systemprompt_logging/services/
format.rs

1use std::fmt::{self, Write};
2use tracing::field::{Field, Visit};
3use tracing_subscriber::field::{MakeVisitor, VisitFmt, VisitOutput};
4use tracing_subscriber::fmt::format::Writer;
5
6use crate::sanitize::{REDACTION_PLACEHOLDER, escape_control, is_redacted, is_system_sentinel};
7
8#[derive(Debug, Clone, Copy, Default)]
9pub struct FilterSystemFields;
10
11impl FilterSystemFields {
12    pub const fn new() -> Self {
13        Self
14    }
15}
16
17#[derive(Debug)]
18pub struct FilteringVisitor<'a> {
19    writer: Writer<'a>,
20    is_first: bool,
21    result: fmt::Result,
22}
23
24impl<'a> FilteringVisitor<'a> {
25    const fn new(writer: Writer<'a>) -> Self {
26        Self {
27            writer,
28            is_first: true,
29            result: Ok(()),
30        }
31    }
32
33    fn record_filtered(&mut self, field: &Field, value: &dyn fmt::Debug) {
34        if self.result.is_err() {
35            return;
36        }
37
38        let debug_str = format!("{:?}", value);
39        if is_system_sentinel(&debug_str) {
40            return;
41        }
42
43        self.write_value(field.name(), &debug_str);
44    }
45
46    fn write_value(&mut self, name: &str, rendered: &str) {
47        let safe = if is_redacted(name) {
48            REDACTION_PLACEHOLDER.to_owned()
49        } else {
50            escape_control(rendered)
51        };
52        self.result = self.write_field(name, &safe);
53    }
54
55    fn write_field(&mut self, name: &str, value: &str) -> fmt::Result {
56        if self.is_first {
57            self.is_first = false;
58        } else {
59            self.writer.write_char(' ')?;
60        }
61        write!(self.writer, "{}={}", name, value)
62    }
63}
64
65impl Visit for FilteringVisitor<'_> {
66    fn record_debug(&mut self, field: &Field, value: &dyn fmt::Debug) {
67        self.record_filtered(field, value);
68    }
69
70    fn record_str(&mut self, field: &Field, value: &str) {
71        if self.result.is_err() {
72            return;
73        }
74        if is_system_sentinel(value) {
75            return;
76        }
77        self.write_value(field.name(), &format!("{:?}", value));
78    }
79}
80
81impl VisitOutput<fmt::Result> for FilteringVisitor<'_> {
82    fn finish(self) -> fmt::Result {
83        self.result
84    }
85}
86
87impl VisitFmt for FilteringVisitor<'_> {
88    fn writer(&mut self) -> &mut dyn Write {
89        &mut self.writer
90    }
91}
92
93impl<'a> MakeVisitor<Writer<'a>> for FilterSystemFields {
94    type Visitor = FilteringVisitor<'a>;
95
96    fn make_visitor(&self, target: Writer<'a>) -> Self::Visitor {
97        FilteringVisitor::new(target)
98    }
99}
systemprompt_logging/services/format.rs

systemprompt_logging/services/
format.rs
