allow arbitrary config params with more efficient repr (#30)

* switch to compressed config

* remove some allocs and combine pw and authkeys into a single enum

* allow arbitrary options

* remove some redundant configs

* clean up

* more cleanup

* replication

* fix

* fix lints

* simplify

* dont treat user separately

* do not duplicate the encoding of params

postgres-protocol/src/authentication/sasl.rs

@@ -117,7 +117,7 @@ enum Credentials<const N: usize> {
     /// A regular password as a vector of bytes.
     Password(Vec<u8>),
     /// A precomputed pair of keys.
-    Keys(Box<ScramKeys<N>>),
+    Keys(ScramKeys<N>),
 }
 
 enum State {
@@ -176,7 +176,7 @@ impl ScramSha256 {
 
     /// Constructs a new instance which will use the provided key pair for authentication.
     pub fn new_with_keys(keys: ScramKeys<32>, channel_binding: ChannelBinding) -> ScramSha256 {
-        let password = Credentials::Keys(keys.into());
+        let password = Credentials::Keys(keys);
         ScramSha256::new_inner(password, channel_binding, nonce())
     }
 

postgres-protocol/src/lib.rs

@@ -68,7 +68,7 @@ macro_rules! from_usize {
         impl FromUsize for $t {
             #[inline]
             fn from_usize(x: usize) -> io::Result<$t> {
-                if x > <$t>::max_value() as usize {
+                if x > <$t>::MAX as usize {
                     Err(io::Error::new(
                         io::ErrorKind::InvalidInput,
                         "value too large to transmit",

postgres-protocol/src/message/frontend.rs

@@ -271,6 +271,66 @@ where
     })
 }
 
+#[inline]
+pub fn startup_message_cstr(
+    parameters: &StartupMessageParams,
+    buf: &mut BytesMut,
+) -> io::Result<()> {
+    write_body(buf, |buf| {
+        // postgres protocol version 3.0(196608) in bigger-endian
+        buf.put_i32(0x00_03_00_00);
+        buf.put_slice(&parameters.params);
+        buf.put_u8(0);
+        Ok(())
+    })
+}
+
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+pub struct StartupMessageParams {
+    params: BytesMut,
+}
+
+impl StartupMessageParams {
+    /// Set parameter's value by its name.
+    pub fn insert(&mut self, name: &str, value: &str) -> Result<(), io::Error> {
+        if name.contains('\0') | value.contains('\0') {
+            return Err(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "string contains embedded null",
+            ));
+        }
+        self.params.put(name.as_bytes());
+        self.params.put(&b"\0"[..]);
+        self.params.put(value.as_bytes());
+        self.params.put(&b"\0"[..]);
+        Ok(())
+    }
+
+    pub fn str_iter(&self) -> impl Iterator<Item = (&str, &str)> {
+        let params =
+            std::str::from_utf8(&self.params).expect("should be validated as utf8 already");
+        StrParamsIter(params)
+    }
+
+    /// Get parameter's value by its name.
+    pub fn get(&self, name: &str) -> Option<&str> {
+        self.str_iter().find_map(|(k, v)| (k == name).then_some(v))
+    }
+}
+
+struct StrParamsIter<'a>(&'a str);
+
+impl<'a> Iterator for StrParamsIter<'a> {
+    type Item = (&'a str, &'a str);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let (key, r) = self.0.split_once('\0')?;
+        let (value, r) = r.split_once('\0')?;
+        self.0 = r;
+        Some((key, value))
+    }
+}
+
 #[inline]
 pub fn sync(buf: &mut BytesMut) {
     buf.put_u8(b'S');

postgres-types/src/lib.rs

@@ -1172,7 +1172,7 @@ impl ToSql for IpAddr {
 }
 
 fn downcast(len: usize) -> Result<i32, Box<dyn Error + Sync + Send>> {
-    if len > i32::max_value() as usize {
+    if len > i32::MAX as usize {
         Err("value too large to transmit".into())
     } else {
         Ok(len as i32)

postgres-types/src/special.rs

@@ -1,7 +1,6 @@
 use bytes::BytesMut;
 use postgres_protocol::types;
 use std::error::Error;
-use std::{i32, i64};
 
 use crate::{FromSql, IsNull, ToSql, Type};
 

postgres/src/config.rs

@@ -145,12 +145,6 @@ impl Config {
         self
     }
 
-    /// Gets the password to authenticate with, if one has been configured with
-    /// the `password` method.
-    pub fn get_password(&self) -> Option<&[u8]> {
-        self.config.get_password()
-    }
-
     /// Sets precomputed protocol-specific keys to authenticate with.
     /// When set, this option will override `password`.
     /// See [`AuthKeys`] for more information.
@@ -159,12 +153,6 @@ impl Config {
         self
     }
 
-    /// Gets precomputed protocol-specific keys to authenticate with.
-    /// if one has been configured with the `auth_keys` method.
-    pub fn get_auth_keys(&self) -> Option<AuthKeys> {
-        self.config.get_auth_keys()
-    }
-
     /// Sets the name of the database to connect to.
     ///
     /// Defaults to the user.
@@ -185,24 +173,12 @@ impl Config {
         self
     }
 
-    /// Gets the command line options used to configure the server, if the
-    /// options have been set with the `options` method.
-    pub fn get_options(&self) -> Option<&str> {
-        self.config.get_options()
-    }
-
     /// Sets the value of the `application_name` runtime parameter.
     pub fn application_name(&mut self, application_name: &str) -> &mut Config {
         self.config.application_name(application_name);
         self
     }
 
-    /// Gets the value of the `application_name` runtime parameter, if it has
-    /// been set with the `application_name` method.
-    pub fn get_application_name(&self) -> Option<&str> {
-        self.config.get_application_name()
-    }
-
     /// Sets the SSL configuration.
     ///
     /// Defaults to `prefer`.