implements the filter query

index-scheduler/src/lib.rs

@@ -16,16 +16,30 @@ use std::{collections::HashMap, sync::RwLock};
 use milli::heed::{Database, Env, EnvOpenOptions, RoTxn, RwTxn};
 use milli::{Index, RoaringBitmapCodec, BEU32};
 use roaring::RoaringBitmap;
+use serde::Deserialize;
 
 pub type Result<T> = std::result::Result<T, Error>;
 pub type TaskId = u32;
 type IndexName = String;
 type IndexUuid = String;
 
+const DEFAULT_LIMIT: fn() -> u32 = || 20;
+
+#[derive(Debug, Clone, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Query {
+    #[serde(default = "DEFAULT_LIMIT")]
+    limit: u32,
+    from: Option<u32>,
+    status: Option<Vec<Status>>,
+    #[serde(rename = "type")]
+    kind: Option<Vec<Kind>>,
+    index_uid: Option<Vec<String>>,
+}
+
 /// This module is responsible for two things;
 /// 1. Resolve the name of the indexes.
 /// 2. Schedule the tasks.
-
 #[derive(Clone)]
 pub struct IndexScheduler {
     // Keep track of the opened indexes and is used
@@ -91,13 +105,54 @@ impl IndexScheduler {
         Ok(index)
     }
 
-    fn next_task_id(&self, rtxn: &RoTxn) -> Result<TaskId> {
+    fn last_task_id(&self, rtxn: &RoTxn) -> Result<Option<TaskId>> {
         Ok(self
             .all_tasks
             .remap_data_type::<DecodeIgnore>()
             .last(rtxn)?
-            .map(|(k, _)| k.get())
+            .map(|(k, _)| k.get() + 1))
-            .unwrap_or(0))
+    }
+
+    fn next_task_id(&self, rtxn: &RoTxn) -> Result<TaskId> {
+        Ok(self.last_task_id(rtxn)?.unwrap_or_default())
+    }
+
+    /// Returns the tasks corresponding to the query.
+    pub fn get_tasks(&self, query: Query) -> Result<Vec<Task>> {
+        let rtxn = self.env.read_txn()?;
+        let last_task_id = match self.last_task_id(&rtxn)? {
+            Some(tid) => query.from.map(|from| from.min(tid)).unwrap_or(tid),
+            None => return Ok(Vec::new()),
+        };
+
+        // This is the list of all the tasks.
+        let mut tasks = RoaringBitmap::from_iter(0..last_task_id);
+
+        if let Some(status) = query.status {
+            let mut status_tasks = RoaringBitmap::new();
+            for status in status {
+                status_tasks |= self.get_status(&rtxn, status)?;
+            }
+            tasks &= status_tasks;
+        }
+
+        if let Some(kind) = query.kind {
+            let mut kind_tasks = RoaringBitmap::new();
+            for kind in kind {
+                kind_tasks |= self.get_kind(&rtxn, kind)?;
+            }
+            tasks &= kind_tasks;
+        }
+
+        if let Some(index) = query.index_uid {
+            let mut index_tasks = RoaringBitmap::new();
+            for index in index {
+                index_tasks |= self.get_index(&rtxn, &index)?;
+            }
+            tasks &= index_tasks;
+        }
+
+        self.get_existing_tasks(&rtxn, tasks.into_iter().rev().take(query.limit as usize))
     }
 
     /// Register a new task in the scheduler. If it fails and data was associated with the task