1 /**
2  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
3  * All rights reserved.
4  *
5  * This source code is licensed under the BSD-style license found in the
6  * LICENSE file in the root directory of https://github.com/facebook/zstd.
7  * An additional grant of patent rights can be found in the PATENTS file in the
8  * same directory.
9  *
10  * This program is free software; you can redistribute it and/or modify it under
11  * the terms of the GNU General Public License version 2 as published by the
12  * Free Software Foundation. This program is dual-licensed; you may select
13  * either version 2 of the GNU General Public License ("GPL") or BSD license
14  * ("BSD").
15  */
16 
17 /*-*************************************
18 *  Dependencies
19 ***************************************/
20 #include "error_private.h"
21 #include "zstd_internal.h" /* declaration of ZSTD_isError, ZSTD_getErrorName, ZSTD_getErrorCode, ZSTD_getErrorString, ZSTD_versionNumber */
22 
23 /*=**************************************************************
24 *  Custom allocator
25 ****************************************************************/
26 
27 #define stack_push(stack, size)                                 \
28 	({                                                      \
29 		void *const ptr = ZSTD_PTR_ALIGN((stack)->ptr); \
30 		(stack)->ptr = (char *)ptr + (size);            \
31 		(stack)->ptr <= (stack)->end ? ptr : NULL;      \
32 	})
33 
ZSTD_initStack(void * workspace,size_t workspaceSize)34 ZSTD_customMem __init ZSTD_initStack(void *workspace, size_t workspaceSize)
35 {
36 	ZSTD_customMem stackMem = {ZSTD_stackAlloc, ZSTD_stackFree, workspace};
37 	ZSTD_stack *stack = (ZSTD_stack *)workspace;
38 	/* Verify preconditions */
39 	if (!workspace || workspaceSize < sizeof(ZSTD_stack) || workspace != ZSTD_PTR_ALIGN(workspace)) {
40 		ZSTD_customMem error = {NULL, NULL, NULL};
41 		return error;
42 	}
43 	/* Initialize the stack */
44 	stack->ptr = workspace;
45 	stack->end = (char *)workspace + workspaceSize;
46 	stack_push(stack, sizeof(ZSTD_stack));
47 	return stackMem;
48 }
49 
ZSTD_stackAllocAll(void * opaque,size_t * size)50 void *__init ZSTD_stackAllocAll(void *opaque, size_t *size)
51 {
52 	ZSTD_stack *stack = (ZSTD_stack *)opaque;
53 	*size = (BYTE const *)stack->end - (BYTE *)ZSTD_PTR_ALIGN(stack->ptr);
54 	return stack_push(stack, *size);
55 }
56 
ZSTD_stackAlloc(void * opaque,size_t size)57 void *__init cf_check ZSTD_stackAlloc(void *opaque, size_t size)
58 {
59 	ZSTD_stack *stack = (ZSTD_stack *)opaque;
60 	return stack_push(stack, size);
61 }
ZSTD_stackFree(void * opaque,void * address)62 void __init cf_check ZSTD_stackFree(void *opaque, void *address)
63 {
64 	(void)opaque;
65 	(void)address;
66 }
67 
ZSTD_malloc(size_t size,ZSTD_customMem customMem)68 void *__init ZSTD_malloc(size_t size, ZSTD_customMem customMem) { return customMem.customAlloc(customMem.opaque, size); }
69 
ZSTD_free(void * ptr,ZSTD_customMem customMem)70 void __init ZSTD_free(void *ptr, ZSTD_customMem customMem)
71 {
72 	if (ptr != NULL)
73 		customMem.customFree(customMem.opaque, ptr);
74 }
75