Struct Context 

pub struct Context { /* private fields */ }

Execution context provided to nodes during execution.

The context provides access to:

• Arena for reading/writing data
• Pipeline configuration
• Trace metadata
• Logging and metrics
• External providers (clock, HTTP, RNG, etc.)

Providers

The context includes pluggable providers for external dependencies, enabling deterministic testing by mocking these dependencies.

In production, real providers are used automatically. In tests, use TestContext or the with_providers() constructor to inject mocks.

Implementations

impl Context

pub fn new( trace_id: TraceId, node_id: NodeId, reader: ArenaReader, writer: ArenaWriter, wal: Arc<Wal>, ) -> Self

Create a new execution context with default (real) providers.

pub fn with_providers( trace_id: TraceId, node_id: NodeId, reader: ArenaReader, writer: ArenaWriter, wal: Arc<Wal>, clock: Arc<dyn ClockProvider>, http: Arc<dyn HttpProvider>, rng: Arc<dyn RngProvider>, uuid: Arc<dyn UuidProvider>, fs: Arc<dyn FsProvider>, env: Arc<dyn EnvProvider>, secrets: Arc<dyn SecretsProvider>, ) -> Self

Create a new execution context with custom providers.

This is primarily used for testing to inject mock providers.

pub fn trace_id(&self) -> TraceId

Get the current trace ID.

pub fn node_id(&self) -> NodeId

Get the current node ID.

pub fn read_bytes(&self, ptr: RelPtr<()>) -> Result<Vec<u8>>

Read bytes from the arena using a relative pointer.

pub fn write_bytes(&self, bytes: &[u8]) -> Result<RelPtr<()>>

Write bytes to the arena and return a relative pointer.

pub fn read_raw(&self, offset: ArenaOffset, size: usize) -> Result<Vec<u8>>

Read raw bytes from the arena at a specific offset.

pub fn write_raw(&self, bytes: &[u8]) -> Result<RelPtr<()>>

Write raw bytes to the arena.

pub fn log(&self, message: impl AsRef<str>)

Log a message associated with this execution.

pub fn warn(&self, message: impl AsRef<str>)

Log a warning message.

pub fn error(&self, message: impl AsRef<str>)

Log an error message.

pub fn write_position(&self) -> ArenaOffset

Get the current write position in the arena.

pub fn wal(&self) -> &Wal

Get the WAL handle.

pub fn clock(&self) -> &dyn ClockProvider

Get the clock provider.

pub fn http(&self) -> &dyn HttpProvider

Get the HTTP provider.

pub fn rng(&self) -> &dyn RngProvider

Get the RNG provider.

pub fn uuid_provider(&self) -> &dyn UuidProvider

Get the UUID provider.

pub fn fs(&self) -> &dyn FsProvider

Get the filesystem provider.

pub fn env_provider(&self) -> &dyn EnvProvider

Get the environment provider.

pub fn secrets(&self) -> &dyn SecretsProvider

Get the secrets provider.

pub fn now(&self) -> u64

Get current time in nanoseconds (monotonic).

pub fn system_time_millis(&self) -> u64

Get current system time in milliseconds since UNIX epoch.

pub fn new_uuid(&self) -> Uuid

Generate a new UUID.

pub fn random_u64(&self) -> u64

Generate a random u64.

pub fn random_f64(&self) -> f64

Generate a random f64 in [0, 1).

pub fn env_var(&self, key: &str) -> Option<String>

Get an environment variable.

pub fn secret(&self, key: &str) -> Option<String>

Get a secret.