fix(s3vectors): s3vec type upgrade issue (supabase#580)

* fix(s3vec): s3vec type upgrade issue

* fix(build): conditionally generate s3vec SQL only if S3VECTORS_FDW feature is enabled

Author: burmecia

wrappers/build.rs

@@ -0,0 +1,80 @@
+use std::fs;
+use std::path::Path;
+
+fn main() {
+    if std::env::var("CARGO_FEATURE_S3VECTORS_FDW").is_ok() {
+        generate_s3vec_type_sql();
+    }
+}
+
+/// Generates `s3vec_type_sql.rs` in OUT_DIR, which contains the `pgrx::extension_sql!` call
+/// for the S3Vec type with the correct versioned library name embedded as a string literal.
+///
+/// This indirection is necessary because `pgrx::extension_sql!` requires a string literal
+/// (not a macro expression like `concat!(env!(...), ...)`), but we need the library name
+/// (e.g. "wrappers-0.6.0") to be derived from the crate version at compile time.
+///
+/// The generated file is included in `s3vec.rs` via:
+///   `include!(concat!(env!("OUT_DIR"), "/s3vec_type_sql.rs"));`
+fn generate_s3vec_type_sql() {
+    let out_dir = std::env::var("OUT_DIR").expect("OUT_DIR not set");
+    let pkg_name = std::env::var("CARGO_PKG_NAME").expect("CARGO_PKG_NAME not set");
+    let pkg_version = std::env::var("CARGO_PKG_VERSION").expect("CARGO_PKG_VERSION not set");
+    let lib_name = format!("{pkg_name}-{pkg_version}");
+
+    // The outer r##"..."## delimiter allows r#"..."# to appear inside the format string.
+    let content = format!(
+        r##"// @generated by build.rs — do not edit by hand.
+// Library name "{lib_name}" is embedded at compile time from CARGO_PKG_NAME/VERSION.
+pgrx::extension_sql!(
+    r#"DO $s3vec_upgrade$
+BEGIN
+    -- 1. Shell type (must exist before the in/out functions reference it)
+    BEGIN
+        CREATE TYPE S3Vec;
+    EXCEPTION WHEN duplicate_object THEN NULL;
+    END;
+
+    -- 2. Input function
+    BEGIN
+        CREATE FUNCTION "s3vec_in"("input" cstring)
+            RETURNS S3Vec
+            IMMUTABLE PARALLEL SAFE
+            LANGUAGE c
+            AS '{lib_name}', 's3vec_in_wrapper';
+    EXCEPTION WHEN duplicate_object THEN NULL;
+    END;
+
+    -- 3. Output function
+    BEGIN
+        CREATE FUNCTION "s3vec_out"("input" S3Vec)
+            RETURNS cstring
+            IMMUTABLE STRICT PARALLEL SAFE
+            LANGUAGE c
+            AS '{lib_name}', 's3vec_out_wrapper';
+    EXCEPTION WHEN duplicate_object THEN NULL;
+    END;
+
+    -- 4. Complete type definition (must come after in/out functions)
+    BEGIN
+        CREATE TYPE S3Vec (
+            INTERNALLENGTH = variable,
+            INPUT = s3vec_in,
+            OUTPUT = s3vec_out,
+            STORAGE = extended
+        );
+    EXCEPTION WHEN duplicate_object THEN NULL;
+    END;
+END
+$s3vec_upgrade$;
+"#,
+    name = "s3vec_type",
+    creates = [Type(S3Vec)],
+);
+"##
+    );
+
+    let out_path = Path::new(&out_dir).join("s3vec_type_sql.rs");
+    fs::write(&out_path, content)
+        .unwrap_or_else(|e| panic!("failed to write {}: {e}", out_path.display()));
+}

wrappers/src/fdw/s3vectors_fdw/s3vec.rs

@@ -8,6 +8,7 @@ use std::ffi::CStr;
 
 #[derive(Debug, Default, PostgresType, Serialize, Deserialize)]
 #[inoutfuncs]
+#[pgrx(sql = false)] // SQL is written manually below to support idempotent upgrades
 pub(super) struct S3Vec {
     pub key: String,
     pub data: Vec<f32>,
@@ -39,6 +40,19 @@ impl InOutFuncs for S3Vec {
     }
 }
 
+// Idempotent SQL for S3Vec type and its in/out functions.
+//
+// pgrx generates plain CREATE TYPE / CREATE FUNCTION (no OR REPLACE / IF NOT EXISTS),
+// which fails when upgrading from a version that already has S3Vec.  By setting
+// sql = false above and writing the SQL here we wrap every statement in a nested
+// BEGIN/EXCEPTION WHEN duplicate_object THEN NULL block so the whole block
+// succeeds whether or not the objects already exist.
+//
+// pgrx::extension_sql! requires a string literal, so build.rs generates
+// s3vec_type_sql.rs with the versioned library name (e.g. "wrappers-0.6.0")
+// embedded as a literal from CARGO_PKG_NAME/VERSION at compile time.
+include!(concat!(env!("OUT_DIR"), "/s3vec_type_sql.rs"));
+
 impl From<&ListOutputVector> for S3Vec {
     fn from(v: &ListOutputVector) -> Self {
         let data = if let Some(VectorData::Float32(vector_data)) = &v.data {