harmos-runtime 0.1.4

/* ***
 *
 * Harmos
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * ***
 */

/* === Modules === */

/* === Re-Exports === */

/* === Imports === */

// Standard Library Imports
use std::convert::Infallible;
// Third Party Imports

// Local Imports

/* === Constants === */

/* === Macros === */

/* === Type Aliases === */

/* === Structs === */

/* === Enums === */

#[derive(Debug, thiserror::Error)]
pub enum Error<E = Infallible> {
    #[error("runtime shutdown budget expired during {phase}; cleanup remains owned")]
    ShutdownTimeout { phase: &'static str },

    #[error("authenticated caller identity is required")]
    Unauthenticated,

    #[error("caller is not permitted to perform this action")]
    PermissionDenied,

    #[error("record protobuf schema is invalid: {source}")]
    RecordSchema {
        #[source]
        source: crate::schema::Error,
    },

    #[error("record protobuf payload is invalid: {source}")]
    RecordPayload {
        #[source]
        source: crate::schema::PayloadError,
    },

    #[error("record declaration is unavailable: {source}")]
    RecordDeclaration {
        #[source]
        source: crate::state::DecodeError,
    },

    #[error(transparent)]
    OperationRefused(#[from] crate::Refusal),

    #[error("operation child lane `{child}` would cycle with held lane `{parent}`")]
    OperationLaneCycle { parent: &'static str, child: &'static str },

    #[cfg(any(feature = "plugin", feature = "plugin-guest", feature = "plugin-sidecar"))]
    #[error("operation caller is unavailable: {source}")]
    OperationCaller {
        #[source]
        source: crate::plugin::DispatchError,
    },

    #[error("caller `{caller}` may not invoke operation `{operation}` on `{owner}`")]
    OperationUnauthorized { caller: String, owner: String, operation: String },

    #[error("operation `{operation}` payload is unreadable: {source}")]
    OperationPayload {
        operation: String,

        #[source]
        source: harmos_domain::MessageError,
    },

    #[error("operation `{operation}` panicked")]
    OperationPanicked { operation: String },

    #[error("operation declaration is invalid: {source}")]
    OperationDeclaration {
        #[source]
        source: harmos_domain::Error,
    },

    // Prints its own line; the cause is the source, read through `failure()`.
    #[error("operation `{operation}` failed")]
    OperationFailed {
        operation: String,

        #[source]
        source: std::sync::Arc<dyn std::error::Error + Send + Sync>,
    },

    #[error("operation `{operation}` could not finalize its invocation state")]
    OperationFinalization {
        operation: String,
        outcome: Option<std::sync::Arc<Error>>,

        #[source]
        source: std::sync::Arc<Error>,
    },

    #[error("operation physical settlement failed: {source}")]
    OperationSettlement {
        #[source]
        source: std::sync::Arc<Error>,
    },

    #[cfg(any(feature = "plugin", feature = "plugin-guest", feature = "plugin-sidecar"))]
    #[error("plugin lifecycle failed: {source}")]
    PluginLifecycle {
        #[source]
        source: Box<crate::plugin::PluginFailure>,
    },

    #[error("{domain} task failed: {source}")]
    TaskFailed {
        domain: &'static str,

        #[source]
        source: std::sync::Arc<dyn std::error::Error + Send + Sync>,
    },

    #[error("{domain} is not ready")]
    NotReady { domain: &'static str },

    #[error("persistence failed: {source}")]
    Persistence {
        #[source]
        source: std::sync::Arc<Error>,
    },

    #[error("{domain} admission is closed")]
    Closing { domain: &'static str },

    #[error("{domain} `{name}` is already registered")]
    AlreadyRegistered { domain: &'static str, name: String },

    #[error("{domain} `{name}` is not registered")]
    NotRegistered { domain: &'static str, name: String },

    #[error("backend {operation} failed ({kind:?}): {source}")]
    Backend {
        operation: &'static str,
        kind: BackendFailure,

        #[source]
        source: Box<dyn std::error::Error + Send + Sync>,
    },

    #[error("invalid {field}: {reason}")]
    InvalidInput { field: &'static str, reason: &'static str },

    #[error("{resource} capacity is exhausted")]
    ResourceExhausted { resource: &'static str },

    #[error("positions belong to different store histories")]
    DifferentHistory,

    #[error("the read view has expired")]
    ViewExpired,

    #[error("retained data begins at {available}, but {requested} was requested")]
    Gap { requested: u64, available: u64 },

    #[error("required journal capture failed")]
    CaptureFailed,

    #[error("the requested state boundary splits a logical commit")]
    IncompleteCommit,

    #[error("the logical commit could not be prepared: {0}")]
    Preparation(PreparationError),

    #[error("the transaction was refused: {0}")]
    Rejected(E),

    #[error("the undo conflicts with the current state: {0}")]
    UndoConflict(E),

    #[error("the redo conflicts with the current state: {0}")]
    RedoConflict(E),

    #[error("this principal has nothing to undo in scope")]
    NothingToUndo,

    #[error("this principal has nothing to redo in scope")]
    NothingToRedo,

    #[error("the supplied origin is above the requested position")]
    OriginAhead,

    #[error("the requested query frontier is above the applied position")]
    FrontierAhead,

    #[error("the requested position is beneath the retained-history horizon")]
    BeneathHorizon,

    #[error("the requested position is below the in-memory tail's floor")]
    BeyondTail,

    #[error("the journal is not admitting requests")]
    Unavailable,
}

pub use harmos_storage::BackendFailure;

pub use harmos_domain::state::PreparationError;

/* === Traits === */

/* === Implementations === */

impl<E> From<harmos_storage::Error> for Error<E> {
    fn from(error: harmos_storage::Error) -> Self {
        use harmos_storage::Error as Storage;
        match error {
            Storage::OperationFailed { operation, source } => Self::OperationFailed { operation, source },
            Storage::NotReady { domain } => Self::NotReady { domain },
            Storage::Persistence { source } => Self::Persistence {
                source: std::sync::Arc::new(std::sync::Arc::try_unwrap(source).map(Error::from).unwrap_or_else(|source| {
                    Error::backend("storage persistence", source.backend_failure().unwrap_or(BackendFailure::Permanent), source)
                })),
            },
            Storage::Closing { domain } => Self::Closing { domain },
            Storage::AlreadyRegistered { domain, name } => Self::AlreadyRegistered { domain, name },
            Storage::Backend { operation, kind, source } => Self::Backend { operation, kind, source },
            Storage::InvalidInput { field, reason } => Self::InvalidInput { field, reason },
            Storage::ResourceExhausted { resource } => Self::ResourceExhausted { resource },
            Storage::Gap { requested, available } => Self::Gap { requested, available },
            Storage::Domain(source) => source.into(),
        }
    }
}

impl<E> From<harmos_domain::Error> for Error<E> {
    fn from(error: harmos_domain::Error) -> Self {
        match error {
            harmos_domain::Error::InvalidInput { field, reason } => Self::InvalidInput { field, reason },
            harmos_domain::Error::ResourceExhausted { resource } => Self::ResourceExhausted { resource },
            harmos_domain::Error::DifferentHistory => Self::DifferentHistory,
            harmos_domain::Error::Corrupt { operation, source } => Self::backend(operation, BackendFailure::Corrupt, source),
            source => Self::OperationDeclaration { source },
        }
    }
}

impl<E> From<harmos_domain::operations::ContextError> for Error<E> {
    fn from(error: harmos_domain::operations::ContextError) -> Self {
        use harmos_domain::operations::ContextError;
        match error {
            ContextError::Duplicate { name } => Self::AlreadyRegistered { domain: "call context", name },
            ContextError::Missing { name } => Self::NotRegistered { domain: "call context", name },
            ContextError::Decode { .. } => Self::InvalidInput { field: "call context", reason: "portable value is unreadable" },
            ContextError::Budget => Self::InvalidInput { field: "call context", reason: "portable values exceed their budget" },
        }
    }
}

impl<E> Error<E> {
    // The structured failure this error carries from a plugin, with its cause
    // written once at the origin and the operation frame the host added.
    pub fn failure(&self) -> Option<&harmos_domain::Failure> {
        match self {
            Self::OperationFailed { source, .. } | Self::TaskFailed { source, .. } => carried(source.as_ref()),
            // The Attempt's Outcome Names The Failure; Cleanup Is Secondary
            Self::OperationFinalization { outcome, source, .. } => outcome.as_deref().and_then(Error::failure).or_else(|| source.failure()),
            Self::OperationSettlement { source } => source.failure(),
            #[cfg(any(feature = "plugin", feature = "plugin-guest", feature = "plugin-sidecar"))]
            Self::PluginLifecycle { source } => carried(source.as_ref()),
            _ => None,
        }
    }

    pub fn backend(operation: &'static str, kind: BackendFailure, source: impl std::error::Error + Send + Sync + 'static) -> Self {
        Self::Backend { operation, kind, source: Box::new(source) }
    }
}

/* === Public Functions === */

/* === Private Functions === */

// The first failure along a source chain, read through the carrier that
// transported it where that carrier hides it behind a transparent line.
fn carried<'a>(source: &'a (dyn std::error::Error + 'static)) -> Option<&'a harmos_domain::Failure> {
    std::iter::successors(Some(source), |link| link.source()).find_map(|link| {
        if let Some(error) = link.downcast_ref::<Error>() {
            return error.failure();
        }
        #[cfg(feature = "plugin-sidecar")]
        if let Some(error) = link.downcast_ref::<crate::operations::NativeError>() {
            return error.failure();
        }
        #[cfg(all(feature = "plugin-guest", not(target_arch = "wasm32")))]
        if let Some(error) = link.downcast_ref::<crate::operations::ComponentError>() {
            return error.failure();
        }
        harmos_domain::Failure::find(link)
    })
}

/* === Tests === */