Struct tiff_encoder::write::ByteBlock

pub struct ByteBlock(pub Vec<u8>);

Datablock that consists of a list of bytes.

It is possible to store any block of data in a ByteBlock, but that would require to know the Endianness of the file beforehand, so the bytes are written in the correct order.

Using a Datablock, on the other hand, allows to make use of the functionality of an EndianFile, so the data can be written without worrying about the endianness.

Examples

Creating a ByteBlock from a Vec<u8>:

use tiff_encoder::prelude::*;

// A vector holding arbitrary u8 data.
// This is the data we want to store as a Byteblock.
let data_8bits: Vec<u8> = vec![0; 65536];

// Create an Offsets of a single Byteblock from the buffer.
// This is the value that can be used directly as an IFD entry value.
let byte_block = ByteBlock::single(data_8bits);

Creating a ByteBlock from a Vec<u32>:

extern crate byteorder;
// Crate byteorder will be used to write 32-bit information in a 8-bit buffer.
use byteorder::{LittleEndian, WriteBytesExt};
use tiff_encoder::prelude::*;


// A vector holding arbitrary u32 data.
// This is the data we want to store as a Byteblock.
let data_32bits: Vec<u32> = vec![0; 65536];

// First, let's store the data in a u8 buffer.
let mut image_bytes = Vec::with_capacity(262144); // 65536*4 (each u32 has a size of 4 bytes)
for val in data_32bits {
    // A little endian TIFF file is assumed in this example.
    image_bytes.write_u32::<LittleEndian>(val).unwrap();
}

// Create an Offsets of a single Byteblock from the buffer.
// This is the value that can be used directly as an IFD entry value.
let byte_block = ByteBlock::single(image_bytes);

Methods

impl ByteBlock

pub fn offsets(blocks: Vec<Vec<u8>>) -> Offsets<ByteBlock>

Constructs an Offsets of ByteBlocks from a vector of vectors of bytes.

Each vector of bytes represents one ByteBlock.

pub fn single(block: Vec<u8>) -> Offsets<ByteBlock>

Constructs an Offsets from a vector of bytes.

This vector of bytes represents a single ByteBlock.

Trait Implementations

impl Datablock for ByteBlock

fn size(&self) -> u32

The number of bytes occupied by this Datablock.

fn write_to(self, file: &mut EndianFile) -> Result<()>

Writes this Datablock to an [EndianFile]. The number of bytes written must be exactly same number as returned by [size(&self)].