adaptivegrain/vapoursynth/src/plugin.rs
2019-05-30 11:06:53 +00:00

113 lines
3.8 KiB
Rust

//! VapourSynth plugins.
use std::ffi::{CStr, CString, NulError};
use std::marker::PhantomData;
use std::ops::Deref;
use std::ptr::NonNull;
use vapoursynth_sys as ffi;
use api::API;
use map::{Map, OwnedMap};
use plugins::{self, FilterFunction};
/// A VapourSynth plugin.
#[derive(Debug, Clone, Copy)]
pub struct Plugin<'core> {
handle: NonNull<ffi::VSPlugin>,
_owner: PhantomData<&'core ()>,
}
unsafe impl<'core> Send for Plugin<'core> {}
unsafe impl<'core> Sync for Plugin<'core> {}
impl<'core> Plugin<'core> {
/// Wraps `handle` in a `Plugin`.
///
/// # Safety
/// The caller must ensure `handle` is valid and API is cached.
#[inline]
pub(crate) unsafe fn from_ptr(handle: *mut ffi::VSPlugin) -> Self {
Self {
handle: NonNull::new_unchecked(handle),
_owner: PhantomData,
}
}
/// Returns a map containing a list of the filters exported by a plugin.
///
/// Keys: the filter names;
///
/// Values: the filter name followed by its argument string, separated by a semicolon.
// TODO: parse the values on the crate side and return a nice struct.
#[inline]
pub fn functions(&self) -> OwnedMap<'core> {
unsafe { OwnedMap::from_ptr(API::get_cached().get_functions(self.handle.as_ptr())) }
}
/// Returns the absolute path to the plugin, including the plugin's file name. This is the real
/// location of the plugin, i.e. there are no symbolic links in the path.
///
/// Path elements are always delimited with forward slashes.
#[cfg(feature = "gte-vapoursynth-api-31")]
#[inline]
pub fn path(&self) -> Option<&'core CStr> {
let ptr = unsafe { API::get_cached().get_plugin_path(self.handle.as_ptr()) };
if ptr.is_null() {
None
} else {
Some(unsafe { CStr::from_ptr(ptr) })
}
}
/// Invokes a filter.
///
/// `invoke()` makes sure the filter has no compat input nodes, checks that the args passed to
/// the filter are consistent with the argument list registered by the plugin that contains the
/// filter, creates the filter, and checks that the filter doesn't return any compat nodes. If
/// everything goes smoothly, the filter will be ready to generate frames after `invoke()`
/// returns.
///
/// Returns a map containing the filter's return value(s). Use `Map::error()` to check if the
/// filter was invoked successfully.
///
/// Most filters will either add an error to the map, or one or more clips with the key `clip`.
/// The exception to this are functions, for example `LoadPlugin`, which doesn't return any
/// clips for obvious reasons.
#[inline]
pub fn invoke(&self, name: &str, args: &Map<'core>) -> Result<OwnedMap<'core>, NulError> {
let name = CString::new(name)?;
Ok(unsafe {
OwnedMap::from_ptr(API::get_cached().invoke(
self.handle.as_ptr(),
name.as_ptr(),
args.deref(),
))
})
}
/// Registers a filter function to be exported by a non-readonly plugin.
#[inline]
pub fn register_function<F: FilterFunction>(&self, filter_function: F) -> Result<(), NulError> {
// TODO: this is almost the same code as plugins::ffi::call_register_function().
let name_cstring = CString::new(filter_function.name())?;
let args_cstring = CString::new(filter_function.args())?;
let data = Box::new(plugins::ffi::FilterFunctionData::<F> {
filter_function,
name: name_cstring,
});
unsafe {
API::get_cached().register_function(
data.name.as_ptr(),
args_cstring.as_ptr(),
plugins::ffi::create::<F>,
Box::into_raw(data) as _,
self.handle.as_ptr(),
);
}
Ok(())
}
}