chore(proxy): vendor a subset of rust-postgres (#9930)

Our rust-postgres fork is getting messy. Mostly because proxy wants more
control over the raw protocol than tokio-postgres provides. As such,
it's diverging more and more. Storage and compute also make use of
rust-postgres, but in more normal usage, thus they don't need our crazy
changes.

Idea: 
* proxy maintains their subset
* other teams use a minimal patch set against upstream rust-postgres

Reviewing this code will be difficult. To implement it, I
1. Copied tokio-postgres, postgres-protocol and postgres-types from
00940fcdb5
2. Updated their package names with the `2` suffix to make them compile
in the workspace.
3. Updated proxy to use those packages
4. Copied in the code from tokio-postgres-rustls 0.13 (with some patches
applied https://github.com/jbg/tokio-postgres-rustls/pull/32
https://github.com/jbg/tokio-postgres-rustls/pull/33)
5. Removed as much dead code as I could find in the vendored libraries
6. Updated the tokio-postgres-rustls code to use our existing channel
binding implementation

libs/proxy/postgres-types2/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "postgres-types2"
+version = "0.1.0"
+edition = "2018"
+license = "MIT/Apache-2.0"
+
+[dependencies]
+bytes.workspace = true
+fallible-iterator.workspace = true
+postgres-protocol2 = { path = "../postgres-protocol2" }

libs/proxy/postgres-types2/src/lib.rs

@@ -0,0 +1,477 @@
+//! Conversions to and from Postgres types.
+//!
+//! This crate is used by the `tokio-postgres` and `postgres` crates. You normally don't need to depend directly on it
+//! unless you want to define your own `ToSql` or `FromSql` definitions.
+#![doc(html_root_url = "https://docs.rs/postgres-types/0.2")]
+#![warn(clippy::all, rust_2018_idioms, missing_docs)]
+
+use fallible_iterator::FallibleIterator;
+use postgres_protocol2::types;
+use std::any::type_name;
+use std::error::Error;
+use std::fmt;
+use std::sync::Arc;
+
+use crate::type_gen::{Inner, Other};
+
+#[doc(inline)]
+pub use postgres_protocol2::Oid;
+
+use bytes::BytesMut;
+
+/// Generates a simple implementation of `ToSql::accepts` which accepts the
+/// types passed to it.
+macro_rules! accepts {
+    ($($expected:ident),+) => (
+        fn accepts(ty: &$crate::Type) -> bool {
+            matches!(*ty, $($crate::Type::$expected)|+)
+        }
+    )
+}
+
+/// Generates an implementation of `ToSql::to_sql_checked`.
+///
+/// All `ToSql` implementations should use this macro.
+macro_rules! to_sql_checked {
+    () => {
+        fn to_sql_checked(
+            &self,
+            ty: &$crate::Type,
+            out: &mut $crate::private::BytesMut,
+        ) -> ::std::result::Result<
+            $crate::IsNull,
+            Box<dyn ::std::error::Error + ::std::marker::Sync + ::std::marker::Send>,
+        > {
+            $crate::__to_sql_checked(self, ty, out)
+        }
+    };
+}
+
+// WARNING: this function is not considered part of this crate's public API.
+// It is subject to change at any time.
+#[doc(hidden)]
+pub fn __to_sql_checked<T>(
+    v: &T,
+    ty: &Type,
+    out: &mut BytesMut,
+) -> Result<IsNull, Box<dyn Error + Sync + Send>>
+where
+    T: ToSql,
+{
+    if !T::accepts(ty) {
+        return Err(Box::new(WrongType::new::<T>(ty.clone())));
+    }
+    v.to_sql(ty, out)
+}
+
+// mod pg_lsn;
+#[doc(hidden)]
+pub mod private;
+// mod special;
+mod type_gen;
+
+/// A Postgres type.
+#[derive(PartialEq, Eq, Clone, Hash)]
+pub struct Type(Inner);
+
+impl fmt::Debug for Type {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt::Debug::fmt(&self.0, fmt)
+    }
+}
+
+impl fmt::Display for Type {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.schema() {
+            "public" | "pg_catalog" => {}
+            schema => write!(fmt, "{}.", schema)?,
+        }
+        fmt.write_str(self.name())
+    }
+}
+
+impl Type {
+    /// Creates a new `Type`.
+    pub fn new(name: String, oid: Oid, kind: Kind, schema: String) -> Type {
+        Type(Inner::Other(Arc::new(Other {
+            name,
+            oid,
+            kind,
+            schema,
+        })))
+    }
+
+    /// Returns the `Type` corresponding to the provided `Oid` if it
+    /// corresponds to a built-in type.
+    pub fn from_oid(oid: Oid) -> Option<Type> {
+        Inner::from_oid(oid).map(Type)
+    }
+
+    /// Returns the OID of the `Type`.
+    pub fn oid(&self) -> Oid {
+        self.0.oid()
+    }
+
+    /// Returns the kind of this type.
+    pub fn kind(&self) -> &Kind {
+        self.0.kind()
+    }
+
+    /// Returns the schema of this type.
+    pub fn schema(&self) -> &str {
+        match self.0 {
+            Inner::Other(ref u) => &u.schema,
+            _ => "pg_catalog",
+        }
+    }
+
+    /// Returns the name of this type.
+    pub fn name(&self) -> &str {
+        self.0.name()
+    }
+}
+
+/// Represents the kind of a Postgres type.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[non_exhaustive]
+pub enum Kind {
+    /// A simple type like `VARCHAR` or `INTEGER`.
+    Simple,
+    /// An enumerated type along with its variants.
+    Enum(Vec<String>),
+    /// A pseudo-type.
+    Pseudo,
+    /// An array type along with the type of its elements.
+    Array(Type),
+    /// A range type along with the type of its elements.
+    Range(Type),
+    /// A multirange type along with the type of its elements.
+    Multirange(Type),
+    /// A domain type along with its underlying type.
+    Domain(Type),
+    /// A composite type along with information about its fields.
+    Composite(Vec<Field>),
+}
+
+/// Information about a field of a composite type.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Field {
+    name: String,
+    type_: Type,
+}
+
+impl Field {
+    /// Creates a new `Field`.
+    pub fn new(name: String, type_: Type) -> Field {
+        Field { name, type_ }
+    }
+
+    /// Returns the name of the field.
+    pub fn name(&self) -> &str {
+        &self.name
+    }
+
+    /// Returns the type of the field.
+    pub fn type_(&self) -> &Type {
+        &self.type_
+    }
+}
+
+/// An error indicating that a `NULL` Postgres value was passed to a `FromSql`
+/// implementation that does not support `NULL` values.
+#[derive(Debug, Clone, Copy)]
+pub struct WasNull;
+
+impl fmt::Display for WasNull {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        fmt.write_str("a Postgres value was `NULL`")
+    }
+}
+
+impl Error for WasNull {}
+
+/// An error indicating that a conversion was attempted between incompatible
+/// Rust and Postgres types.
+#[derive(Debug)]
+pub struct WrongType {
+    postgres: Type,
+    rust: &'static str,
+}
+
+impl fmt::Display for WrongType {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            fmt,
+            "cannot convert between the Rust type `{}` and the Postgres type `{}`",
+            self.rust, self.postgres,
+        )
+    }
+}
+
+impl Error for WrongType {}
+
+impl WrongType {
+    /// Creates a new `WrongType` error.
+    pub fn new<T>(ty: Type) -> WrongType {
+        WrongType {
+            postgres: ty,
+            rust: type_name::<T>(),
+        }
+    }
+}
+
+/// An error indicating that a as_text conversion was attempted on a binary
+/// result.
+#[derive(Debug)]
+pub struct WrongFormat {}
+
+impl Error for WrongFormat {}
+
+impl fmt::Display for WrongFormat {
+    fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            fmt,
+            "cannot read column as text while it is in binary format"
+        )
+    }
+}
+
+/// A trait for types that can be created from a Postgres value.
+pub trait FromSql<'a>: Sized {
+    /// Creates a new value of this type from a buffer of data of the specified
+    /// Postgres `Type` in its binary format.
+    ///
+    /// The caller of this method is responsible for ensuring that this type
+    /// is compatible with the Postgres `Type`.
+    fn from_sql(ty: &Type, raw: &'a [u8]) -> Result<Self, Box<dyn Error + Sync + Send>>;
+
+    /// Creates a new value of this type from a `NULL` SQL value.
+    ///
+    /// The caller of this method is responsible for ensuring that this type
+    /// is compatible with the Postgres `Type`.
+    ///
+    /// The default implementation returns `Err(Box::new(WasNull))`.
+    #[allow(unused_variables)]
+    fn from_sql_null(ty: &Type) -> Result<Self, Box<dyn Error + Sync + Send>> {
+        Err(Box::new(WasNull))
+    }
+
+    /// A convenience function that delegates to `from_sql` and `from_sql_null` depending on the
+    /// value of `raw`.
+    fn from_sql_nullable(
+        ty: &Type,
+        raw: Option<&'a [u8]>,
+    ) -> Result<Self, Box<dyn Error + Sync + Send>> {
+        match raw {
+            Some(raw) => Self::from_sql(ty, raw),
+            None => Self::from_sql_null(ty),
+        }
+    }
+
+    /// Determines if a value of this type can be created from the specified
+    /// Postgres `Type`.
+    fn accepts(ty: &Type) -> bool;
+}
+
+/// A trait for types which can be created from a Postgres value without borrowing any data.
+///
+/// This is primarily useful for trait bounds on functions.
+pub trait FromSqlOwned: for<'a> FromSql<'a> {}
+
+impl<T> FromSqlOwned for T where T: for<'a> FromSql<'a> {}
+
+impl<'a, T: FromSql<'a>> FromSql<'a> for Option<T> {
+    fn from_sql(ty: &Type, raw: &'a [u8]) -> Result<Option<T>, Box<dyn Error + Sync + Send>> {
+        <T as FromSql>::from_sql(ty, raw).map(Some)
+    }
+
+    fn from_sql_null(_: &Type) -> Result<Option<T>, Box<dyn Error + Sync + Send>> {
+        Ok(None)
+    }
+
+    fn accepts(ty: &Type) -> bool {
+        <T as FromSql>::accepts(ty)
+    }
+}
+
+impl<'a, T: FromSql<'a>> FromSql<'a> for Vec<T> {
+    fn from_sql(ty: &Type, raw: &'a [u8]) -> Result<Vec<T>, Box<dyn Error + Sync + Send>> {
+        let member_type = match *ty.kind() {
+            Kind::Array(ref member) => member,
+            _ => panic!("expected array type"),
+        };
+
+        let array = types::array_from_sql(raw)?;
+        if array.dimensions().count()? > 1 {
+            return Err("array contains too many dimensions".into());
+        }
+
+        array
+            .values()
+            .map(|v| T::from_sql_nullable(member_type, v))
+            .collect()
+    }
+
+    fn accepts(ty: &Type) -> bool {
+        match *ty.kind() {
+            Kind::Array(ref inner) => T::accepts(inner),
+            _ => false,
+        }
+    }
+}
+
+impl<'a> FromSql<'a> for String {
+    fn from_sql(ty: &Type, raw: &'a [u8]) -> Result<String, Box<dyn Error + Sync + Send>> {
+        <&str as FromSql>::from_sql(ty, raw).map(ToString::to_string)
+    }
+
+    fn accepts(ty: &Type) -> bool {
+        <&str as FromSql>::accepts(ty)
+    }
+}
+
+impl<'a> FromSql<'a> for &'a str {
+    fn from_sql(ty: &Type, raw: &'a [u8]) -> Result<&'a str, Box<dyn Error + Sync + Send>> {
+        match *ty {
+            ref ty if ty.name() == "ltree" => types::ltree_from_sql(raw),
+            ref ty if ty.name() == "lquery" => types::lquery_from_sql(raw),
+            ref ty if ty.name() == "ltxtquery" => types::ltxtquery_from_sql(raw),
+            _ => types::text_from_sql(raw),
+        }
+    }
+
+    fn accepts(ty: &Type) -> bool {
+        match *ty {
+            Type::VARCHAR | Type::TEXT | Type::BPCHAR | Type::NAME | Type::UNKNOWN => true,
+            ref ty
+                if (ty.name() == "citext"
+                    || ty.name() == "ltree"
+                    || ty.name() == "lquery"
+                    || ty.name() == "ltxtquery") =>
+            {
+                true
+            }
+            _ => false,
+        }
+    }
+}
+
+macro_rules! simple_from {
+    ($t:ty, $f:ident, $($expected:ident),+) => {
+        impl<'a> FromSql<'a> for $t {
+            fn from_sql(_: &Type, raw: &'a [u8]) -> Result<$t, Box<dyn Error + Sync + Send>> {
+                types::$f(raw)
+            }
+
+            accepts!($($expected),+);
+        }
+    }
+}
+
+simple_from!(i8, char_from_sql, CHAR);
+simple_from!(u32, oid_from_sql, OID);
+
+/// An enum representing the nullability of a Postgres value.
+pub enum IsNull {
+    /// The value is NULL.
+    Yes,
+    /// The value is not NULL.
+    No,
+}
+
+/// A trait for types that can be converted into Postgres values.
+pub trait ToSql: fmt::Debug {
+    /// Converts the value of `self` into the binary format of the specified
+    /// Postgres `Type`, appending it to `out`.
+    ///
+    /// The caller of this method is responsible for ensuring that this type
+    /// is compatible with the Postgres `Type`.
+    ///
+    /// The return value indicates if this value should be represented as
+    /// `NULL`. If this is the case, implementations **must not** write
+    /// anything to `out`.
+    fn to_sql(&self, ty: &Type, out: &mut BytesMut) -> Result<IsNull, Box<dyn Error + Sync + Send>>
+    where
+        Self: Sized;
+
+    /// Determines if a value of this type can be converted to the specified
+    /// Postgres `Type`.
+    fn accepts(ty: &Type) -> bool
+    where
+        Self: Sized;
+
+    /// An adaptor method used internally by Rust-Postgres.
+    ///
+    /// *All* implementations of this method should be generated by the
+    /// `to_sql_checked!()` macro.
+    fn to_sql_checked(
+        &self,
+        ty: &Type,
+        out: &mut BytesMut,
+    ) -> Result<IsNull, Box<dyn Error + Sync + Send>>;
+
+    /// Specify the encode format
+    fn encode_format(&self, _ty: &Type) -> Format {
+        Format::Binary
+    }
+}
+
+/// Supported Postgres message format types
+///
+/// Using Text format in a message assumes a Postgres `SERVER_ENCODING` of `UTF8`
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum Format {
+    /// Text format (UTF-8)
+    Text,
+    /// Compact, typed binary format
+    Binary,
+}
+
+impl ToSql for &str {
+    fn to_sql(&self, ty: &Type, w: &mut BytesMut) -> Result<IsNull, Box<dyn Error + Sync + Send>> {
+        match *ty {
+            ref ty if ty.name() == "ltree" => types::ltree_to_sql(self, w),
+            ref ty if ty.name() == "lquery" => types::lquery_to_sql(self, w),
+            ref ty if ty.name() == "ltxtquery" => types::ltxtquery_to_sql(self, w),
+            _ => types::text_to_sql(self, w),
+        }
+        Ok(IsNull::No)
+    }
+
+    fn accepts(ty: &Type) -> bool {
+        match *ty {
+            Type::VARCHAR | Type::TEXT | Type::BPCHAR | Type::NAME | Type::UNKNOWN => true,
+            ref ty
+                if (ty.name() == "citext"
+                    || ty.name() == "ltree"
+                    || ty.name() == "lquery"
+                    || ty.name() == "ltxtquery") =>
+            {
+                true
+            }
+            _ => false,
+        }
+    }
+
+    to_sql_checked!();
+}
+
+macro_rules! simple_to {
+    ($t:ty, $f:ident, $($expected:ident),+) => {
+        impl ToSql for $t {
+            fn to_sql(&self,
+                      _: &Type,
+                      w: &mut BytesMut)
+                      -> Result<IsNull, Box<dyn Error + Sync + Send>> {
+                types::$f(*self, w);
+                Ok(IsNull::No)
+            }
+
+            accepts!($($expected),+);
+
+            to_sql_checked!();
+        }
+    }
+}
+
+simple_to!(u32, oid_to_sql, OID);

libs/proxy/postgres-types2/src/private.rs

@@ -0,0 +1,34 @@
+use crate::{FromSql, Type};
+pub use bytes::BytesMut;
+use std::error::Error;
+
+pub fn read_be_i32(buf: &mut &[u8]) -> Result<i32, Box<dyn Error + Sync + Send>> {
+    if buf.len() < 4 {
+        return Err("invalid buffer size".into());
+    }
+    let mut bytes = [0; 4];
+    bytes.copy_from_slice(&buf[..4]);
+    *buf = &buf[4..];
+    Ok(i32::from_be_bytes(bytes))
+}
+
+pub fn read_value<'a, T>(
+    type_: &Type,
+    buf: &mut &'a [u8],
+) -> Result<T, Box<dyn Error + Sync + Send>>
+where
+    T: FromSql<'a>,
+{
+    let len = read_be_i32(buf)?;
+    let value = if len < 0 {
+        None
+    } else {
+        if len as usize > buf.len() {
+            return Err("invalid buffer size".into());
+        }
+        let (head, tail) = buf.split_at(len as usize);
+        *buf = tail;
+        Some(head)
+    };
+    T::from_sql_nullable(type_, value)
+}