Enum ReadPreference 

pub enum ReadPreference {
    Primary,
    PrimaryPreferred,
    Secondary,
    SecondaryPreferred,
    Nearest,
    Region(String),
    TagSet(Vec<HashMap<String, String>>),
}

Read preference for query routing.

Variants

Primary

Always read from primary.

PrimaryPreferred

Prefer primary, fallback to secondary.

Secondary

Always read from secondary.

SecondaryPreferred

Prefer secondary, fallback to primary.

Nearest

Read from nearest replica by latency.

Region(String)

Read from specific region.

TagSet(Vec<HashMap<String, String>>)

Custom tag set (MongoDB).

Implementations

impl ReadPreference

pub fn region(region: impl Into<String>) -> Self

Create a region preference.

pub fn tag_set(tags: Vec<HashMap<String, String>>) -> Self

Create a tag set preference.

pub fn to_mongodb(&self) -> &'static str

Convert to MongoDB read preference string.

pub fn allows_primary(&self) -> bool

Check if this preference allows reading from primary.

pub fn allows_secondary(&self) -> bool

Check if this preference allows reading from secondary.

Trait Implementations

impl Clone for ReadPreference

fn clone(&self) -> ReadPreference

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ReadPreference

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ReadPreference

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ReadPreference

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl PartialEq for ReadPreference

fn eq(&self, other: &ReadPreference) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for ReadPreference

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for ReadPreference

impl StructuralPartialEq for ReadPreference