Trait io::BlockReader
source · pub trait BlockReader: BlockIo {
// Required method
fn read_blocks(
&mut self,
buffer: &mut [u8],
block_offset: usize
) -> Result<usize, IoError>;
}Expand description
A trait that represents an I/O stream (e.g., an I/O device) that can be read from in blocks.
The block size specifies the minimum granularity of each transfer,
as given by the BlockIo::block_size() function.
A BlockReader is not aware of the current block offset into the stream;
thus, each read operation requires a starting offset:
the number of blocks from the beginning of the I/O stream at which the read should start.
Required Methods§
sourcefn read_blocks(
&mut self,
buffer: &mut [u8],
block_offset: usize
) -> Result<usize, IoError>
fn read_blocks( &mut self, buffer: &mut [u8], block_offset: usize ) -> Result<usize, IoError>
Reads blocks of data from this reader into the given buffer.
The number of blocks read is dictated by the length of the given buffer.
Arguments
buffer: the buffer into which data will be read. The length of this buffer must be a multiple of the block size.block_offset: the offset in number of blocks from the beginning of this reader.
Return
If successful, returns the number of blocks read into the given buffer.
Otherwise, returns an error.