/**
 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */



/*-*************************************
*  Dependencies
***************************************/
#include "error_private.h"
#include "zstd_internal.h"           /* declaration of ZSTD_isError, ZSTD_getErrorName, ZSTD_getErrorCode, ZSTD_getErrorString, ZSTD_versionNumber */
#include <linux/kernel.h>


/*-****************************************
*  Version
******************************************/
unsigned ZSTD_versionNumber (void) { return ZSTD_VERSION_NUMBER; }


/*=**************************************************************
*  Custom allocator
****************************************************************/

#define stack_push(stack, size) ({                                             \
		void* const ptr = ZSTD_PTR_ALIGN((stack)->ptr);                            \
		(stack)->ptr = (char*)ptr + (size);                                        \
		(stack)->ptr <= (stack)->end ? ptr : NULL;                                 \
	})

ZSTD_customMem ZSTD_initStack(void* workspace, size_t workspaceSize) {
	ZSTD_customMem stackMem = { ZSTD_stackAlloc, ZSTD_stackFree, workspace };
	ZSTD_stack* stack = (ZSTD_stack*) workspace;
	/* Verify preconditions */
	if (!workspace || workspaceSize < sizeof(ZSTD_stack) || workspace != ZSTD_PTR_ALIGN(workspace)) {
		ZSTD_customMem error = {NULL, NULL, NULL};
		return error;
	}
	/* Initialize the stack */
	stack->ptr = workspace;
	stack->end = (char*)workspace + workspaceSize;
	stack_push(stack, sizeof(ZSTD_stack));
	return stackMem;
}

void* ZSTD_stackAllocAll(void* opaque, size_t* size) {
	ZSTD_stack* stack = (ZSTD_stack*)opaque;
	*size = stack->end - ZSTD_PTR_ALIGN(stack->ptr);
	return stack_push(stack, *size);
}

void* ZSTD_stackAlloc(void* opaque, size_t size) {
	ZSTD_stack* stack = (ZSTD_stack*)opaque;
	return stack_push(stack, size);
}
void ZSTD_stackFree(void* opaque, void* address) {
	(void)opaque;
	(void)address;
}

void* ZSTD_malloc(size_t size, ZSTD_customMem customMem)
{
	return customMem.customAlloc(customMem.opaque, size);
}

void ZSTD_free(void* ptr, ZSTD_customMem customMem)
{
	if (ptr!=NULL)
		customMem.customFree(customMem.opaque, ptr);
}