33
44use crate :: {
55 config:: {
6- self , agent_config:: AgentConfigFile , agent_task:: AgentTaskFile , dynamic:: DynamicConfigFile ,
6+ agent_config:: { self , AgentConfigFile } ,
7+ agent_task:: { self , AgentTaskFile } ,
8+ dynamic:: { self , DynamicConfigFile } ,
79 } ,
810 RemoteConfigPath , RemoteConfigProduct , RemoteConfigSource ,
911} ;
1012use std:: any:: Any ;
1113use std:: collections:: HashMap ;
14+ use std:: fmt:: { Debug , Display , Formatter , Result } ;
1215
13- /// Opaque parsed payload for a remote config product. Product crates implement this on their own
14- /// types and export a [`ProductParser`] factory; the RC crate stores and distributes the results
15- /// without knowing their concrete type.
16- pub trait RemoteConfigParsedData : Send + Sync + ' static {
16+ /// Opaque parsed payload of a remote config product. Implemented by every type that impls
17+ /// [`RemoteConfigContent`]; product crates do not implement this trait directly.
18+ ///
19+ /// Use `parsed.as_any().downcast_ref::<T>()` to recover the concrete product type.
20+ pub trait RemoteConfigParsedData : Any + Debug + Send + Sync + ' static {
1721 fn as_any ( & self ) -> & dyn Any ;
18- fn product ( & self ) -> RemoteConfigProduct ;
22+ }
23+ impl < T : RemoteConfigContent > RemoteConfigParsedData for T {
24+ fn as_any ( & self ) -> & dyn Any {
25+ self
26+ }
27+ }
28+
29+ /// Typed contract a product crate provides so the registry can build a parser for [`Self`].
30+ pub trait RemoteConfigContent : Any + Debug + Send + Sync + ' static {
31+ const PRODUCT : RemoteConfigProduct ;
32+ fn parse ( data : & [ u8 ] ) -> anyhow:: Result < Self >
33+ where
34+ Self : Sized ;
1935}
2036
2137/// A product-specific parser: converts raw bytes into a parsed payload.
2238pub type ProductParser =
2339 Box < dyn Fn ( & [ u8 ] ) -> anyhow:: Result < Box < dyn RemoteConfigParsedData > > + Send + Sync > ;
2440
41+ /// Returned by [`ParserRegistry::register`] when a parser is already registered for a product.
42+ #[ derive( Debug ) ]
43+ pub struct AlreadyRegistered ( pub RemoteConfigProduct ) ;
44+
45+ impl Display for AlreadyRegistered {
46+ fn fmt ( & self , f : & mut Formatter < ' _ > ) -> Result {
47+ write ! ( f, "parser already registered for product {}" , self . 0 )
48+ }
49+ }
50+
51+ impl std:: error:: Error for AlreadyRegistered { }
52+
2553/// Maps [`RemoteConfigProduct`] variants to their parser functions.
2654///
27- /// Consumers build a registry (optionally starting from [`default_registry`]) and inject it into
28- /// the file storage or fetcher. Products with no registered parser return [`IgnoredProduct`]
29- /// so callers can track the config without processing its contents.
55+ /// Build a registry (optionally starting from [`default_registry`]) and inject it into the file
56+ /// storage or fetcher. Products with no registered parser yield `Ok(None)` so callers can still
57+ /// track the config without processing its contents.
3058pub struct ParserRegistry {
3159 parsers : HashMap < RemoteConfigProduct , ProductParser > ,
3260}
@@ -38,21 +66,45 @@ impl ParserRegistry {
3866 }
3967 }
4068
41- /// Register a parser for a product. Replaces any existing parser for that product.
42- pub fn register ( & mut self , product : RemoteConfigProduct , parser : ProductParser ) {
69+ /// Register `parser` for `product`. Errors if a parser is already registered for `product` —
70+ /// silent overwrites would mask configuration mistakes.
71+ pub fn register (
72+ & mut self ,
73+ product : RemoteConfigProduct ,
74+ parser : ProductParser ,
75+ ) -> anyhow:: Result < ( ) , AlreadyRegistered > {
76+ if self . parsers . contains_key ( & product) {
77+ return Err ( AlreadyRegistered ( product) ) ;
78+ }
4379 self . parsers . insert ( product, parser) ;
80+ Ok ( ( ) )
81+ }
82+
83+ /// Builder-style registration of a typed [`RemoteConfigContent`] implementor.
84+ /// Panics if `T::PRODUCT` is already registered — intended for one-shot setup at the start of
85+ /// a process where a collision is a programmer error worth surfacing immediately.
86+ #[ must_use]
87+ pub fn with < T : RemoteConfigContent > ( mut self ) -> Self {
88+ let parser: ProductParser = Box :: new ( |data : & [ u8 ] | {
89+ let parsed = T :: parse ( data) ?;
90+ Ok ( Box :: new ( parsed) as Box < dyn RemoteConfigParsedData > )
91+ } ) ;
92+ #[ allow( clippy:: expect_used) ]
93+ self . register ( T :: PRODUCT , parser)
94+ . expect ( "ParserRegistry::with: parser already registered" ) ;
95+ self
4496 }
4597
46- /// Parse `data` for `product`. Returns [`IgnoredProduct`] (not an error) when no parser is
98+ /// Parse `data` for `product`. Returns `Ok(None)` (not an error) when no parser is
4799/// registered, so callers can still track the config in their bookkeeping structures.
48100pub fn parse (
49101 & self ,
50102 product : RemoteConfigProduct ,
51103 data : & [ u8 ] ,
52- ) -> anyhow:: Result < Box < dyn RemoteConfigParsedData > > {
104+ ) -> anyhow:: Result < Option < Box < dyn RemoteConfigParsedData > > > {
53105 match self . parsers . get ( & product) {
54- Some ( parser) => parser ( data) ,
55- None => Ok ( Box :: new ( IgnoredProduct ( product ) ) ) ,
106+ Some ( parser) => parser ( data) . map ( Some ) ,
107+ None => Ok ( None ) ,
56108 }
57109 }
58110}
@@ -63,94 +115,58 @@ impl Default for ParserRegistry {
63115 }
64116}
65117
66- // ── Implementations for RC-internal product types ───────── ───────────────────
118+ // ── RemoteConfigContent impls for RC-internal product types ───────────────────
67119
68- /// Sentinel returned by [`ParserRegistry::parse`] when no parser is registered for a product.
69- /// Consumers that want to handle only specific products can downcast and ignore this type.
70- pub struct IgnoredProduct ( pub RemoteConfigProduct ) ;
120+ impl RemoteConfigContent for AgentConfigFile {
121+ const PRODUCT : RemoteConfigProduct = RemoteConfigProduct :: AgentConfig ;
71122
72- impl RemoteConfigParsedData for IgnoredProduct {
73- fn as_any ( & self ) -> & dyn Any {
74- self
75- }
76- fn product ( & self ) -> RemoteConfigProduct {
77- self . 0
123+ fn parse ( data : & [ u8 ] ) -> anyhow:: Result < Self > {
124+ Ok ( agent_config:: parse_json ( data) ?)
78125 }
79126}
80127
81- impl RemoteConfigParsedData for DynamicConfigFile {
82- fn as_any ( & self ) -> & dyn Any {
83- self
84- }
85- fn product ( & self ) -> RemoteConfigProduct {
86- RemoteConfigProduct :: ApmTracing
87- }
88- }
128+ impl RemoteConfigContent for AgentTaskFile {
129+ const PRODUCT : RemoteConfigProduct = RemoteConfigProduct :: AgentTask ;
89130
90- impl RemoteConfigParsedData for AgentConfigFile {
91- fn as_any ( & self ) -> & dyn Any {
92- self
93- }
94- fn product ( & self ) -> RemoteConfigProduct {
95- RemoteConfigProduct :: AgentConfig
131+ fn parse ( data : & [ u8 ] ) -> anyhow:: Result < Self > {
132+ Ok ( agent_task:: parse_json ( data) ?)
96133 }
97134}
98135
99- impl RemoteConfigParsedData for AgentTaskFile {
100- fn as_any ( & self ) -> & dyn Any {
101- self
102- }
103- fn product ( & self ) -> RemoteConfigProduct {
104- RemoteConfigProduct :: AgentTask
136+ impl RemoteConfigContent for DynamicConfigFile {
137+ const PRODUCT : RemoteConfigProduct = RemoteConfigProduct :: ApmTracing ;
138+
139+ fn parse ( data : & [ u8 ] ) -> anyhow:: Result < Self > {
140+ Ok ( dynamic:: parse_json ( data) ?)
105141 }
106142}
107143
108- /// Returns a registry pre-loaded with parsers for the RC-internal products:
109- /// [`RemoteConfigProduct::AgentConfig`], [`RemoteConfigProduct::AgentTask`], and
110- /// [`RemoteConfigProduct::ApmTracing`].
144+ /// Returns a registry pre-loaded with parsers for the RC-internal products.
111145///
112- /// Consumers that need additional product parsers (live-debugger, FFE, …) should call
113- /// [`ParserRegistry::register `] on the returned registry before use .
146+ /// Consumers that need additional product parsers (live-debugger, FFE, …) should chain
147+ /// [`ParserRegistry::with `] on the returned registry.
114148pub fn default_registry ( ) -> ParserRegistry {
115- let mut registry = ParserRegistry :: new ( ) ;
116- registry. register (
117- RemoteConfigProduct :: AgentConfig ,
118- Box :: new ( |data : & [ u8 ] | {
119- let parsed = config:: agent_config:: parse_json ( data) ?;
120- Ok ( Box :: new ( parsed) as Box < dyn RemoteConfigParsedData > )
121- } ) ,
122- ) ;
123- registry. register (
124- RemoteConfigProduct :: AgentTask ,
125- Box :: new ( |data : & [ u8 ] | {
126- let parsed = config:: agent_task:: parse_json ( data) ?;
127- Ok ( Box :: new ( parsed) as Box < dyn RemoteConfigParsedData > )
128- } ) ,
129- ) ;
130- registry. register (
131- RemoteConfigProduct :: ApmTracing ,
132- Box :: new ( |data : & [ u8 ] | {
133- let parsed = config:: dynamic:: parse_json ( data) ?;
134- Ok ( Box :: new ( parsed) as Box < dyn RemoteConfigParsedData > )
135- } ) ,
136- ) ;
137- registry
149+ ParserRegistry :: new ( )
150+ . with :: < AgentConfigFile > ( )
151+ . with :: < AgentTaskFile > ( )
152+ . with :: < DynamicConfigFile > ( )
138153}
139154
140155// ── RemoteConfigValue ─────────────────────────────────────────────────────────
141156
142157pub struct RemoteConfigValue {
143158 pub source : RemoteConfigSource ,
144- pub data : Box < dyn RemoteConfigParsedData > ,
159+ pub product : RemoteConfigProduct ,
160+ pub data : Option < Box < dyn RemoteConfigParsedData > > ,
145161 pub config_id : String ,
146162 pub name : String ,
147163}
148164
149- impl std :: fmt :: Debug for RemoteConfigValue {
150- fn fmt ( & self , f : & mut std :: fmt :: Formatter < ' _ > ) -> std :: fmt :: Result {
165+ impl Debug for RemoteConfigValue {
166+ fn fmt ( & self , f : & mut Formatter < ' _ > ) -> Result {
151167 f. debug_struct ( "RemoteConfigValue" )
152168 . field ( "source" , & self . source )
153- . field ( "product" , & self . data . product ( ) )
169+ . field ( "product" , & self . product )
154170 . field ( "config_id" , & self . config_id )
155171 . field ( "name" , & self . name )
156172 . finish ( )
@@ -163,6 +179,7 @@ impl RemoteConfigValue {
163179 let data = registry. parse ( path. product , data) ?;
164180 Ok ( RemoteConfigValue {
165181 source : path. source ,
182+ product : path. product ,
166183 data,
167184 config_id : path. config_id . to_string ( ) ,
168185 name : path. name . to_string ( ) ,
0 commit comments