BlobNode BlobNode byteCount checkInvariant destImageFile dump elementName isAttached isRoot operator Node parent pathName read write

void read ( uint8_t *  buf, int64_t  start, size_t  count  ) Read a buffer of bytes from a blob. Parameters: [in] buf A memory buffer to store bytes read from the blob. [in] start The index of the first byte in blob to read. [in] count The number of bytes to read. The memory buffer buf must be able to store at least count bytes. The data is stored in a binary section of the ImageFile with checksum protection, so undetected corruption is very unlikely. It is an error to attempt to read outside the declared size of the Blob. The format of the data read is opaque (unspecified by the ASTM E57 data format standard). Since buf is a byte buffer, byte ordering is irrelevant (it will come out in the same order that it went in). There is no constraint on the ordering of reads. Any part of the Blob data can be read zero or more times. Precondition: The destination ImageFile must be open (i.e. destImageFile().isOpen()). buf != NULL 0 <= start < byteCount() 0 <= count (start + count) < byteCount() Exceptions: E57_ERROR_BAD_API_ARGUMENT E57_ERROR_IMAGEFILE_NOT_OPEN E57_ERROR_LSEEK_FAILED E57_ERROR_READ_FAILED E57_ERROR_BAD_CHECKSUM E57_ERROR_INTERNAL All objects in undocumented state See also: BlobCreate.cpp example, BlobNode::byteCount, BlobNode::write