github.com/cellofellow/gopkg@v0.0.0-20140722061823-eec0544a62ad/image/webp/libwebp/src/utils/utils.c (about)

     1  // Copyright 2012 Google Inc. All Rights Reserved.
     2  //
     3  // Use of this source code is governed by a BSD-style license
     4  // that can be found in the COPYING file in the root of the source
     5  // tree. An additional intellectual property rights grant can be found
     6  // in the file PATENTS. All contributing project authors may
     7  // be found in the AUTHORS file in the root of the source tree.
     8  // -----------------------------------------------------------------------------
     9  //
    10  // Misc. common utility functions
    11  //
    12  // Author: Skal (pascal.massimino@gmail.com)
    13  
    14  #include <stdlib.h>
    15  #include "./utils.h"
    16  
    17  //------------------------------------------------------------------------------
    18  // Checked memory allocation
    19  
    20  // Returns 0 in case of overflow of nmemb * size.
    21  static int CheckSizeArgumentsOverflow(uint64_t nmemb, size_t size) {
    22    const uint64_t total_size = nmemb * size;
    23    if (nmemb == 0) return 1;
    24    if ((uint64_t)size > WEBP_MAX_ALLOCABLE_MEMORY / nmemb) return 0;
    25    if (total_size != (size_t)total_size) return 0;
    26    return 1;
    27  }
    28  
    29  void* WebPSafeMalloc(uint64_t nmemb, size_t size) {
    30    if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
    31    assert(nmemb * size > 0);
    32    return malloc((size_t)(nmemb * size));
    33  }
    34  
    35  void* WebPSafeCalloc(uint64_t nmemb, size_t size) {
    36    if (!CheckSizeArgumentsOverflow(nmemb, size)) return NULL;
    37    assert(nmemb * size > 0);
    38    return calloc((size_t)nmemb, size);
    39  }
    40  
    41  //------------------------------------------------------------------------------
    42