From 8224b70405d91063944c594675f00f06f4318fa4 Mon Sep 17 00:00:00 2001
From: Felix Ableitner <me@nutomic.com>
Date: Tue, 5 Apr 2022 14:31:12 +0200
Subject: [PATCH] some progress

---
 src/crawl.rs | 72 ++++++++++++++++++++++++++++------------------------
 1 file changed, 39 insertions(+), 33 deletions(-)

diff --git a/src/crawl.rs b/src/crawl.rs
index f811776..a178c1a 100644
--- a/src/crawl.rs
+++ b/src/crawl.rs
@@ -3,53 +3,58 @@ use crate::node_info::NodeInfo;
 use crate::REQUEST_TIMEOUT;
 use anyhow::anyhow;
 use anyhow::Error;
+use futures::executor::block_on_stream;
 use futures::future::join_all;
 use futures::stream::FuturesUnordered;
-use futures::{stream, try_join, StreamExt, TryStreamExt};
+use futures::{future, stream, try_join, StreamExt, TryStreamExt};
 use reqwest::Client;
 use serde::Serialize;
+use std::cmp::max;
 use std::collections::VecDeque;
 use std::future::Future;
+use std::sync::{Arc, Mutex};
 
 pub async fn crawl(
     start_instances: Vec<String>,
     exclude: Vec<String>,
     max_depth: i32,
 ) -> Result<(Vec<InstanceDetails>, i32), Error> {
+    let exclude = Arc::new(exclude);
     let mut pending_instances: VecDeque<CrawlInstanceTask> = start_instances
         .iter()
-        .map(|s| CrawlInstanceTask::new(s.to_string(), 0))
+        .map(|s| CrawlInstanceTask::new(s.to_string(), 0, exclude.clone()))
         .collect();
-    let mut crawled_instances = vec![];
-    let mut instance_details = vec![];
+    let mut crawled_instances = Mutex::new(vec![]);
+    //let mut instance_details = vec![];
     //let mut failed_instances = 0;
-    let mut futures = stream::iter(pending_instances)
-        .then(|instance: CrawlInstanceTask| async {
-            crawled_instances.push(instance.domain.clone());
-            crawl_instance(instance, exclude.clone(), max_depth).await?
-        })
-        .flat_map(|(instance_details, depth)| {
-            let futures = instance_details
-                .linked_instances
-                .iter()
-                .map(|i| {
-                    crawled_instances.push(i.clone());
+
+    let stream = Box::pin(
+        stream::iter(pending_instances)
+            .then(|task: CrawlInstanceTask| async {
+                crawled_instances.lock().unwrap().push(task.domain.clone());
+                crawl_instance(task, max_depth).await.unwrap()
+            })
+            .flat_map(|(instance_details, task)| {
+                let futures = instance_details.linked_instances.iter().map(|i| {
+                    crawled_instances.lock().unwrap().push(i.clone());
                     crawl_instance(
-                        CrawlInstanceTask::new(i.clone(), depth),
-                        exclude.clone(),
+                        CrawlInstanceTask::new(i.clone(), task.depth + 1, task.exclude.clone()),
                         max_depth,
                     )
-                })
-                .collect();
+                });
 
-            stream::iter(futures)
-        })
-        .collect::<FuturesUnordered<dyn Future<Output = Result<(InstanceDetails, i32), Error>>>>()
+                stream::iter(futures)
+            }),
+    );
+
+    let crawl_result: Vec<Result<InstanceDetails, Error>> = stream
+        .buffer_unordered(10)
+        .map_ok(|(details, _)| details)
+        .collect()
         .await;
 
     todo!()
     /*
-    let mut crawl_result: Vec<InstanceDetails> = todo!();
 
     // Sort by active monthly users descending
     crawl_result.sort_by_key(|i| i.users_active_month);
@@ -60,17 +65,13 @@ pub async fn crawl(
 }
 
 async fn crawl_instance(
-    current_instance: CrawlInstanceTask,
-    exclude: Vec<String>,
+    task: CrawlInstanceTask,
     max_depth: i32,
-) -> Result<(InstanceDetails, i32), Error> {
-    if current_instance.depth > max_depth || exclude.contains(&current_instance.domain) {
+) -> Result<(InstanceDetails, CrawlInstanceTask), Error> {
+    if task.depth > max_depth || task.exclude.contains(&task.domain) {
         return Err(anyhow!("max depth reached"));
     }
-    Ok((
-        fetch_instance_details(&current_instance.domain).await?,
-        current_instance.depth + 1,
-    ))
+    Ok((fetch_instance_details(&task.domain).await?, task))
 }
 
 #[derive(Serialize, Clone)]
@@ -95,11 +96,16 @@ pub struct InstanceDetails {
 struct CrawlInstanceTask {
     domain: String,
     depth: i32,
+    exclude: Arc<Vec<String>>,
 }
 
 impl CrawlInstanceTask {
-    pub fn new(domain: String, depth: i32) -> CrawlInstanceTask {
-        CrawlInstanceTask { domain, depth }
+    pub fn new(domain: String, depth: i32, exclude: Arc<Vec<String>>) -> CrawlInstanceTask {
+        CrawlInstanceTask {
+            domain,
+            depth,
+            exclude,
+        }
     }
 }