Support for all custom value operations on plugin custom values (#12088)

# Description

Adds support for the following operations on plugin custom values, in
addition to `to_base_value` which was already present:

- `follow_path_int()`
- `follow_path_string()`
- `partial_cmp()`
- `operation()`
- `Drop` (notification, if opted into with
`CustomValue::notify_plugin_on_drop`)

There are additionally customizable methods within the `Plugin` and
`StreamingPlugin` traits for implementing these functions in a way that
requires access to the plugin state, as a registered handle model such
as might be used in a dataframes plugin would.

`Value::append` was also changed to handle custom values correctly.

# User-Facing Changes

- Signature of `CustomValue::follow_path_string` and
`CustomValue::follow_path_int` changed to give access to the span of the
custom value itself, useful for some errors.
- Plugins using custom values have to be recompiled because the engine
will try to do custom value operations that aren't supported
- Plugins can do more things 🎉 

# Tests + Formatting
Tests were added for all of the new custom values functionality.

- 🟢 `toolkit fmt`
- 🟢 `toolkit clippy`
- 🟢 `toolkit test`
- 🟢 `toolkit test stdlib`

# After Submitting
- [ ] Document protocol reference `CustomValueOp` variants:
  - [ ] `FollowPathInt`
  - [ ] `FollowPathString`
  - [ ] `PartialCmp`
  - [ ] `Operation`
  - [ ] `Dropped`
- [ ] Document `notify_on_drop` optional field in `PluginCustomValue`
This commit is contained in:
Devyn Cairns 2024-03-12 02:37:08 -07:00 committed by GitHub
parent 8a250d2e08
commit 73f3c0b60b
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
19 changed files with 1065 additions and 156 deletions

View File

@ -34,13 +34,23 @@ impl CustomValue for NuDataFrame {
self
}
fn follow_path_int(&self, count: usize, span: Span) -> Result<Value, ShellError> {
self.get_value(count, span)
fn follow_path_int(
&self,
_self_span: Span,
count: usize,
path_span: Span,
) -> Result<Value, ShellError> {
self.get_value(count, path_span)
}
fn follow_path_string(&self, column_name: String, span: Span) -> Result<Value, ShellError> {
let column = self.column(&column_name, span)?;
Ok(column.into_value(span))
fn follow_path_string(
&self,
_self_span: Span,
column_name: String,
path_span: Span,
) -> Result<Value, ShellError> {
let column = self.column(&column_name, path_span)?;
Ok(column.into_value(path_span))
}
fn partial_cmp(&self, other: &Value) -> Option<std::cmp::Ordering> {

View File

@ -372,19 +372,29 @@ impl CustomValue for SQLiteDatabase {
self
}
fn follow_path_int(&self, _count: usize, span: Span) -> Result<Value, ShellError> {
fn follow_path_int(
&self,
_self_span: Span,
_index: usize,
path_span: Span,
) -> Result<Value, ShellError> {
// In theory we could support this, but tables don't have an especially well-defined order
Err(ShellError::IncompatiblePathAccess { type_name: "SQLite databases do not support integer-indexed access. Try specifying a table name instead".into(), span })
Err(ShellError::IncompatiblePathAccess { type_name: "SQLite databases do not support integer-indexed access. Try specifying a table name instead".into(), span: path_span })
}
fn follow_path_string(&self, _column_name: String, span: Span) -> Result<Value, ShellError> {
let db = open_sqlite_db(&self.path, span)?;
fn follow_path_string(
&self,
_self_span: Span,
_column_name: String,
path_span: Span,
) -> Result<Value, ShellError> {
let db = open_sqlite_db(&self.path, path_span)?;
read_single_table(db, _column_name, span, self.ctrlc.clone()).map_err(|e| {
read_single_table(db, _column_name, path_span, self.ctrlc.clone()).map_err(|e| {
ShellError::GenericError {
error: "Failed to read from SQLite database".into(),
msg: e.to_string(),
span: Some(span),
span: Some(path_span),
help: None,
inner: vec![],
}

View File

@ -16,7 +16,7 @@ nu-protocol = { path = "../nu-protocol", version = "0.91.1" }
bincode = "1.3"
rmp-serde = "1.1"
serde = { version = "1.0" }
serde = "1.0"
serde_json = { workspace = true }
log = "0.4"
miette = { workspace = true }

View File

@ -12,8 +12,8 @@ use nu_protocol::{
use crate::{
protocol::{
CallInfo, CustomValueOp, EngineCall, EngineCallId, EngineCallResponse, PluginCall,
PluginCallId, PluginCallResponse, PluginCustomValue, PluginInput, PluginOption,
CallInfo, CustomValueOp, EngineCall, EngineCallId, EngineCallResponse, Ordering,
PluginCall, PluginCallId, PluginCallResponse, PluginCustomValue, PluginInput, PluginOption,
ProtocolInfo,
},
LabeledError, PluginOutput,
@ -683,6 +683,16 @@ impl EngineInterface {
self.write(PluginOutput::Option(PluginOption::GcDisabled(disabled)))?;
self.flush()
}
/// Write a call response of [`Ordering`], for `partial_cmp`.
pub(crate) fn write_ordering(
&self,
ordering: Option<impl Into<Ordering>>,
) -> Result<(), ShellError> {
let response = PluginCallResponse::Ordering(ordering.map(|o| o.into()));
self.write(PluginOutput::CallResponse(self.context()?, response))?;
self.flush()
}
}
impl Interface for EngineInterface {

View File

@ -496,7 +496,7 @@ fn manager_consume_call_custom_value_op_forwards_to_receiver_with_context() -> R
op,
} => {
assert_eq!(Some(32), engine.context);
assert_eq!("TestCustomValue", custom_value.item.name);
assert_eq!("TestCustomValue", custom_value.item.name());
assert!(
matches!(op, CustomValueOp::ToBaseValue),
"incorrect op: {op:?}"
@ -600,11 +600,12 @@ fn manager_prepare_pipeline_data_embeds_deserialization_errors_in_streams() -> R
{
let manager = TestCase::new().engine();
let invalid_custom_value = PluginCustomValue {
name: "Invalid".into(),
data: vec![0; 8], // should fail to decode to anything
source: None,
};
let invalid_custom_value = PluginCustomValue::new(
"Invalid".into(),
vec![0; 8], // should fail to decode to anything
false,
None,
);
let span = Span::new(20, 30);
let data = manager.prepare_pipeline_data(
@ -965,9 +966,9 @@ fn interface_prepare_pipeline_data_serializes_custom_values() -> Result<(), Shel
.expect("custom value is not a PluginCustomValue, probably not serialized");
let expected = test_plugin_custom_value();
assert_eq!(expected.name, custom_value.name);
assert_eq!(expected.data, custom_value.data);
assert!(custom_value.source.is_none());
assert_eq!(expected.name(), custom_value.name());
assert_eq!(expected.data(), custom_value.data());
assert!(custom_value.source().is_none());
Ok(())
}
@ -994,9 +995,9 @@ fn interface_prepare_pipeline_data_serializes_custom_values_in_streams() -> Resu
.expect("custom value is not a PluginCustomValue, probably not serialized");
let expected = test_plugin_custom_value();
assert_eq!(expected.name, custom_value.name);
assert_eq!(expected.data, custom_value.data);
assert!(custom_value.source.is_none());
assert_eq!(expected.name(), custom_value.name());
assert_eq!(expected.data(), custom_value.data());
assert!(custom_value.source().is_none());
Ok(())
}

View File

@ -6,15 +6,15 @@ use std::{
};
use nu_protocol::{
IntoInterruptiblePipelineData, ListStream, PipelineData, PluginSignature, ShellError, Spanned,
Value,
ast::Operator, IntoInterruptiblePipelineData, IntoSpanned, ListStream, PipelineData,
PluginSignature, ShellError, Span, Spanned, Value,
};
use crate::{
plugin::{context::PluginExecutionContext, gc::PluginGc, PluginSource},
protocol::{
CallInfo, CustomValueOp, EngineCall, EngineCallId, EngineCallResponse, PluginCall,
PluginCallId, PluginCallResponse, PluginCustomValue, PluginInput, PluginOption,
CallInfo, CustomValueOp, EngineCall, EngineCallId, EngineCallResponse, Ordering,
PluginCall, PluginCallId, PluginCallResponse, PluginCustomValue, PluginInput, PluginOption,
PluginOutput, ProtocolInfo, StreamId, StreamMessage,
},
sequence::Sequence,
@ -454,6 +454,9 @@ impl InterfaceManager for PluginInterfaceManager {
let response = match response {
PluginCallResponse::Error(err) => PluginCallResponse::Error(err),
PluginCallResponse::Signature(sigs) => PluginCallResponse::Signature(sigs),
PluginCallResponse::Ordering(ordering) => {
PluginCallResponse::Ordering(ordering)
}
PluginCallResponse::PipelineData(data) => {
// If there's an error with initializing this stream, change it to a plugin
// error response, but send it anyway
@ -804,22 +807,93 @@ impl PluginInterface {
}
}
/// Do a custom value op that expects a value response (i.e. most of them)
fn custom_value_op_expecting_value(
&self,
value: Spanned<PluginCustomValue>,
op: CustomValueOp,
) -> Result<Value, ShellError> {
let op_name = op.name();
let span = value.span;
let call = PluginCall::CustomValueOp(value, op);
match self.plugin_call(call, &None)? {
PluginCallResponse::PipelineData(out_data) => Ok(out_data.into_value(span)),
PluginCallResponse::Error(err) => Err(err.into()),
_ => Err(ShellError::PluginFailedToDecode {
msg: format!("Received unexpected response to custom value {op_name}() call"),
}),
}
}
/// Collapse a custom value to its base value.
pub(crate) fn custom_value_to_base_value(
&self,
value: Spanned<PluginCustomValue>,
) -> Result<Value, ShellError> {
let span = value.span;
let call = PluginCall::CustomValueOp(value, CustomValueOp::ToBaseValue);
self.custom_value_op_expecting_value(value, CustomValueOp::ToBaseValue)
}
/// Follow a numbered cell path on a custom value - e.g. `value.0`.
pub(crate) fn custom_value_follow_path_int(
&self,
value: Spanned<PluginCustomValue>,
index: Spanned<usize>,
) -> Result<Value, ShellError> {
self.custom_value_op_expecting_value(value, CustomValueOp::FollowPathInt(index))
}
/// Follow a named cell path on a custom value - e.g. `value.column`.
pub(crate) fn custom_value_follow_path_string(
&self,
value: Spanned<PluginCustomValue>,
column_name: Spanned<String>,
) -> Result<Value, ShellError> {
self.custom_value_op_expecting_value(value, CustomValueOp::FollowPathString(column_name))
}
/// Invoke comparison logic for custom values.
pub(crate) fn custom_value_partial_cmp(
&self,
value: PluginCustomValue,
mut other_value: Value,
) -> Result<Option<Ordering>, ShellError> {
PluginCustomValue::verify_source(&mut other_value, &self.state.source)?;
// Note: the protocol is always designed to have a span with the custom value, but this
// operation doesn't support one.
let call = PluginCall::CustomValueOp(
value.into_spanned(Span::unknown()),
CustomValueOp::PartialCmp(other_value),
);
match self.plugin_call(call, &None)? {
PluginCallResponse::PipelineData(out_data) => Ok(out_data.into_value(span)),
PluginCallResponse::Ordering(ordering) => Ok(ordering),
PluginCallResponse::Error(err) => Err(err.into()),
_ => Err(ShellError::PluginFailedToDecode {
msg: "Received unexpected response to plugin CustomValueOp::ToBaseValue call"
.into(),
msg: "Received unexpected response to custom value partial_cmp() call".into(),
}),
}
}
/// Invoke functionality for an operator on a custom value.
pub(crate) fn custom_value_operation(
&self,
left: Spanned<PluginCustomValue>,
operator: Spanned<Operator>,
mut right: Value,
) -> Result<Value, ShellError> {
PluginCustomValue::verify_source(&mut right, &self.state.source)?;
self.custom_value_op_expecting_value(left, CustomValueOp::Operation(operator, right))
}
/// Notify the plugin about a dropped custom value.
pub(crate) fn custom_value_dropped(&self, value: PluginCustomValue) -> Result<(), ShellError> {
// Note: the protocol is always designed to have a span with the custom value, but this
// operation doesn't support one.
self.custom_value_op_expecting_value(
value.into_spanned(Span::unknown()),
CustomValueOp::Dropped,
)
.map(|_| ())
}
}
/// Check that custom values in call arguments come from the right source

View File

@ -649,7 +649,7 @@ fn manager_prepare_pipeline_data_adds_source_to_values() -> Result<(), ShellErro
.downcast_ref()
.expect("custom value is not a PluginCustomValue");
if let Some(source) = &custom_value.source {
if let Some(source) = custom_value.source() {
assert_eq!("test", source.name());
} else {
panic!("source was not set");
@ -679,7 +679,7 @@ fn manager_prepare_pipeline_data_adds_source_to_list_streams() -> Result<(), She
.downcast_ref()
.expect("custom value is not a PluginCustomValue");
if let Some(source) = &custom_value.source {
if let Some(source) = custom_value.source() {
assert_eq!("test", source.name());
} else {
panic!("source was not set");
@ -1092,12 +1092,13 @@ fn interface_custom_value_to_base_value() -> Result<(), ShellError> {
fn normal_values(interface: &PluginInterface) -> Vec<Value> {
vec![
Value::test_int(5),
Value::test_custom_value(Box::new(PluginCustomValue {
name: "SomeTest".into(),
data: vec![1, 2, 3],
Value::test_custom_value(Box::new(PluginCustomValue::new(
"SomeTest".into(),
vec![1, 2, 3],
false,
// Has the same source, so it should be accepted
source: Some(interface.state.source.clone()),
})),
Some(interface.state.source.clone()),
))),
]
}
@ -1145,17 +1146,19 @@ fn bad_custom_values() -> Vec<Value> {
// Native custom value (not PluginCustomValue) should be rejected
Value::test_custom_value(Box::new(expected_test_custom_value())),
// Has no source, so it should be rejected
Value::test_custom_value(Box::new(PluginCustomValue {
name: "SomeTest".into(),
data: vec![1, 2, 3],
source: None,
})),
Value::test_custom_value(Box::new(PluginCustomValue::new(
"SomeTest".into(),
vec![1, 2, 3],
false,
None,
))),
// Has a different source, so it should be rejected
Value::test_custom_value(Box::new(PluginCustomValue {
name: "SomeTest".into(),
data: vec![1, 2, 3],
source: Some(PluginSource::new_fake("pluto").into()),
})),
Value::test_custom_value(Box::new(PluginCustomValue::new(
"SomeTest".into(),
vec![1, 2, 3],
false,
Some(PluginSource::new_fake("pluto").into()),
))),
]
}

View File

@ -1,6 +1,8 @@
use nu_engine::documentation::get_flags_section;
use nu_protocol::ast::Operator;
use std::cmp::Ordering;
use std::ffi::OsStr;
use std::sync::mpsc::TrySendError;
use std::sync::{mpsc, Arc, Mutex};
@ -21,7 +23,9 @@ use std::os::unix::process::CommandExt;
#[cfg(windows)]
use std::os::windows::process::CommandExt;
use nu_protocol::{PipelineData, PluginSignature, ShellError, Spanned, Value};
use nu_protocol::{
CustomValue, IntoSpanned, PipelineData, PluginSignature, ShellError, Spanned, Value,
};
use self::gc::PluginGc;
@ -279,6 +283,112 @@ pub trait Plugin: Sync {
call: &EvaluatedCall,
input: &Value,
) -> Result<Value, LabeledError>;
/// Collapse a custom value to plain old data.
///
/// The default implementation of this method just calls [`CustomValue::to_base_value`], but
/// the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_to_base_value(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
) -> Result<Value, LabeledError> {
let _ = engine;
custom_value
.item
.to_base_value(custom_value.span)
.map_err(LabeledError::from)
}
/// Follow a numbered cell path on a custom value - e.g. `value.0`.
///
/// The default implementation of this method just calls [`CustomValue::follow_path_int`], but
/// the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_follow_path_int(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
index: Spanned<usize>,
) -> Result<Value, LabeledError> {
let _ = engine;
custom_value
.item
.follow_path_int(custom_value.span, index.item, index.span)
.map_err(LabeledError::from)
}
/// Follow a named cell path on a custom value - e.g. `value.column`.
///
/// The default implementation of this method just calls [`CustomValue::follow_path_string`],
/// but the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_follow_path_string(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
column_name: Spanned<String>,
) -> Result<Value, LabeledError> {
let _ = engine;
custom_value
.item
.follow_path_string(custom_value.span, column_name.item, column_name.span)
.map_err(LabeledError::from)
}
/// Implement comparison logic for custom values.
///
/// The default implementation of this method just calls [`CustomValue::partial_cmp`], but
/// the method can be implemented differently if accessing plugin state is desirable.
///
/// Note that returning an error here is unlikely to produce desired behavior, as `partial_cmp`
/// lacks a way to produce an error. At the moment the engine just logs the error, and the
/// comparison returns `None`.
fn custom_value_partial_cmp(
&self,
engine: &EngineInterface,
custom_value: Box<dyn CustomValue>,
other_value: Value,
) -> Result<Option<Ordering>, LabeledError> {
let _ = engine;
Ok(custom_value.partial_cmp(&other_value))
}
/// Implement functionality for an operator on a custom value.
///
/// The default implementation of this method just calls [`CustomValue::operation`], but
/// the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_operation(
&self,
engine: &EngineInterface,
left: Spanned<Box<dyn CustomValue>>,
operator: Spanned<Operator>,
right: Value,
) -> Result<Value, LabeledError> {
let _ = engine;
left.item
.operation(left.span, operator.item, operator.span, &right)
.map_err(LabeledError::from)
}
/// Handle a notification that all copies of a custom value within the engine have been dropped.
///
/// This notification is only sent if [`CustomValue::notify_plugin_on_drop`] was true. Unlike
/// the other custom value handlers, a span is not provided.
///
/// Note that a new custom value is created each time it is sent to the engine - if you intend
/// to accept a custom value and send it back, you may need to implement some kind of unique
/// reference counting in your plugin, as you will receive multiple drop notifications even if
/// the data within is identical.
///
/// The default implementation does nothing. Any error generated here is unlikely to be visible
/// to the user, and will only show up in the engine's log output.
fn custom_value_dropped(
&self,
engine: &EngineInterface,
custom_value: Box<dyn CustomValue>,
) -> Result<(), LabeledError> {
let _ = (engine, custom_value);
Ok(())
}
}
/// The streaming API for a Nushell plugin
@ -357,6 +467,112 @@ pub trait StreamingPlugin: Sync {
call: &EvaluatedCall,
input: PipelineData,
) -> Result<PipelineData, LabeledError>;
/// Collapse a custom value to plain old data.
///
/// The default implementation of this method just calls [`CustomValue::to_base_value`], but
/// the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_to_base_value(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
) -> Result<Value, LabeledError> {
let _ = engine;
custom_value
.item
.to_base_value(custom_value.span)
.map_err(LabeledError::from)
}
/// Follow a numbered cell path on a custom value - e.g. `value.0`.
///
/// The default implementation of this method just calls [`CustomValue::follow_path_int`], but
/// the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_follow_path_int(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
index: Spanned<usize>,
) -> Result<Value, LabeledError> {
let _ = engine;
custom_value
.item
.follow_path_int(custom_value.span, index.item, index.span)
.map_err(LabeledError::from)
}
/// Follow a named cell path on a custom value - e.g. `value.column`.
///
/// The default implementation of this method just calls [`CustomValue::follow_path_string`],
/// but the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_follow_path_string(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
column_name: Spanned<String>,
) -> Result<Value, LabeledError> {
let _ = engine;
custom_value
.item
.follow_path_string(custom_value.span, column_name.item, column_name.span)
.map_err(LabeledError::from)
}
/// Implement comparison logic for custom values.
///
/// The default implementation of this method just calls [`CustomValue::partial_cmp`], but
/// the method can be implemented differently if accessing plugin state is desirable.
///
/// Note that returning an error here is unlikely to produce desired behavior, as `partial_cmp`
/// lacks a way to produce an error. At the moment the engine just logs the error, and the
/// comparison returns `None`.
fn custom_value_partial_cmp(
&self,
engine: &EngineInterface,
custom_value: Box<dyn CustomValue>,
other_value: Value,
) -> Result<Option<Ordering>, LabeledError> {
let _ = engine;
Ok(custom_value.partial_cmp(&other_value))
}
/// Implement functionality for an operator on a custom value.
///
/// The default implementation of this method just calls [`CustomValue::operation`], but
/// the method can be implemented differently if accessing plugin state is desirable.
fn custom_value_operation(
&self,
engine: &EngineInterface,
left: Spanned<Box<dyn CustomValue>>,
operator: Spanned<Operator>,
right: Value,
) -> Result<Value, LabeledError> {
let _ = engine;
left.item
.operation(left.span, operator.item, operator.span, &right)
.map_err(LabeledError::from)
}
/// Handle a notification that all copies of a custom value within the engine have been dropped.
///
/// This notification is only sent if [`CustomValue::notify_plugin_on_drop`] was true. Unlike
/// the other custom value handlers, a span is not provided.
///
/// Note that a new custom value is created each time it is sent to the engine - if you intend
/// to accept a custom value and send it back, you may need to implement some kind of unique
/// reference counting in your plugin, as you will receive multiple drop notifications even if
/// the data within is identical.
///
/// The default implementation does nothing. Any error generated here is unlikely to be visible
/// to the user, and will only show up in the engine's log output.
fn custom_value_dropped(
&self,
engine: &EngineInterface,
custom_value: Box<dyn CustomValue>,
) -> Result<(), LabeledError> {
let _ = (engine, custom_value);
Ok(())
}
}
/// All [Plugin]s can be used as [StreamingPlugin]s, but input streams will be fully consumed
@ -381,6 +597,59 @@ impl<T: Plugin> StreamingPlugin for T {
<Self as Plugin>::run(self, name, engine, call, &input_value)
.map(|value| PipelineData::Value(value, None))
}
fn custom_value_to_base_value(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
) -> Result<Value, LabeledError> {
<Self as Plugin>::custom_value_to_base_value(self, engine, custom_value)
}
fn custom_value_follow_path_int(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
index: Spanned<usize>,
) -> Result<Value, LabeledError> {
<Self as Plugin>::custom_value_follow_path_int(self, engine, custom_value, index)
}
fn custom_value_follow_path_string(
&self,
engine: &EngineInterface,
custom_value: Spanned<Box<dyn CustomValue>>,
column_name: Spanned<String>,
) -> Result<Value, LabeledError> {
<Self as Plugin>::custom_value_follow_path_string(self, engine, custom_value, column_name)
}
fn custom_value_partial_cmp(
&self,
engine: &EngineInterface,
custom_value: Box<dyn CustomValue>,
other_value: Value,
) -> Result<Option<Ordering>, LabeledError> {
<Self as Plugin>::custom_value_partial_cmp(self, engine, custom_value, other_value)
}
fn custom_value_operation(
&self,
engine: &EngineInterface,
left: Spanned<Box<dyn CustomValue>>,
operator: Spanned<Operator>,
right: Value,
) -> Result<Value, LabeledError> {
<Self as Plugin>::custom_value_operation(self, engine, left, operator, right)
}
fn custom_value_dropped(
&self,
engine: &EngineInterface,
custom_value: Box<dyn CustomValue>,
) -> Result<(), LabeledError> {
<Self as Plugin>::custom_value_dropped(self, engine, custom_value)
}
}
/// Function used to implement the communication protocol between
@ -580,7 +849,7 @@ pub fn serve_plugin(plugin: &impl StreamingPlugin, encoder: impl PluginEncoder +
custom_value,
op,
} => {
try_or_report!(engine, custom_value_op(&engine, custom_value, op));
try_or_report!(engine, custom_value_op(plugin, &engine, custom_value, op));
}
}
}
@ -591,22 +860,65 @@ pub fn serve_plugin(plugin: &impl StreamingPlugin, encoder: impl PluginEncoder +
}
fn custom_value_op(
plugin: &impl StreamingPlugin,
engine: &EngineInterface,
custom_value: Spanned<PluginCustomValue>,
op: CustomValueOp,
) -> Result<(), ShellError> {
let local_value = custom_value
.item
.deserialize_to_custom_value(custom_value.span)?;
.deserialize_to_custom_value(custom_value.span)?
.into_spanned(custom_value.span);
match op {
CustomValueOp::ToBaseValue => {
let result = local_value
.to_base_value(custom_value.span)
let result = plugin
.custom_value_to_base_value(engine, local_value)
.map(|value| PipelineData::Value(value, None));
engine
.write_response(result)
.and_then(|writer| writer.write_background())?;
Ok(())
.and_then(|writer| writer.write())
}
CustomValueOp::FollowPathInt(index) => {
let result = plugin
.custom_value_follow_path_int(engine, local_value, index)
.map(|value| PipelineData::Value(value, None));
engine
.write_response(result)
.and_then(|writer| writer.write())
}
CustomValueOp::FollowPathString(column_name) => {
let result = plugin
.custom_value_follow_path_string(engine, local_value, column_name)
.map(|value| PipelineData::Value(value, None));
engine
.write_response(result)
.and_then(|writer| writer.write())
}
CustomValueOp::PartialCmp(mut other_value) => {
PluginCustomValue::deserialize_custom_values_in(&mut other_value)?;
match plugin.custom_value_partial_cmp(engine, local_value.item, other_value) {
Ok(ordering) => engine.write_ordering(ordering),
Err(err) => engine
.write_response(Err(err))
.and_then(|writer| writer.write()),
}
}
CustomValueOp::Operation(operator, mut right) => {
PluginCustomValue::deserialize_custom_values_in(&mut right)?;
let result = plugin
.custom_value_operation(engine, local_value, operator, right)
.map(|value| PipelineData::Value(value, None));
engine
.write_response(result)
.and_then(|writer| writer.write())
}
CustomValueOp::Dropped => {
let result = plugin
.custom_value_dropped(engine, local_value.item)
.map(|_| PipelineData::Empty);
engine
.write_response(result)
.and_then(|writer| writer.write())
}
}
}

View File

@ -10,8 +10,8 @@ pub(crate) mod test_util;
pub use evaluated_call::EvaluatedCall;
use nu_protocol::{
engine::Closure, Config, PipelineData, PluginSignature, RawStream, ShellError, Span, Spanned,
Value,
ast::Operator, engine::Closure, Config, PipelineData, PluginSignature, RawStream, ShellError,
Span, Spanned, Value,
};
pub use plugin_custom_value::PluginCustomValue;
pub use protocol_info::ProtocolInfo;
@ -131,6 +131,31 @@ pub enum PluginCall<D> {
pub enum CustomValueOp {
/// [`to_base_value()`](nu_protocol::CustomValue::to_base_value)
ToBaseValue,
/// [`follow_path_int()`](nu_protocol::CustomValue::follow_path_int)
FollowPathInt(Spanned<usize>),
/// [`follow_path_string()`](nu_protocol::CustomValue::follow_path_string)
FollowPathString(Spanned<String>),
/// [`partial_cmp()`](nu_protocol::CustomValue::partial_cmp)
PartialCmp(Value),
/// [`operation()`](nu_protocol::CustomValue::operation)
Operation(Spanned<Operator>, Value),
/// Notify that the custom value has been dropped, if
/// [`notify_plugin_on_drop()`](nu_protocol::CustomValue::notify_plugin_on_drop) is true
Dropped,
}
impl CustomValueOp {
/// Get the name of the op, for error messages.
pub(crate) fn name(&self) -> &'static str {
match self {
CustomValueOp::ToBaseValue => "to_base_value",
CustomValueOp::FollowPathInt(_) => "follow_path_int",
CustomValueOp::FollowPathString(_) => "follow_path_string",
CustomValueOp::PartialCmp(_) => "partial_cmp",
CustomValueOp::Operation(_, _) => "operation",
CustomValueOp::Dropped => "dropped",
}
}
}
/// Any data sent to the plugin
@ -306,6 +331,7 @@ impl From<ShellError> for LabeledError {
pub enum PluginCallResponse<D> {
Error(LabeledError),
Signature(Vec<PluginSignature>),
Ordering(Option<Ordering>),
PipelineData(D),
}
@ -330,6 +356,34 @@ pub enum PluginOption {
GcDisabled(bool),
}
/// This is just a serializable version of [std::cmp::Ordering], and can be converted 1:1
#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub enum Ordering {
Less,
Equal,
Greater,
}
impl From<std::cmp::Ordering> for Ordering {
fn from(value: std::cmp::Ordering) -> Self {
match value {
std::cmp::Ordering::Less => Ordering::Less,
std::cmp::Ordering::Equal => Ordering::Equal,
std::cmp::Ordering::Greater => Ordering::Greater,
}
}
}
impl From<Ordering> for std::cmp::Ordering {
fn from(value: Ordering) -> Self {
match value {
Ordering::Less => std::cmp::Ordering::Less,
Ordering::Equal => std::cmp::Ordering::Equal,
Ordering::Greater => std::cmp::Ordering::Greater,
}
}
}
/// Information received from the plugin
///
/// Note: exported for internal use, not public.

View File

@ -1,9 +1,9 @@
use std::sync::Arc;
use std::{cmp::Ordering, sync::Arc};
use nu_protocol::{CustomValue, ShellError, Span, Spanned, Value};
use nu_protocol::{ast::Operator, CustomValue, IntoSpanned, ShellError, Span, Value};
use serde::{Deserialize, Serialize};
use crate::plugin::PluginSource;
use crate::plugin::{PluginInterface, PluginSource};
#[cfg(test)]
mod tests;
@ -22,41 +22,171 @@ mod tests;
/// values sent matches the plugin it is being sent to.
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct PluginCustomValue {
/// The name of the custom value as defined by the plugin (`value_string()`)
pub name: String,
/// The bincoded representation of the custom value on the plugin side
pub data: Vec<u8>,
#[serde(flatten)]
shared: SerdeArc<SharedContent>,
/// Which plugin the custom value came from. This is not defined on the plugin side. The engine
/// side is responsible for maintaining it, and it is not sent over the serialization boundary.
#[serde(skip, default)]
pub(crate) source: Option<Arc<PluginSource>>,
source: Option<Arc<PluginSource>>,
}
/// Content shared across copies of a plugin custom value.
#[derive(Clone, Debug, Serialize, Deserialize)]
struct SharedContent {
/// The name of the custom value as defined by the plugin (`value_string()`)
name: String,
/// The bincoded representation of the custom value on the plugin side
data: Vec<u8>,
/// True if the custom value should notify the source if all copies of it are dropped.
///
/// This is not serialized if `false`, since most custom values don't need it.
#[serde(default, skip_serializing_if = "is_false")]
notify_on_drop: bool,
}
fn is_false(b: &bool) -> bool {
!b
}
#[typetag::serde]
impl CustomValue for PluginCustomValue {
fn clone_value(&self, span: nu_protocol::Span) -> nu_protocol::Value {
fn clone_value(&self, span: Span) -> Value {
Value::custom_value(Box::new(self.clone()), span)
}
fn value_string(&self) -> String {
self.name.clone()
self.name().to_owned()
}
fn to_base_value(
fn to_base_value(&self, span: Span) -> Result<Value, ShellError> {
self.get_plugin(Some(span), "get base value")?
.custom_value_to_base_value(self.clone().into_spanned(span))
}
fn follow_path_int(
&self,
span: nu_protocol::Span,
) -> Result<nu_protocol::Value, nu_protocol::ShellError> {
self_span: Span,
index: usize,
path_span: Span,
) -> Result<Value, ShellError> {
self.get_plugin(Some(self_span), "follow cell path")?
.custom_value_follow_path_int(
self.clone().into_spanned(self_span),
index.into_spanned(path_span),
)
}
fn follow_path_string(
&self,
self_span: Span,
column_name: String,
path_span: Span,
) -> Result<Value, ShellError> {
self.get_plugin(Some(self_span), "follow cell path")?
.custom_value_follow_path_string(
self.clone().into_spanned(self_span),
column_name.into_spanned(path_span),
)
}
fn partial_cmp(&self, other: &Value) -> Option<Ordering> {
self.get_plugin(Some(other.span()), "perform comparison")
.and_then(|plugin| {
// We're passing Span::unknown() here because we don't have one, and it probably
// shouldn't matter here and is just a consequence of the API
plugin.custom_value_partial_cmp(self.clone(), other.clone())
})
.unwrap_or_else(|err| {
// We can't do anything with the error other than log it.
log::warn!(
"Error in partial_cmp on plugin custom value (source={source:?}): {err}",
source = self.source
);
None
})
.map(|ordering| ordering.into())
}
fn operation(
&self,
lhs_span: Span,
operator: Operator,
op_span: Span,
right: &Value,
) -> Result<Value, ShellError> {
self.get_plugin(Some(lhs_span), "invoke operator")?
.custom_value_operation(
self.clone().into_spanned(lhs_span),
operator.into_spanned(op_span),
right.clone(),
)
}
fn as_any(&self) -> &dyn std::any::Any {
self
}
}
impl PluginCustomValue {
/// Create a new [`PluginCustomValue`].
pub(crate) fn new(
name: String,
data: Vec<u8>,
notify_on_drop: bool,
source: Option<Arc<PluginSource>>,
) -> PluginCustomValue {
PluginCustomValue {
shared: SerdeArc(Arc::new(SharedContent {
name,
data,
notify_on_drop,
})),
source,
}
}
/// The name of the custom value as defined by the plugin (`value_string()`)
pub fn name(&self) -> &str {
&self.shared.name
}
/// The bincoded representation of the custom value on the plugin side
pub fn data(&self) -> &[u8] {
&self.shared.data
}
/// True if the custom value should notify the source if all copies of it are dropped.
pub fn notify_on_drop(&self) -> bool {
self.shared.notify_on_drop
}
/// Which plugin the custom value came from. This is not defined on the plugin side. The engine
/// side is responsible for maintaining it, and it is not sent over the serialization boundary.
#[cfg(test)]
pub(crate) fn source(&self) -> &Option<Arc<PluginSource>> {
&self.source
}
/// Create the [`PluginCustomValue`] with the given source.
#[cfg(test)]
pub(crate) fn with_source(mut self, source: Option<Arc<PluginSource>>) -> PluginCustomValue {
self.source = source;
self
}
/// Helper to get the plugin to implement an op
fn get_plugin(&self, span: Option<Span>, for_op: &str) -> Result<PluginInterface, ShellError> {
let wrap_err = |err: ShellError| ShellError::GenericError {
error: format!(
"Unable to spawn plugin `{}` to get base value",
"Unable to spawn plugin `{}` to {for_op}",
self.source
.as_ref()
.map(|s| s.name())
.unwrap_or("<unknown>")
),
msg: err.to_string(),
span: Some(span),
span,
help: None,
inner: vec![err],
};
@ -69,25 +199,13 @@ impl CustomValue for PluginCustomValue {
// Envs probably should be passed here, but it's likely that the plugin is already running
let empty_envs = std::iter::empty::<(&str, &str)>();
let plugin = source
.persistent(Some(span))
.and_then(|p| p.get(|| Ok(empty_envs)))
.map_err(wrap_err)?;
plugin
.custom_value_to_base_value(Spanned {
item: self.clone(),
span,
})
source
.persistent(span)
.and_then(|p| p.get(|| Ok(empty_envs)))
.map_err(wrap_err)
}
fn as_any(&self) -> &dyn std::any::Any {
self
}
}
impl PluginCustomValue {
/// Serialize a custom value into a [`PluginCustomValue`]. This should only be done on the
/// plugin side.
pub(crate) fn serialize_from_custom_value(
@ -95,12 +213,9 @@ impl PluginCustomValue {
span: Span,
) -> Result<PluginCustomValue, ShellError> {
let name = custom_value.value_string();
let notify_on_drop = custom_value.notify_plugin_on_drop();
bincode::serialize(custom_value)
.map(|data| PluginCustomValue {
name,
data,
source: None,
})
.map(|data| PluginCustomValue::new(name, data, notify_on_drop, None))
.map_err(|err| ShellError::CustomValueFailedToEncode {
msg: err.to_string(),
span,
@ -113,7 +228,7 @@ impl PluginCustomValue {
&self,
span: Span,
) -> Result<Box<dyn CustomValue>, ShellError> {
bincode::deserialize::<Box<dyn CustomValue>>(&self.data).map_err(|err| {
bincode::deserialize::<Box<dyn CustomValue>>(self.data()).map_err(|err| {
ShellError::CustomValueFailedToDecode {
msg: err.to_string(),
span,
@ -199,7 +314,7 @@ impl PluginCustomValue {
Ok(())
} else {
Err(ShellError::CustomValueIncorrectForPlugin {
name: custom_value.name.clone(),
name: custom_value.name().to_owned(),
span,
dest_plugin: source.name().to_owned(),
src_plugin: custom_value.source.as_ref().map(|s| s.name().to_owned()),
@ -363,3 +478,62 @@ impl PluginCustomValue {
}
}
}
impl Drop for PluginCustomValue {
fn drop(&mut self) {
// If the custom value specifies notify_on_drop and this is the last copy, we need to let
// the plugin know about it if we can.
if self.source.is_some() && self.notify_on_drop() && Arc::strong_count(&self.shared) == 1 {
self.get_plugin(None, "drop")
// While notifying drop, we don't need a copy of the source
.and_then(|plugin| {
plugin.custom_value_dropped(PluginCustomValue {
shared: self.shared.clone(),
source: None,
})
})
.unwrap_or_else(|err| {
// We shouldn't do anything with the error except log it
let name = self.name();
log::warn!("Failed to notify drop of custom value ({name}): {err}")
});
}
}
}
/// A serializable `Arc`, to avoid having to have the serde `rc` feature enabled.
#[derive(Clone, Debug)]
#[repr(transparent)]
struct SerdeArc<T>(Arc<T>);
impl<T> Serialize for SerdeArc<T>
where
T: Serialize,
{
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
self.0.serialize(serializer)
}
}
impl<'de, T> Deserialize<'de> for SerdeArc<T>
where
T: Deserialize<'de>,
{
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
T::deserialize(deserializer).map(Arc::new).map(SerdeArc)
}
}
impl<T> std::ops::Deref for SerdeArc<T> {
type Target = Arc<T>;
fn deref(&self) -> &Self::Target {
&self.0
}
}

View File

@ -19,7 +19,7 @@ fn serialize_deserialize() -> Result<(), ShellError> {
let original_value = TestCustomValue(32);
let span = Span::test_data();
let serialized = PluginCustomValue::serialize_from_custom_value(&original_value, span)?;
assert_eq!(original_value.value_string(), serialized.name);
assert_eq!(original_value.value_string(), serialized.name());
assert!(serialized.source.is_none());
let deserialized = serialized.deserialize_to_custom_value(span)?;
let downcasted = deserialized
@ -36,8 +36,8 @@ fn expected_serialize_output() -> Result<(), ShellError> {
let span = Span::test_data();
let serialized = PluginCustomValue::serialize_from_custom_value(&original_value, span)?;
assert_eq!(
test_plugin_custom_value().data,
serialized.data,
test_plugin_custom_value().data(),
serialized.data(),
"The bincode configuration is probably different from what we expected. \
Fix test_plugin_custom_value() to match it"
);
@ -417,8 +417,11 @@ fn serialize_in_root() -> Result<(), ShellError> {
let custom_value = val.as_custom_value()?;
if let Some(plugin_custom_value) = custom_value.as_any().downcast_ref::<PluginCustomValue>() {
assert_eq!("TestCustomValue", plugin_custom_value.name);
assert_eq!(test_plugin_custom_value().data, plugin_custom_value.data);
assert_eq!("TestCustomValue", plugin_custom_value.name());
assert_eq!(
test_plugin_custom_value().data(),
plugin_custom_value.data()
);
assert!(plugin_custom_value.source.is_none());
} else {
panic!("Failed to downcast to PluginCustomValue");
@ -443,7 +446,8 @@ fn serialize_in_range() -> Result<(), ShellError> {
.downcast_ref()
.unwrap_or_else(|| panic!("{name} not PluginCustomValue"));
assert_eq!(
"TestCustomValue", plugin_custom_value.name,
"TestCustomValue",
plugin_custom_value.name(),
"{name} name not set correctly"
);
Ok(())
@ -465,7 +469,8 @@ fn serialize_in_record() -> Result<(), ShellError> {
.downcast_ref()
.unwrap_or_else(|| panic!("'{key}' not PluginCustomValue"));
assert_eq!(
"TestCustomValue", plugin_custom_value.name,
"TestCustomValue",
plugin_custom_value.name(),
"'{key}' name not set correctly"
);
Ok(())
@ -484,7 +489,8 @@ fn serialize_in_list() -> Result<(), ShellError> {
.downcast_ref()
.unwrap_or_else(|| panic!("[{index}] not PluginCustomValue"));
assert_eq!(
"TestCustomValue", plugin_custom_value.name,
"TestCustomValue",
plugin_custom_value.name(),
"[{index}] name not set correctly"
);
Ok(())
@ -506,7 +512,8 @@ fn serialize_in_closure() -> Result<(), ShellError> {
.downcast_ref()
.unwrap_or_else(|| panic!("[{index}] not PluginCustomValue"));
assert_eq!(
"TestCustomValue", plugin_custom_value.name,
"TestCustomValue",
plugin_custom_value.name(),
"[{index}] name not set correctly"
);
Ok(())

View File

@ -31,11 +31,7 @@ pub(crate) fn test_plugin_custom_value() -> PluginCustomValue {
let data = bincode::serialize(&expected_test_custom_value() as &dyn CustomValue)
.expect("bincode serialization of the expected_test_custom_value() failed");
PluginCustomValue {
name: "TestCustomValue".into(),
data,
source: None,
}
PluginCustomValue::new("TestCustomValue".into(), data, false, None)
}
pub(crate) fn expected_test_custom_value() -> TestCustomValue {
@ -43,8 +39,5 @@ pub(crate) fn expected_test_custom_value() -> TestCustomValue {
}
pub(crate) fn test_plugin_custom_value_with_source() -> PluginCustomValue {
PluginCustomValue {
source: Some(PluginSource::new_fake("test").into()),
..test_plugin_custom_value()
}
test_plugin_custom_value().with_source(Some(PluginSource::new_fake("test").into()))
}

View File

@ -176,11 +176,7 @@ macro_rules! generate_tests {
let custom_value_op = PluginCall::CustomValueOp(
Spanned {
item: PluginCustomValue {
name: "Foo".into(),
data: data.clone(),
source: None,
},
item: PluginCustomValue::new("Foo".into(), data.clone(), false, None),
span,
},
CustomValueOp::ToBaseValue,
@ -200,8 +196,8 @@ macro_rules! generate_tests {
match returned {
PluginInput::Call(2, PluginCall::CustomValueOp(val, op)) => {
assert_eq!("Foo", val.item.name);
assert_eq!(data, val.item.data);
assert_eq!("Foo", val.item.name());
assert_eq!(data, val.item.data());
assert_eq!(span, val.span);
#[allow(unreachable_patterns)]
match op {
@ -320,11 +316,12 @@ macro_rules! generate_tests {
let span = Span::new(2, 30);
let value = Value::custom_value(
Box::new(PluginCustomValue {
name: name.into(),
data: data.clone(),
source: None,
}),
Box::new(PluginCustomValue::new(
name.into(),
data.clone(),
true,
None,
)),
span,
);
@ -354,8 +351,9 @@ macro_rules! generate_tests {
.as_any()
.downcast_ref::<PluginCustomValue>()
{
assert_eq!(name, plugin_val.name);
assert_eq!(data, plugin_val.data);
assert_eq!(name, plugin_val.name());
assert_eq!(data, plugin_val.data());
assert!(plugin_val.notify_on_drop());
} else {
panic!("returned CustomValue is not a PluginCustomValue");
}

View File

@ -26,18 +26,30 @@ pub trait CustomValue: fmt::Debug + Send + Sync {
fn as_any(&self) -> &dyn std::any::Any;
/// Follow cell path by numeric index (e.g. rows)
fn follow_path_int(&self, _count: usize, span: Span) -> Result<Value, ShellError> {
fn follow_path_int(
&self,
self_span: Span,
index: usize,
path_span: Span,
) -> Result<Value, ShellError> {
let _ = (self_span, index);
Err(ShellError::IncompatiblePathAccess {
type_name: self.value_string(),
span,
span: path_span,
})
}
/// Follow cell path by string key (e.g. columns)
fn follow_path_string(&self, _column_name: String, span: Span) -> Result<Value, ShellError> {
fn follow_path_string(
&self,
self_span: Span,
column_name: String,
path_span: Span,
) -> Result<Value, ShellError> {
let _ = (self_span, column_name);
Err(ShellError::IncompatiblePathAccess {
type_name: self.value_string(),
span,
span: path_span,
})
}
@ -54,11 +66,23 @@ pub trait CustomValue: fmt::Debug + Send + Sync {
/// Default impl raises [`ShellError::UnsupportedOperator`].
fn operation(
&self,
_lhs_span: Span,
lhs_span: Span,
operator: Operator,
op: Span,
_right: &Value,
right: &Value,
) -> Result<Value, ShellError> {
let _ = (lhs_span, right);
Err(ShellError::UnsupportedOperator { operator, span: op })
}
/// For custom values in plugins: return `true` here if you would like to be notified when all
/// copies of this custom value are dropped in the engine.
///
/// The notification will take place via
/// [`.custom_value_dropped()`](crate::StreamingPlugin::custom_value_dropped) on the plugin.
///
/// The default is `false`.
fn notify_plugin_on_drop(&self) -> bool {
false
}
}

View File

@ -1106,8 +1106,9 @@ impl Value {
});
}
}
Value::CustomValue { val, .. } => {
current = match val.follow_path_int(*count, *origin_span) {
Value::CustomValue { ref val, .. } => {
current =
match val.follow_path_int(current.span(), *count, *origin_span) {
Ok(val) => val,
Err(err) => {
if *optional {
@ -1249,8 +1250,22 @@ impl Value {
current = Value::list(list, span);
}
Value::CustomValue { val, .. } => {
current = val.follow_path_string(column_name.clone(), *origin_span)?;
Value::CustomValue { ref val, .. } => {
current = match val.follow_path_string(
current.span(),
column_name.clone(),
*origin_span,
) {
Ok(val) => val,
Err(err) => {
if *optional {
return Ok(Value::nothing(*origin_span));
// short-circuit
} else {
return Err(err);
}
}
}
}
Value::Nothing { .. } if *optional => {
return Ok(Value::nothing(*origin_span)); // short-circuit
@ -2652,6 +2667,9 @@ impl Value {
val.extend(rhs);
Ok(Value::binary(val, span))
}
(Value::CustomValue { val: lhs, .. }, rhs) => {
lhs.operation(self.span(), Operator::Math(Math::Append), op, rhs)
}
_ => Err(ShellError::OperatorMismatch {
op_span: op,
lhs_ty: self.get_type().to_string(),

View File

@ -1,7 +1,9 @@
use nu_protocol::{CustomValue, ShellError, Span, Value};
use std::cmp::Ordering;
use nu_protocol::{ast, CustomValue, ShellError, Span, Value};
use serde::{Deserialize, Serialize};
#[derive(Clone, Debug, Serialize, Deserialize)]
#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
pub struct CoolCustomValue {
pub(crate) cool: String,
}
@ -44,7 +46,7 @@ impl CoolCustomValue {
#[typetag::serde]
impl CustomValue for CoolCustomValue {
fn clone_value(&self, span: nu_protocol::Span) -> Value {
fn clone_value(&self, span: Span) -> Value {
Value::custom_value(Box::new(self.clone()), span)
}
@ -52,13 +54,94 @@ impl CustomValue for CoolCustomValue {
self.typetag_name().to_string()
}
fn to_base_value(&self, span: nu_protocol::Span) -> Result<Value, ShellError> {
fn to_base_value(&self, span: Span) -> Result<Value, ShellError> {
Ok(Value::string(
format!("I used to be a custom value! My data was ({})", self.cool),
span,
))
}
fn follow_path_int(
&self,
_self_span: Span,
index: usize,
path_span: Span,
) -> Result<Value, ShellError> {
if index == 0 {
Ok(Value::string(&self.cool, path_span))
} else {
Err(ShellError::AccessBeyondEnd {
max_idx: 0,
span: path_span,
})
}
}
fn follow_path_string(
&self,
self_span: Span,
column_name: String,
path_span: Span,
) -> Result<Value, ShellError> {
if column_name == "cool" {
Ok(Value::string(&self.cool, path_span))
} else {
Err(ShellError::CantFindColumn {
col_name: column_name,
span: path_span,
src_span: self_span,
})
}
}
fn partial_cmp(&self, other: &Value) -> Option<Ordering> {
if let Value::CustomValue { val, .. } = other {
val.as_any()
.downcast_ref()
.and_then(|other: &CoolCustomValue| PartialOrd::partial_cmp(self, other))
} else {
None
}
}
fn operation(
&self,
lhs_span: Span,
operator: ast::Operator,
op_span: Span,
right: &Value,
) -> Result<Value, ShellError> {
match operator {
// Append the string inside `cool`
ast::Operator::Math(ast::Math::Append) => {
if let Some(right) = right
.as_custom_value()
.ok()
.and_then(|c| c.as_any().downcast_ref::<CoolCustomValue>())
{
Ok(Value::custom_value(
Box::new(CoolCustomValue {
cool: format!("{}{}", self.cool, right.cool),
}),
op_span,
))
} else {
Err(ShellError::OperatorMismatch {
op_span,
lhs_ty: self.typetag_name().into(),
lhs_span,
rhs_ty: right.get_type().to_string(),
rhs_span: right.span(),
})
}
}
_ => Err(ShellError::UnsupportedOperator {
operator,
span: op_span,
}),
}
}
fn as_any(&self) -> &dyn std::any::Any {
self
}

View File

@ -0,0 +1,50 @@
use nu_protocol::{record, CustomValue, ShellError, Span, Value};
use serde::{Deserialize, Serialize};
#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct DropCheck {
pub(crate) msg: String,
}
impl DropCheck {
pub(crate) fn new(msg: String) -> DropCheck {
DropCheck { msg }
}
pub(crate) fn into_value(self, span: Span) -> Value {
Value::custom_value(Box::new(self), span)
}
pub(crate) fn notify(&self) {
eprintln!("DropCheck was dropped: {}", self.msg);
}
}
#[typetag::serde]
impl CustomValue for DropCheck {
fn clone_value(&self, span: Span) -> Value {
self.clone().into_value(span)
}
fn value_string(&self) -> String {
"DropCheck".into()
}
fn to_base_value(&self, span: Span) -> Result<Value, ShellError> {
Ok(Value::record(
record! {
"msg" => Value::string(&self.msg, span)
},
span,
))
}
fn as_any(&self) -> &dyn std::any::Any {
self
}
fn notify_plugin_on_drop(&self) -> bool {
// This is what causes Nushell to let us know when the value is dropped
true
}
}

View File

@ -1,11 +1,14 @@
mod cool_custom_value;
mod drop_check;
mod second_custom_value;
use cool_custom_value::CoolCustomValue;
use drop_check::DropCheck;
use second_custom_value::SecondCustomValue;
use nu_plugin::{serve_plugin, EngineInterface, MsgPackSerializer, Plugin};
use nu_plugin::{EvaluatedCall, LabeledError};
use nu_protocol::{Category, PluginSignature, ShellError, SyntaxShape, Value};
use second_custom_value::SecondCustomValue;
use nu_protocol::{Category, CustomValue, PluginSignature, ShellError, SyntaxShape, Value};
struct CustomValuePlugin;
@ -34,6 +37,10 @@ impl Plugin for CustomValuePlugin {
"the custom value to update",
)
.category(Category::Experimental),
PluginSignature::build("custom-value drop-check")
.usage("Generates a custom value that prints a message when dropped")
.required("msg", SyntaxShape::String, "the message to print on drop")
.category(Category::Experimental),
]
}
@ -49,6 +56,7 @@ impl Plugin for CustomValuePlugin {
"custom-value generate2" => self.generate2(engine, call),
"custom-value update" => self.update(call, input),
"custom-value update-arg" => self.update(call, &call.req(0)?),
"custom-value drop-check" => self.drop_check(call),
_ => Err(LabeledError {
label: "Plugin call with wrong name signature".into(),
msg: "the signature used to call the plugin does not match any name in the plugin signature vector".into(),
@ -56,6 +64,18 @@ impl Plugin for CustomValuePlugin {
}),
}
}
fn custom_value_dropped(
&self,
_engine: &EngineInterface,
custom_value: Box<dyn CustomValue>,
) -> Result<(), LabeledError> {
// This is how we implement our drop behavior for DropCheck.
if let Some(drop_check) = custom_value.as_any().downcast_ref::<DropCheck>() {
drop_check.notify();
}
Ok(())
}
}
impl CustomValuePlugin {
@ -101,6 +121,10 @@ impl CustomValuePlugin {
}
.into())
}
fn drop_check(&self, call: &EvaluatedCall) -> Result<Value, LabeledError> {
Ok(DropCheck::new(call.req(0)?).into_value(call.head))
}
}
fn main() {

View File

@ -79,6 +79,57 @@ fn can_get_describe_plugin_custom_values() {
assert_eq!(actual.out, "CoolCustomValue");
}
#[test]
fn can_get_plugin_custom_value_int_cell_path() {
let actual = nu_with_plugins!(
cwd: "tests",
plugin: ("nu_plugin_custom_values"),
"(custom-value generate).0"
);
assert_eq!(actual.out, "abc");
}
#[test]
fn can_get_plugin_custom_value_string_cell_path() {
let actual = nu_with_plugins!(
cwd: "tests",
plugin: ("nu_plugin_custom_values"),
"(custom-value generate).cool"
);
assert_eq!(actual.out, "abc");
}
#[test]
fn can_sort_plugin_custom_values() {
let actual = nu_with_plugins!(
cwd: "tests",
plugin: ("nu_plugin_custom_values"),
"[(custom-value generate | custom-value update) (custom-value generate)] | sort | each { print } | ignore"
);
assert_eq!(
actual.out,
"I used to be a custom value! My data was (abc)\
I used to be a custom value! My data was (abcxyz)"
);
}
#[test]
fn can_append_plugin_custom_values() {
let actual = nu_with_plugins!(
cwd: "tests",
plugin: ("nu_plugin_custom_values"),
"(custom-value generate) ++ (custom-value generate)"
);
assert_eq!(
actual.out,
"I used to be a custom value! My data was (abcabc)"
);
}
// There are currently no custom values defined by the engine that aren't hidden behind an extra
// feature
#[cfg(feature = "sqlite")]
@ -116,3 +167,16 @@ fn fails_if_passing_custom_values_across_plugins() {
.err
.contains("the `inc` plugin does not support this kind of value"));
}
#[test]
fn drop_check_custom_value_prints_message_on_drop() {
let actual = nu_with_plugins!(
cwd: "tests",
plugin: ("nu_plugin_custom_values"),
// We build an array with the value copied twice to verify that it only gets dropped once
"do { |v| [$v $v] } (custom-value drop-check 'Hello') | ignore"
);
assert_eq!(actual.err, "DropCheck was dropped: Hello\n");
assert!(actual.status.success());
}