524 lines
18 KiB
Rust
524 lines
18 KiB
Rust
use notify::DebouncedEvent;
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use notify::Watcher;
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use notify::RecursiveMode;
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use notify::watcher;
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use std::fs;
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use std::future;
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use std::io;
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use std::path::PathBuf;
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use std::sync::Arc;
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use std::sync::mpsc::channel;
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use std::thread;
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use std::time::Duration;
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use syndicate::actor::*;
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use syndicate::error::Error;
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use syndicate::during;
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use syndicate::enclose;
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use syndicate::schemas::dataspace;
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use syndicate::schemas::dataspace_patterns as P;
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use syndicate::supervise::{Supervisor, SupervisorConfiguration};
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use syndicate::value::BinarySource;
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use syndicate::value::IOBinarySource;
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use syndicate::value::Map;
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use syndicate::value::NestedValue;
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use syndicate::value::NoEmbeddedDomainCodec;
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use syndicate::value::Reader;
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use syndicate::value::Record;
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use syndicate::value::Set;
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use syndicate::value::Value;
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use syndicate::value::ViaCodec;
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use syndicate::value::signed_integer::SignedInteger;
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use crate::language::language;
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use crate::lifecycle;
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use crate::schemas::internal_services;
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use syndicate_macros::during;
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pub fn on_demand(t: &mut Activation, config_ds: Arc<Cap>, root_ds: Arc<Cap>) {
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t.spawn(syndicate::name!("on_demand", module = module_path!()), move |t| {
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Ok(during!(
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t, config_ds, language(), <run-service $spec: internal_services::ConfigWatcher>, |t| {
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Supervisor::start(
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t,
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syndicate::name!(parent: None, "config", spec = ?spec),
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SupervisorConfiguration::default(),
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enclose!((config_ds, spec) lifecycle::updater(config_ds, spec)),
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enclose!((config_ds, root_ds) move |t|
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enclose!((config_ds, root_ds, spec) run(t, config_ds, root_ds, spec))))
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}))
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});
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}
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fn convert_notify_error(e: notify::Error) -> Error {
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syndicate::error::error(&format!("Notify error: {:?}", e), AnyValue::new(false))
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}
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#[derive(Debug, Clone)]
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enum Instruction {
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Assert {
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target: String,
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template: AnyValue,
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},
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React {
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target: String,
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pattern_template: AnyValue,
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body: Box<Instruction>,
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},
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Sequence {
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instructions: Vec<Instruction>,
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},
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}
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#[derive(Debug)]
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enum Symbolic {
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Reference(String),
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Binder(String),
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Discard,
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Literal(String),
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}
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fn analyze(s: &str) -> Symbolic {
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if s == "_" {
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Symbolic::Discard
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} else if s.starts_with("?") {
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Symbolic::Binder(s[1..].to_owned())
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} else if s.starts_with("$") {
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Symbolic::Reference(s[1..].to_owned())
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} else if s.starts_with("=") {
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Symbolic::Literal(s[1..].to_owned())
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} else {
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Symbolic::Literal(s.to_owned())
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}
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}
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fn bad_instruction(message: String) -> io::Error {
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io::Error::new(io::ErrorKind::InvalidData, message)
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}
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fn discard() -> P::Pattern {
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P::Pattern::DDiscard(Box::new(P::DDiscard))
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}
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#[derive(Debug)]
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struct PatternInstantiator<'e> {
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env: &'e Env,
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binding_names: Vec<String>,
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}
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#[derive(Debug, Clone)]
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struct Env(Map<String, AnyValue>);
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impl<'e> PatternInstantiator<'e> {
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fn instantiate_pattern(&mut self, template: &AnyValue) -> io::Result<P::Pattern> {
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Ok(match template.value() {
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Value::Boolean(_) |
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Value::Float(_) |
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Value::Double(_) |
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Value::SignedInteger(_) |
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Value::String(_) |
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Value::ByteString(_) |
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Value::Embedded(_) =>
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P::Pattern::DLit(Box::new(P::DLit { value: template.clone() })),
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Value::Symbol(s) => match analyze(s) {
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Symbolic::Discard => discard(),
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Symbolic::Binder(s) => {
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self.binding_names.push(s);
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P::Pattern::DBind(Box::new(P::DBind { pattern: discard() }))
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}
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Symbolic::Reference(s) =>
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P::Pattern::DLit(Box::new(P::DLit {
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value: self.env.0.get(&s)
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.ok_or_else(|| bad_instruction(
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format!("Undefined pattern-template variable: {:?}", template)))?
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.clone(),
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})),
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Symbolic::Literal(s) =>
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P::Pattern::DLit(Box::new(P::DLit {
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value: Value::Symbol(s).wrap(),
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})),
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},
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Value::Record(r) =>
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P::Pattern::DCompound(Box::new(P::DCompound::Rec {
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ctor: Box::new(P::CRec {
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label: r.label().clone(),
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arity: r.fields().len().into(),
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}),
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members: r.fields().iter().enumerate()
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.map(|(i, p)| Ok((i.into(), self.instantiate_pattern(p)?)))
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.filter(|e| discard() != e.as_ref().unwrap().1)
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.collect::<io::Result<Map<SignedInteger, P::Pattern>>>()?,
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})),
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Value::Sequence(v) =>
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P::Pattern::DCompound(Box::new(P::DCompound::Arr {
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ctor: Box::new(P::CArr {
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arity: v.len().into(),
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}),
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members: v.iter().enumerate()
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.map(|(i, p)| Ok((i.into(), self.instantiate_pattern(p)?)))
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.filter(|e| discard() != e.as_ref().unwrap().1)
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.collect::<io::Result<Map<SignedInteger, P::Pattern>>>()?,
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})),
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Value::Set(_) =>
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Err(bad_instruction(format!("Sets not permitted in patterns: {:?}", template)))?,
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Value::Dictionary(v) =>
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P::Pattern::DCompound(Box::new(P::DCompound::Dict {
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ctor: Box::new(P::CDict),
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members: v.iter()
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.map(|(a, b)| Ok((a.clone(), self.instantiate_pattern(b)?)))
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.collect::<io::Result<Map<AnyValue, P::Pattern>>>()?,
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})),
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})
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}
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}
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impl Env {
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fn lookup_target(&self, target: &String) -> io::Result<Arc<Cap>> {
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Ok(self.0.get(target)
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.ok_or_else(|| bad_instruction(format!("Undefined target variable: {:?}", target)))?
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.value().to_embedded()?.clone())
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}
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fn instantiate_value(&self, template: &AnyValue) -> io::Result<AnyValue> {
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Ok(match template.value() {
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Value::Boolean(_) |
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Value::Float(_) |
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Value::Double(_) |
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Value::SignedInteger(_) |
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Value::String(_) |
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Value::ByteString(_) |
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Value::Embedded(_) =>
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template.clone(),
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Value::Symbol(s) => match analyze(s) {
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Symbolic::Binder(_) | Symbolic::Discard =>
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Err(bad_instruction(
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format!("Invalid use of wildcard in template: {:?}", template)))?,
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Symbolic::Reference(s) =>
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self.0.get(&s).ok_or_else(|| bad_instruction(
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format!("Undefined template variable: {:?}", template)))?.clone(),
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Symbolic::Literal(s) =>
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Value::Symbol(s).wrap(),
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},
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Value::Record(r) =>
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Value::Record(Record(r.fields_vec().iter().map(|a| self.instantiate_value(a))
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.collect::<Result<Vec<_>, _>>()?)).wrap(),
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Value::Sequence(v) =>
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Value::Sequence(v.iter().map(|a| self.instantiate_value(a))
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.collect::<Result<Vec<_>, _>>()?).wrap(),
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Value::Set(v) =>
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Value::Set(v.iter().map(|a| self.instantiate_value(a))
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.collect::<Result<Set<_>, _>>()?).wrap(),
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Value::Dictionary(v) =>
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Value::Dictionary(v.iter().map(|(a,b)| Ok((self.instantiate_value(a)?,
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self.instantiate_value(b)?)))
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.collect::<io::Result<Map<_, _>>>()?).wrap(),
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})
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}
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}
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impl Instruction {
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fn eval(&self, t: &mut Activation, env: &Env) -> io::Result<()> {
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match self {
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Instruction::Assert { target, template } => {
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env.lookup_target(target)?.assert(t, &(), &env.instantiate_value(template)?);
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}
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Instruction::React { target, pattern_template, body } => {
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let mut inst = PatternInstantiator {
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env,
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binding_names: Vec::new(),
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};
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let pattern = inst.instantiate_pattern(pattern_template)?;
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let binding_names = inst.binding_names;
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let observer = during::entity(env.clone())
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.on_asserted_facet(enclose!(
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(binding_names, body) move |env, t, captures: AnyValue| {
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if let Some(captures) = captures.value_owned().into_sequence() {
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let mut env = env.clone();
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for (k, v) in binding_names.iter().zip(captures) {
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env.0.insert(k.clone(), v);
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}
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body.eval(t, &env)?;
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}
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Ok(())
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}))
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.create_cap(t);
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env.lookup_target(target)?.assert(t, language(), &dataspace::Observe {
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pattern,
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observer,
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});
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}
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Instruction::Sequence { instructions } => {
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for i in instructions {
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i.eval(t, env)?;
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}
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}
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}
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Ok(())
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}
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fn parse<'t>(target: &str, tokens: &'t [AnyValue]) -> io::Result<Option<(Instruction, &'t [AnyValue])>> {
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if tokens.len() == 0 {
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return Ok(None);
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}
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if tokens[0].value().is_record() || tokens[0].value().is_dictionary() {
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return Ok(Some((Instruction::Assert {
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target: target.to_owned(),
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template: tokens[0].clone(),
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}, &tokens[1..])));
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}
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if let Some(tokens) = tokens[0].value().as_sequence() {
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return Ok(Some((Instruction::Sequence {
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instructions: Instruction::parse_all(target, tokens)?,
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}, &tokens[1..])));
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}
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if let Some(s) = tokens[0].value().as_symbol() {
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match analyze(s) {
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Symbolic::Binder(s) =>
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if s.len() == 0 {
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if tokens.len() == 1 {
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Err(bad_instruction(format!("Missing pattern and instruction in react")))?;
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} else {
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let pattern_template = tokens[1].clone();
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match Instruction::parse(target, &tokens[2..])? {
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None =>
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Err(bad_instruction(format!("Missing instruction in react with pattern {:?}", tokens[1])))?,
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Some((body, tokens)) =>
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return Ok(Some((Instruction::React {
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target: target.to_owned(),
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pattern_template,
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body: Box::new(body),
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}, tokens))),
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}
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}
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} else {
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Err(bad_instruction(format!("Invalid use of pattern binder in target: {:?}", tokens[0])))?;
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},
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Symbolic::Discard =>
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Err(bad_instruction(format!("Invalid use of discard in target: {:?}", tokens[0])))?,
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Symbolic::Reference(s) =>
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if tokens.len() == 1 {
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Err(bad_instruction(format!("Missing instruction after retarget: {:?}", tokens[0])))?;
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} else if tokens[1].value().is_symbol() {
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Err(bad_instruction(format!("Two retargets in a row: {:?} {:?}", tokens[0], tokens[1])))?;
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} else {
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return Instruction::parse(&s, &tokens[1..]);
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},
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Symbolic::Literal(_) =>
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/* fall through */ (),
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}
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}
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Err(bad_instruction(format!("Invalid token: {:?}", tokens[0])))?
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}
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fn parse_all(target: &str, mut tokens: &[AnyValue]) -> io::Result<Vec<Instruction>> {
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let mut instructions = Vec::new();
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while let Some((i, more)) = Instruction::parse(target, tokens)? {
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instructions.push(i);
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tokens = more;
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}
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Ok(instructions)
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}
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}
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fn process_existing_file(
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t: &mut Activation,
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config_ds: &Arc<Cap>,
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root_ds: &Arc<Cap>,
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path: &PathBuf,
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) -> io::Result<Option<FacetId>> {
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let tokens: Vec<AnyValue> = IOBinarySource::new(fs::File::open(path)?)
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.text::<AnyValue, _>(ViaCodec::new(NoEmbeddedDomainCodec))
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.configured(true)
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.collect::<Result<Vec<_>, _>>()?;
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let instructions = Instruction::parse_all("config", &tokens)?;
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if instructions.is_empty() {
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Ok(None)
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} else {
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let mut env = Map::new();
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env.insert("config".to_owned(), AnyValue::domain(config_ds.clone()));
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env.insert("root".to_owned(), AnyValue::domain(root_ds.clone()));
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match t.facet(|t| Ok(Instruction::Sequence { instructions }.eval(t, &Env(env))?)) {
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Ok(facet_id) => Ok(Some(facet_id)),
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Err(error) => {
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tracing::error!(?path, ?error);
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Ok(None)
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}
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}
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}
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}
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fn process_path(
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t: &mut Activation,
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config_ds: &Arc<Cap>,
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root_ds: &Arc<Cap>,
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path: &PathBuf,
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) -> io::Result<Option<FacetId>> {
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match fs::metadata(path) {
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Ok(md) => if md.is_file() {
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process_existing_file(t, config_ds, root_ds, path)
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} else {
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Ok(None)
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}
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Err(e) => if e.kind() != io::ErrorKind::NotFound {
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Err(e)?
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} else {
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Ok(None)
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}
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}
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}
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fn is_hidden(path: &PathBuf) -> bool {
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match path.file_name().and_then(|n| n.to_str()) {
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Some(n) => n.starts_with("."),
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None => true, // ?
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}
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}
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fn scan_file(
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t: &mut Activation,
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path_state: &mut Map<PathBuf, FacetId>,
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config_ds: &Arc<Cap>,
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root_ds: &Arc<Cap>,
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path: &PathBuf,
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) -> bool {
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if is_hidden(path) {
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return true;
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}
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tracing::info!("scan_file: {:?}", path);
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match process_path(t, config_ds, root_ds, path) {
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Ok(maybe_facet_id) => {
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if let Some(facet_id) = maybe_facet_id {
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path_state.insert(path.clone(), facet_id);
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}
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true
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},
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Err(e) => {
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tracing::warn!("scan_file: {:?}: {:?}", path, e);
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false
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}
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}
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}
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fn initial_scan(
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t: &mut Activation,
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path_state: &mut Map<PathBuf, FacetId>,
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config_ds: &Arc<Cap>,
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root_ds: &Arc<Cap>,
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path: &PathBuf,
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) {
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if is_hidden(path) {
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return;
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}
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match fs::metadata(path) {
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Ok(md) => if md.is_file() {
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scan_file(t, path_state, config_ds, root_ds, path);
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} else {
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match fs::read_dir(path) {
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Ok(entries) => for er in entries {
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match er {
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Ok(e) => initial_scan(t, path_state, config_ds, root_ds, &e.path()),
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Err(e) => tracing::warn!(
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"initial_scan: transient during scan of {:?}: {:?}", path, e),
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}
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}
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Err(e) => tracing::warn!("initial_scan: enumerating {:?}: {:?}", path, e),
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}
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},
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Err(e) => tracing::warn!("initial_scan: `stat`ing {:?}: {:?}", path, e),
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}
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}
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fn run(
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t: &mut Activation,
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config_ds: Arc<Cap>,
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root_ds: Arc<Cap>,
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spec: internal_services::ConfigWatcher,
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) -> ActorResult {
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let path = fs::canonicalize(spec.path.clone())?;
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tracing::info!("watching {:?}", &path);
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let (tx, rx) = channel();
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let mut watcher = watcher(tx, Duration::from_millis(100)).map_err(convert_notify_error)?;
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watcher.watch(&path, RecursiveMode::Recursive).map_err(convert_notify_error)?;
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let facet = t.facet.clone();
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thread::spawn(move || {
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let mut path_state: Map<PathBuf, FacetId> = Map::new();
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{
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let root_path = path.clone().into();
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facet.activate(Account::new(syndicate::name!("initial_scan")), |t| {
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initial_scan(t, &mut path_state, &config_ds, &root_ds, &root_path);
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config_ds.assert(t, language(), &lifecycle::ready(&spec));
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Ok(())
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}).unwrap();
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tracing::trace!("initial_scan complete");
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}
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let mut rescan = |paths: Vec<PathBuf>| {
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facet.activate(Account::new(syndicate::name!("rescan")), |t| {
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let mut to_stop = Vec::new();
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for path in paths.into_iter() {
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let maybe_facet_id = path_state.remove(&path);
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let new_content_ok = scan_file(t, &mut path_state, &config_ds, &root_ds, &path);
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if let Some(old_facet_id) = maybe_facet_id {
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if new_content_ok {
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to_stop.push(old_facet_id);
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} else {
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path_state.insert(path, old_facet_id);
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}
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}
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}
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for facet_id in to_stop.into_iter() {
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t.stop_facet(facet_id)?;
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}
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Ok(())
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}).unwrap()
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};
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while let Ok(event) = rx.recv() {
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tracing::trace!("notification: {:?}", &event);
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match event {
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DebouncedEvent::NoticeWrite(_p) |
|
|
DebouncedEvent::NoticeRemove(_p) =>
|
|
(),
|
|
DebouncedEvent::Create(p) |
|
|
DebouncedEvent::Write(p) |
|
|
DebouncedEvent::Chmod(p) |
|
|
DebouncedEvent::Remove(p) =>
|
|
rescan(vec![p]),
|
|
DebouncedEvent::Rename(p, q) =>
|
|
rescan(vec![p, q]),
|
|
_ =>
|
|
tracing::info!("{:?}", event),
|
|
}
|
|
}
|
|
|
|
let _ = facet.activate(Account::new(syndicate::name!("termination")), |t| {
|
|
tracing::trace!("linked thread terminating associated facet");
|
|
t.stop()
|
|
});
|
|
|
|
tracing::trace!("linked thread done");
|
|
});
|
|
|
|
t.linked_task(syndicate::name!("cancel-wait"), async move {
|
|
future::pending::<()>().await;
|
|
drop(watcher);
|
|
Ok(LinkedTaskTermination::KeepFacet)
|
|
});
|
|
|
|
Ok(())
|
|
}
|