initial commit

.cargo/config.toml

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+[target.'cfg(target_os="macos")']
+# Postgres symbols won't be available until runtime
+rustflags = ["-Clink-arg=-Wl,-undefined,dynamic_lookup"]

.gitignore

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+.DS_Store
+.idea/
+/target
+*.iml
+**/*.rs.bk
+Cargo.lock

Cargo.toml

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+[package]
+name = "pqddlread"
+version = "0.0.0"
+edition = "2021"
+
+[lib]
+crate-type = ["cdylib"]
+
+[features]
+default = ["pg13"]
+pg11 = ["pgrx/pg11", "pgrx-tests/pg11" ]
+pg12 = ["pgrx/pg12", "pgrx-tests/pg12" ]
+pg13 = ["pgrx/pg13", "pgrx-tests/pg13" ]
+pg14 = ["pgrx/pg14", "pgrx-tests/pg14" ]
+pg15 = ["pgrx/pg15", "pgrx-tests/pg15" ]
+pg16 = ["pgrx/pg16", "pgrx-tests/pg16" ]
+pg_test = []
+
+[dependencies]
+pgrx = "=0.11.4"
+
+[dev-dependencies]
+pgrx-tests = "=0.11.4"
+
+[profile.dev]
+panic = "unwind"
+
+[profile.release]
+panic = "unwind"
+opt-level = 3
+lto = "fat"
+codegen-units = 1

README.md

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+Базовый пример установки хука на `ExecutorEnd_hook`. Для наглядности в примере сразу вызывается сбой после завершения выполнения любого запроса.  
+Как выглядит работа:
+```sql
+psql (13.15)
+Type "help" for help.
+
+pqddlread=# create extension pqddlread;
+CREATE EXTENSION
+pqddlread=# -- Хук пока не установлен, все запросы выполняются.
+pqddlread=# select 1;
+ ?column?
+----------
+        1
+(1 row)
+
+pqddlread=# -- Устанавливаем хук. Он сразу же заработает т.к. на момент завершения вызова функции хук уже стоит.
+pqddlread=# select pqddlread();
+ERROR:  This panic indicates that hook was called successfully. Last query info: QueryDesc { operation: 1, plannedstmt: 0x5f9ec2a32650, sourceText: 0x5f9ec2958740, snapshot: 0x5f9ec29df648, crosscheck_snapshot: 0x0, dest: 0x5f9ec2a327c0, params: 0x0, queryEnv: 0x0, instrument_options: 0, tupDesc: 0x5f9ec2a2c3b0, estate: 0x5f9ec2a2bf70, planstate: 0x5f9ec2a2c1a8, already_executed: true, totaltime: 0x0 }
+pqddlread=# -- Теперь ВСЕ запросы сломаны :)
+pqddlread=# select 1;
+ERROR:  This panic indicates that hook was called successfully. Last query info: QueryDesc { operation: 1, plannedstmt: 0x5f9ec2a32458, sourceText: 0x5f9ec2958740, snapshot: 0x5f9ec2a1c868, crosscheck_snapshot: 0x0, dest: 0x5f9ec2a325c8, params: 0x0, queryEnv: 0x0, instrument_options: 0, tupDesc: 0x5f9ec29dfa50, estate: 0x5f9ec29df610, planstate: 0x5f9ec29df848, already_executed: true, totaltime: 0x0 }
+pqddlread=# -- Хук выводит всю информацию о запросе. Мы можем делать с ней что угодно.
+```

pqddlread.control

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+comment = 'pqddlread:  Created by pgrx'
+default_version = '@CARGO_VERSION@'
+module_pathname = '$libdir/pqddlread'
+relocatable = false
+superuser = true

src/hook.rs

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+use pgrx::prelude::*;
+use pgrx::hooks::PgHooks;
+use pgrx::hooks::HookResult;
+
+pub struct Catcher {}
+
+impl Catcher {
+    pub fn new() -> &'static mut (dyn PgHooks + 'static) {
+        let val: &'static mut Catcher = Box::leak(Box::new(Catcher {}));
+        val
+    }
+}
+
+impl PgHooks for Catcher {
+    fn executor_finish(
+        &mut self,
+        query_desc: PgBox<pg_sys::QueryDesc>,
+        prev_hook: fn(query_desc: PgBox<pg_sys::QueryDesc>) -> HookResult<()>,
+    ) -> HookResult<()> {
+        panic!("{}", format!("This panic indicates that hook was called successfully. Last query info: {:?}", query_desc));
+        prev_hook(query_desc)
+    }
+}

src/lib.rs

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+use pgrx::prelude::*;
+
+mod hook;
+
+::pgrx::pg_module_magic!();
+
+#[pg_extern]
+fn pqddlread() {
+    unsafe {
+        pgrx::hooks::register_hook(hook::Catcher::new());
+    }
+}