lib/zstd/zstd_common.c

   1 // SPDX-License-Identifier: (GPL-2.0 or BSD-3-Clause-Clear)
   2 /**
   3  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
   4  * All rights reserved.
   5  */
   6
   7 /*-*************************************
   8 *  Dependencies
   9 ***************************************/
  10 #include "error_private.h"
  11 #include "zstd_internal.h" /* declaration of ZSTD_isError, ZSTD_getErrorName, ZSTD_getErrorCode, ZSTD_getErrorString, ZSTD_versionNumber */
  12 #include <linux/kernel.h>
  13
  14 /*=**************************************************************
  15 *  Custom allocator
  16 ****************************************************************/
  17
  18 #define stack_push(stack, size)                                 \
  19         ({                                                      \
  20                 void *const ptr = ZSTD_PTR_ALIGN((stack)->ptr); \
  21                 (stack)->ptr = (char *)ptr + (size);            \
  22                 (stack)->ptr <= (stack)->end ? ptr : NULL;      \
  23         })
  24
  25 ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize)
  26 {
  27         ZSTD_customMem stackMem = {ZSTD_stackAlloc, ZSTD_stackFree, workspace};
  28         ZSTD_stack *stack = (ZSTD_stack *)workspace;
  29         /* Verify preconditions */
  30         if (!workspace || workspaceSize < sizeof(ZSTD_stack) || workspace != ZSTD_PTR_ALIGN(workspace)) {
  31                 ZSTD_customMem error = {NULL, NULL, NULL};
  32                 return error;
  33         }
  34         /* Initialize the stack */
  35         stack->ptr = workspace;
  36         stack->end = (char *)workspace + workspaceSize;
  37         stack_push(stack, sizeof(ZSTD_stack));
  38         return stackMem;
  39 }
  40
  41 void *ZSTD_stackAllocAll(void *opaque, size_t *size)
  42 {
  43         ZSTD_stack *stack = (ZSTD_stack *)opaque;
  44         *size = (BYTE const *)stack->end - (BYTE *)ZSTD_PTR_ALIGN(stack->ptr);
  45         return stack_push(stack, *size);
  46 }
  47
  48 void *ZSTD_stackAlloc(void *opaque, size_t size)
  49 {
  50         ZSTD_stack *stack = (ZSTD_stack *)opaque;
  51         return stack_push(stack, size);
  52 }
  53 void ZSTD_stackFree(void *opaque, void *address)
  54 {
  55         (void)opaque;
  56         (void)address;
  57 }
  58
  59 void *ZSTD_malloc(size_t size, ZSTD_customMem customMem) { return customMem.customAlloc(customMem.opaque, size); }
  60
  61 void ZSTD_free(void *ptr, ZSTD_customMem customMem)
  62 {
  63         if (ptr != NULL)
  64                 customMem.customFree(customMem.opaque, ptr);
  65 }