|virtual pdf_long||Read (char *pBuffer, pdf_long lLen, pdf_long *pTotalLeft=0)=0|
An interface for reading blocks of data from an a data source.
Read data from the input stream
|pBuffer||the data will be stored into this buffer|
|lLen||the size of the buffer and number of bytes that will be read|
|pTotalLeft||total bytes left (needed for AES IV and padding)|