pub struct Options { /* private fields */ }Expand description
Options for creating an ARENA
Implementations§
Source§impl Options
impl Options
Sourcepub const fn with_lock_meta(self, lock_meta: bool) -> Self
pub const fn with_lock_meta(self, lock_meta: bool) -> Self
Set if lock the meta of the Allocator in the memory to prevent OS from swapping out the header of Allocator.
When using memory map backed Allocator, the meta of the Allocator
is in the header, meta is frequently accessed,
lock (mlock on the header) the meta can reduce the page fault,
but yes, this means that one Allocator will have one page are locked in memory,
and will not be swapped out. So, this is a trade-off between performance and memory usage.
Default is true.
This configuration has no effect on windows and vec backed Allocator.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_lock_meta(false);Sourcepub const fn with_read(self, read: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_read(self, read: bool) -> Self
memmap and non-target_family="wasm" only.Sets the option for read access.
This option, when true, will indicate that the file should be
read-able if opened.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_read(true);Sourcepub const fn with_write(self, write: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_write(self, write: bool) -> Self
memmap and non-target_family="wasm" only.Sets the option for write access.
This option, when true, will indicate that the file should be
write-able if opened.
If the file already exists, any write calls on it will overwrite its contents, without truncating it.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_write(true);Sourcepub const fn with_append(self, append: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_append(self, append: bool) -> Self
memmap and non-target_family="wasm" only.Sets the option for the append mode.
This option, when true, means that writes will append to a file instead
of overwriting previous contents.
Note that setting .write(true).append(true) has the same effect as
setting only .append(true).
For most filesystems, the operating system guarantees that all writes are atomic: no writes get mangled because another process writes at the same time.
One maybe obvious note when using append-mode: make sure that all data
that belongs together is written to the file in one operation. This
can be done by concatenating strings before passing them to write(),
or using a buffered writer (with a buffer of adequate size),
and calling flush() when the message is complete.
If a file is opened with both read and append access, beware that after
opening, and after every write, the position for reading may be set at the
end of the file. So, before writing, save the current position (using
seek(SeekFrom::Current(opts))), and restore it before the next read.
§Note
This function doesn’t create the file if it doesn’t exist. Use the
Options::with_create method to do so.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_append(true);Sourcepub const fn with_truncate(self, truncate: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_truncate(self, truncate: bool) -> Self
memmap and non-target_family="wasm" only.Sets the option for truncating a previous file.
If a file is successfully opened with this option set it will truncate the file to opts length if it already exists.
The file must be opened with write access for truncate to work.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_write(true).with_truncate(true);Sourcepub const fn with_create(self, val: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_create(self, val: bool) -> Self
memmap and non-target_family="wasm" only.Sets the option to create a new file, or open it if it already exists. If the file does not exist, it is created and set the lenght of the file to the given size.
In order for the file to be created, Options::with_write or
Options::with_append access must be used.
See also std::fs::write() for a simple function to
create a file with some given data.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_write(true).with_create(true);Sourcepub const fn with_create_new(self, val: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_create_new(self, val: bool) -> Self
memmap and non-target_family="wasm" only.Sets the option to create a new file and set the file length to the given value, failing if it already exists.
No file is allowed to exist at the target location, also no (dangling) symlink. In this way, if the call succeeds, the file returned is guaranteed to be new.
This option is useful because it is atomic. Otherwise between checking whether a file exists and creating a new one, the file may have been created by another process (a TOCTOU race condition / attack).
If .with_create_new(true) is set, .with_create() and .with_truncate() are
ignored.
The file must be opened with write or append access in order to create a new file.
§Examples
use rarena_allocator::Options;
let file = Options::new()
.with_write(true)
.with_create_new(true);Sourcepub const fn with_offset(self, offset: u64) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_offset(self, offset: u64) -> Self
memmap and non-target_family="wasm" only.Sourcepub const fn with_stack(self, stack: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_stack(self, stack: bool) -> Self
memmap and non-target_family="wasm" only.Configures the anonymous memory map to be suitable for a process or thread stack.
This option corresponds to the MAP_STACK flag on Linux. It has no effect on Windows.
This option has no effect on file-backed memory maps and vec backed Allocator.
§Example
use rarena_allocator::Options;
let stack = Options::new().with_stack(true);Sourcepub const fn with_huge(self, page_bits: Option<u8>) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_huge(self, page_bits: Option<u8>) -> Self
memmap and non-target_family="wasm" only.Configures the anonymous memory map to be allocated using huge pages.
This option corresponds to the MAP_HUGETLB flag on Linux. It has no effect on Windows.
The size of the requested page can be specified in page bits. If not provided, the system default is requested. The requested length should be a multiple of this, or the mapping will fail.
This option has no effect on file-backed memory maps and vec backed Allocator.
§Example
use rarena_allocator::Options;
let stack = Options::new().with_huge(Some(8));Sourcepub const fn with_populate(self, populate: bool) -> Self
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn with_populate(self, populate: bool) -> Self
memmap and non-target_family="wasm" only.Populate (prefault) page tables for a mapping.
For a file mapping, this causes read-ahead on the file. This will help to reduce blocking on page faults later.
This option corresponds to the MAP_POPULATE flag on Linux. It has no effect on Windows.
This option has no effect on vec backed Allocator.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_populate(true);Source§impl Options
impl Options
Sourcepub const fn lock_meta(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn lock_meta(&self) -> bool
memmap and non-target_family="wasm" only.Get if lock the meta of the Allocator in the memory to prevent OS from swapping out the header of Allocator.
When using memory map backed Allocator, the meta of the Allocator
is in the header, meta is frequently accessed,
lock (mlock on the header) the meta can reduce the page fault,
but yes, this means that one Allocator will have one page are locked in memory,
and will not be swapped out. So, this is a trade-off between performance and memory usage.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_lock_meta(false);
assert_eq!(opts.lock_meta(), false);Sourcepub const fn read(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn read(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the file should be opened with read access.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_read(true);
assert_eq!(opts.read(), true);Sourcepub const fn write(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn write(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the file should be opened with write access.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_write(true);
assert_eq!(opts.write(), true);Sourcepub const fn append(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn append(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the file should be opened with append access.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_append(true);
assert_eq!(opts.append(), true);Sourcepub const fn truncate(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn truncate(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the file should be opened with truncate access.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_truncate(true);
assert_eq!(opts.truncate(), true);Sourcepub const fn create(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn create(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the file should be created if it does not exist.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_create(true);
assert_eq!(opts.create(), true);Sourcepub const fn create_new(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn create_new(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the file should be created if it does not exist and fail if it does.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_create_new(true);
assert_eq!(opts.create_new(), true);Sourcepub const fn offset(&self) -> u64
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn offset(&self) -> u64
memmap and non-target_family="wasm" only.Returns the offset of the memory map.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_offset(30);
assert_eq!(opts.offset(), 30);Sourcepub const fn stack(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn stack(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the memory map should be suitable for a process or thread stack.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_stack(true);
assert_eq!(opts.stack(), true);Sourcepub const fn huge(&self) -> Option<u8>
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn huge(&self) -> Option<u8>
memmap and non-target_family="wasm" only.Returns the page bits of the memory map.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_huge(Some(8));
assert_eq!(opts.huge(), Some(8));Sourcepub const fn populate(&self) -> bool
Available on crate feature memmap and non-target_family="wasm" only.
pub const fn populate(&self) -> bool
memmap and non-target_family="wasm" only.Returns true if the memory map should populate (prefault) page tables for a mapping.
§Examples
use rarena_allocator::Options;
let opts = Options::new().with_populate(true);
assert_eq!(opts.populate(), true);Source§impl Options
impl Options
Sourcepub fn map_anon<A: Allocator>(self) -> Result<A>
Available on crate feature memmap and non-target_family="wasm" only.
pub fn map_anon<A: Allocator>(self) -> Result<A>
memmap and non-target_family="wasm" only.Creates a new allocator backed by an anonymous mmap.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = Options::new().with_capacity(100).map_anon::<Arena>().unwrap();Sourcepub unsafe fn map<A: Allocator, P: AsRef<Path>>(self, p: P) -> Result<A>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map<A: Allocator, P: AsRef<Path>>(self, p: P) -> Result<A>
memmap and non-target_family="wasm" only.Opens a read only allocator backed by a mmap file.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = unsafe { Options::new().with_read(true).map::<Arena, _>(&path,).unwrap() };
Sourcepub unsafe fn map_with_path_builder<A: Allocator, PB, E>(
self,
path_builder: PB,
) -> Result<A, Either<E, Error>>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map_with_path_builder<A: Allocator, PB, E>( self, path_builder: PB, ) -> Result<A, Either<E, Error>>
memmap and non-target_family="wasm" only.Opens a read only allocator backed by a mmap file with the given path builder.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Allocator, Options};
let arena = unsafe { Options::new().with_read(true).map_with_path_builder::<Arena, _, std::io::Error>(|| Ok(path.to_path_buf())).unwrap() };
Sourcepub unsafe fn map_copy<A: Allocator, P: AsRef<Path>>(self, path: P) -> Result<A>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map_copy<A: Allocator, P: AsRef<Path>>(self, path: P) -> Result<A>
memmap and non-target_family="wasm" only.Creates a new allocator backed by a copy-on-write memory map backed by a file.
Data written to the allocator will not be visible by other processes, and will not be carried through to the underlying file.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = unsafe { Options::new().with_capacity(100).with_read(true).with_write(true).with_create_new(true).map_copy::<Arena, _>(&path,).unwrap() };
Sourcepub unsafe fn map_copy_with_path_builder<A: Allocator, PB, E>(
self,
path_builder: PB,
) -> Result<A, Either<E, Error>>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map_copy_with_path_builder<A: Allocator, PB, E>( self, path_builder: PB, ) -> Result<A, Either<E, Error>>
memmap and non-target_family="wasm" only.Creates a new allocator backed by a copy-on-write memory map backed by a file with the given path builder.
Data written to the allocator will not be visible by other processes, and will not be carried through to the underlying file.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = unsafe { Options::new().with_capacity(100).with_create_new(true).with_read(true).with_write(true).map_copy_with_path_builder::<Arena, _, std::io::Error>(|| Ok(path.to_path_buf()),).unwrap() };
Sourcepub unsafe fn map_copy_read_only<A: Allocator, P: AsRef<Path>>(
self,
path: P,
) -> Result<A>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map_copy_read_only<A: Allocator, P: AsRef<Path>>( self, path: P, ) -> Result<A>
memmap and non-target_family="wasm" only.Opens a read only allocator backed by a copy-on-write read-only memory map backed by a file.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = unsafe { Options::new().with_read(true).map_copy_read_only::<Arena, _>(&path,).unwrap() };
Sourcepub unsafe fn map_copy_read_only_with_path_builder<A: Allocator, PB, E>(
self,
path_builder: PB,
) -> Result<A, Either<E, Error>>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map_copy_read_only_with_path_builder<A: Allocator, PB, E>( self, path_builder: PB, ) -> Result<A, Either<E, Error>>
memmap and non-target_family="wasm" only.Opens a read only allocator backed by a copy-on-write read-only memory map backed by a file with the given path builder.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = unsafe {
Options::new().with_read(true).map_copy_read_only_with_path_builder::<Arena, _, std::io::Error>(|| Ok(path.to_path_buf())).unwrap()
};
Sourcepub unsafe fn map_mut<A: Allocator, P: AsRef<Path>>(self, path: P) -> Result<A>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map_mut<A: Allocator, P: AsRef<Path>>(self, path: P) -> Result<A>
memmap and non-target_family="wasm" only.Creates a new allocator backed by a mmap with the given path.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = unsafe {
Options::new()
.with_capacity(100)
.with_create_new(true)
.with_read(true)
.with_write(true)
.map_mut::<Arena, _>(&path).unwrap()
};
Sourcepub unsafe fn map_mut_with_path_builder<A: Allocator, PB, E>(
self,
path_builder: PB,
) -> Result<A, Either<E, Error>>
Available on crate feature memmap and non-target_family="wasm" only.
pub unsafe fn map_mut_with_path_builder<A: Allocator, PB, E>( self, path_builder: PB, ) -> Result<A, Either<E, Error>>
memmap and non-target_family="wasm" only.Creates a new allocator backed by a mmap with the given path builder.
§Safety
All file-backed memory map constructors are marked unsafe because of the potential for
Undefined Behavior (UB) using the map if the underlying file is subsequently modified, in or
out of process. Applications must consider the risk and take appropriate precautions when
using file-backed maps. Solutions such as file permissions, locks or process-private (e.g.
unlinked) files exist but are platform specific and limited.
§Example
use rarena_allocator::{sync::Arena, Options, Allocator};
let arena = unsafe {
Options::new()
.with_create_new(true)
.with_read(true)
.with_write(true)
.with_capacity(100)
.map_mut_with_path_builder::<Arena, _, std::io::Error>(|| Ok(path.to_path_buf())).unwrap()
};
Source§impl Options
impl Options
Sourcepub fn data_offset_unify<A: Allocator>(&self) -> usize
pub fn data_offset_unify<A: Allocator>(&self) -> usize
Returns the data offset of the ARENA if the ARENA is in unified memory layout.
See also Options::data_offset.
§Example
use rarena_allocator::{sync, unsync, Options, Allocator};
// Create a sync ARENA.
let opts = Options::new().with_capacity(100);
let data_offset_from_opts = opts.data_offset::<sync::Arena>();
let arena = opts.alloc::<sync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());
let data_offset_from_opts = opts.data_offset_unify::<sync::Arena>();
let arena = opts.with_unify(true).alloc::<sync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());
// Create a unsync ARENA.
let opts = Options::new().with_capacity(100);
let data_offset_from_opts = opts.data_offset::<unsync::Arena>();
let arena = opts.alloc::<unsync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());
let data_offset_from_opts = opts.data_offset_unify::<unsync::Arena>();
let arena = opts.with_unify(true).alloc::<unsync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());Sourcepub fn data_offset<A: Allocator>(&self) -> usize
pub fn data_offset<A: Allocator>(&self) -> usize
Returns the data offset of the ARENA if the ARENA is not in unified memory layout.
As the file backed ARENA will only use the unified memory layout and ignore the unify configuration of Options,
so see also Options::data_offset_unify, if you want to get the data offset of the ARENA in unified memory layout.
§Example
use rarena_allocator::{sync, unsync, Options, Allocator};
// Create a sync ARENA.
let opts = Options::new().with_capacity(100);
let data_offset_from_opts = opts.data_offset::<sync::Arena>();
let arena = opts.alloc::<sync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());
let data_offset_from_opts = opts.data_offset_unify::<sync::Arena>();
let arena = opts.with_unify(true).alloc::<sync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());
// Create a unsync ARENA.
let opts = Options::new().with_capacity(100);
let data_offset_from_opts = opts.data_offset::<unsync::Arena>();
let arena = opts.alloc::<unsync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());
let data_offset_from_opts = opts.data_offset_unify::<unsync::Arena>();
let arena = opts.with_unify(true).alloc::<unsync::Arena>().unwrap();
assert_eq!(data_offset_from_opts, arena.data_offset());Sourcepub const fn with_reserved(self, reserved: u32) -> Self
pub const fn with_reserved(self, reserved: u32) -> Self
Set the reserved of the ARENA.
The reserved is used to configure the start position of the ARENA. This is useful
when you want to add some bytes before the ARENA, e.g. when using the memory map file backed ARENA,
you can set the reserved to the size to 8 to store a 8 bytes checksum.
The default reserved is 0.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_reserved(8);Sourcepub const fn with_maximum_alignment(self, alignment: usize) -> Self
pub const fn with_maximum_alignment(self, alignment: usize) -> Self
Set the maximum alignment of the ARENA.
If you are trying to allocate a T which requires a larger alignment than this value,
then will lead to read_unaligned, which is undefined behavior on some platforms.
The alignment must be a power of 2.
The default maximum alignment is 8.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_maximum_alignment(16);Sourcepub const fn with_capacity(self, capacity: u32) -> Self
pub const fn with_capacity(self, capacity: u32) -> Self
Set the capacity of the ARENA. If the ARENA is backed by a memory map and the original file size is less than the capacity, then the file will be resized to the capacity.
For vec backed ARENA and anonymous memory map backed ARENA, this configuration is required.
For file backed ARENA, this configuration is optional, if the capacity is not set, then the capacity will be the original file size.
The capacity must be greater than the minimum capacity of the ARENA.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_capacity(2048);Sourcepub const fn maybe_capacity(self, capacity: Option<u32>) -> Self
pub const fn maybe_capacity(self, capacity: Option<u32>) -> Self
Set or unset the capacity of the ARENA. If the ARENA is backed by a memory map and the original file size is less than the capacity, then the file will be resized to the capacity.
For vec backed ARENA and anonymous memory map backed ARENA, this configuration is required.
For file backed ARENA, this configuration is optional, if the capacity is not set, then the capacity will be the original file size.
The capacity must be greater than the minimum capacity of the ARENA.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_capacity(2048);
/// some business logic
let opts = opts.maybe_capacity(None);Sourcepub const fn with_minimum_segment_size(self, minimum_segment_size: u32) -> Self
pub const fn with_minimum_segment_size(self, minimum_segment_size: u32) -> Self
Set the minimum segment size of the ARENA.
This value controls the size of the holes.
The default minimum segment size is 48 bytes.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_minimum_segment_size(64);Sourcepub const fn with_maximum_retries(self, maximum_retries: u8) -> Self
pub const fn with_maximum_retries(self, maximum_retries: u8) -> Self
Set the maximum retries of the ARENA.
This value controls how many times the ARENA will retry to allocate from slow path.
The default maximum retries is 5.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_maximum_retries(10);Sourcepub const fn with_unify(self, unify: bool) -> Self
pub const fn with_unify(self, unify: bool) -> Self
Set if use the unify memory layout of the ARENA.
File backed ARENA has different memory layout with other kind backed ARENA,
set this value to true will unify the memory layout of the ARENA, which means
all kinds of backed ARENA will have the same memory layout.
This value will be ignored if the ARENA is backed by a file backed memory map.
The default value is false.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_unify(true);Sourcepub const fn with_magic_version(self, magic_version: u16) -> Self
pub const fn with_magic_version(self, magic_version: u16) -> Self
Sourcepub const fn with_freelist(self, freelist: Freelist) -> Self
pub const fn with_freelist(self, freelist: Freelist) -> Self
Set the freelist configuration for the ARENA.
The default freelist is Freelist::Optimistic.
§Example
use rarena_allocator::{Options, Freelist};
let opts = Options::new().with_freelist(Freelist::Pessimistic);Sourcepub const fn reserved(&self) -> u32
pub const fn reserved(&self) -> u32
Get the reserved of the ARENA.
The reserved is used to configure the start position of the ARENA. This is useful
when you want to add some bytes before the ARENA, e.g. when using the memory map file backed ARENA,
you can set the reserved to the size to 8 to store a 8 bytes checksum.
The default reserved is 0.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_reserved(8);
assert_eq!(opts.reserved(), 8);Sourcepub const fn maximum_alignment(&self) -> usize
pub const fn maximum_alignment(&self) -> usize
Get the maximum alignment of the ARENA.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_maximum_alignment(16);
assert_eq!(opts.maximum_alignment(), 16);Sourcepub const fn capacity(&self) -> u32
pub const fn capacity(&self) -> u32
Get the capacity of the ARENA.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_capacity(2048);
assert_eq!(opts.capacity(), 2048);Sourcepub const fn minimum_segment_size(&self) -> u32
pub const fn minimum_segment_size(&self) -> u32
Get the minimum segment size of the ARENA.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_minimum_segment_size(64);
assert_eq!(opts.minimum_segment_size(), 64);Sourcepub const fn maximum_retries(&self) -> u8
pub const fn maximum_retries(&self) -> u8
Get the maximum retries of the ARENA. This value controls how many times the ARENA will retry to allocate from slow path.
The default maximum retries is 5.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_maximum_retries(10);
assert_eq!(opts.maximum_retries(), 10);Sourcepub const fn unify(&self) -> bool
pub const fn unify(&self) -> bool
Get if use the unify memory layout of the ARENA.
File backed ARENA has different memory layout with other kind backed ARENA,
set this value to true will unify the memory layout of the ARENA, which means
all kinds of backed ARENA will have the same memory layout.
This value will be ignored if the ARENA is backed by a file backed memory map.
The default value is false.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_unify(true);
assert_eq!(opts.unify(), true);Sourcepub const fn magic_version(&self) -> u16
pub const fn magic_version(&self) -> u16
Get the external version of the ARENA,
this is used by the application using Allocator
to ensure that it doesn’t open the Allocator
with incompatible data format.
The default value is 0.
§Example
use rarena_allocator::Options;
let opts = Options::new().with_magic_version(1);
assert_eq!(opts.magic_version(), 1);Source§impl Options
impl Options
Sourcepub fn alloc<A: Allocator>(self) -> Result<A, Error>
pub fn alloc<A: Allocator>(self) -> Result<A, Error>
Create a new Allocator which is backed by a Vec.
§Example
use rarena_allocator::{sync, unsync, Options};
// Create a sync ARENA.
let arena = Options::new().with_capacity(100).alloc::<sync::Arena>().unwrap();
// Create a unsync ARENA.
let arena = Options::new().with_capacity(100).alloc::<unsync::Arena>().unwrap();Trait Implementations§
impl Copy for Options
Auto Trait Implementations§
impl Freeze for Options
impl RefUnwindSafe for Options
impl Send for Options
impl Sync for Options
impl Unpin for Options
impl UnwindSafe for Options
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Source§impl<T> CloneToUninit for Twhere
T: Clone,
impl<T> CloneToUninit for Twhere
T: Clone,
Source§impl<K, Q> Comparable<Q> for K
impl<K, Q> Comparable<Q> for K
Source§impl<K, Q> Equivalent<Q> for K
impl<K, Q> Equivalent<Q> for K
Source§fn equivalent(&self, key: &Q) -> bool
fn equivalent(&self, key: &Q) -> bool
key and return true if they are equal.Source§impl<T> Instrument for T
impl<T> Instrument for T
Source§fn instrument(self, span: Span) -> Instrumented<Self>
fn instrument(self, span: Span) -> Instrumented<Self>
Source§fn in_current_span(self) -> Instrumented<Self>
fn in_current_span(self) -> Instrumented<Self>
Source§impl<T> IntoEither for T
impl<T> IntoEither for T
Source§fn into_either(self, into_left: bool) -> Either<Self, Self>
fn into_either(self, into_left: bool) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left is true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read moreSource§fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
self into a Left variant of Either<Self, Self>
if into_left(&self) returns true.
Converts self into a Right variant of Either<Self, Self>
otherwise. Read more