Method: Magick::Image._load

Defined in:
ext/RMagick/rmimage.cpp

._load(str) ⇒ Magic::Image

Implement marshalling.

Parameters:

  • str (String) —

    the marshalled string

Returns:

  • (Magic::Image) —

    a new image

See Also:



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# File 'ext/RMagick/rmimage.cpp', line 8877

VALUE
Image__load(VALUE klass ATTRIBUTE_UNUSED, VALUE str)
{
    Image *image;
    ImageInfo *info;
    DumpedImage mi;
    ExceptionInfo *exception;
    char *blob;
    size_t length;

    blob = rm_str2cstr(str, &length);

    // Must be as least as big as the 1st 4 fields in DumpedImage
    if (length <= (long)(sizeof(DumpedImage)-MaxTextExtent))
    {
        rb_raise(rb_eTypeError, "image is invalid or corrupted (too short)");
    }

    // Retrieve & validate the image format from the header portion
    mi.id = ((DumpedImage *)blob)->id;
    if (mi.id != DUMPED_IMAGE_ID)
    {
        rb_raise(rb_eTypeError, "image is invalid or corrupted (invalid header)");
    }

    mi.mj = ((DumpedImage *)blob)->mj;
    mi.mi = ((DumpedImage *)blob)->mi;
    if (   mi.mj != DUMPED_IMAGE_MAJOR_VERS
           || mi.mi > DUMPED_IMAGE_MINOR_VERS)
    {
        rb_raise(rb_eTypeError, "incompatible image format (can't be read)\n"
                 "\tformat version %d.%d required; %d.%d given",
                 DUMPED_IMAGE_MAJOR_VERS, DUMPED_IMAGE_MINOR_VERS,
                 mi.mj, mi.mi);
    }

    mi.len = ((DumpedImage *)blob)->len;

    // Must be bigger than the header
    if (length <= (mi.len + sizeof(DumpedImage) - MaxTextExtent))
    {
        rb_raise(rb_eTypeError, "image is invalid or corrupted (too short)");
    }

    info = CloneImageInfo(NULL);

    memcpy(info->magick, ((DumpedImage *)blob)->magick, mi.len);
    info->magick[mi.len] = '\0';

    exception = AcquireExceptionInfo();

    blob += offsetof(DumpedImage, magick) + mi.len;
    length -= offsetof(DumpedImage, magick) + mi.len;
    GVL_STRUCT_TYPE(BlobToImage) args = { info, blob, (size_t)length, exception };
    image = (Image *)CALL_FUNC_WITHOUT_GVL(GVL_FUNC(BlobToImage), &args);
    DestroyImageInfo(info);

    rm_check_exception(exception, image, DestroyOnError);
    DestroyExceptionInfo(exception);

    return rm_image_new(image);
}