extract packet crate (#3029)

* extract packet crate

* typo

* sort deps

* update digest

* add doc_auto_cfg like in #3121

* fix frozen-abi

Cargo.toml

@@ -122,6 +122,7 @@ members = [
     "sdk/native-token",
     "sdk/package-metadata",
     "sdk/package-metadata-macro",
+    "sdk/packet",
     "sdk/precompile-error",
     "sdk/program",
     "sdk/program-entrypoint",
@@ -237,6 +238,7 @@ bytes = "1.8"
 bzip2 = "0.4.4"
 caps = "0.5.5"
 cargo_metadata = "0.15.4"
+cfg_eval = "0.1.2"
 chrono = { version = "0.4.38", default-features = false }
 chrono-humanize = "0.2.3"
 clap = "2.33.1"
@@ -447,6 +449,7 @@ solana-nohash-hasher = "0.2.1"
 solana-notifier = { path = "notifier", version = "=2.1.0" }
 solana-package-metadata = { path = "sdk/package-metadata", version = "=2.1.0" }
 solana-package-metadata-macro = { path = "sdk/package-metadata-macro", version = "=2.1.0" }
+solana-packet = { path = "sdk/packet", version = "=2.1.0" }
 solana-perf = { path = "perf", version = "=2.1.0" }
 solana-poh = { path = "poh", version = "=2.1.0" }
 solana-poseidon = { path = "poseidon", version = "=2.1.0" }

core/src/banking_trace.rs

@@ -65,7 +65,7 @@ pub struct BankingTracer {
 #[cfg_attr(
     feature = "frozen-abi",
     derive(AbiExample),
-    frozen_abi(digest = "F5GH1poHbPqipU4DB3MczhSxHZw4o27f3C7QnMVirFci")
+    frozen_abi(digest = "6PCDw6YSEivfbwhbPmE4NAsXb88ZX6hkFnruP8B38nma")
 )]
 #[derive(Serialize, Deserialize, Debug)]
 pub struct TimedTracedEvent(pub std::time::SystemTime, pub TracedEvent);

sdk/Cargo.toml

@@ -101,6 +101,7 @@ solana-frozen-abi-macro = { workspace = true, optional = true, features = [
 ] }
 solana-instruction = { workspace = true }
 solana-native-token = { workspace = true }
+solana-packet = { workspace = true, features = ["bincode", "serde"] }
 solana-precompile-error = { workspace = true, optional = true }
 solana-program = { workspace = true }
 solana-program-memory = { workspace = true }

sdk/packet/Cargo.toml

@@ -0,0 +1,44 @@
+[package]
+name = "solana-packet"
+description = "The definition of a Solana network packet."
+documentation = "https://docs.rs/solana-packet"
+version = { workspace = true }
+authors = { workspace = true }
+repository = { workspace = true }
+homepage = { workspace = true }
+license = { workspace = true }
+edition = { workspace = true }
+
+[dependencies]
+bincode = { workspace = true, optional = true }
+bitflags = { workspace = true }
+cfg_eval = { workspace = true, optional = true }
+serde = { workspace = true, optional = true }
+serde_derive = { workspace = true, optional = true }
+serde_with = { workspace = true, optional = true, features = ["macros"] }
+solana-frozen-abi = { workspace = true, optional = true, features = ["frozen-abi"] }
+solana-frozen-abi-macro = { workspace = true, optional = true, features = ["frozen-abi"] }
+
+[dev-dependencies]
+solana-packet = { path = ".", features = ["dev-context-only-utils"] }
+static_assertions = { workspace = true }
+
+[features]
+bincode = ["dep:bincode", "serde"]
+dev-context-only-utils = ["bincode"]
+serde = [
+    "bitflags/serde",
+    "dep:cfg_eval",
+    "dep:serde",
+    "dep:serde_derive",
+    "dep:serde_with"
+]
+frozen-abi = ["dep:solana-frozen-abi", "dep:solana-frozen-abi-macro"]
+
+[package.metadata.docs.rs]
+targets = ["x86_64-unknown-linux-gnu"]
+all-features = true
+rustdoc-args = ["--cfg=docsrs"]
+
+[lints]
+workspace = true

sdk/src/packet.rs → sdk/packet/src/lib.rs

@@ -1,16 +1,24 @@
 //! The definition of a Solana network packet.
+#![cfg_attr(feature = "frozen-abi", feature(min_specialization))]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
 
+#[cfg(feature = "bincode")]
+use bincode::{Options, Result};
+#[cfg(feature = "frozen-abi")]
+use solana_frozen_abi_macro::AbiExample;
 use {
-    bincode::{Options, Result},
     bitflags::bitflags,
-    serde::{Deserialize, Serialize},
-    serde_with::{serde_as, Bytes},
     std::{
-        fmt, io,
+        fmt,
         net::{IpAddr, Ipv4Addr, SocketAddr},
         slice::SliceIndex,
     },
 };
+#[cfg(feature = "serde")]
+use {
+    serde_derive::{Deserialize, Serialize},
+    serde_with::{serde_as, Bytes},
+};
 
 #[cfg(test)]
 static_assertions::const_assert_eq!(PACKET_DATA_SIZE, 1232);
@@ -22,7 +30,8 @@ pub const PACKET_DATA_SIZE: usize = 1280 - 40 - 8;
 
 bitflags! {
     #[repr(C)]
-    #[derive(Copy, Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+    #[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+    #[derive(Copy, Clone, Debug, PartialEq, Eq)]
     pub struct PacketFlags: u8 {
         const DISCARD        = 0b0000_0001;
         const FORWARDED      = 0b0000_0010;
@@ -39,7 +48,8 @@ bitflags! {
 }
 
 #[cfg_attr(feature = "frozen-abi", derive(AbiExample))]
-#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+#[derive(Clone, Debug, PartialEq, Eq)]
 #[repr(C)]
 pub struct Meta {
     pub size: usize,
@@ -88,14 +98,18 @@ impl ::solana_frozen_abi::abi_example::EvenAsOpaque for PacketFlags {
 //   https://github.com/serde-rs/serde/pull/1860
 // ryoqun's dirty experiments:
 //   https://github.com/ryoqun/serde-array-comparisons
-#[serde_as]
+//
+// We use the cfg_eval crate as advised by the serde_with guide:
+// https://docs.rs/serde_with/latest/serde_with/guide/serde_as/index.html#gating-serde_as-on-features
+#[cfg_attr(feature = "serde", cfg_eval::cfg_eval, serde_as)]
 #[cfg_attr(feature = "frozen-abi", derive(AbiExample))]
-#[derive(Clone, Eq, Serialize, Deserialize)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+#[derive(Clone, Eq)]
 #[repr(C)]
 pub struct Packet {
     // Bytes past Packet.meta.size are not valid to read from.
     // Use Packet.data(index) to read from the buffer.
-    #[serde_as(as = "Bytes")]
+    #[cfg_attr(feature = "serde", serde_as(as = "Bytes"))]
     buffer: [u8; PACKET_DATA_SIZE],
     meta: Meta,
 }
@@ -144,19 +158,21 @@ impl Packet {
         &mut self.meta
     }
 
-    pub fn from_data<T: Serialize>(dest: Option<&SocketAddr>, data: T) -> Result<Self> {
+    #[cfg(feature = "bincode")]
+    pub fn from_data<T: serde::Serialize>(dest: Option<&SocketAddr>, data: T) -> Result<Self> {
         let mut packet = Self::default();
         Self::populate_packet(&mut packet, dest, &data)?;
         Ok(packet)
     }
 
-    pub fn populate_packet<T: Serialize>(
+    #[cfg(feature = "bincode")]
+    pub fn populate_packet<T: serde::Serialize>(
         &mut self,
         dest: Option<&SocketAddr>,
         data: &T,
     ) -> Result<()> {
         debug_assert!(!self.meta.discard());
-        let mut wr = io::Cursor::new(self.buffer_mut());
+        let mut wr = std::io::Cursor::new(self.buffer_mut());
         bincode::serialize_into(&mut wr, data)?;
         self.meta.size = wr.position() as usize;
         if let Some(dest) = dest {
@@ -165,6 +181,7 @@ impl Packet {
         Ok(())
     }
 
+    #[cfg(feature = "bincode")]
     pub fn deserialize_slice<T, I>(&self, index: I) -> Result<T>
     where
         T: serde::de::DeserializeOwned,

sdk/src/lib.rs

@@ -81,7 +81,6 @@ pub mod native_loader;
 pub mod net;
 pub mod nonce_account;
 pub mod offchain_message;
-pub mod packet;
 pub mod poh_config;
 pub mod precompiles;
 pub mod program_utils;
@@ -120,6 +119,8 @@ pub use solana_decode_error as decode_error;
 pub use solana_derivation_path as derivation_path;
 #[deprecated(since = "2.1.0", note = "Use `solana-feature-set` crate instead")]
 pub use solana_feature_set as feature_set;
+#[deprecated(since = "2.1.0", note = "Use `solana-packet` crate instead")]
+pub use solana_packet as packet;
 #[deprecated(since = "2.1.0", note = "Use `solana-program-memory` crate instead")]
 pub use solana_program_memory as program_memory;
 #[deprecated(since = "2.1.0", note = "Use `solana_pubkey::pubkey` instead")]