedKey = hash( key );
if ( bucketsSize_ )
{
BucketIndex bucketIndex = hashedKey % bucketsSize_;
ValueInternalLink **previous = 0;
BucketIndex index;
for ( ValueInternalLink *current = &buckets_[bucketIndex];
current != 0;
previous = ¤t->next_, current = current->next_ )
{
for ( index=0; index < ValueInternalLink::itemPerLink; ++index )
{
if ( current->items_[index].isItemAvailable() )
return setNewItem( key, isStatic, current, index );
if ( strcmp( key, current->keys_[index] ) == 0 )
return current->items_[index];
}
}
}
reserveDelta( 1 );
return unsafeAdd( key, isStatic, hashedKey );
}
void
ValueInternalMap::remove( const char *key )
{
HashKey hashedKey = hash( key );
if ( !bucketsSize_ )
return;
BucketIndex bucketIndex = hashedKey % bucketsSize_;
for ( ValueInternalLink *link = &buckets_[bucketIndex];
link != 0;
link = link->next_ )
{
BucketIndex index;
for ( index =0; index < ValueInternalLink::itemPerLink; ++index )
{
if ( link->items_[index].isItemAvailable() )
return;
if ( strcmp( key, link->keys_[index] ) == 0 )
{
doActualRemove( link, index, bucketIndex );
return;
}
}
}
}
void
ValueInternalMap::doActualRemove( ValueInternalLink *link,
BucketIndex index,
BucketIndex bucketIndex )
{
// find last item of the bucket and swap it with the 'removed' one.
// set removed items flags to 'available'.
// if last page only contains 'available' items, then desallocate it (it's empty)
ValueInternalLink *&lastLink = getLastLinkInBucket( index );
BucketIndex lastItemIndex = 1; // a link can never be empty, so start at 1
for ( ;
lastItemIndex < ValueInternalLink::itemPerLink;
++lastItemIndex ) // may be optimized with dicotomic search
{
if ( lastLink->items_[lastItemIndex].isItemAvailable() )
break;
}
BucketIndex lastUsedIndex = lastItemIndex - 1;
Value *valueToDelete = &link->items_[index];
Value *valueToPreserve = &lastLink->items_[lastUsedIndex];
if ( valueToDelete != valueToPreserve )
valueToDelete->swap( *valueToPreserve );
if ( lastUsedIndex == 0 ) // page is now empty
{ // remove it from bucket linked list and delete it.
ValueInternalLink *linkPreviousToLast = lastLink->previous_;
if ( linkPreviousToLast != 0 ) // can not deleted bucket link.
{
mapAllocator()->releaseMapLink( lastLink );
linkPreviousToLast->next_ = 0;
lastLink = linkPreviousToLast;
}
}
else
{
Value dummy;
valueToPreserve->swap( dummy ); // restore deleted to default Value.
valueToPreserve->setItemUsed( false );
}
--itemCount_;
}
ValueInternalLink *&
ValueInternalMap::getLastLinkInBucket( BucketIndex bucketIndex )
{
if ( bucketIndex == bucketsSize_ - 1 )
return tailLink_;
ValueInternalLink *&previous = buckets_[bucketIndex+1].previous_;
if ( !previous )
previous = &buckets_[bucketIndex];
return previous;
}
Value &
ValueInternalMap::setNewItem( const char *key,
bool isStatic,
ValueInternalLink *link,
BucketIndex index )
{
char *duplicatedKey = valueAllocator()->makeMemberName( key );
++itemCount_;
link->keys_[index] = duplicatedKey;
link->items_[index].setItemUsed();
link->items_[index].setMemberNameIsStatic( isStatic );
return link->items_[index]; // items already default constructed.
}
Value &
ValueInternalMap::unsafeAdd( const char *key,
bool isStatic,
HashKey hashedKey )
{
JSON_ASSERT_MESSAGE( bucketsSize_ > 0, "ValueInternalMap::unsafeAdd(): internal logic error." );
BucketIndex bucketIndex = hashedKey % bucketsSize_;
ValueInternalLink *&previousLink = getLastLinkInBucket( bucketIndex );
ValueInternalLink *link = previousLink;
BucketIndex index;
for ( index =0; index < ValueInternalLink::itemPerLink; ++index )
{
if ( link->items_[index].isItemAvailable() )
break;
}
if ( index == ValueInternalLink::itemPerLink ) // need to add a new page
{
ValueInternalLink *newLink = mapAllocator()->allocateMapLink();
index = 0;
link->next_ = newLink;
previousLink = newLink;
link = newLink;
}
return setNewItem( key, isStatic, link, index );
}
ValueInternalMap::HashKey
ValueInternalMap::hash( const char *key ) const
{
HashKey hash = 0;
while ( *key )
hash += *key++ * 37;
return hash;
}
int
ValueInternalMap::compare( const ValueInternalMap &other ) const
{
int sizeDiff( itemCount_ - other.itemCount_ );
if ( sizeDiff != 0 )
return sizeDiff;
// Strict order guaranty is required. Compare all keys FIRST, then compare values.
IteratorState it;
IteratorState itEnd;
makeBeginIterator( it );
makeEndIterator( itEnd );
for ( ; !equals(it,itEnd); increment(it) )
{
if ( !other.find( key( it ) ) )
return 1;
}
// All keys are equals, let's compare values
makeBeginIterator( it );
for ( ; !equals(it,itEnd); increment(it) )
{
const Value *otherValue = other.find( key( it ) );
int valueDiff = value(it).compare( *otherValue );
if ( valueDiff != 0 )
return valueDiff;
}
return 0;
}
void
ValueInternalMap::makeBeginIterator( IteratorState &it ) const
{
it.map_ = const_cast<ValueInternalMap *>( this );
it.bucketIndex_ = 0;
it.itemIndex_ = 0;
it.link_ = buckets_;
}
void
ValueInternalMap::makeEndIterator( IteratorState &it ) const
{
it.map_ = const_cast<ValueInternalMap *>( this );
it.bucketIndex_ = bucketsSize_;
it.itemIndex_ = 0;
it.link_ = 0;
}
bool
ValueInternalMap::equals( const IteratorState &x, const IteratorState &other )
{
return x.map_ == other.map_
&& x.bucketIndex_ == other.bucketIndex_
&& x.link_ == other.link_
&& x.itemIndex_ == other.itemIndex_;
}
void
ValueInternalMap::incrementBucket( IteratorState &iterator )
{
++iterator.bucketIndex_;
JSON_ASSERT_MESSAGE( iterator.bucketIndex_ <= iterator.map_->bucketsSize_,
"ValueInternalMap::increment(): attempting to iterate beyond end." );
if ( iterator.bucketIndex_ == iterator.map_->bucketsSize_ )
iterator.link_ = 0;
else
iterator.link_ = &(iterator.map_->buckets_[iterator.bucketIndex_]);
iterator.itemIndex_ = 0;
}
void
ValueInternalMap::increment( IteratorState &iterator )
{
JSON_ASSERT_MESSAGE( iterator.map_, "Attempting to iterator using invalid iterator." );
++iterator.itemIndex_;
if ( iterator.itemIndex_ == ValueInternalLink::itemPerLink )
{
JSON_ASSERT_MESSAGE( iterator.link_ != 0,
"ValueInternalMap::increment(): attempting to iterate beyond end." );
iterator.link_ = iterator.link_->next_;
if ( iterator.link_ == 0 )
incrementBucket( iterator );
}
else if ( iterator.link_->items_[iterator.itemIndex_].isItemAvailable() )
{
incrementBucket( iterator );
}
}
void
ValueInternalMap::decrement( IteratorState &iterator )
{
if ( iterator.itemIndex_ == 0 )
{
JSON_ASSERT_MESSAGE( iterator.map_, "Attempting to iterate using invalid iterator." );
if ( iterator.link_ == &iterator.map_->buckets_[iterator.bucketIndex_] )
{
JSON_ASSERT_MESSAGE( iterator.bucketIndex_ > 0, "Attempting to iterate beyond beginning." );
--(iterator.bucketIndex_);
}
iterator.link_ = iterator.link_->previous_;
iterator.itemIndex_ = ValueInternalLink::itemPerLink - 1;
}
}
const char *
ValueInternalMap::key( const IteratorState &iterator )
{
JSON_ASSERT_MESSAGE( iterator.link_, "Attempting to iterate using invalid iterator." );
return iterator.link_->keys_[iterator.itemIndex_];
}
const char *
ValueInternalMap::key( const IteratorState &iterator, bool &isStatic )
{
JSON_ASSERT_MESSAGE( iterator.link_, "Attempting to iterate using invalid iterator." );
isStatic = iterator.link_->items_[iterator.itemIndex_].isMemberNameStatic();
return iterator.link_->keys_[iterator.itemIndex_];
}
Value &
ValueInternalMap::value( const IteratorState &iterator )
{
JSON_ASSERT_MESSAGE( iterator.link_, "Attempting to iterate using invalid iterator." );
return iterator.link_->items_[iterator.itemIndex_];
}
int
ValueInternalMap::distance( const IteratorState &x, const IteratorState &y )
{
int offset = 0;
IteratorState it = x;
while ( !equals( it, y ) )
increment( it );
return offset;
}
