Struct vpk0::Encoder

pub struct Encoder<'a, R> { /* fields omitted */ }

Specify the encoding settings, such as window size, logging, input, and output

To create a new Encoder, use for_reader(), for_file(), or for_bytes(). Then, change any of the encoding settings with Encoder’s helper methods. Finally, encode the input data with encode_to_writer(), encode_to_file(), or encode_to_vec().

let input = b"ABBACABBCADFEGABA";
let compressed = Encoder::for_bytes(input)
    .two_sample()
    .lzss_backend(LzssBackend::Kmp)
    .with_logging(&mut ::std::io::stdout())
    .encode_to_vec();

The default encoding settings are as follows:

• One Sample encoding
• No user offset or length values
• No logging
• LZSS settings:
  • 16 bit window (65536 bytes)
  • 8 bit lookahead (256 bytes)
  • Minimum match of 3 bytes
  • Brute match searching

Implementations

impl<'a, R: Read> Encoder<'a, R>

pub fn for_reader(rdr: R) -> Self

Create a new Encoder for the data in rdr.

pub fn method(&mut self, method: VpkMethod) -> &mut Self

Set the encoded VPK file to use either a one sample offset lookback, or a two sample lookback.

In one sample mode, the offset value is directly encoded into the output. In two sample mode, the offset value is divided by four. Then the remainder (if necessary) and quotient are stored in the output.

pub fn one_sample(&mut self) -> &mut Self

Conveince method to set one sample encoding without importing VpkMethod.

pub fn two_sample(&mut self) -> &mut Self

Conveince method to set two sample encoding without importing VpkMethod.

pub fn with_lzss_settings(&mut self, settings: LzssSettings) -> &mut Self

Set the settings used for the underyling lzss compression. See LzssSettings for more details.

pub fn lzss_backend(&mut self, backend: LzssBackend) -> &mut Self

Set the algorithm used to search for LZSS matches when encoding

pub fn with_offsets(&mut self, o: &'a str) -> &mut Self

Manually set the offset Huffman Tree with a text based representation of a tree. This representation can be extracted from a vpk0 file by vpk_info or Decoder::trees.

let compressed = Encoder::for_bytes(b"sam I am I am sam")
    .with_offsets("(3, (7, 10))")
    .encode_to_vec();

Note that the encoding will fail if there is an offset whose size in bits is larger than the largest provided offset.

pub fn optional_offsets(&mut self, offsets: Option<&'a str>) -> &mut Self

Set the offset Huffman Tree if offsets.is_some(), else create the offset tree from the input data.

pub fn with_lengths(&mut self, l: &'a str) -> &mut Self

Manually set the length Huffman Tree with a text based representation of a tree. This representation can be extracted from a vpk0 file by vpk_info or Decoder::trees.

let compressed = Encoder::for_bytes(b"sam I am I am sam")
    .with_lengths("((3, 5), (7, (12, 16))")
    .encode_to_vec();

Note that the encoding will fail if there is an offset whose size in bits is larger than the largest provided offset.

pub fn optional_lengths(&mut self, lengths: Option<&'a str>) -> &mut Self

Set the length Huffman Tree if offsets.is_some(), else create the offset tree from the input data.

pub fn with_logging<L: Write>(&mut self, log: &'a mut L) -> &mut Self

Write debugging and diagnotic information to log while the input is being encoded.

pub fn encode_to_writer<W: Write>(&mut self, wtr: W) -> Result<(), VpkError>

Start the encoding and write the compressed data out to wtr

pub fn encode_to_file<P: AsRef<Path>>(&mut self, f: P) -> Result<(), VpkError>

Start the encoding and write the compressed data out to the newly created File f

pub fn encode_to_vec(&mut self) -> Result<Vec<u8>, VpkError>

Start the encoding and return the compressed data in a Vec<u8>.

impl<'a> Encoder<'a, BufReader<File>>

pub fn for_file<P: AsRef<Path>>(p: P) -> Result<Self, VpkError>

Create a new Encoder for the file at p.

impl<'a> Encoder<'a, Cursor<&'a [u8]>>

pub fn for_bytes(bytes: &'a [u8]) -> Self

Create a new Encoder for the data the bytes slice.