feat: add support for wasm

Adds support for compiling to WASM environments that provide JS via
wasm-bindgen. Because there's no standardized socket API the caller must
provide a connection that implements AsyncRead/AsyncWrite to
connect_raw.

Cargo.toml

@@ -1,4 +1,5 @@
 [workspace]
+resolver = "2"
 members = [
     "codegen",
     "postgres",

postgres-protocol/Cargo.toml

@@ -19,3 +19,6 @@ memchr = "2.0"
 rand = "0.8"
 sha2 = "0.10"
 stringprep = "0.1"
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom = { version = "0.2.9", features = ["js"] }

tokio-postgres/Cargo.toml

@@ -55,6 +55,14 @@ pin-project-lite = "0.2"
 phf = "0.11"
 postgres-protocol = { version = "0.6.5", path = "../postgres-protocol" }
 postgres-types = { version = "0.2.4", path = "../postgres-types" }
+tokio = { version = "1.27", default-features = false }
+tokio-util = { version = "0.7", default-features = false }
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+tokio = { version = "1.27", features = ["io-util"], default-features = false }
+tokio-util = { version = "0.7", features = ["codec"], default-features = false }
+
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 socket2 = { version = "0.5", features = ["all"] }
 tokio = { version = "1.27", features = ["io-util"] }
 tokio-util = { version = "0.7", features = ["codec"] }

tokio-postgres/src/config.rs

@@ -3,6 +3,7 @@
 #[cfg(feature = "runtime")]
 use crate::connect::connect;
 use crate::connect_raw::connect_raw;
+#[cfg(not(target_arch = "wasm32"))]
 use crate::keepalive::KeepaliveConfig;
 #[cfg(feature = "runtime")]
 use crate::tls::MakeTlsConnect;
@@ -165,6 +166,7 @@ pub struct Config {
     pub(crate) connect_timeout: Option<Duration>,
     pub(crate) tcp_user_timeout: Option<Duration>,
     pub(crate) keepalives: bool,
+    #[cfg(not(target_arch = "wasm32"))]
     pub(crate) keepalive_config: KeepaliveConfig,
     pub(crate) target_session_attrs: TargetSessionAttrs,
     pub(crate) channel_binding: ChannelBinding,
@@ -179,11 +181,6 @@ impl Default for Config {
 impl Config {
     /// Creates a new configuration.
     pub fn new() -> Config {
-        let keepalive_config = KeepaliveConfig {
-            idle: Duration::from_secs(2 * 60 * 60),
-            interval: None,
-            retries: None,
-        };
         Config {
             user: None,
             password: None,
@@ -196,7 +193,12 @@ impl Config {
             connect_timeout: None,
             tcp_user_timeout: None,
             keepalives: true,
-            keepalive_config,
+            #[cfg(not(target_arch = "wasm32"))]
+            keepalive_config: KeepaliveConfig {
+                idle: Duration::from_secs(2 * 60 * 60),
+                interval: None,
+                retries: None,
+            },
             target_session_attrs: TargetSessionAttrs::Any,
             channel_binding: ChannelBinding::Prefer,
         }
@@ -377,13 +379,15 @@ impl Config {
     /// Sets the amount of idle time before a keepalive packet is sent on the connection.
     ///
     /// This is ignored for Unix domain sockets, or if the `keepalives` option is disabled. Defaults to 2 hours.
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn keepalives_idle(&mut self, keepalives_idle: Duration) -> &mut Config {
         self.keepalive_config.idle = keepalives_idle;
         self
     }
 
     /// Gets the configured amount of idle time before a keepalive packet will
     /// be sent on the connection.
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn get_keepalives_idle(&self) -> Duration {
         self.keepalive_config.idle
     }
@@ -392,25 +396,29 @@ impl Config {
     /// On Windows, this sets the value of the tcp_keepalive struct’s keepaliveinterval field.
     ///
     /// This is ignored for Unix domain sockets, or if the `keepalives` option is disabled.
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn keepalives_interval(&mut self, keepalives_interval: Duration) -> &mut Config {
         self.keepalive_config.interval = Some(keepalives_interval);
         self
     }
 
     /// Gets the time interval between TCP keepalive probes.
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn get_keepalives_interval(&self) -> Option<Duration> {
         self.keepalive_config.interval
     }
 
     /// Sets the maximum number of TCP keepalive probes that will be sent before dropping a connection.
     ///
     /// This is ignored for Unix domain sockets, or if the `keepalives` option is disabled.
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn keepalives_retries(&mut self, keepalives_retries: u32) -> &mut Config {
         self.keepalive_config.retries = Some(keepalives_retries);
         self
     }
 
     /// Gets the maximum number of TCP keepalive probes that will be sent before dropping a connection.
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn get_keepalives_retries(&self) -> Option<u32> {
         self.keepalive_config.retries
     }
@@ -503,12 +511,14 @@ impl Config {
                     self.tcp_user_timeout(Duration::from_secs(timeout as u64));
                 }
             }
+            #[cfg(not(target_arch = "wasm32"))]
             "keepalives" => {
                 let keepalives = value
                     .parse::<u64>()
                     .map_err(|_| Error::config_parse(Box::new(InvalidValue("keepalives"))))?;
                 self.keepalives(keepalives != 0);
             }
+            #[cfg(not(target_arch = "wasm32"))]
             "keepalives_idle" => {
                 let keepalives_idle = value
                     .parse::<i64>()
@@ -517,6 +527,7 @@ impl Config {
                     self.keepalives_idle(Duration::from_secs(keepalives_idle as u64));
                 }
             }
+            #[cfg(not(target_arch = "wasm32"))]
             "keepalives_interval" => {
                 let keepalives_interval = value.parse::<i64>().map_err(|_| {
                     Error::config_parse(Box::new(InvalidValue("keepalives_interval")))
@@ -525,6 +536,7 @@ impl Config {
                     self.keepalives_interval(Duration::from_secs(keepalives_interval as u64));
                 }
             }
+            #[cfg(not(target_arch = "wasm32"))]
             "keepalives_retries" => {
                 let keepalives_retries = value.parse::<u32>().map_err(|_| {
                     Error::config_parse(Box::new(InvalidValue("keepalives_retries")))
@@ -614,7 +626,8 @@ impl fmt::Debug for Config {
             }
         }
 
-        f.debug_struct("Config")
+        let mut config_dbg = &mut f.debug_struct("Config");
+        config_dbg = config_dbg
             .field("user", &self.user)
             .field("password", &self.password.as_ref().map(|_| Redaction {}))
             .field("dbname", &self.dbname)
@@ -625,10 +638,17 @@ impl fmt::Debug for Config {
             .field("port", &self.port)
             .field("connect_timeout", &self.connect_timeout)
             .field("tcp_user_timeout", &self.tcp_user_timeout)
-            .field("keepalives", &self.keepalives)
-            .field("keepalives_idle", &self.keepalive_config.idle)
-            .field("keepalives_interval", &self.keepalive_config.interval)
-            .field("keepalives_retries", &self.keepalive_config.retries)
+            .field("keepalives", &self.keepalives);
+
+        #[cfg(not(target_arch = "wasm32"))]
+        {
+            config_dbg = config_dbg
+                .field("keepalives_idle", &self.keepalive_config.idle)
+                .field("keepalives_interval", &self.keepalive_config.interval)
+                .field("keepalives_retries", &self.keepalive_config.retries);
+        }
+
+        config_dbg
             .field("target_session_attrs", &self.target_session_attrs)
             .field("channel_binding", &self.channel_binding)
             .finish()

tokio-postgres/src/lib.rs

@@ -163,6 +163,7 @@ mod copy_in;
 mod copy_out;
 pub mod error;
 mod generic_client;
+#[cfg(not(target_arch = "wasm32"))]
 mod keepalive;
 mod maybe_tls_stream;
 mod portal;