cargo-pgrx: reduce trivial dep usages (#1499)

I noticed #1468 would allow us to also remove a dependency or two from
cargo-pgrx, so I started work by removing once_cell from it and a few
other spots in our tree, although we use it so pervasively it's not
realistic to remove it entirely. It was actually secretly in our public
API, behind a `#[doc(hidden)]`, for some reason.

I then noticed a bunch of other easy removals from cargo-pgrx:
- serde_derive should not be used directly
- flate2, prettyplease, syn, and unescape are not directly used anymore
- nix crate maintenance has gotten better, but it is a big dep for 1 bool

cargo-pgrx/Cargo.toml

@@ -28,38 +28,38 @@ pgrx-pg-config.workspace = true
 pgrx-sql-entity-graph.workspace = true
 
 cargo_toml.workspace = true
-eyre.workspace = true
-owo-colors.workspace = true
+libc.workspace = true
 regex.workspace = true
-unescape.workspace = true
-url.workspace = true
 
 cargo_metadata = "0.17.0"
 clap = { version = "4.4.2", features = [ "env", "suggestions", "cargo", "derive", "wrap_help" ] }
 clap-cargo = { version = "0.11.0", features = [ "cargo_metadata" ] }
-semver = "1.0.20"
-env_proxy = "0.4.1"
-prettyplease = "0.2.15"
+jobslot = "0.2.12" # as seen in gmake -j{N}
+semver = "1.0.20" # checking pgrx versions match
+tempfile = "3.8.0"
+toml = "0.8.2" # our config files
+
+# SQL schema generation
+object = "0.32.1"
 proc-macro2 = { version = "1.0.69", features = [ "span-locations" ] }
 quote = "1.0.33"
-ureq = { version = "2.8.0", default-features = false, features = [ "gzip" ] }
-serde = { version = "1.0", features = [ "derive" ] }
-serde_derive = "1.0"
-serde-xml-rs = "0.6.0"
-syn = { version = "2.0.18", features = [ "extra-traits", "full", "fold", "parsing" ] }
-object = "0.32.1"
-once_cell = "1.18.0"
+
+# emit better diagnostics
 color-eyre = "0.6.2"
+eyre.workspace = true
+owo-colors.workspace = true
 tracing = "0.1"
 tracing-error = "0.2.0"
 tracing-subscriber = { version = "0.3.17", features = [ "env-filter" ] }
-flate2 = { version = "1.0.27", default-features = false, features = ["rust_backend"] }
-tempfile = "3.8.0"
-nix = { version = "0.27", default-features = false, features = ["user"] }
-toml = "0.8.2"
-jobslot = "0.2.12"
+
+# for downloading/unpacking things from the Postgres file servers
 bzip2 = "0.4.4"
+env_proxy = "0.4.1"
+serde = { version = "1.0", features = [ "derive" ] }
+serde-xml-rs = "0.6.0"
 tar = "0.4.40"
+ureq = { version = "2.8.0", default-features = false, features = [ "gzip" ] }
+url.workspace = true
 
 [features]
 default = ["rustls"]

cargo-pgrx/src/command/init.rs

@@ -590,8 +590,9 @@ fn get_pg_installdir(pgdir: &PathBuf) -> PathBuf {
 
 #[cfg(unix)]
 fn is_root_user() -> bool {
-    use nix::unistd::Uid;
-    Uid::effective().is_root()
+    // SAFETY: No, the `nix` crate does not do anything more clever:
+    // check if effective user ID is 0, AKA "root"
+    unsafe { libc::geteuid() == 0 }
 }
 
 /// Incorrectly answers false, reverting pgrx to pre-root-aware behavior,

cargo-pgrx/src/command/install.rs

@@ -14,15 +14,14 @@ use crate::profile::CargoProfile;
 use crate::CommandExecute;
 use cargo_toml::Manifest;
 use eyre::{eyre, WrapErr};
-use once_cell::sync::Lazy;
 use owo_colors::OwoColorize;
 use pgrx_pg_config::{cargo::PgrxManifestExt, get_target_dir, PgConfig, Pgrx};
 use std::collections::HashMap;
 use std::fs;
 use std::io::BufReader;
 use std::path::{Path, PathBuf};
 use std::process::Stdio;
-use std::sync::{Arc, Mutex};
+use std::sync::{Arc, Mutex, OnceLock};
 
 /// Type used for memoizing expensive to calculate values.
 /// `Arc<Mutex>` is needed to get around compiler safety checks.
@@ -453,12 +452,14 @@ pub(crate) fn find_library_file(
     Ok(library_file_path)
 }
 
-static CARGO_VERSION: Lazy<MemoizeKeyValue> = Lazy::new(|| Arc::new(Mutex::new(HashMap::new())));
+static CARGO_VERSION: OnceLock<MemoizeKeyValue> = OnceLock::new();
 
 pub(crate) fn get_version(manifest_path: impl AsRef<Path>) -> eyre::Result<String> {
     let path_string = manifest_path.as_ref().to_owned();
 
-    if let Some(version) = CARGO_VERSION.lock().unwrap().get(&path_string) {
+    if let Some(version) =
+        CARGO_VERSION.get_or_init(Default::default).lock().unwrap().get(&path_string)
+    {
         return Ok(version.clone());
     }
 
@@ -481,16 +482,20 @@ pub(crate) fn get_version(manifest_path: impl AsRef<Path>) -> eyre::Result<Strin
         None => return Err(eyre!("cannot determine extension version number.  Is the `default_version` property declared in the control file?")),
     };
 
-    CARGO_VERSION.lock().unwrap().insert(path_string, version.clone());
+    CARGO_VERSION
+        .get_or_init(Default::default)
+        .lock()
+        .unwrap()
+        .insert(path_string, version.clone());
     Ok(version)
 }
 
-static GIT_HASH: Lazy<MemoizeKeyValue> = Lazy::new(|| Arc::new(Mutex::new(HashMap::new())));
+static GIT_HASH: OnceLock<MemoizeKeyValue> = OnceLock::new();
 
 fn get_git_hash(manifest_path: impl AsRef<Path>) -> eyre::Result<String> {
     let path_string = manifest_path.as_ref().to_owned();
 
-    if let Some(hash) = GIT_HASH.lock().unwrap().get(&path_string) {
+    if let Some(hash) = GIT_HASH.get_or_init(Default::default).lock().unwrap().get(&path_string) {
         Ok(hash.clone())
     } else {
         let hash = match get_property(manifest_path, "git_hash")? {
@@ -500,7 +505,7 @@ fn get_git_hash(manifest_path: impl AsRef<Path>) -> eyre::Result<String> {
             )),
         };
 
-        GIT_HASH.lock().unwrap().insert(path_string, hash.clone());
+        GIT_HASH.get_or_init(Default::default).lock().unwrap().insert(path_string, hash.clone());
 
         Ok(hash)
     }

cargo-pgrx/src/command/version.rs

@@ -23,7 +23,7 @@ mod rss {
     use eyre::WrapErr;
     use owo_colors::OwoColorize;
     use pgrx_pg_config::{PgMinorVersion, PgVersion};
-    use serde_derive::Deserialize;
+    use serde::Deserialize;
     use std::collections::BTreeMap;
     use url::Url;
 

pgrx-pg-sys/Cargo.toml

@@ -60,4 +60,3 @@ proc-macro2 = "1.0.69"
 quote = "1.0.33"
 syn = { version = "1.0.109", features = [ "extra-traits", "full", "fold", "parsing" ] }
 shlex = "1.3" # shell lexing, also used by many of our deps
-once_cell = "1.18.0"

pgrx-pg-sys/build.rs

@@ -9,7 +9,6 @@
 //LICENSE Use of this source code is governed by the MIT license that can be found in the LICENSE file.
 use bindgen::callbacks::{DeriveTrait, ImplementsTrait, MacroParsingBehavior};
 use eyre::{eyre, WrapErr};
-use once_cell::sync::Lazy;
 use pgrx_pg_config::{
     is_supported_major_version, prefix_path, PgConfig, PgConfigSelector, Pgrx, SUPPORTED_VERSIONS,
 };
@@ -19,6 +18,7 @@ use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::fs;
 use std::path::{self, PathBuf}; // disambiguate path::Path and syn::Type::Path
 use std::process::{Command, Output};
+use std::sync::OnceLock;
 use syn::{ForeignItem, Item, ItemConst};
 
 const BLOCKLISTED_TYPES: [&str; 3] = ["Datum", "NullableDatum", "Oid"];
@@ -1026,8 +1026,7 @@ fn run_command(mut command: &mut Command, version: &str) -> eyre::Result<Output>
 
 // Plausibly it would be better to generate a regex to pass to bindgen for this,
 // but this is less error-prone for now.
-static BLOCKLISTED: Lazy<BTreeSet<&'static str>> =
-    Lazy::new(|| build::sym_blocklist::SYMBOLS.iter().copied().collect::<BTreeSet<&str>>());
+static BLOCKLISTED: OnceLock<BTreeSet<&'static str>> = OnceLock::new();
 fn is_blocklisted_item(item: &ForeignItem) -> bool {
     let sym_name = match item {
         ForeignItem::Fn(f) => &f.sig.ident,
@@ -1036,7 +1035,9 @@ fn is_blocklisted_item(item: &ForeignItem) -> bool {
         ForeignItem::Static(s) => &s.ident,
         _ => return false,
     };
-    BLOCKLISTED.contains(sym_name.to_string().as_str())
+    BLOCKLISTED
+        .get_or_init(|| build::sym_blocklist::SYMBOLS.iter().copied().collect::<BTreeSet<&str>>())
+        .contains(sym_name.to_string().as_str())
 }
 
 fn apply_pg_guard(items: &Vec<syn::Item>) -> eyre::Result<proc_macro2::TokenStream> {

pgrx-sql-entity-graph/Cargo.toml

@@ -26,14 +26,14 @@ no-schema-generation = []
 
 [dependencies]
 eyre.workspace = true
-unescape.workspace = true
 thiserror.workspace = true
 
 convert_case = "0.6.0"
 petgraph = "0.6.4"
 proc-macro2 = { version = "1.0.69", features = [ "span-locations" ] }
 quote = "1.0.33"
 syn = { version = "1.0.109", features = [ "extra-traits", "full", "fold", "parsing" ] }
+unescape = "0.1.0" # for escaped-character-handling
 
 # colorized sql output
 owo-colors = { optional = true, workspace = true }

pgrx-tests/Cargo.toml

@@ -58,7 +58,6 @@ thiserror.workspace = true
 owo-colors.workspace = true
 
 clap-cargo = "0.11.0"
-once_cell = "1.18.0"
 postgres = "0.19.7"
 proptest = { version = "1", optional = true }
 serde = "1.0"

pgrx-tests/src/framework.rs

@@ -11,7 +11,6 @@ use std::collections::HashSet;
 use std::process::{Command, Stdio};
 
 use eyre::{eyre, WrapErr};
-use once_cell::sync::Lazy;
 use owo_colors::OwoColorize;
 use pgrx::prelude::*;
 use pgrx_pg_config::{
@@ -21,7 +20,7 @@ use postgres::error::DbError;
 use std::collections::HashMap;
 use std::io::{BufRead, BufReader, Write};
 use std::path::PathBuf;
-use std::sync::{Arc, Mutex};
+use std::sync::{Arc, Mutex, OnceLock};
 use std::time::Duration;
 use sysinfo::{Pid, ProcessExt, System, SystemExt};
 
@@ -36,13 +35,7 @@ struct SetupState {
     system_session_id: String,
 }
 
-static TEST_MUTEX: Lazy<Mutex<SetupState>> = Lazy::new(|| {
-    Mutex::new(SetupState {
-        installed: false,
-        loglines: Arc::new(Mutex::new(HashMap::new())),
-        system_session_id: "NONE".to_string(),
-    })
-});
+static TEST_MUTEX: OnceLock<Mutex<SetupState>> = OnceLock::new();
 
 // The goal of this closure is to allow "wrapping" of anything that might issue
 // an SQL simple_query or query using either a postgres::Client or
@@ -198,14 +191,23 @@ fn format_loglines(session_id: &str, loglines: &LogLines) -> String {
 fn initialize_test_framework(
     postgresql_conf: Vec<&'static str>,
 ) -> eyre::Result<(LogLines, String)> {
-    let mut state = TEST_MUTEX.lock().unwrap_or_else(|_| {
-        // This used to immediately throw an std::process::exit(1), but it
-        // would consume both stdout and stderr, resulting in error messages
-        // not being displayed unless you were running tests with --nocapture.
-        panic!(
+    let mut state = TEST_MUTEX
+        .get_or_init(|| {
+            Mutex::new(SetupState {
+                installed: false,
+                loglines: Arc::new(Mutex::new(HashMap::new())),
+                system_session_id: "NONE".to_string(),
+            })
+        })
+        .lock()
+        .unwrap_or_else(|_| {
+            // This used to immediately throw an std::process::exit(1), but it
+            // would consume both stdout and stderr, resulting in error messages
+            // not being displayed unless you were running tests with --nocapture.
+            panic!(
             "Could not obtain test mutex. A previous test may have hard-aborted while holding it."
         );
-    });
+        });
 
     if !state.installed {
         shutdown::register_shutdown_hook();

pgrx/src/lib.rs

@@ -83,9 +83,6 @@ pub mod varlena;
 pub mod wrappers;
 pub mod xid;
 
-#[doc(hidden)]
-pub use once_cell;
-
 /// Not ready for public exposure.
 mod layout;
 mod ptr;