Struct DurableContext

Source

pub struct DurableContext { /* private fields */ }

Expand description

Main context for a durable execution invocation.

DurableContext is created at the start of each Lambda invocation. It loads the complete operation state from AWS (paginating if necessary), initializes the replay engine, and provides the interface for durable operations.

§Construction

Use DurableContext::new to create a context from the invocation payload. The constructor paginates through all remaining operations automatically.

§Examples

use durable_lambda_core::context::DurableContext;
use durable_lambda_core::backend::RealBackend;
use durable_lambda_core::types::ExecutionMode;
use std::sync::Arc;
use std::collections::HashMap;

let config = aws_config::load_defaults(aws_config::BehaviorVersion::latest()).await;
let client = aws_sdk_lambda::Client::new(&config);
let backend = Arc::new(RealBackend::new(client));

let ctx = DurableContext::new(
    backend,
    "arn:aws:lambda:us-east-1:123456789:durable-execution/my-exec".to_string(),
    "initial-token".to_string(),
    vec![],       // initial operations from invocation payload
    None,         // no more pages
).await?;

match ctx.execution_mode() {
    ExecutionMode::Replaying => println!("Replaying from history"),
    ExecutionMode::Executing => println!("Executing new operations"),
}

Implementations§

Source §

impl DurableContext

Source

pub async fn new( backend: Arc<dyn DurableBackend>, arn: String, checkpoint_token: String, initial_operations: Vec<Operation>, next_marker: Option<String>, ) -> Result<Self, DurableError>

Create a new DurableContext from invocation parameters.

Loads the complete operation state by paginating through get_execution_state until all pages are fetched. Initializes the replay engine with the full operations map.

§Arguments

backend — The durable execution backend (real or mock).
arn — The durable execution ARN.
checkpoint_token — The initial checkpoint token from the invocation payload.
initial_operations — First page of operations from the invocation payload.
next_marker — Pagination marker for additional pages (None if complete).

§Errors

Returns DurableError if paginating the execution state fails.

Source

pub fn execution_mode(&self) -> ExecutionMode

Return the current execution mode (Replaying or Executing).

§Examples

use durable_lambda_core::types::ExecutionMode;
match ctx.execution_mode() {
    ExecutionMode::Replaying => { /* returning cached results */ }
    ExecutionMode::Executing => { /* running new operations */ }
}

Source

pub fn is_replaying(&self) -> bool

Return whether the context is currently replaying from history.

§Examples

if ctx.is_replaying() {
    println!("Replaying cached operations");
}

Source

pub fn arn(&self) -> &str

Return a reference to the durable execution ARN.

§Examples

println!("Execution ARN: {}", ctx.arn());

Source

pub fn checkpoint_token(&self) -> &str

Return the current checkpoint token.

§Examples

let token = ctx.checkpoint_token();

Source

pub fn set_checkpoint_token(&mut self, token: String)

Update the checkpoint token (called after a successful checkpoint).

§Examples

ctx.set_checkpoint_token("new-token-from-aws".to_string());

Source

pub fn backend(&self) -> &Arc<dyn DurableBackend>

Return a reference to the backend.

§Examples

let _backend = ctx.backend();

Source

pub fn replay_engine_mut(&mut self) -> &mut ReplayEngine

Return a mutable reference to the replay engine.

§Examples

let engine = ctx.replay_engine_mut();

Source

pub fn create_child_context(&self, parent_op_id: &str) -> DurableContext

Create a child context for isolated operation ID namespacing.

The child context shares the same backend and ARN but gets its own ReplayEngine with a parent-scoped OperationIdGenerator. Operations within the child context produce deterministic IDs scoped under parent_op_id, preventing collisions with the parent or sibling contexts.

Used internally by parallel and child_context operations.

§Arguments

parent_op_id — The operation ID that scopes this child context

§Examples

let child = ctx.create_child_context("branch-op-id");
// child operations will have IDs scoped under "branch-op-id"

Source

pub fn replay_engine(&self) -> &ReplayEngine

Return a reference to the replay engine.

§Examples

let engine = ctx.replay_engine();
assert!(!engine.operations().is_empty() || true);

Source

pub fn parent_op_id(&self) -> Option<&str>

Return the parent operation ID, if this is a child context.

Returns None for the root context. Returns the parent’s operation ID for child contexts created via create_child_context. Used by replay-safe logging for hierarchical tracing.

§Examples

if let Some(parent_id) = ctx.parent_op_id() {
    println!("Child context under parent: {parent_id}");
}

Source

pub fn enable_batch_mode(&mut self)

Enable batch checkpoint mode.

When enabled, step operation checkpoints (START and SUCCEED/FAIL) are accumulated in memory instead of being sent immediately. Call flush_batch to send all accumulated updates in a single AWS API call.

Batch mode applies only to step operations. wait, invoke, and callback always send checkpoints immediately because they produce suspension errors that require the checkpoint to be persisted before the function exits.

§Examples

ctx.enable_batch_mode();
let _: Result<i32, String> = ctx.step("step1", || async { Ok(1) }).await?;
let _: Result<i32, String> = ctx.step("step2", || async { Ok(2) }).await?;
ctx.flush_batch().await?;  // sends all updates in one call

Source

pub fn is_batch_mode(&self) -> bool

Return whether batch checkpoint mode is active.

Source

pub fn pending_update_count(&self) -> usize

Return the number of pending (unflushed) updates.

Source

pub fn compensation_count(&self) -> usize

Return the number of registered compensation closures.

Useful for asserting compensation registration in tests.

§Examples

assert_eq!(ctx.compensation_count(), 0);

Source

pub async fn flush_batch(&mut self) -> Result<(), DurableError>

Flush all accumulated checkpoint updates in a single AWS API call.

No-op if no updates are pending. After flushing, the checkpoint token is updated from the response.

§Errors

Returns DurableError if the batch checkpoint call fails.

§Examples

ctx.enable_batch_mode();
// ... run several steps ...
ctx.flush_batch().await?;

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impl DurableContext

Source

pub async fn create_callback( &mut self, name: &str, options: CallbackOptions, ) -> Result<CallbackHandle, DurableError>

Register a callback and return a handle with the server-generated callback ID.

During execution mode, sends a START checkpoint with callback configuration and returns a CallbackHandle containing the callback_id that external systems use to signal completion via SendDurableExecutionCallbackSuccess, SendDurableExecutionCallbackFailure, or SendDurableExecutionCallbackHeartbeat.

During replay mode, extracts the cached callback_id from history without sending any checkpoint.

Important: This method NEVER suspends. Suspension happens in callback_result when the callback hasn’t been signaled yet.

§Arguments

name — Human-readable name for the callback operation
options — Timeout configuration (see CallbackOptions)

§Errors

Returns DurableError::CheckpointFailed if the AWS checkpoint API call fails or if the callback_id cannot be extracted from the response.

§Examples

use durable_lambda_core::types::CallbackOptions;

let handle = ctx.create_callback("approval", CallbackOptions::new()).await?;
println!("Callback ID for external system: {}", handle.callback_id);

Source

pub fn callback_result<T: DeserializeOwned>( &self, handle: &CallbackHandle, ) -> Result<T, DurableError>

Check the result of a previously created callback.

Return the deserialized success payload if the callback has been signaled with success. Return an error if the callback failed, timed out, or hasn’t been signaled yet.

Important: This is NOT an async/durable operation — it only reads the current operation state. It does NOT generate an operation ID or create checkpoints.

§Arguments

handle — The CallbackHandle returned by create_callback

§Errors

Returns DurableError::CallbackSuspended if the callback has not been signaled yet (the handler should propagate this to exit). Returns DurableError::CallbackFailed if the callback was signaled with failure, was cancelled, or timed out. Returns DurableError::Deserialization if the callback result cannot be deserialized as type T.

§Examples

use durable_lambda_core::types::CallbackOptions;

let handle = ctx.create_callback("approval", CallbackOptions::new()).await?;
// ... pass handle.callback_id to external system ...
let result: String = ctx.callback_result(&handle)?;

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impl DurableContext

Source

pub async fn child_context<T, F, Fut>( &mut self, name: &str, f: F, ) -> Result<T, DurableError>
where T: Serialize + DeserializeOwned + Send, F: FnOnce(DurableContext) -> Fut + Send, Fut: Future<Output = Result<T, DurableError>> + Send,

Execute an isolated subflow with its own checkpoint namespace.

The closure receives an owned child DurableContext whose operations are namespaced under this child context’s operation ID, preventing collisions with the parent or sibling child contexts.

During replay mode, returns the cached result without re-executing the closure.

§Arguments

name — Human-readable name for the child context operation
f — Closure receiving an owned DurableContext for the subflow

§Errors

Returns DurableError::ChildContextFailed if the child context is found in a failed state during replay. Returns DurableError::CheckpointFailed if checkpoint API calls fail.

§Examples

let result: i32 = ctx.child_context("sub_workflow", |mut child_ctx| async move {
    let r: Result<i32, String> = child_ctx.step("inner_step", || async { Ok(42) }).await?;
    Ok(r.unwrap())
}).await?;
assert_eq!(result, 42);

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impl DurableContext

Source

pub async fn step_with_compensation<T, E, F, Fut, G, GFut>( &mut self, name: &str, forward_fn: F, compensate_fn: G, ) -> Result<Result<T, E>, DurableError>
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static, G: FnOnce(T) -> GFut + Send + 'static, GFut: Future<Output = Result<(), DurableError>> + Send + 'static,

Execute a forward step and register a compensation closure on success.

Delegates the forward execution to step. If the step succeeds (returns Ok(Ok(value))), the compensate_fn closure is registered and will be executed by run_compensations.

If the forward step fails (returns Ok(Err(e))), no compensation is registered — only successful steps have compensations that need undoing.

§Arguments

name — Human-readable name for the forward step operation.
forward_fn — Closure to execute the forward step.
compensate_fn — Closure to execute when rolling back; receives the forward step’s success value.

§Returns

Ok(Ok(T)) — Forward step succeeded; compensation registered.
Ok(Err(E)) — Forward step returned a user error; no compensation registered.
Err(DurableError) — SDK-level failure (checkpoint, serialization).

§Examples

// Book a hotel room and register its cancellation as compensation
let booking_result: Result<String, String> = ctx.step_with_compensation(
    "book_hotel",
    || async { Ok("BOOKING-123".to_string()) },
    |booking_id| async move {
        // Cancel the hotel booking
        println!("Cancelling booking: {booking_id}");
        Ok(())
    },
).await?;

// Later, roll back all registered compensations
let comp_result = ctx.run_compensations().await?;
assert!(comp_result.all_succeeded);

Source

pub async fn step_with_compensation_opts<T, E, F, Fut, G, GFut>( &mut self, name: &str, options: StepOptions, forward_fn: F, compensate_fn: G, ) -> Result<Result<T, E>, DurableError>
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static, G: FnOnce(T) -> GFut + Send + 'static, GFut: Future<Output = Result<(), DurableError>> + Send + 'static,

Execute a forward step (with options) and register a compensation closure on success.

Like step_with_compensation but accepts StepOptions for configuring retries, backoff, and timeouts on the forward step.

§Arguments

name — Human-readable name for the forward step operation.
options — Step configuration (retries, backoff, timeout).
forward_fn — Closure to execute the forward step.
compensate_fn — Closure to execute when rolling back.

§Examples

use durable_lambda_core::types::StepOptions;

let result: Result<String, String> = ctx.step_with_compensation_opts(
    "book_hotel",
    StepOptions::new().retries(3),
    || async { Ok("BOOKING-123".to_string()) },
    |booking_id| async move {
        println!("Cancelling: {booking_id}");
        Ok(())
    },
).await?;

Source

pub async fn run_compensations( &mut self, ) -> Result<CompensationResult, DurableError>

Execute all registered compensations in reverse registration order.

Drains the registered compensations and executes them in LIFO order (last registered runs first — stack semantics). Each compensation is checkpointed with Context/START + Context/SUCCEED|FAIL using sub_type = "Compensation".

All compensations are attempted even if earlier ones fail. The returned CompensationResult captures the per-item outcomes.

During replay, completed compensations are skipped — their status is read from the execution history to support partial rollback resume.

§Returns

Returns Ok(CompensationResult) always (individual failures are captured in the result items, not propagated as errors). Returns Err(DurableError) only on AWS checkpoint failures.

§Examples

// After some compensable steps fail:
let result = ctx.run_compensations().await?;

if !result.all_succeeded {
    for item in &result.items {
        if let Some(err) = &item.error {
            eprintln!("Compensation {} failed: {}", item.name, err);
        }
    }
}

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impl DurableContext

Source

pub async fn invoke<T, P>( &mut self, name: &str, function_name: &str, payload: &P, ) -> Result<T, DurableError>
where T: DeserializeOwned, P: Serialize,

Durably invoke another Lambda function and return its result.

During execution mode, serializes the payload, sends a START checkpoint with the target function name, and returns DurableError::InvokeSuspended to signal the function should exit. The server invokes the target function asynchronously and re-invokes this Lambda when complete.

During replay mode, returns the cached result without re-invoking the target function.

If the target function completes immediately (detected via the double-check pattern), the result is returned directly without suspending.

§Arguments

name — Human-readable name for the invoke operation
function_name — Name or ARN of the target Lambda function
payload — Input payload to send to the target function

§Errors

Returns DurableError::InvokeSuspended when the invoke has been checkpointed and the target is still executing — the handler must propagate this to exit. Returns DurableError::InvokeFailed if the target function failed, timed out, or was stopped. Returns DurableError::Serialization if the payload cannot be serialized. Returns DurableError::Deserialization if the result cannot be deserialized as type T. Returns DurableError::CheckpointFailed if the AWS checkpoint API call fails.

§Examples

let result: String = ctx.invoke(
    "call_processor",
    "payment-processor-lambda",
    &serde_json::json!({"order_id": 123}),
).await?;
println!("Target returned: {result}");

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impl DurableContext

Source

pub fn log(&self, message: &str)

Emit a replay-safe info-level log message.

During execution mode, emits the message via tracing::info! with execution context enrichment (execution ARN, parent ID for child contexts). During replay mode, the call is a no-op — no log output is produced.

§Arguments

message — The log message to emit

§Examples

ctx.log("Order processing started");
// During replay, this produces no output.

Source

pub fn log_with_data(&self, message: &str, data: &Value)

Emit a replay-safe info-level log message with structured data.

During execution mode, emits the message and structured data via tracing::info!. During replay mode, the call is a no-op.

§Arguments

message — The log message to emit
data — Structured data to include in the log event

§Examples

ctx.log_with_data("Order processed", &serde_json::json!({"order_id": 42}));

Source

pub fn log_debug(&self, message: &str)

Emit a replay-safe debug-level log message.

During execution mode, emits via tracing::debug!. During replay mode, the call is a no-op.

§Arguments

message — The log message to emit

§Examples

ctx.log_debug("Validating order fields");

Source

pub fn log_warn(&self, message: &str)

Emit a replay-safe warn-level log message.

During execution mode, emits via tracing::warn!. During replay mode, the call is a no-op.

§Arguments

message — The log message to emit

§Examples

ctx.log_warn("Inventory below threshold");

Source

pub fn log_error(&self, message: &str)

Emit a replay-safe error-level log message.

During execution mode, emits via tracing::error!. During replay mode, the call is a no-op.

§Arguments

message — The log message to emit

§Examples

ctx.log_error("Payment gateway timeout");

Source

pub fn log_debug_with_data(&self, message: &str, data: &Value)

Emit a replay-safe debug-level log message with structured data.

During execution mode, emits via tracing::debug! with data field. During replay mode, the call is a no-op.

§Arguments

message — The log message to emit
data — Structured data to include in the log event

§Examples

ctx.log_debug_with_data("Request details", &serde_json::json!({"method": "POST"}));

Source

pub fn log_warn_with_data(&self, message: &str, data: &Value)

Emit a replay-safe warn-level log message with structured data.

During execution mode, emits via tracing::warn! with data field. During replay mode, the call is a no-op.

§Arguments

message — The log message to emit
data — Structured data to include in the log event

§Examples

ctx.log_warn_with_data("Retry attempt", &serde_json::json!({"attempt": 3}));

Source

pub fn log_error_with_data(&self, message: &str, data: &Value)

Emit a replay-safe error-level log message with structured data.

During execution mode, emits via tracing::error! with data field. During replay mode, the call is a no-op.

§Arguments

message — The log message to emit
data — Structured data to include in the log event

§Examples

ctx.log_error_with_data("Payment failed", &serde_json::json!({"error": "timeout"}));

Source §

impl DurableContext

Source

pub async fn map<T, I, F, Fut>( &mut self, name: &str, items: Vec, options: MapOptions, f: F, ) -> Result<BatchResult<T>, DurableError>
where T: Serialize + DeserializeOwned + Send + 'static, I: Send + 'static, F: FnOnce(I, DurableContext) -> Fut + Send + 'static + Clone, Fut: Future<Output = Result<T, DurableError>> + Send + 'static,

Process a collection of items in parallel and return their results.

Apply the closure f to each item concurrently. Each item receives an owned child DurableContext with an isolated checkpoint namespace. Items execute via tokio::spawn and must satisfy Send + 'static.

When batch_size is configured via MapOptions, items process in sequential batches — each batch completes before the next begins.

During replay mode, returns the cached BatchResult without re-executing any item closures.

§Arguments

name — Human-readable name for the map operation
items — Collection of items to process
options — Map configuration (batching)
f — Closure applied to each item with an owned child context

§Errors

Returns DurableError::MapFailed if the map operation itself fails (e.g., checkpoint error, task panic). Individual item failures are captured in the BatchResult rather than propagated as errors. Returns DurableError::CheckpointFailed if checkpoint API calls fail.

§Examples

use durable_lambda_core::types::MapOptions;
use durable_lambda_core::context::DurableContext;
use durable_lambda_core::error::DurableError;

let items = vec![1, 2, 3];
let result = ctx.map(
    "process_items",
    items,
    MapOptions::new(),
    |item: i32, mut child_ctx: DurableContext| async move {
        let r: Result<i32, String> = child_ctx.step("double", move || async move { Ok(item * 2) }).await?;
        Ok(r.unwrap())
    },
).await?;
assert_eq!(result.results.len(), 3);

Source §

impl DurableContext

Source

pub async fn parallel<T, F, Fut>( &mut self, name: &str, branches: Vec<F>, _options: ParallelOptions, ) -> Result<BatchResult<T>, DurableError>
where T: Serialize + DeserializeOwned + Send + 'static, F: FnOnce(DurableContext) -> Fut + Send + 'static, Fut: Future<Output = Result<T, DurableError>> + Send + 'static,

Execute multiple branches concurrently and return their results.

Each branch receives an owned child DurableContext with an isolated checkpoint namespace. Branches execute concurrently via tokio::spawn and must satisfy Send + 'static bounds.

During replay mode, returns the cached BatchResult without re-executing any branches.

§Arguments

name — Human-readable name for the parallel operation
branches — Collection of branch closures, each receiving an owned DurableContext
_options — Parallel configuration (reserved for future completion criteria)

§Errors

Returns DurableError::ParallelFailed if the parallel operation itself fails (e.g., checkpoint error). Individual branch failures are captured in the BatchResult rather than propagated as errors. Returns DurableError::CheckpointFailed if checkpoint API calls fail.

§Examples

use durable_lambda_core::types::ParallelOptions;
use durable_lambda_core::context::DurableContext;
use durable_lambda_core::error::DurableError;
use std::pin::Pin;
use std::future::Future;

type BranchFn = Box<dyn FnOnce(DurableContext) -> Pin<Box<dyn Future<Output = Result<i32, DurableError>> + Send>> + Send>;

let branches: Vec<BranchFn> = vec![
    Box::new(|mut ctx| Box::pin(async move {
        let r: Result<i32, String> = ctx.step("validate", || async { Ok(1) }).await?;
        Ok(r.unwrap())
    })),
    Box::new(|mut ctx| Box::pin(async move {
        let r: Result<i32, String> = ctx.step("check", || async { Ok(2) }).await?;
        Ok(r.unwrap())
    })),
];

let result = ctx.parallel("fan_out", branches, ParallelOptions::new()).await?;
assert_eq!(result.results.len(), 2);

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impl DurableContext

Source

pub async fn step<T, E, F, Fut>( &mut self, name: &str, f: F, ) -> Result<Result<T, E>, DurableError>
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static,

Execute a named step with checkpointing.

During execution mode, runs the closure and checkpoints the result to AWS. During replay mode, returns the previously checkpointed result without executing the closure.

This is a convenience wrapper around step_with_options with default options (no retries).

§Arguments

name — Human-readable step name, used as checkpoint metadata
f — Closure to execute (skipped during replay)

§Returns

Returns Ok(Ok(T)) on successful step execution or replay. Returns Ok(Err(E)) when the step closure returned an error (also checkpointed). Returns Err(DurableError) on SDK-level failures (checkpoint, serialization).

§Errors

Returns DurableError::Serialization if the result cannot be serialized to JSON. Returns DurableError::Deserialization if a cached result cannot be deserialized. Returns DurableError::CheckpointFailed or DurableError::AwsSdkOperation if the AWS checkpoint API call fails.

§Examples

let result: Result<i32, String> = ctx.step("validate_order", || async {
    Ok(42)
}).await?;

match result {
    Ok(value) => println!("Step succeeded: {value}"),
    Err(e) => println!("Step failed: {e}"),
}

Source

pub async fn step_with_options<T, E, F, Fut>( &mut self, name: &str, options: StepOptions, f: F, ) -> Result<Result<T, E>, DurableError>
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static,

Execute a named step with checkpointing and retry configuration.

During execution mode, runs the closure and checkpoints the result. If the closure fails and retries are configured, sends a RETRY checkpoint and returns DurableError::StepRetryScheduled to signal the function should exit. The server re-invokes the Lambda after the backoff delay.

During replay mode, returns the previously checkpointed result without executing the closure.

§Arguments

name — Human-readable step name, used as checkpoint metadata
options — Retry configuration (see StepOptions)
f — Closure to execute (skipped during replay)

§Errors

Returns DurableError::StepRetryScheduled when a retry has been scheduled — the handler must propagate this to exit the function. Returns DurableError::Serialization if the result cannot be serialized. Returns DurableError::Deserialization if a cached result cannot be deserialized.

§Examples

use durable_lambda_core::types::StepOptions;

let result: Result<i32, String> = ctx.step_with_options(
    "charge_payment",
    StepOptions::new().retries(3).backoff_seconds(5),
    || async { Ok(100) },
).await?;

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impl DurableContext

Source

pub async fn wait( &mut self, name: &str, duration_secs: i32, ) -> Result<(), DurableError>

Suspend execution for the specified duration.

During execution mode, sends a START checkpoint with the wait duration and returns DurableError::WaitSuspended to signal the function should exit. The durable execution server re-invokes the Lambda after the duration elapses.

During replay mode, returns Ok(()) immediately if the wait has already completed (status SUCCEEDED in history).

§Arguments

name — Human-readable name for the wait operation
duration_secs — Duration to wait in seconds (1 to 31,622,400)

§Errors

Returns DurableError::WaitSuspended when the wait has been checkpointed — the handler must propagate this to exit the function. Returns DurableError::CheckpointFailed if the AWS checkpoint API call fails.

§Examples

// Wait 30 seconds before continuing.
ctx.wait("cooldown", 30).await?;

// Execution continues here after the wait completes.
println!("Wait completed!");

Trait Implementations§

Source §

impl DurableContextOps for DurableContext

Source §

fn step<T, E, F, Fut>( &mut self, name: &str, f: F, ) -> impl Future<Output = Result<Result<T, E>, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static,

Execute a named step with checkpointing. Read more

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fn step_with_options<T, E, F, Fut>( &mut self, name: &str, options: StepOptions, f: F, ) -> impl Future<Output = Result<Result<T, E>, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static,

Execute a named step with checkpointing and retry configuration. Read more

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fn wait( &mut self, name: &str, duration_secs: i32, ) -> impl Future<Output = Result<(), DurableError>> + Send

Suspend execution for the specified duration. Read more

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fn create_callback( &mut self, name: &str, options: CallbackOptions, ) -> impl Future<Output = Result<CallbackHandle, DurableError>> + Send

Register a callback and return a handle with the server-generated callback ID. Read more

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fn invoke<T, P>( &mut self, name: &str, function_name: &str, payload: &P, ) -> impl Future<Output = Result<T, DurableError>> + Send
where T: DeserializeOwned + Send, P: Serialize + Sync,

Durably invoke another Lambda function and return its result. Read more

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fn parallel<T, F, Fut>( &mut self, name: &str, branches: Vec<F>, options: ParallelOptions, ) -> impl Future<Output = Result<BatchResult<T>, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send + 'static, F: FnOnce(DurableContext) -> Fut + Send + 'static, Fut: Future<Output = Result<T, DurableError>> + Send + 'static,

Execute multiple branches concurrently and return their results. Read more

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fn child_context<T, F, Fut>( &mut self, name: &str, f: F, ) -> impl Future<Output = Result<T, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send, F: FnOnce(DurableContext) -> Fut + Send, Fut: Future<Output = Result<T, DurableError>> + Send,

Execute an isolated subflow with its own checkpoint namespace. Read more

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fn map<T, I, F, Fut>( &mut self, name: &str, items: Vec, options: MapOptions, f: F, ) -> impl Future<Output = Result<BatchResult<T>, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send + 'static, I: Send + 'static, F: FnOnce(I, DurableContext) -> Fut + Send + 'static + Clone, Fut: Future<Output = Result<T, DurableError>> + Send + 'static,

Process a collection of items in parallel and return their results. Read more

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fn step_with_compensation<T, E, F, Fut, G, GFut>( &mut self, name: &str, forward_fn: F, compensate_fn: G, ) -> impl Future<Output = Result<Result<T, E>, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static, G: FnOnce(T) -> GFut + Send + 'static, GFut: Future<Output = Result<(), DurableError>> + Send + 'static,

Execute a forward step and register a compensation closure on success. Read more

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fn step_with_compensation_opts<T, E, F, Fut, G, GFut>( &mut self, name: &str, options: StepOptions, forward_fn: F, compensate_fn: G, ) -> impl Future<Output = Result<Result<T, E>, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static, G: FnOnce(T) -> GFut + Send + 'static, GFut: Future<Output = Result<(), DurableError>> + Send + 'static,

Execute a forward step (with options) and register a compensation closure on success. Read more

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fn run_compensations( &mut self, ) -> impl Future<Output = Result<CompensationResult, DurableError>> + Send

Execute all registered compensations in reverse registration order. Read more

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fn callback_result<T: DeserializeOwned>( &self, handle: &CallbackHandle, ) -> Result<T, DurableError>

Check the result of a previously created callback. Read more

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fn execution_mode(&self) -> ExecutionMode

Return the current execution mode (Replaying or Executing).

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fn is_replaying(&self) -> bool

Return whether the context is currently replaying from history.

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fn arn(&self) -> &str

Return a reference to the durable execution ARN.

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fn checkpoint_token(&self) -> &str

Return the current checkpoint token.

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fn log(&self, message: &str)

Emit a replay-safe info-level log message.

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fn log_with_data(&self, message: &str, data: &Value)

Emit a replay-safe info-level log message with structured data.

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fn log_debug(&self, message: &str)

Emit a replay-safe debug-level log message.

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fn log_warn(&self, message: &str)

Emit a replay-safe warn-level log message.

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fn log_error(&self, message: &str)

Emit a replay-safe error-level log message.

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fn log_debug_with_data(&self, message: &str, data: &Value)

Emit a replay-safe debug-level log message with structured data.

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fn log_warn_with_data(&self, message: &str, data: &Value)

Emit a replay-safe warn-level log message with structured data.

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fn log_error_with_data(&self, message: &str, data: &Value)

Emit a replay-safe error-level log message with structured data.

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fn enable_batch_mode(&mut self)

Enable batch checkpoint mode. Read more

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fn flush_batch( &mut self, ) -> impl Future<Output = Result<(), DurableError>> + Send

Flush accumulated batch checkpoint updates. Read more

Auto Trait Implementations§

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impl !UnwindSafe for DurableContext

Blanket Implementations§

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impl<T> Any for T
where T: 'static + ?Sized,

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more

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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

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impl<T> BorrowMut<T> for T
where T: ?Sized,

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fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more

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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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impl<T> Instrument for T

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fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more

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fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more

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impl<T, U> Into for T
where U: From<T>,

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fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

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impl<T> IntoEither for T

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fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts 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 more

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fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts 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

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impl<Unshared, Shared> IntoShared<Shared> for Unshared
where Shared: FromUnshared<Unshared>,

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fn into_shared(self) -> Shared

Creates a shared type from an unshared type.

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impl<T> Same for T

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type Output = T

Should always be Self

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impl<T, U> TryFrom for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.

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fn try_from(value: U) -> Result<T, <T as TryFrom>::Error>

Performs the conversion.

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impl<T, U> TryInto for T
where U: TryFrom<T>,

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type Error = >::Error

The type returned in the event of a conversion error.

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

Performs the conversion.

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impl<T> WithSubscriber for T

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fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more

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fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more

Struct DurableContext Copy item path

§Construction

§Examples

Implementations§

impl DurableContext

pub async fn new( backend: Arc<dyn DurableBackend>, arn: String, checkpoint_token: String, initial_operations: Vec<Operation>, next_marker: Option<String>, ) -> Result<Self, DurableError>

§Arguments

§Errors

pub fn execution_mode(&self) -> ExecutionMode

§Examples

pub fn is_replaying(&self) -> bool

§Examples

pub fn arn(&self) -> &str

§Examples

pub fn checkpoint_token(&self) -> &str

§Examples

pub fn set_checkpoint_token(&mut self, token: String)

§Examples

pub fn backend(&self) -> &Arc<dyn DurableBackend>

§Examples

pub fn replay_engine_mut(&mut self) -> &mut ReplayEngine

§Examples

pub fn create_child_context(&self, parent_op_id: &str) -> DurableContext

§Arguments

§Examples

pub fn replay_engine(&self) -> &ReplayEngine

§Examples

pub fn parent_op_id(&self) -> Option<&str>

§Examples

pub fn enable_batch_mode(&mut self)

§Examples

pub fn is_batch_mode(&self) -> bool

pub fn pending_update_count(&self) -> usize

pub fn compensation_count(&self) -> usize

§Examples

pub async fn flush_batch(&mut self) -> Result<(), DurableError>

§Errors

§Examples

impl DurableContext

pub async fn create_callback( &mut self, name: &str, options: CallbackOptions, ) -> Result<CallbackHandle, DurableError>

§Arguments

§Errors

§Examples

pub fn callback_result<T: DeserializeOwned>( &self, handle: &CallbackHandle, ) -> Result<T, DurableError>

§Arguments

§Errors

§Examples

impl DurableContext

pub async fn child_context<T, F, Fut>( &mut self, name: &str, f: F, ) -> Result<T, DurableError>where T: Serialize + DeserializeOwned + Send, F: FnOnce(DurableContext) -> Fut + Send, Fut: Future<Output = Result<T, DurableError>> + Send,

§Arguments

§Errors

§Examples

impl DurableContext

§Arguments

§Returns

§Examples

§Arguments

§Examples

pub async fn run_compensations( &mut self, ) -> Result<CompensationResult, DurableError>

§Returns

§Examples

impl DurableContext

pub async fn invoke<T, P>( &mut self, name: &str, function_name: &str, payload: &P, ) -> Result<T, DurableError>where T: DeserializeOwned, P: Serialize,

§Arguments

§Errors

§Examples

impl DurableContext

pub fn log(&self, message: &str)

§Arguments

§Examples

pub fn log_with_data(&self, message: &str, data: &Value)

§Arguments

§Examples

pub fn log_debug(&self, message: &str)

§Arguments

§Examples

pub fn log_warn(&self, message: &str)

§Arguments

§Examples

pub fn log_error(&self, message: &str)

Struct DurableContext

pub async fn child_context<T, F, Fut>( &mut self, name: &str, f: F, ) -> Result<T, DurableError>
where T: Serialize + DeserializeOwned + Send, F: FnOnce(DurableContext) -> Fut + Send, Fut: Future<Output = Result<T, DurableError>> + Send,

pub async fn invoke<T, P>( &mut self, name: &str, function_name: &str, payload: &P, ) -> Result<T, DurableError>
where T: DeserializeOwned, P: Serialize,

pub async fn step<T, E, F, Fut>( &mut self, name: &str, f: F, ) -> Result<Result<T, E>, DurableError>
where T: Serialize + DeserializeOwned + Send + 'static, E: Serialize + DeserializeOwned + Send + 'static, F: FnOnce() -> Fut + Send + 'static, Fut: Future<Output = Result<T, E>> + Send + 'static,

fn invoke<T, P>( &mut self, name: &str, function_name: &str, payload: &P, ) -> impl Future<Output = Result<T, DurableError>> + Send
where T: DeserializeOwned + Send, P: Serialize + Sync,

fn child_context<T, F, Fut>( &mut self, name: &str, f: F, ) -> impl Future<Output = Result<T, DurableError>> + Send
where T: Serialize + DeserializeOwned + Send, F: FnOnce(DurableContext) -> Fut + Send, Fut: Future<Output = Result<T, DurableError>> + Send,