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/****************************************************************
* *
* Copyright (c) 2020-2022 YottaDB LLC and/or its subsidiaries. *
* All rights reserved. *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
use std::ffi::CStr;
use crate::{YDBResult, simple_api::call_in::*};
use super::Context;
/// Make an FFI call to M.
///
/// `ci_t` is equivalent to a variadic function with the following signature:
/// ```ignore
/// unsafe fn ci_t(tptoken: u64, err_buffer: Vec<u8>, routine: &CStr, ...) -> YDBResult<Vec<u8>>;
/// ```
/// However, since Rust does not allow implementing variadic functions, it is a macro instead.
///
/// # Safety
/// Each argument passed (after `routine`) must correspond to the appropriate argument expected by `routine`.
/// If `routine` returns a value, the first argument must be a pointer to an out parameter in which to store the value.
/// All arguments must be [representable as C types][repr-c].
///
/// # See also
/// - [C to M FFI](https://docs.yottadb.com/MultiLangProgGuide/cprogram.html#calling-m-routines)
/// - [The M documentation on call-ins](https://docs.yottadb.com/ProgrammersGuide/extrout.html#calls-from-external-routines-call-ins)
/// - [`cip_t!`], which allows caching the `routine` lookup, making future calls faster.
///
/// # Example
/// Call the M routine described by `HelloWorld1` in the call-in table.
/// See also `examples/m-ffi/helloworld1.m` and `examples/m-ffi/calltab.ci`.
/// ```
/// use std::env;
/// use std::ffi::CString;
/// use std::os::raw::c_char;
/// use yottadb::{craw, ci_t, TpToken};
///
/// env::set_var("ydb_routines", "examples/m-ffi");
/// env::set_var("ydb_ci", "examples/m-ffi/calltab.ci");
///
/// let mut buf = Vec::<u8>::with_capacity(100);
/// let mut msg = craw::ydb_string_t { length: buf.capacity() as u64, address: buf.as_mut_ptr() as *mut c_char };
/// let routine = CString::new("HelloWorld1").unwrap();
/// unsafe {
/// ci_t!(TpToken::default(), Vec::new(), &routine, &mut msg as *mut _).unwrap();
/// buf.set_len(msg.length as usize);
/// }
/// assert_eq!(&buf, b"entry called");
/// ```
/// [repr-c]: https://doc.rust-lang.org/nomicon/ffi.html#interoperability-with-foreign-code
/// [`cip_t!`]: crate::cip_t!
#[macro_export]
macro_rules! ci_t {
($tptoken: expr, $err_buffer: expr, $routine: expr $(, $args: expr)* $(,)?) => {{
let tptoken: $crate::TpToken = $tptoken;
let err_buffer: ::std::vec::Vec<u8> = $err_buffer;
let routine: &::std::ffi::CStr = $routine;
$crate::resize_call(tptoken, err_buffer, |tptoken, err_buffer_p| {
$crate::craw::ydb_ci_t(tptoken, err_buffer_p, routine.as_ptr(), $($args),*)
})
}}
}
/// Make a FFI call to M using a cached function descriptor.
///
/// `cip_t` is equivalent to a variadic function with the following signature:
/// ```ignore
/// unsafe fn ci_t(tptoken: u64, err_buffer: Vec<u8>, routine: CallInDescriptor, ...) -> YDBResult<Vec<u8>>;
/// ```
/// However, since Rust does not allow implementing variadic functions, it is a macro instead.
///
/// # See also
/// - [`CallInDescriptor`](crate::CallInDescriptor)
/// - [`ci_t!`], which has more information about call-ins in YottaDB.
///
/// # Safety
/// Each argument passed (after `routine`) must correspond to the appropriate argument expected by `routine`.
/// If `routine` returns a value, the first argument must be a pointer to an out parameter in which to store the value.
/// All arguments must be [representable as C types][repr-c].
///
/// [repr-c]: https://doc.rust-lang.org/nomicon/ffi.html#interoperability-with-foreign-code
///
/// # Example
/// Call the M routine described by `HelloWorld1` in the call-in table.
/// See also `examples/m-ffi/helloworld1.m` and `examples/m-ffi/calltab.ci`.
/// ```
/// use std::env;
/// use std::ffi::CString;
/// use std::os::raw::c_char;
/// use yottadb::{craw, cip_t, CallInDescriptor, TpToken};
///
/// env::set_var("ydb_routines", "examples/m-ffi");
/// env::set_var("ydb_ci", "examples/m-ffi/calltab.ci");
///
/// let mut buf = Vec::<u8>::with_capacity(100);
/// let mut msg = craw::ydb_string_t { length: buf.capacity() as u64, address: buf.as_mut_ptr() as *mut c_char };
/// let mut routine = CallInDescriptor::new(CString::new("HelloWorld1").unwrap());
/// unsafe {
/// cip_t!(TpToken::default(), Vec::new(), &mut routine, &mut msg as *mut _).unwrap();
/// buf.set_len(msg.length as usize);
/// }
/// assert_eq!(&buf, b"entry called");
/// ```
/// [`ci_t!`]: crate::ci_t!
#[macro_export]
macro_rules! cip_t {
($tptoken: expr, $err_buffer: expr, $routine: expr, $($args: expr),* $(,)?) => {{
let tptoken: $crate::TpToken = $tptoken;
let err_buffer: ::std::vec::Vec<u8> = $err_buffer;
let routine: &mut $crate::CallInDescriptor = $routine;
$crate::resize_call(tptoken, err_buffer, |tptoken, err_buffer_p| {
$crate::craw::ydb_cip_t(tptoken, err_buffer_p, routine.as_mut_ptr(), $($args),*)
})
}}
}
/// Call-in functions
impl Context {
/// Open the call-in table stored in `file` and return its file descriptor.
///
/// You can later switch the active call-in table by calling [`ci_tab_switch`] with the file descriptor.
///
/// # See also
/// - [C SimpleAPI documentation](https://docs.yottadb.com/MultiLangProgGuide/cprogram.html#ydb-ci-tab-open-ydb-ci-tab-open-t)
/// - [Call-in interface](https://docs.yottadb.com/ProgrammersGuide/extrout.html#call-in-interface)
/// - [`ci_t!`] and [`cip_t!`]
///
/// [`cip_t!`]: crate::cip_t!
/// [`ci_t!`]: crate::ci_t!
///
/// # Errors
// The upstream documentation says
// > YDB_ERR_PARAMINVALID if the input parameters fname or ret_value are NULL; or
// PARAMINVALID is not possible because `ptr` and `&mut ret_val` are always non-null.
/// - a negative [error return code] (for example, if the call-in table in the file had parse errors).
///
/// [`ci_tab_switch`]: Context::ci_tab_switch()
/// [error return code]: https://docs.yottadb.com/MessageRecovery/errormsgref.html#zmessage-codes
///
/// # Example
/// ```
/// # fn main() -> yottadb::YDBResult<()> {
/// use std::ffi::CString;
/// use yottadb::Context;
///
/// let ctx = Context::new();
/// let file = CString::new("examples/m-ffi/calltab.ci").unwrap();
/// let descriptor = ctx.ci_tab_open(&file)?;
/// # Ok(())
/// # }
pub fn ci_tab_open(&self, file: &CStr) -> YDBResult<CallInTableDescriptor> {
let tptoken = self.tptoken();
let buffer = self.take_buffer();
let (descriptor, buffer) = ci_tab_open_t(tptoken, buffer, file)?;
*self.context.buffer.borrow_mut() = buffer;
Ok(descriptor)
}
/// Switch the active call-in table to `new_handle`. Returns the previously active table.
///
/// `new_handle` is a file descriptor returned by [`ci_tab_open`].
///
/// # Errors
// The upstream docs say this:
// > YDB_ERR_PARAMINVALID if the output parameter ret_old_handle is NULL or if the input parameter new_handle points to an invalid handle (i.e. not returned by a prior ydb_ci_tab_open()/ydb_ci_tab_open_t()) call)
// YDB_ERR_PARAMINVALID isn't possible because
// a) we always pass in `&ret_val`, which is non-null, and
// b) we pass in a handle from `CallInDescriptor`, which can only be created by `ci_tab_open_t`
/// - [a negative error return code](https://docs.yottadb.com/MessageRecovery/errormsgref.html#standard-error-codes)
///
/// [`ci_tab_open`]: Context::ci_tab_open()
///
/// # Example
/// ```
/// # fn main() -> yottadb::YDBResult<()> {
/// use std::ffi::CString;
/// use yottadb::Context;
///
/// let ctx = Context::new();
/// let file = CString::new("examples/m-ffi/calltab.ci").unwrap();
/// let descriptor = ctx.ci_tab_open(&file)?;
/// let old_ci_table = ctx.ci_tab_switch(descriptor)?;
/// # Ok(())
/// # }
/// ```
pub fn ci_tab_switch(
&self, new_handle: CallInTableDescriptor,
) -> YDBResult<CallInTableDescriptor> {
let tptoken = self.tptoken();
let buffer = self.take_buffer();
let (descriptor, buffer) = ci_tab_switch_t(tptoken, buffer, new_handle)?;
*self.context.buffer.borrow_mut() = buffer;
Ok(descriptor)
}
}
#[cfg(test)]
mod test {
use std::env;
use std::ffi::CString;
use std::os::raw::c_char;
use super::*;
use crate::craw::{self, ydb_string_t, ydb_long_t};
use crate::YDB_NOTTP;
use crate::test_lock::LockGuard;
fn call<F: FnOnce() -> T, T>(f: F) -> T {
let _guard = LockGuard::read();
env::set_var("ydb_routines", "examples/m-ffi");
env::set_var("ydb_ci", "examples/m-ffi/calltab.ci");
f()
}
// no arguments already tested by doc-test
#[test]
fn string_args() {
call(|| {
let mut routine = CallInDescriptor::new(CString::new("HelloWorld2").unwrap());
let mut ret_buf = Vec::<u8>::with_capacity(100);
let mut ret_msg = ydb_string_t {
length: ret_buf.capacity() as u64,
address: ret_buf.as_mut_ptr() as *mut c_char,
};
let buf1 = b"parm1";
let mut msg1 =
ydb_string_t { length: buf1.len() as u64, address: buf1.as_ptr() as *mut c_char };
let buf2 = b"parm2";
let mut msg2 =
ydb_string_t { length: buf2.len() as u64, address: buf2.as_ptr() as *mut c_char };
let buf3 = b"parm3";
let mut msg3 =
ydb_string_t { length: buf3.len() as u64, address: buf3.as_ptr() as *mut c_char };
unsafe {
cip_t!(
YDB_NOTTP,
Vec::new(),
&mut routine,
&mut ret_msg,
&mut msg1 as *mut _,
&mut msg2 as *mut _,
&mut msg3 as *mut _
)
.unwrap();
ret_buf.set_len(ret_msg.length as usize);
};
assert_eq!(&ret_buf, b"parm3parm2parm1");
});
}
#[test]
fn int_args() {
call(|| {
use crate::craw::ydb_long_t;
let mut routine = CallInDescriptor::new(CString::new("Add").unwrap());
let a = 1 as ydb_long_t;
let b = 2 as ydb_long_t;
let mut out = 0;
unsafe {
cip_t!(YDB_NOTTP, Vec::new(), &mut routine, &mut out, a, b).unwrap();
}
assert_eq!(out, 3);
// make sure it works if called multiple times
unsafe {
cip_t!(YDB_NOTTP, Vec::new(), &mut routine, &mut out, a, b).unwrap();
}
assert_eq!(out, 3);
// make sure it works with `ci_t`
let mut routine = routine.into_cstr();
unsafe {
ci_t!(YDB_NOTTP, Vec::new(), &mut routine, &mut out, a, b).unwrap();
}
assert_eq!(out, 3);
});
}
#[test]
fn no_args() {
call(|| {
let mut routine = CStr::from_bytes_with_nul(b"noop\0").unwrap();
unsafe {
ci_t!(YDB_NOTTP, Vec::new(), &mut routine).unwrap();
}
});
}
#[test]
fn no_callin_env_var() {
// This modifies the active call-in table and so cannot run in parallel with other tests in
// this module.
let _guard = LockGuard::write();
// NOTE: this does NOT set ydb_ci
env::set_var("ydb_routines", "examples/m-ffi");
let file = CString::new("examples/m-ffi/calltab.ci").unwrap();
let (descriptor, err_buf) = ci_tab_open_t(YDB_NOTTP, Vec::new(), &file).unwrap();
ci_tab_switch_t(YDB_NOTTP, err_buf, descriptor).unwrap();
// same as doc-test for `ci_t`
let mut buf = Vec::<u8>::with_capacity(100);
let mut msg = ydb_string_t {
length: buf.capacity() as u64,
address: buf.as_mut_ptr() as *mut c_char,
};
let routine = CString::new("HelloWorld1").unwrap();
unsafe {
ci_t!(YDB_NOTTP, Vec::new(), &routine, &mut msg as *mut _).unwrap();
buf.set_len(msg.length as usize);
}
assert_eq!(&buf, b"entry called");
}
#[test]
fn tab_open_switch() {
// This test cannot run in parallel with any others.
let _guard = LockGuard::write();
// NOTE: this does NOT set ydb_ci
env::set_var("ydb_routines", "examples/m-ffi");
let small_file = CString::new("examples/m-ffi/small_calltab.ci").unwrap();
let mut routine = CallInDescriptor::new(CString::new("Add").unwrap());
let a = 1 as ydb_long_t;
let b = 2 as ydb_long_t;
let mut out = 0;
// first try a table that doesn't have `Add`
let (small_fd, _) = ci_tab_open_t(YDB_NOTTP, Vec::new(), &small_file).unwrap();
ci_tab_switch_t(YDB_NOTTP, Vec::new(), small_fd).unwrap();
let err =
unsafe { cip_t!(YDB_NOTTP, Vec::new(), &mut routine, &mut out, a, b).unwrap_err() };
assert_eq!(err.status, craw::YDB_ERR_CINOENTRY);
assert_eq!(out, 0);
// now try a table that does
let big_file = CString::new("examples/m-ffi/calltab.ci").unwrap();
let (big_fd, _) = ci_tab_open_t(YDB_NOTTP, Vec::new(), &big_file).unwrap();
let (small_fd, _) = ci_tab_switch_t(YDB_NOTTP, Vec::new(), big_fd).unwrap();
unsafe { cip_t!(YDB_NOTTP, Vec::new(), &mut routine, &mut out, a, b).unwrap() };
assert_eq!(out, 3);
// make sure the call works even though the calltable has been changed back
out = 0;
ci_tab_switch_t(YDB_NOTTP, Vec::new(), small_fd).unwrap();
unsafe { cip_t!(YDB_NOTTP, Vec::new(), &mut routine, &mut out, a, b).unwrap() };
assert_eq!(out, 3);
// make sure the old descriptor still works and updates the `Add` function name when called with `ci_t`
let mut routine = routine.into_cstr();
out = 0;
let err =
unsafe { ci_t!(YDB_NOTTP, Vec::new(), &mut routine, &mut out, a, b).unwrap_err() };
assert_eq!(err.status, craw::YDB_ERR_CINOENTRY);
assert_eq!(out, 0);
// switch back the calltable to use an environment variable now that we're done
ci_tab_switch_t(YDB_NOTTP, Vec::new(), CallInTableDescriptor::default()).unwrap();
}
#[test]
// Test that M FFI works from within a transaction
fn call_in_tp() {
use crate::simple_api::{tp_st, TransactionStatus};
// Set up environment variables
call(|| {
let do_callin = |tptoken| {
// Create a C string with a no-op M function
let mut routine = CStr::from_bytes_with_nul(b"noop\0").unwrap();
unsafe {
// Call the `noop` M function
ci_t!(tptoken, Vec::new(), &mut routine).unwrap();
}
Ok(TransactionStatus::Ok)
};
// Start a transaction before making the call
tp_st(YDB_NOTTP, Vec::new(), do_callin, "BATCH", &[]).unwrap();
});
}
}