From f0291719485854c8fb02efb9870e364405bc1afb Mon Sep 17 00:00:00 2001
From: nazeh <ar.nazeh@gmail.com>
Date: Fri, 27 Sep 2024 12:53:11 +0300
Subject: [PATCH] feat(homeserver): add DEFAULT_LIST_LIMIT and
 DEFAULT_MAX_LIST_LIMIT

---
 pubky-homeserver/src/database.rs              |  1 -
 .../src/database/tables/events.rs             | 50 +++++++++++++++++
 pubky-homeserver/src/routes/feed.rs           | 53 ++-----------------
 3 files changed, 54 insertions(+), 50 deletions(-)

diff --git a/pubky-homeserver/src/database.rs b/pubky-homeserver/src/database.rs
index b655a45..9eb291f 100644
--- a/pubky-homeserver/src/database.rs
+++ b/pubky-homeserver/src/database.rs
@@ -9,7 +9,6 @@ pub mod tables;
 
 use tables::{Tables, TABLES_COUNT};
 
-pub const MAX_LIST_LIMIT: u16 = 100;
 pub const DEFAULT_MAP_SIZE: usize = 10995116277760; // 10TB (not = disk-space used)
 
 #[derive(Debug, Clone)]
diff --git a/pubky-homeserver/src/database/tables/events.rs b/pubky-homeserver/src/database/tables/events.rs
index cf82e18..c04554b 100644
--- a/pubky-homeserver/src/database/tables/events.rs
+++ b/pubky-homeserver/src/database/tables/events.rs
@@ -10,6 +10,8 @@ use heed::{
 use postcard::{from_bytes, to_allocvec};
 use serde::{Deserialize, Serialize};
 
+use crate::database::DB;
+
 /// Event [Timestamp] base32 => Encoded event.
 pub type EventsTable = Database<Str, Bytes>;
 
@@ -56,3 +58,51 @@ impl Event {
         }
     }
 }
+
+const MAX_LIST_LIMIT: u16 = 1000;
+const DEFAULT_LIST_LIMIT: u16 = 100;
+
+impl DB {
+    pub fn list_events(
+        &self,
+        limit: Option<u16>,
+        cursor: Option<&str>,
+    ) -> anyhow::Result<Vec<String>> {
+        let txn = self.env.read_txn()?;
+
+        let limit = limit.unwrap_or(DEFAULT_LIST_LIMIT).min(MAX_LIST_LIMIT);
+
+        let mut cursor = cursor.unwrap_or("0000000000000");
+
+        // Cursor smaller than 13 character is invalid
+        // TODO: should we send an error instead?
+        if cursor.len() < 13 {
+            cursor = "0000000000000"
+        }
+
+        let mut result: Vec<String> = vec![];
+        let mut next_cursor = cursor.to_string();
+
+        for _ in 0..limit {
+            match self.tables.events.get_greater_than(&txn, &next_cursor)? {
+                Some((timestamp, event_bytes)) => {
+                    let event = Event::deserialize(event_bytes)?;
+
+                    let line = format!("{} {}", event.operation(), event.url());
+                    next_cursor = timestamp.to_string();
+
+                    result.push(line);
+                }
+                None => break,
+            };
+        }
+
+        if !result.is_empty() {
+            result.push(format!("cursor: {next_cursor}"))
+        }
+
+        txn.commit()?;
+
+        Ok(result)
+    }
+}
diff --git a/pubky-homeserver/src/routes/feed.rs b/pubky-homeserver/src/routes/feed.rs
index bd426f3..0afe504 100644
--- a/pubky-homeserver/src/routes/feed.rs
+++ b/pubky-homeserver/src/routes/feed.rs
@@ -7,61 +7,16 @@ use axum::{
     response::IntoResponse,
 };
 
-use crate::{
-    database::{tables::events::Event, MAX_LIST_LIMIT},
-    error::Result,
-    server::AppState,
-};
+use crate::{error::Result, server::AppState};
 
 pub async fn feed(
     State(state): State<AppState>,
     Query(params): Query<HashMap<String, String>>,
 ) -> Result<impl IntoResponse> {
-    let txn = state.db.env.read_txn()?;
+    let limit = params.get("limit").and_then(|l| l.parse::<u16>().ok());
+    let cursor = params.get("cursor").map(|c| c.as_str());
 
-    let limit = params
-        .get("limit")
-        .and_then(|l| l.parse::<u16>().ok())
-        .unwrap_or(MAX_LIST_LIMIT)
-        .min(MAX_LIST_LIMIT);
-
-    let mut cursor = params
-        .get("cursor")
-        .map(|c| c.as_str())
-        .unwrap_or("0000000000000");
-
-    // Guard against bad cursor
-    if cursor.len() < 13 {
-        cursor = "0000000000000"
-    }
-
-    let mut result: Vec<String> = vec![];
-    let mut next_cursor = cursor.to_string();
-
-    for _ in 0..limit {
-        match state
-            .db
-            .tables
-            .events
-            .get_greater_than(&txn, &next_cursor)?
-        {
-            Some((timestamp, event_bytes)) => {
-                let event = Event::deserialize(event_bytes)?;
-
-                let line = format!("{} {}", event.operation(), event.url());
-                next_cursor = timestamp.to_string();
-
-                result.push(line);
-            }
-            None => break,
-        };
-    }
-
-    if !result.is_empty() {
-        result.push(format!("cursor: {next_cursor}"))
-    }
-
-    txn.commit()?;
+    let result = state.db.list_events(limit, cursor)?;
 
     Ok(Response::builder()
         .status(StatusCode::OK)