drk/interactive: scan and subscribe infra added

Cargo.lock

@@ -2468,6 +2468,7 @@ dependencies = [
  "darkfi_money_contract",
  "easy-parallel",
  "lazy_static",
+ "libc",
  "linenoise-rs",
  "log",
  "num-bigint",

bin/drk/Cargo.toml

@@ -21,6 +21,7 @@ darkfi-serial = "0.5.0"
 blake3 = "1.8.2"
 bs58 = "0.5.1"
 lazy_static = "1.5.0"
+libc = "0.2"
 linenoise-rs = "0.1.1"
 log = "0.4.27"
 num-bigint = "0.4.6"

bin/drk/src/interactive.rs

@@ -16,9 +16,12 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+use std::{io::ErrorKind, mem::zeroed, ptr::null_mut, str::FromStr};
+
+use libc::{fd_set, select, timeval, FD_SET, FD_ZERO};
 use linenoise_rs::{
-    linenoise, linenoise_history_add, linenoise_history_load, linenoise_history_save,
-    linenoise_set_completion_callback, linenoise_set_hints_callback,
+    linenoise_history_add, linenoise_history_load, linenoise_history_save,
+    linenoise_set_completion_callback, linenoise_set_hints_callback, LinenoiseState,
 };
 
 use darkfi::{cli_desc, system::StoppableTask, util::path::expand_path};
@@ -42,6 +45,11 @@ fn help() {
     println!("\tkaching: Fun");
     println!("\tping: Send a ping request to the darkfid RPC endpoint");
     println!("\tcompletions: Generate a SHELL completion script and print to stdout");
+    println!(
+        "\tsubscribe: Perform a scan and then subscribe to darkfid to listen for incoming blocks"
+    );
+    println!("\tunsubscribe: Stops the background subscription, if its active");
+    println!("\tscan: Scan the blockchain and parse relevant transactions");
 }
 
 /// Auxiliary function to define the interactive shell completions.
@@ -63,6 +71,21 @@ fn completion(buf: &str, lc: &mut Vec<String>) {
 
     if buf.starts_with("c") {
         lc.push("completions".to_string());
+        return
+    }
+
+    if buf.starts_with("su") {
+        lc.push("subscribe".to_string());
+        return
+    }
+
+    if buf.starts_with("u") {
+        lc.push("unsubscribe".to_string());
+        return
+    }
+
+    if buf.starts_with("sc") {
+        lc.push("scan".to_string());
     }
 }
 
@@ -70,17 +93,19 @@ fn completion(buf: &str, lc: &mut Vec<String>) {
 fn hints(buf: &str) -> Option<(String, i32, bool)> {
     match buf {
         "completions " => Some(("{shell}".to_string(), 35, false)), // 35 = magenta
+        "scan " => Some(("--reset {height}".to_string(), 35, false)), // 35 = magenta
         _ => None,
     }
 }
 
 /// Auxiliary function to start provided Drk as an interactive shell.
+/// Only sane/linenoise terminals are suported.
 pub async fn interactive(drk: &Drk, history_path: &str) {
     // Expand the history file path
     let history_path = match expand_path(history_path) {
         Ok(p) => p,
         Err(e) => {
-            println!("Error while expanding history file path: {e}");
+            eprintln!("Error while expanding history file path: {e}");
             return
         }
     };
@@ -99,23 +124,93 @@ pub async fn interactive(drk: &Drk, history_path: &str) {
     let _ = linenoise_history_load(history_file);
 
     // Create a detached task to use for block subscription
-    let subscription_active = false;
+    let mut subscription_active = false;
     let subscription_task = StoppableTask::new();
 
+    // Create two bounded smol channels, so we can have 2 way
+    // communication between the shell thread and the background task.
+    let (_shell_sender, shell_receiver) = smol::channel::bounded::<()>(1);
+    let (background_sender, _background_receiver) = smol::channel::bounded::<()>(1);
+
     // Start the interactive shell
     loop {
-        // Grab input or end if Ctrl-D or Ctrl-C was pressed
-        let Some(line) = linenoise("drk> ") else {
-            // Stop the subscription task if its active
-            if subscription_active {
-                subscription_task.stop().await;
+        // Generate the linoise state structure
+        let mut state = match LinenoiseState::edit_start(-1, -1, "drk> ") {
+            Ok(s) => s,
+            Err(e) => {
+                eprintln!("Error while generating linenoise state: {e}");
+                break
             }
+        };
 
-            // Write history file
-            let _ = linenoise_history_save(history_file);
+        // Read until we get a line to process
+        let mut line = None;
+        loop {
+            let retval = unsafe {
+                // Setup read buffers
+                let mut readfds: fd_set = zeroed();
+                FD_ZERO(&mut readfds);
+                FD_SET(state.get_fd(), &mut readfds);
 
-            return
-        };
+                // Setup a 1 second timeout to check if background
+                // process wants to print.
+                let mut tv = timeval { tv_sec: 1, tv_usec: 0 };
+
+                // Wait timeout or input
+                select(state.get_fd() + 1, &mut readfds, null_mut(), null_mut(), &mut tv)
+            };
+
+            // Handle error
+            if retval == -1 {
+                eprintln!("Error while reading linenoise buffers");
+                break
+            }
+
+            // Check if background process wants to print anything
+            if shell_receiver.is_full() {
+                // Consume the channel message
+                if let Err(e) = shell_receiver.recv().await {
+                    eprintln!("Error while reading shell receiver channel: {e}");
+                    break
+                }
+
+                // Signal background task it can start printing
+                let _ = state.hide();
+                if let Err(e) = background_sender.send(()).await {
+                    eprintln!("Error while sending to background task channel: {e}");
+                    break
+                }
+
+                // Wait signal that it finished
+                if let Err(e) = shell_receiver.recv().await {
+                    eprintln!("Error while reading shell receiver channel: {e}");
+                    break
+                }
+                let _ = state.show();
+            }
+
+            // Check if we have a line to process
+            if retval <= 0 {
+                continue
+            }
+
+            // Process linenoise feed
+            match state.edit_feed() {
+                Ok(Some(l)) => line = Some(l),
+                Ok(None) => { /* Do nothing */ }
+                Err(e) if e.kind() == ErrorKind::Interrupted => { /* Do nothing */ }
+                Err(e) if e.kind() == ErrorKind::WouldBlock => {
+                    // Need more input, continue
+                    continue;
+                }
+                Err(e) => eprintln!("Error while reading linenoise feed: {e}"),
+            }
+            break
+        }
+        let _ = state.edit_stop();
+
+        // Grab input or end if Ctrl-D or Ctrl-C was pressed
+        let Some(line) = line else { break };
 
         // Check if line is empty
         if line.is_empty() {
@@ -137,9 +232,22 @@ pub async fn interactive(drk: &Drk, history_path: &str) {
             "kaching" => kaching().await,
             "ping" => handle_ping(drk).await,
             "completions" => handle_completions(&parts),
+            "subscribe" => {
+                handle_subscribe(drk, &mut subscription_active, &subscription_task).await
+            }
+            "unsubscribe" => handle_unsubscribe(&mut subscription_active, &subscription_task).await,
+            "scan" => handle_scan(drk, &subscription_active, &parts).await,
             _ => println!("Unreconized command: {}", parts[0]),
         }
     }
+
+    // Stop the subscription task if its active
+    if subscription_active {
+        subscription_task.stop().await;
+    }
+
+    // Write history file
+    let _ = linenoise_history_save(history_file);
 }
 
 /// Auxiliary function to define the ping command handling.
@@ -161,3 +269,75 @@ fn handle_completions(parts: &[&str]) {
         println!("Error while executing completions command: {e}")
     }
 }
+
+/// Auxiliary function to define the subscribe command handling.
+async fn handle_subscribe(
+    drk: &Drk,
+    subscription_active: &mut bool,
+    _subscription_task: &StoppableTask,
+) {
+    if *subscription_active {
+        println!("Subscription is already active!")
+    }
+
+    if let Err(e) = drk.scan_blocks().await {
+        println!("Failed during scanning: {e:?}");
+        return
+    }
+    println!("Finished scanning blockchain");
+
+    // TODO: subscribe
+
+    *subscription_active = true;
+}
+
+/// Auxiliary function to define the unsubscribe command handling.
+async fn handle_unsubscribe(subscription_active: &mut bool, subscription_task: &StoppableTask) {
+    if !*subscription_active {
+        println!("Subscription is already inactive!")
+    }
+    subscription_task.stop().await;
+    *subscription_active = false;
+}
+
+/// Auxiliary function to define the scan command handling.
+async fn handle_scan(drk: &Drk, subscription_active: &bool, parts: &[&str]) {
+    if *subscription_active {
+        println!("Subscription is already active!");
+        return
+    }
+
+    // Check correct command structure
+    if parts.len() != 1 && parts.len() != 3 {
+        println!("Malformed `scan` command");
+        return
+    }
+
+    // Check if reset was requested
+    if parts.len() == 3 {
+        if parts[1] != "--reset" {
+            println!("Malformed `scan` command");
+            println!("Usage: scan --reset {{height}}");
+            return
+        }
+
+        let height = match u32::from_str(parts[2]) {
+            Ok(h) => h,
+            Err(e) => {
+                println!("Invalid reset height: {e:?}");
+                return
+            }
+        };
+
+        if let Err(e) = drk.reset_to_height(height) {
+            println!("Failed during wallet reset: {e:?}");
+            return
+        }
+    }
+
+    if let Err(e) = drk.scan_blocks().await {
+        println!("Failed during scanning: {e:?}");
+        return
+    }
+    println!("Finished scanning blockchain");
+}