Builder to create a multi-threaded stream encoder.
pub fn new() -> MtStreamBuilder[src]
Creates a new blank builder to create a multithreaded encoding
pub fn threads(&mut self, threads: u32) -> &mut MtStreamBuilder[src]
Configures the number of worker threads to use
pub fn block_size(&mut self, block_size: u64) -> &mut MtStreamBuilder[src]
Configures the maximum uncompressed size of a block
The encoder will start a new .xz block every
process the caller may tell
liblzma to start a new block earlier.
With LZMA2, a recommended block size is 2-4 times the LZMA2 dictionary size. With very small dictionaries, it is recommended to use at least 1 MiB block size for good compression ratio, even if this is more than four times the dictionary size. Note that these are only recommendations for typical use cases; feel free to use other values. Just keep in mind that using a block size less than the LZMA2 dictionary size is waste of RAM.
Set this to 0 to let liblzma choose the block size depending on the
compression options. For LZMA2 it will be 3*
dict_size or 1 MiB,
whichever is more.
For each thread, about 3 *
block_size bytes of memory will be
allocated. This may change in later liblzma versions. If so, the memory
usage will probably be reduced, not increased.
pub fn timeout_ms(&mut self, timeout: u32) -> &mut MtStreamBuilder[src]
Timeout to allow
process to return early
Multithreading can make liblzma to consume input and produce output in a very bursty way: it may first read a lot of input to fill internal buffers, then no input or output occurs for a while.
In single-threaded mode,
process won't return until it has either
consumed all the input or filled the output buffer. If this is done in
multithreaded mode, it may cause a call
process to take even tens of
seconds, which isn't acceptable in all applications.
To avoid very long blocking times in
process, a timeout (in
milliseconds) may be set here. If
process would block longer than this number of milliseconds, it will return with Ok`. Reasonable
values are 100 ms or more. The xz command line tool uses 300 ms.
If long blocking times are fine for you, set timeout to a special
value of 0, which will disable the timeout mechanism and will make
process block until all the input is consumed or the output
buffer has been filled.
pub fn preset(&mut self, preset: u32) -> &mut MtStreamBuilder[src]
Compression preset (level and possible flags)
The preset is set just like with
Stream::new_easy_encoder. The preset
is ignored if filters below have been specified.
pub fn filters(&mut self, filters: Filters) -> &mut MtStreamBuilder[src]
Configure a custom filter chain
pub fn check(&mut self, check: Check) -> &mut MtStreamBuilder[src]
Configures the integrity check type
Calculate approximate memory usage of multithreaded .xz encoder
Initialize multithreaded .xz stream encoder.
impl RefUnwindSafe for MtStreamBuilder
impl !Send for MtStreamBuilder
impl !Sync for MtStreamBuilder
impl Unpin for MtStreamBuilder
impl UnwindSafe for MtStreamBuilder
type Error = Infallible
The type returned in the event of a conversion error.