LXR linux/lib/zstd/zstd

   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#include <linux/kernel.h>
  23
  24/*=**************************************************************
  25*  Custom allocator
  26****************************************************************/
  27
  28#define stack_push(stack, size)                                 \
  29        ({                                                      \
  30                void *const ptr = ZSTD_PTR_ALIGN((stack)->ptr); \
  31                (stack)->ptr = (char *)ptr + (size);            \
  32                (stack)->ptr <= (stack)->end ? ptr : NULL;      \
  33        })
  34
  35ZSTD_customMem ZSTD_initStack(void *workspace, size_t workspaceSize)
  36{
  37        ZSTD_customMem stackMem = {ZSTD_stackAlloc, ZSTD_stackFree, workspace};
  38        ZSTD_stack *stack = (ZSTD_stack *)workspace;
  39        /* Verify preconditions */
  40        if (!workspace || workspaceSize < sizeof(ZSTD_stack) || workspace != ZSTD_PTR_ALIGN(workspace)) {
  41                ZSTD_customMem error = {NULL, NULL, NULL};
  42                return error;
  43        }
  44        /* Initialize the stack */
  45        stack->ptr = workspace;
  46        stack->end = (char *)workspace + workspaceSize;
  47        stack_push(stack, sizeof(ZSTD_stack));
  48        return stackMem;
  49}
  50
  51void *ZSTD_stackAllocAll(void *opaque, size_t *size)
  52{
  53        ZSTD_stack *stack = (ZSTD_stack *)opaque;
  54        *size = (BYTE const *)stack->end - (BYTE *)ZSTD_PTR_ALIGN(stack->ptr);
  55        return stack_push(stack, *size);
  56}
  57
  58void *ZSTD_stackAlloc(void *opaque, size_t size)
  59{
  60        ZSTD_stack *stack = (ZSTD_stack *)opaque;
  61        return stack_push(stack, size);
  62}
  63void ZSTD_stackFree(void *opaque, void *address)
  64{
  65        (void)opaque;
  66        (void)address;
  67}
  68
  69void *ZSTD_malloc(size_t size, ZSTD_customMem customMem) { return customMem.customAlloc(customMem.opaque, size); }
  70
  71void ZSTD_free(void *ptr, ZSTD_customMem customMem)
  72{
  73        if (ptr != NULL)
  74                customMem.customFree(customMem.opaque, ptr);
  75}
  76