checkInvariant close compressedVectorNode dump isOpen read read seek

unsigned read ( std::vector< SourceDestBuffer > &  dbufs ) Request transfer of block of data from CompressedVectorNode into given destination buffers. Parameters: [in] dbufs Vector of memory buffers that will receive data read from a CompressedVectorNode. The dbufs must all have the same capacity. The specified dbufs must have same number of elements as previously designated SourceDestBuffer vector. The each SourceDestBuffer within dbufs must be identical to the previously designated SourceDestBuffer except for capacity and buffer address. The dbufs locations are saved so that a later call to CompressedVectorReader::read() can be used without having to re-specify the SourceDestBuffers. The function will always return the full number of records requested (the capacity of the SourceDestBuffers) unless it has reached the end of the CompressedVectorNode, in which case it will return less than the capacity of the SourceDestBuffers. Partial reads will store the records at the beginning of the SourceDestBuffers. It is not an error to call this function after all records in the CompressedVectorNode have been read (the function returns 0). If a conversion or bounds error occurs during the transfer, the CompressedVectorReader is left in an undocumented state (it can't be used any further). If a file I/O or checksum error occurs during the transfer, both the CompressedVectorReader and the associated ImageFile are left in an undocumented state (they can't be used any further). The API user is responsible for ensuring that the underlying memory buffers represented in the SourceDestBuffers still exist when this function is called. The E57 Foundation Implementation cannot detect that a memory buffer been destroyed. Precondition: The associated ImageFile must be open. This CompressedVectorReader must be open (i.e isOpen()) Returns: The number of records read. Exceptions: E57_ERROR_IMAGEFILE_NOT_OPEN E57_ERROR_READER_NOT_OPEN E57_ERROR_PATH_UNDEFINED E57_ERROR_BUFFER_SIZE_MISMATCH E57_ERROR_BUFFER_DUPLICATE_PATHNAME E57_ERROR_CONVERSION_REQUIRED This CompressedVectorReader in undocumented state E57_ERROR_VALUE_NOT_REPRESENTABLE This CompressedVectorReader in undocumented state E57_ERROR_SCALED_VALUE_NOT_REPRESENTABLE This CompressedVectorReader in undocumented state E57_ERROR_REAL64_TOO_LARGE This CompressedVectorReader in undocumented state E57_ERROR_EXPECTING_NUMERIC This CompressedVectorReader in undocumented state E57_ERROR_EXPECTING_USTRING This CompressedVectorReader in undocumented state E57_ERROR_BAD_CV_PACKET This CompressedVectorReader, associated ImageFile in undocumented state E57_ERROR_LSEEK_FAILED This CompressedVectorReader, associated ImageFile in undocumented state E57_ERROR_READ_FAILED This CompressedVectorReader, associated ImageFile in undocumented state E57_ERROR_BAD_CHECKSUM This CompressedVectorReader, associated ImageFile in undocumented state E57_ERROR_INTERNAL All objects in undocumented state See also: SourceDestBufferNumericCreate.cpp example, CompressedVectorReader::read(), CompressedVectorNode::reader, SourceDestBuffer