Function FIO_createDictBuffer

freebsd/contrib/zstd/programs/fileio.c:697–727

! FIO_createDictBuffer() : * creates a buffer, pointed by `*bufferPtr`, * loads `filename` content into it, up to DICTSIZE_MAX bytes. * @return : loaded size * if fileName==NULL, returns 0 and a NULL pointer */

 *  if fileName==NULL, returns 0 and a NULL pointer
 */
static size_t FIO_createDictBuffer(void** bufferPtr, const char* fileName, FIO_prefs_t* const prefs)
{
    FILE* fileHandle;
    U64 fileSize;

    assert(bufferPtr != NULL);
    *bufferPtr = NULL;
    if (fileName == NULL) return 0;

    DISPLAYLEVEL(4,"Loading %s as dictionary \n", fileName);
    fileHandle = fopen(fileName, "rb");
    if (fileHandle==NULL) EXM_THROW(31, "%s: %s", fileName, strerror(errno));

    fileSize = UTIL_getFileSize(fileName);
    {
        size_t const dictSizeMax = prefs->patchFromMode ? prefs->memLimit : DICTSIZE_MAX;
        if (fileSize >  dictSizeMax) {
            EXM_THROW(32, "Dictionary file %s is too large (> %u bytes)",
                            fileName,  (unsigned)dictSizeMax);   /* avoid extreme cases */
        }
    }
    *bufferPtr = malloc((size_t)fileSize);
    if (*bufferPtr==NULL) EXM_THROW(34, "%s", strerror(errno));
    {   size_t const readSize = fread(*bufferPtr, 1, (size_t)fileSize, fileHandle);
        if (readSize != fileSize)
            EXM_THROW(35, "Error reading dictionary file %s : %s",
                    fileName, strerror(errno));
    }
    fclose(fileHandle);
    return (size_t)fileSize;
}