feat(plugins): add TaskQueue host service for persistent background task queues (#5116)

* feat(plugins): define TaskQueue host service interface Add the TaskQueueService interface with CreateQueue, Enqueue, GetTaskStatus, and CancelTask methods plus QueueConfig struct. * feat(plugins): define TaskWorker capability for task execution callbacks * feat(plugins): add taskqueue permission to manifest schema Add TaskQueuePermission with maxConcurrency option. * feat(plugins): implement TaskQueue service with SQLite persistence and workers Per-plugin SQLite database with queues and tasks tables. Worker goroutines dequeue tasks and invoke nd_task_execute callback. Exponential backoff retries, rate limiting via delayMs, automatic cleanup of terminal tasks. * feat(plugins): require TaskWorker capability for taskqueue permission * feat(plugins): register TaskQueue host service in manager * feat(plugins): add test-taskqueue plugin for integration testing * feat(plugins): add integration tests for TaskQueue host service * docs: document TaskQueue module for persistent task queues Signed-off-by: Deluan <deluan@navidrome.org> * fix(plugins): harden TaskQueue host service with validation and safety improvements Add input validation (queue name length, payload size limits), extract status string constants to eliminate raw SQL literals, make CreateQueue idempotent via upsert for crash recovery, fix RetentionMs default check for negative values, cap exponential backoff at 1 hour to prevent overflow, and replace manual mutex-based delay enforcement with rate.Limiter from golang.org/x/time/rate for correct concurrent worker serialization. * refactor(plugins): remove capability check for TaskWorker in TaskQueue host service Signed-off-by: Deluan <deluan@navidrome.org> * fix(plugins): use context-aware database execution in TaskQueue host service Signed-off-by: Deluan <deluan@navidrome.org> * refactor(plugins): streamline task queue configuration and error handling Signed-off-by: Deluan <deluan@navidrome.org> * feat(plugins): increase maxConcurrency for task queue and handle budget exhaustion Signed-off-by: Deluan <deluan@navidrome.org> * refactor(plugins): simplify goroutine management in task queue service Signed-off-by: Deluan <deluan@navidrome.org> * feat(plugins): update TaskWorker interface to return status messages and refactor task queue service Signed-off-by: Deluan <deluan@navidrome.org> * feat(plugins): add ClearQueue function to remove pending tasks from a specified queue Signed-off-by: Deluan <deluan@navidrome.org> * refactor(plugins): use migrateDB for task queue schema and fix constant name collision Replaced the raw db.Exec call in createTaskQueueSchema with migrateDB, matching the pattern used by createKVStoreSchema. This enables version-tracked schema migrations via SQLite's PRAGMA user_version, allowing future schema changes to be appended incrementally. Also renamed cleanupInterval to taskCleanupInterval to resolve a redeclaration conflict with host_kvstore.go. * regenerate PDKs Signed-off-by: Deluan <deluan@navidrome.org> --------- Signed-off-by: Deluan <deluan@navidrome.org>
2026-03-03 13:48:49 -05:00
parent 24ba655dc3
commit 668869b6c7
24 changed files with 3513 additions and 0 deletions
@@ -40,6 +40,7 @@
 //! - [`library`] - provides access to music library metadata for plugins.
 //! - [`scheduler`] - provides task scheduling capabilities for plugins.
 //! - [`subsonicapi`] - provides access to Navidrome's Subsonic API from plugins.
+//! - [`task`] - provides persistent task queues for plugins.
 //! - [`users`] - provides access to user information for plugins.
 //! - [`websocket`] - provides WebSocket communication capabilities for plugins.

@@ -99,6 +100,13 @@ pub mod subsonicapi {
    pub use super::nd_host_subsonicapi::*;
 }

+#[doc(hidden)]
+mod nd_host_task;
+/// provides persistent task queues for plugins.
+pub mod task {
+    pub use super::nd_host_task::*;
+}
+
 #[doc(hidden)]
 mod nd_host_users;
 /// provides access to user information for plugins.
@@ -0,0 +1,258 @@
+// Code generated by ndpgen. DO NOT EDIT.
+//
+// This file contains client wrappers for the Task host service.
+// It is intended for use in Navidrome plugins built with extism-pdk.
+
+use extism_pdk::*;
+use serde::{Deserialize, Serialize};
+use base64::Engine as _;
+use base64::engine::general_purpose::STANDARD as BASE64;
+
+mod base64_bytes {
+    use serde::{self, Deserialize, Deserializer, Serializer};
+    use base64::Engine as _;
+    use base64::engine::general_purpose::STANDARD as BASE64;
+
+    pub fn serialize<S>(bytes: &Vec<u8>, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(&BASE64.encode(bytes))
+    }
+
+    pub fn deserialize<'de, D>(deserializer: D) -> Result<Vec<u8>, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        BASE64.decode(&s).map_err(serde::de::Error::custom)
+    }
+}
+
+/// QueueConfig holds configuration for a task queue.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct QueueConfig {
+    pub concurrency: i32,
+    pub max_retries: i32,
+    pub backoff_ms: i64,
+    pub delay_ms: i64,
+    pub retention_ms: i64,
+}
+
+/// TaskInfo holds the current state of a task.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct TaskInfo {
+    pub status: String,
+    pub message: String,
+    pub attempt: i32,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskCreateQueueRequest {
+    name: String,
+    config: QueueConfig,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskCreateQueueResponse {
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskEnqueueRequest {
+    queue_name: String,
+    #[serde(with = "base64_bytes")]
+    payload: Vec<u8>,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskEnqueueResponse {
+    #[serde(default)]
+    result: String,
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskGetRequest {
+    task_id: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskGetResponse {
+    #[serde(default)]
+    result: Option<TaskInfo>,
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskCancelRequest {
+    task_id: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskCancelResponse {
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[derive(Debug, Clone, Serialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskClearQueueRequest {
+    queue_name: String,
+}
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+struct TaskClearQueueResponse {
+    #[serde(default)]
+    result: i64,
+    #[serde(default)]
+    error: Option<String>,
+}
+
+#[host_fn]
+extern "ExtismHost" {
+    fn task_createqueue(input: Json<TaskCreateQueueRequest>) -> Json<TaskCreateQueueResponse>;
+    fn task_enqueue(input: Json<TaskEnqueueRequest>) -> Json<TaskEnqueueResponse>;
+    fn task_get(input: Json<TaskGetRequest>) -> Json<TaskGetResponse>;
+    fn task_cancel(input: Json<TaskCancelRequest>) -> Json<TaskCancelResponse>;
+    fn task_clearqueue(input: Json<TaskClearQueueRequest>) -> Json<TaskClearQueueResponse>;
+}
+
+/// CreateQueue creates a named task queue with the given configuration.
+/// Zero-value fields in config use sensible defaults.
+/// If a queue with the same name already exists, returns an error.
+/// On startup, this also recovers any stale "running" tasks from a previous crash.
+///
+/// # Arguments
+/// * `name` - String parameter.
+/// * `config` - QueueConfig parameter.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn create_queue(name: &str, config: QueueConfig) -> Result<(), Error> {
+    let response = unsafe {
+        task_createqueue(Json(TaskCreateQueueRequest {
+            name: name.to_owned(),
+            config: config,
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(())
+}
+
+/// Enqueue adds a task to the named queue. Returns the task ID.
+/// payload is opaque bytes passed back to the plugin on execution.
+///
+/// # Arguments
+/// * `queue_name` - String parameter.
+/// * `payload` - Vec<u8> parameter.
+///
+/// # Returns
+/// The result value.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn enqueue(queue_name: &str, payload: Vec<u8>) -> Result<String, Error> {
+    let response = unsafe {
+        task_enqueue(Json(TaskEnqueueRequest {
+            queue_name: queue_name.to_owned(),
+            payload: payload,
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(response.0.result)
+}
+
+/// Get returns the current state of a task including its status,
+/// message, and attempt count.
+///
+/// # Arguments
+/// * `task_id` - String parameter.
+///
+/// # Returns
+/// The result value.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn get(task_id: &str) -> Result<Option<TaskInfo>, Error> {
+    let response = unsafe {
+        task_get(Json(TaskGetRequest {
+            task_id: task_id.to_owned(),
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(response.0.result)
+}
+
+/// Cancel cancels a pending task. Returns error if already
+/// running, completed, or failed.
+///
+/// # Arguments
+/// * `task_id` - String parameter.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn cancel(task_id: &str) -> Result<(), Error> {
+    let response = unsafe {
+        task_cancel(Json(TaskCancelRequest {
+            task_id: task_id.to_owned(),
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(())
+}
+
+/// ClearQueue removes all pending tasks from the named queue.
+/// Running tasks are not affected. Returns the number of tasks removed.
+///
+/// # Arguments
+/// * `queue_name` - String parameter.
+///
+/// # Returns
+/// The result value.
+///
+/// # Errors
+/// Returns an error if the host function call fails.
+pub fn clear_queue(queue_name: &str) -> Result<i64, Error> {
+    let response = unsafe {
+        task_clearqueue(Json(TaskClearQueueRequest {
+            queue_name: queue_name.to_owned(),
+        }))?
+    };
+
+    if let Some(err) = response.0.error {
+        return Err(Error::msg(err));
+    }
+
+    Ok(response.0.result)
+}