/* vim: set ts=4 sw=4 tw=99 et:

  *

  * Copyright (C) 2012 David Anderson

  *

  * This file is part of SourcePawn.

  *

  * SourcePawn 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 3 of the License, or (at your option)

  * any later version.

  * 

  * SourcePawn 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

  * SourcePawn. If not, see http://www.gnu.org/licenses/.

  */

 #include <string.h>

 #include "Array.h"

 #include "FixedArray.h"

 #include "Heap.h"

 #include "Zone.h"

 #include "Structures.h"

 #include "Heap-inl.h"

 using namespace ke;

 ArrayMap *

 ArrayMap::New(Zone *zone, Handle<ArrayType> type)

 {

     Local<Map> obj(zone, zone->allocateMap(MapKind_Array, sizeof(ArrayMap), MapKind_MetaArray));

     if (!obj)

         return NULL;

     Local<ArrayMap> map(zone, ArrayMap::cast(obj));

     map->type_ = type;

     return map;

 }

 ArrayMap *

 ArrayMap::NewDependent(Zone *zone, Handle<ArrayType> type)

 {

     Local<Map> obj(zone, zone->allocateMap(MapKind_DependentArray, sizeof(ArrayMap), MapKind_MetaArray));

     if (!obj)

         return NULL;

     Local<ArrayMap> map(zone, ArrayMap::cast(obj));

     map->type_ = type;

     return map;

 }

 ArrayMap *

 ArrayMap::Attach(Zone *zone, Handle<ArrayType> type)

 {

     if (type->newMap())

         return ArrayMap::cast(type->newMap());

     Local<ArrayMap> map(zone, ArrayMap::New(zone, type));

     if (!map)

         return NULL;

     // Ensure the inner type has an ArrayMap if needed.

     if (type->contained()->isArray()) {

         Local<ArrayType> contained(zone, ArrayType::cast(type->contained()));

         if (!ArrayMap::Attach(zone, contained))

             return NULL;

     }

     type->setNewMap(map);

     return map;

 }

 Array *

 Array::NewRaw(Zone *zone, Handle<ArrayMap> map, unsigned nelements, Heap::Tenure tenure)

 {

     assert(!map->type()->isFixedLength() || nelements == map->type()->fixedLength());

     if (nelements > (INT_MAX / SizeForElement(map->type()))) {

         zone->reportError(Message_ArraySizeTooBig);

         return NULL;

     }

     size_t bytes = sizeof(Array);

     if (map->type()->hasInlineElements())

         bytes += SizeForElement(map->type()) * nelements;

     Local<Array> array(zone, Array::cast(zone->allocate(map, bytes, tenure)));

     if (!array)

         return NULL;

     array->length_ = 0;

     array->elements_ = NULL;

     if (map->type()->hasInlineElements()) {

         // This must be a fixed array containing no traceables.

         assert(nelements > 0);

         assert(map->type()->isFixedLength());

         assert(!map->type()->contained()->isTraceable());

         // Compute an interior |elements_| pointer, such that if elements_

         // is accessed like a FixedArray, we reach the appropriate vector.

         array->elements_ = Address((Array *)array + 1) - ByteArray::offsetToElements();

         array->length_ = nelements;

         memset(array->bytes(), 0, SizeForElement(map->type()) * nelements);

         return array;

     }

     // If there is nothing to allocate, we don't bother creating elements yet.

     if (!nelements)

         return array;

     if (!map->type()->contained()->isTraceable()) {

         size_t nbytes = SizeForElement(map->type()) * nelements;

         Local<ByteArray> elements(zone, ByteArray::New(zone, nbytes, tenure));

         if (!elements)

             return NULL;

         array->updateLengthAndElements(zone, nelements, elements);

         return array;

     }

     Local<FixedArray> elements(zone, FixedArray::New(zone, nelements, tenure));

     if (!elements)

         return NULL;

     array->updateLengthAndElements(zone, nelements, elements);

     // If this is an array of structs, we're required to allocate those structs now.

     if (map->type()->contained()->isStruct()) {

         Local<StructType> childType(zone, StructType::cast(map->type()->contained()));

         Local<StructMap> childMap(zone, childType->newMap());

         Local<Struct> child(zone);

         for (unsigned i = 0; i < nelements; i++) {

             child = Struct::New(zone, childMap, tenure);

             if (!child)

                 return NULL;

             elements->set(zone, i, child);

         }

     }

     return array;

 }

 static Array *

 ConstructSizedArray(Zone *zone, Handle<ArrayMap> map, int dims[MAX_ARRAY_DEPTH],

                     unsigned level, Heap::Tenure tenure)

 {

     Local<Array> array(zone, Array::NewRaw(zone, map, dims[level], tenure));

     if (!array)

         return NULL;

     if (map->type()->contained()->isArray()) {

         Local<ArrayType> childType(zone, ArrayType::cast(map->type()->contained()));

         Local<ArrayMap> childMap(zone, childType->newMap());

         Local<Array> child(zone);

         for (unsigned i = 0; i < unsigned(dims[level]); i++) {

             child = ConstructSizedArray(zone, childMap, dims, level + 1, tenure);

             if (!child)

                 return NULL;

             array->writeObject(zone, i, child);

         }

     }

     return array;

 }

 Array *

 Array::NewSized(Zone *zone, Handle<ArrayMap> map, int dims[MAX_ARRAY_DEPTH], Heap::Tenure tenure)

 {

     for (size_t i = 0; i < map->type()->levels(); i++) {

         if (dims[i] < 0) {

             zone->reportError(Message_InvalidDimensionSize, dims[i], i);

             return NULL;

         }

     }

     return ConstructSizedArray(zone, map, dims, 0, tenure);

 }

 static Array *

 ConstructFixedArray(Zone *zone, Handle<ArrayMap> map, Heap::Tenure tenure)

 {

     unsigned length = map->type()->fixedLength();

     Local<Array> array(zone, Array::NewRaw(zone, map, length, tenure));

     if (!array)

         return NULL;

     if (map->type()->contained()->isArray()) {

         Local<ArrayType> childType(zone, ArrayType::cast(map->type()->contained()));

         Local<ArrayMap> childMap(zone, childType->newMap());

         Local<Array> child(zone);

         if (childMap->type()->isFixedLength()) {

             for (unsigned i = 0; i < length; i++) {

                 child = ConstructFixedArray(zone, childMap, tenure);

                 if (!child)

                     return NULL;

                 array->writeObject(zone, i, child);

             }

         } else {

             for (unsigned i = 0; i < length; i++) {

                 child = Array::NewRaw(zone, childMap, 0, tenure);

                 if (!child)

                     return NULL;

                 array->writeObject(zone, i, child);

             }

         }

     }

     return array;

 }

 Array *

 Array::NewFixed(Zone *zone, Handle<ArrayMap> map, Heap::Tenure tenure)

 {

     return ConstructFixedArray(zone, map, tenure);

 }

 Array *

 Array::NewString(Zone *zone, Handle<ArrayMap> map, char *buffer, size_t length, Heap::Tenure tenure)

 {

     assert(map->type()->isCharArray());

     Local<Array> array(zone);

     if (map->type()->isFixedLength())

         array = Array::NewFixed(zone, map, tenure);

     else

         array = Array::New1D(zone, map, length + 1, tenure);

     if (!array)

         return NULL;

     assert(array->length() >= length + 1);

     memcpy(array->chars(), buffer, length + 1);

     return array;

 }

 Array *

 Array::New1D(Zone *zone, Handle<ArrayMap> map, uint32 elements, Heap::Tenure tenure)

 {

     assert(map->type()->levels());

     return Array::NewRaw(zone, map, elements, tenure);

 }

 Array *

 Array::NewEmpty(Zone *zone, Handle<ArrayMap> map, Heap::Tenure tenure)

 {

     assert(!map->type()->isFixedLength());

     return Array::NewRaw(zone, map, 0, tenure);

 }

 Array *

 Array::NewExternal(Zone *zone, Handle<ArrayMap> map, void *buffer, unsigned length,

                    Heap::Tenure tenure)

 {

     Local<Array> array(zone, Array::cast(zone->allocate(map, sizeof(Array), tenure)));

     if (!array)

         return NULL;

     array->length_ = length;

     array->elements_ = Address(buffer) - ByteArray::offsetToElements();

     return array;

 }

 static bool

 CopyArrayElements(Zone *zone, Handle<Type> contained, Handle<Array> dest, Handle<Array> source)

 {

     if (contained->isTraceable()) {

         if (contained->isStruct()) {

             assert(dest->type()->contained() == contained);

             assert(source->length() == dest->length());

             Local<Struct> left(zone);

             Local<Struct> right(zone);

             for (unsigned i = 0; i < source->length(); i++) {

                 left = Struct::cast(dest->readObject(i));

                 right = Struct::cast(source->readObject(i));

                 if (!Struct::Copy(zone, left, right))

                     return false;

             }

         } else if (contained->isArray() && ArrayType::cast(contained)->isFixedLength()) {

             assert(ArrayType::cast(source->type())->fixedLength() ==

                    ArrayType::cast(contained)->fixedLength());

             Local<Array> left(zone);

             Local<Array> right(zone);

             for (unsigned i = 0; i < source->length(); i++) {

                 left = Array::cast(dest->readObject(i));

                 right = Array::cast(source->readObject(i));

                 if (!Array::ShallowCopy(zone, left, right))

                     return false;

             }

         } else {

             assert(dest->length() == source->length());

             for (unsigned i = 0; i < source->length(); i++)

                 dest->writeObject(zone, i, source->readObject(i));

         }

     } else {

         assert(contained->pod() == dest->type()->contained()->pod());

         assert(contained->pod() == PrimitiveType_Char

                ? source->length() <= dest->length()

                : source->length() == dest->length());

         assert(dest->length());

         memcpy(dest->bytes(), source->bytes(), source->length() * Array::SizeForElement(dest->type()));

     }

     return true;

 }

 // Shallow copy an array. Fixed slots in the destination are copied from

 // the source, but otherwise, references are assigned.

 bool

 Array::ShallowCopy(Zone *zone, Handle<Array> dest, Handle<Array> source)

 {

     Local<Type> contained(zone, dest->type()->contained());

     return CopyArrayElements(zone, contained, dest, source);

 }

 Array *

 Array::DeepCopy(Zone *zone, Handle<Array> source, Heap::Tenure tenure)

 {

     Local<ArrayMap> map(zone, ArrayMap::cast(source->map()));

     Local<Array> dest(zone, Array::NewRaw(zone, map, source->length(), tenure));

     if (!dest)

         return NULL;

     Local<Type> contained(zone, source->type()->contained());

     if (contained->isArray()) {

         assert(false);

         Local<Array> sub(zone);

         for (size_t i = 0; i < source->length(); i++) {

             sub = Array::cast(source->readObject(i));

             sub = DeepCopy(zone, sub, tenure);

             if (!sub)

                 return NULL;

             dest->writeObject(zone, i, sub);

         }

     } else {

         if (!CopyArrayElements(zone, contained, dest, source))

             return NULL;

     }

     return dest;

 }

 Array *

 DependentArray::New(Zone *zone, Handle<Array> source, Handle<ArrayMap> map, unsigned index)

 {

     Local<ArrayType> sourcetype(zone, source->type());

     // Right now we only support char arrays, to avoid nasty deep cloning

     // and to maybe cut off this feature as far as we can.

     assert(sourcetype->isCharArray());

     assert(map->type()->isCharArray());

     // We allow taking 0-length dependent strings. It's safe because any reads

     // or writes will fail.

     assert(index <= source->length());

     unsigned newlen = source->length() - index;

     unsigned eltsize = SizeForElement(sourcetype);

     if (!sourcetype->isFixedLength()) {

         // Simple case, just copy the array.

         Local<ArrayMap> map(zone, sourcetype->newMap());

         Local<Array> dest(zone, Array::NewRaw(zone, map, newlen, Heap::Tenure_Default));

         if (!dest)

             return NULL;

         memcpy(dest->bytes(),

                (Address)source->bytes() + (index * eltsize),

                newlen * eltsize);

         return dest;

     }

     Local<DependentArray> array(zone, DependentArray::cast(zone->allocate(map, sizeof(DependentArray), Heap::Tenure_Default)));

     if (!array)

         return NULL;

     // :GC: This is currently not safe for moving GC! Although we will mark

     // the object owning the interior pointer, the interior pointer could be

     // moved later. We will eventually need some way of dealing with this.

     Address elements = Address(source->bytes()) + (index * eltsize);

     array->root_ = source;

     array->length_ = newlen;

     array->elements_ = elements - ByteArray::offsetToElements();

     return array;

 }