Rayz/tagfilter mutable tagset

[rayz]

Summary

PR to benchmark the tagfilter implementation + mutable tagset changes

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

How did you test this PR?

References

[Copilot]

Pull request overview

This pull request implements a major refactoring of the tag management system in the Saluki codebase. The core change is converting TagSet from a simple Vec<Tag> wrapper to a sophisticated mutable data structure with copy-on-write semantics and an overlay-based mutation model. This enables efficient in-place mutations of tags while preserving immutable sharing through SharedTagSet.

Changes:

• Refactored TagSet to use a base SharedTagSet with an optional mutation overlay (additions and removals bitset) for efficient mutations
• Introduced new FrozenTagSet type as immutable storage backing for SharedTagSet
• Updated all data model types (Trace, Span, Log, EventD, etc.) to use TagSet instead of SharedTagSet
• Simplified transforms like tag_filterlist and host_tags to use direct mutation instead of context resolvers
• Added new mutation methods to Context (with_tags_mut, with_origin_tags_mut, with_tag_sets_mut) with copy-on-write semantics
• Added comprehensive tests and benchmarks for the new TagSet implementation

Reviewed changes

Copilot reviewed 27 out of 31 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
lib/saluki-context/src/tags/tagset/owned.rs	Complete rewrite of TagSet with overlay-based mutation model
lib/saluki-context/src/tags/tagset/shared.rs	Updated to use FrozenTagSet internally
lib/saluki-context/src/tags/tagset/frozen.rs	New immutable storage type
lib/saluki-context/src/context.rs	Updated Context API with in-place mutation methods
lib/saluki-core/src/data_model/event/*.rs	Updated to use TagSet instead of SharedTagSet
lib/saluki-components/src/transforms/tag_filterlist/mod.rs	Simplified to use direct mutation
lib/saluki-components/src/transforms/host_tags/mod.rs	Simplified to use direct mutation
lib/saluki-common/src/collections/bitset.rs	New dense contiguous bitset implementation

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[Copilot]

The from_static_parts method constructs a TagSet by iterating over the tags array and inserting each tag via insert_tag(), which skips duplicates. However, the context key is computed by passing the original tags array to hash_context() on line 46. If the array contains duplicate tags, the hash will include those duplicates, but the TagSet (which is stored in the context) will not contain them (due to deduplication in insert_tag()). This creates a mismatch: the context key is not consistent with the actual tag set stored in the context. The hash should be computed from the actual TagSet that will be stored, not from the original array. Change line 46 to: let (key, _) = hash_context(name, &tag_set, &origin_tags);

Suggested change

	let (key, _) = hash_context(name, tags, &origin_tags);
	let (key, _) = hash_context(name, &tag_set, &origin_tags);

[pr-commenter]

Binary Size Analysis (Agent Data Plane)

Target: 1d50af4 (baseline) vs bfca7a2 (comparison) diff
Analysis Type: Stripped binaries (debug symbols excluded)
Baseline Size: 26.19 MiB
Comparison Size: 26.32 MiB
Size Change: +131.63 KiB (+0.49%)
Pass/Fail Threshold: +5%
Result: PASSED ✅

Changes by Module

Module	File Size	Symbols
core	+39.62 KiB	8740
saluki_components::transforms::tag_filterlist	+35.61 KiB	17
saluki_context::tags::tagset	+11.94 KiB	21
serde_core	+8.71 KiB	338
[sections]	+8.14 KiB	7
smallvec	+8.05 KiB	100
hashbrown	+6.38 KiB	354
agent_data_plane::cli::run	+5.40 KiB	70
saluki_components::transforms::host_tags	-4.73 KiB	8
[Unmapped]	+4.20 KiB	1
figment	-3.03 KiB	94
saluki_context::hash::hash_context	+2.87 KiB	1
axum	+2.79 KiB	212
saluki_context::resolver::TagsResolver	-2.35 KiB	18
saluki_config::dynamic::watcher	-2.34 KiB	2
saluki_components::destinations::prometheus	+2.06 KiB	64
saluki_context::hash::hash_context_with_seen	-1.99 KiB	1
saluki_components::destinations::dsd_stats	+1.99 KiB	10
agent_data_plane::state::metrics	+1.86 KiB	6
tokio	+1.77 KiB	2276

Detailed Symbol Changes

    FILE SIZE        VM SIZE    
 --------------  -------------- 
  [NEW] +1.79Mi  [NEW] +1.79Mi    std::thread::local::LocalKey<T>::with::h7c684d6f9933cd6b
  +1.7%  +212Ki  +1.8%  +192Ki    [22021 Others]
  [NEW]  +119Ki  [NEW]  +119Ki    agent_data_plane::cli::run::create_topology::_{{closure}}::ha521051891c6ebe9
  [NEW] +84.6Ki  [NEW] +84.5Ki    agent_data_plane::internal::control_plane::spawn_control_plane::_{{closure}}::h730296c1b304c20b
  [NEW] +64.2Ki  [NEW] +64.0Ki    saluki_components::common::datadog::io::run_endpoint_io_loop::_{{closure}}::he1e85622a066a7d7
  [NEW] +57.8Ki  [NEW] +57.7Ki    agent_data_plane::cli::run::handle_run_command::_{{closure}}::hed7e33f4806adb0a
  [NEW] +49.5Ki  [NEW] +49.3Ki    saluki_app::bootstrap::AppBootstrapper::bootstrap::_{{closure}}::h91289bd13f483a0d
  [NEW] +48.0Ki  [NEW] +47.8Ki    _<saluki_components::destinations::prometheus::Prometheus as saluki_core::components::destinations::Destination>::run::_{{closure}}::h708c1b0be89825a9
  [NEW] +46.4Ki  [NEW] +46.3Ki    h2::proto::connection::Connection<T,P,B>::poll::h038035d5ccad579f
  [NEW] +46.1Ki  [NEW] +45.9Ki    _<saluki_components::forwarders::otlp::OtlpForwarder as saluki_core::components::forwarders::Forwarder>::run::_{{closure}}::h290133f32882b5e1
  [DEL] -44.1Ki  [DEL] -43.9Ki    saluki_env::workload::providers::remote_agent::RemoteAgentWorkloadProvider::from_configuration::_{{closure}}::hbdb816f02e21b1cf
  [DEL] -44.4Ki  [DEL] -44.2Ki    _<saluki_components::transforms::aggregate::Aggregate as saluki_core::components::transforms::Transform>::run::_{{closure}}::hb4d1ad0684099c4c
  [DEL] -46.0Ki  [DEL] -45.8Ki    _<saluki_components::destinations::prometheus::Prometheus as saluki_core::components::destinations::Destination>::run::_{{closure}}::hea5618e9afd08b63
  [DEL] -46.1Ki  [DEL] -45.9Ki    _<saluki_components::forwarders::otlp::OtlpForwarder as saluki_core::components::forwarders::Forwarder>::run::_{{closure}}::hb0c627893c271e2c
  [DEL] -46.4Ki  [DEL] -46.3Ki    h2::proto::connection::Connection<T,P,B>::poll::h100071ec98c95c21
  [DEL] -49.5Ki  [DEL] -49.4Ki    saluki_app::bootstrap::AppBootstrapper::bootstrap::_{{closure}}::h15f926ef5659e580
  [DEL] -57.8Ki  [DEL] -57.7Ki    agent_data_plane::cli::run::handle_run_command::_{{closure}}::hebabd4c0d26708e2
  [DEL] -64.2Ki  [DEL] -64.0Ki    saluki_components::common::datadog::io::run_endpoint_io_loop::_{{closure}}::h1c7964dcd8ecbead
  [DEL] -84.6Ki  [DEL] -84.5Ki    agent_data_plane::internal::control_plane::spawn_control_plane::_{{closure}}::h78c38079d35f4f77
  [DEL]  -114Ki  [DEL]  -114Ki    agent_data_plane::cli::run::create_topology::_{{closure}}::h4a1b0b37b7e2d03e
  [DEL] -1.79Mi  [DEL] -1.79Mi    std::thread::local::LocalKey<T>::with::he517c09e5477efe1
  +0.5%  +131Ki  +0.5%  +111Ki    TOTAL

[pr-commenter]

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[Copilot]

Pull request overview

Copilot reviewed 27 out of 31 changed files in this pull request and generated no new comments.

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[rayz]

Closing in favor of #1293