Make commands run in DB transaction

Cargo.lock

@@ -2,6 +2,18 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "Inflector"
+version = "0.11.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fe438c63458706e03479442743baae6c88256498e6431708f6dfc520a26515d3"
+
+[[package]]
+name = "aliasable"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "250f629c0161ad8107cf89319e990051fae62832fd343083bea452d93e2205fd"
+
 [[package]]
 name = "ansi_macro"
 version = "0.1.0"
@@ -71,6 +83,7 @@ dependencies = [
  "log",
  "nix",
  "nom",
+ "ouroboros",
  "phf",
  "ring",
  "serde",
@@ -766,6 +779,29 @@ version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "86f0b0d4bf799edbc74508c1e8bf170ff5f41238e5f8225603ca7caaae2b7860"
 
+[[package]]
+name = "ouroboros"
+version = "0.15.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfbb50b356159620db6ac971c6d5c9ab788c9cc38a6f49619fca2a27acb062ca"
+dependencies = [
+ "aliasable",
+ "ouroboros_macro",
+]
+
+[[package]]
+name = "ouroboros_macro"
+version = "0.15.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a0d9d1a6191c4f391f87219d1ea42b23f09ee84d64763cd05ee6ea88d9f384d"
+dependencies = [
+ "Inflector",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "parking_lot"
 version = "0.12.1"
@@ -907,6 +943,30 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b40af805b3121feab8a3c29f04d8ad262fa8e0561883e7653e024ae4479e6de"
 
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "version_check",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "version_check",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.47"

blastmud_game/Cargo.toml

@@ -28,3 +28,4 @@ serde_json = "1.0.91"
 phf = { version = "0.11.1", features = ["macros"] }
 async-trait = "0.1.60"
 nom = "7.1.1"
+ouroboros = "0.15.5"

blastmud_game/src/db.rs

@@ -1,20 +1,30 @@
 use tokio_postgres::{config::Config as PgConfig, row::Row};
-use deadpool_postgres::{Manager, Object, ManagerConfig, Pool,
+use deadpool_postgres::{Manager, Object, ManagerConfig, Pool, Transaction,
                         RecyclingMethod};
 use std::error::Error;
 use std::str::FromStr;
+use ouroboros::self_referencing;
 use uuid::Uuid;
 use tokio_postgres::NoTls;
 use crate::message_handler::ListenerSession;
 use crate::DResult;
 use crate::models::session::Session;
 use serde_json;
+use futures::FutureExt;
 
 #[derive(Clone, Debug)]
 pub struct DBPool {
     pool: Pool
 }
 
+#[self_referencing]
+pub struct DBTrans {
+    conn: Object,
+    #[borrows(mut conn)]
+    #[covariant]
+    pub trans: Option<Transaction<'this>>
+}
+
 #[derive(Clone, Debug)]
 pub struct SendqueueItem {
     pub item: i64,
@@ -90,6 +100,14 @@ impl DBPool {
         Ok(())
     }
 
+    pub async fn start_transaction(self: &Self) -> DResult<DBTrans> {
+        let conn = self.get_conn().await?;
+        Ok(DBTransAsyncSendTryBuilder {
+            conn,
+            trans_builder: |conn| Box::pin(conn.transaction().map(|r| r.map(Some)))
+        }.try_build().await?)
+    }
+    
     pub async fn queue_for_session(self: &Self,
                                        session: &ListenerSession,
                                        message: &str) -> DResult<()> {
@@ -135,3 +153,26 @@ impl DBPool {
             .map(|pool| Self { pool })
     }
 }
+
+impl DBTrans {
+    pub async fn queue_for_session(self: &Self,
+                                   session: &ListenerSession,
+                                   message: &str) -> DResult<()> {
+        self.pg_trans()?
+            .execute("INSERT INTO sendqueue (session, listener, message) VALUES ($1, $2, $3)",
+                     &[&session.session, &session.listener, &message]).await?;
+        Ok(())
+    }
+
+    pub async fn commit(mut self: Self) -> DResult<()> {
+        let trans_opt = self.with_trans_mut(|t| std::mem::replace(t, None));
+        for trans in trans_opt {
+            trans.commit().await?;
+        }
+        Ok(())
+    }
+
+    pub fn pg_trans(self: &Self) -> DResult<&Transaction> {
+        self.borrow_trans().as_ref().ok_or("Transaction already closed".into())
+    }
+}

blastmud_game/src/message_handler/user_commands.rs

@@ -1,6 +1,6 @@
 use super::ListenerSession;
 use crate::DResult;
-use crate::db::DBPool;
+use crate::db::{DBTrans, DBPool};
 use ansi_macro::ansi;
 use phf::phf_map;
 use async_trait::async_trait;
@@ -9,10 +9,9 @@ mod parsing;
 mod ignore;
 mod help;
 
-#[derive(Debug)]
 pub struct VerbContext<'l> {
     session: &'l ListenerSession,
-    pool: &'l DBPool
+    trans: &'l DBTrans
 }
 
 pub enum CommandHandlingError {
@@ -48,31 +47,27 @@ static ALWAYS_AVAILABLE_COMMANDS: UserVerbRegistry = phf_map! {
 
 pub async fn handle(session: &ListenerSession, msg: &str, pool: &DBPool) -> DResult<()> {
     let (cmd, params) = parsing::parse_command_name(msg);
+    let trans = pool.start_transaction().await?;
     let handler_opt = ALWAYS_AVAILABLE_COMMANDS.get(cmd);
 
     match handler_opt {
         None => {
-            pool.queue_for_session(session,
-                                   ansi!(
-                                       "That's not a command I know. Try <bold>help<reset>\r\n"
-                                   )
+            trans.queue_for_session(session,
+                                    ansi!(
+                                        "That's not a command I know. Try <bold>help<reset>\r\n"
+                                    )
             ).await?;
         }
         Some(handler) => {
-            match handler.handle(&VerbContext { session, pool }, cmd, params).await {
+            match handler.handle(&VerbContext { session, trans: &trans }, cmd, params).await {
                 Ok(()) => {}
                 Err(UserError(err_msg)) => {
-                    pool.queue_for_session(session, &(err_msg + "\r\n")).await?;
+                    trans.queue_for_session(session, &(err_msg + "\r\n")).await?;
                 }
                 Err(SystemError(e)) => Err(e)?
             }
         }
     }
-    /*
-    pool.queue_for_session(session,
-                           &format!(ansi!(
-                               "You hear an echo saying: <bggreen><red>{}<reset>\r\n"
-                           ), msg)).await?;
-     */
+    trans.commit().await?;
     Ok(())
 }

blastmud_game/src/message_handler/user_commands/help.rs

@@ -25,7 +25,7 @@ impl UserVerb for Verb {
     async fn handle(self: &Self, ctx: &VerbContext, _verb: &str, remaining: &str) -> UResult<()> {
         let help = HELP_PAGES.get(remaining).ok_or(
             UserError("No help available on that".to_string()))?;
-        ctx.pool.queue_for_session(ctx.session, &(help.to_string() + "\r\n")).await?;
+        ctx.trans.queue_for_session(ctx.session, &(help.to_string() + "\r\n")).await?;
         Ok(())
     }
 }