Enum FirestoreWritePrecondition 

pub enum FirestoreWritePrecondition {
    Exists(bool),
    UpdateTime(DateTime<Utc>),
}

Re-exports all public items from the db module.

The db module contains the core FirestoreDb client and functionalities for interacting with the Firestore database, such as CRUD operations, queries, and transactions. A precondition on a document, used for conditional write operations in Firestore.

Preconditions allow you to specify conditions that must be met for a write operation (create, update, delete) to succeed. If the precondition is not met, the operation will fail, typically with a DataConflictError or similar.

Variants

Exists(bool)

The target document must exist (if true) or must not exist (if false).

• Exists(true): The operation will only succeed if the document already exists. Useful for conditional updates or deletes.
• Exists(false): The operation will only succeed if the document does not already exist. Useful for conditional creates (to prevent overwriting).

UpdateTime(DateTime<Utc>)

The target document must exist and its update_time must match the provided timestamp.

This is used for optimistic concurrency control. The operation will only succeed if the document has not been modified since the specified update_time. The DateTime<Utc> must be microsecond-aligned, as Firestore timestamps have microsecond precision.

Trait Implementations

impl Clone for FirestoreWritePrecondition

fn clone(&self) -> FirestoreWritePrecondition

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FirestoreWritePrecondition

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

Formats the value using the given formatter.

impl PartialEq for FirestoreWritePrecondition

fn eq(&self, other: &FirestoreWritePrecondition) -> 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 TryInto<Precondition> for FirestoreWritePrecondition

type Error = FirestoreError

The type returned in the event of a conversion error.

fn try_into(self) -> Result<Precondition, Self::Error>

Performs the conversion.

impl Eq for FirestoreWritePrecondition

impl StructuralPartialEq for FirestoreWritePrecondition