Struct grep_searcher::MmapChoice [−][src]
pub struct MmapChoice(_);
Controls the strategy used for determining when to use memory maps.
If a searcher is called in circumstances where it is possible to use memory maps, and memory maps are enabled, then it will attempt to do so if it believes it will make the search faster.
By default, memory maps are disabled.
Methods
impl MmapChoice
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impl MmapChoice
pub unsafe fn auto() -> MmapChoice
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pub unsafe fn auto() -> MmapChoice
Use memory maps when they are believed to be advantageous.
The heuristics used to determine whether to use a memory map or not may depend on many things, including but not limited to, file size and platform.
If memory maps are unavailable or cannot be used for a specific input, then normal OS read calls are used instead.
Safety
This constructor is not safe because there is no obvious way to encapsulate the safety of file backed memory maps on all platforms without simultaneously negating some or all of their benefits.
The specific contract the caller is required to uphold isn't precise,
but it basically amounts to something like, "the caller guarantees that
the underlying file won't be mutated." This, of course, isn't feasible
in many environments. However, command line tools may still decide to
take the risk of, say, a SIGBUS
occurring while attempting to read a
memory map.
pub fn never() -> MmapChoice
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pub fn never() -> MmapChoice
Never use memory maps, no matter what. This is the default.
Trait Implementations
impl Clone for MmapChoice
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impl Clone for MmapChoice
fn clone(&self) -> MmapChoice
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fn clone(&self) -> MmapChoice
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
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fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source
. Read more
impl Debug for MmapChoice
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impl Debug for MmapChoice
fn fmt(&self, f: &mut Formatter) -> Result
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fn fmt(&self, f: &mut Formatter) -> Result
Formats the value using the given formatter. Read more
impl Default for MmapChoice
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impl Default for MmapChoice
fn default() -> MmapChoice
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fn default() -> MmapChoice
Returns the "default value" for a type. Read more
Auto Trait Implementations
impl Send for MmapChoice
impl Send for MmapChoice
impl Sync for MmapChoice
impl Sync for MmapChoice