on_disk_read Event

Fires when the OS needs to read data from the virtual disk.

Syntax

class CBDiskDiskReadEventParams(object):
  @property
  def offset() -> int: ...
  @property
  def buffer() -> c_void_p: ...
  @property
  def bytes_to_read() -> int: ...
  @property
  def bytes_read() -> int: ...
  @bytes_read.setter
  def bytes_read(value) -> None: ...
  @property
  def result_code() -> int: ...
  @result_code.setter
  def result_code(value) -> None: ...

# In class CBDisk:
@property
def on_disk_read() -> Callable[[CBDiskDiskReadEventParams], None]: ...
@on_disk_read.setter
def on_disk_read(event_hook: Callable[[CBDiskDiskReadEventParams], None]) -> None: ...

Remarks

This event fires when the OS needs to read data from the virtual disk.

To handle this event properly, applications must read BytesToRead bytes from the block of data associated with the virtual disk, copying it to the memory region pointed to by Buffer. Reading must begin at the specified Offset in the data block, and when reading is complete, applications must set BytesRead to reflect the actual number of bytes read into Buffer. Applications must not attempt to copy more than BytesToRead bytes of data into Buffer.

Please refer to the Buffer Parameters topic for more information on how to work with memory buffer event parameters.

The ResultCode parameter will always be 0 when the event is fired. If the event cannot be handled in a "successful" manner for some reason (e.g., a resource isn't available, security checks failed, etc.), set it to a non-zero value to report an appropriate error. Please refer to the Error Reporting and Handling topic for more information.