lib: cmetrics: upgrade to v2.2.1

lib/cmetrics/.github/workflows/build.yaml

@@ -59,15 +59,12 @@ jobs:
           provenance: false
 
   build-debian:
-    name: Debian Buster build to confirm no issues once used downstream
+    name: Debian Bookworm build to confirm no issues once used downstream
     runs-on: ubuntu-latest
-    container: debian:buster
+    container: debian:bookworm
     steps:
       - name: Set up base image dependencies
         run: |
-          # Update sources to use archive.debian.org (Buster reached end-of-life)
-          sed -i 's/deb.debian.org/archive.debian.org/g' /etc/apt/sources.list
-          sed -i 's/security.debian.org/archive.debian.org/g' /etc/apt/sources.list
           apt-get update
           apt-get install -y build-essential wget make gcc g++ git libcurl4-openssl-dev
 

lib/cmetrics/AGENTS.md

@@ -0,0 +1,148 @@
+# CMetrics repository guide
+
+This is the canonical, vendor-neutral operating guide for automated tools and
+human contributors. Tool-specific files must point here instead of duplicating
+project rules.
+
+## Project role
+
+CMetrics is a standalone C library for creating, mutating, aggregating,
+encoding, and decoding metrics contexts. It is consumed by downstream projects,
+including Fluent Bit, so changes can affect public C APIs and serialized data.
+
+## Repository map
+
+- `include/cmetrics/`: installed public headers; treat layout and declarations
+  as compatibility-sensitive.
+- `src/`: metric implementations, map/index ownership, filters, and codecs.
+- `tests/`: Acutest unit tests, one CTest executable per source file.
+- `benchmarks/`: opt-in benchmark executable and Linux `perf stat` runner.
+- `docs/`: design and behavior notes; agent-neutral workflows are in `docs/ai/`.
+- `cmake/`, `CMakeLists.txt`: build, dependency, install, and packaging rules.
+- `lib/cfl`: CFL Git submodule; owns containers, SDS strings, arenas, and
+  supporting primitives.
+- `lib/fluent-otel-proto`: generated OpenTelemetry protobuf support submodule.
+- `.github/workflows/`: compiler/platform builds, tests, linting, and packages.
+
+Start architecture investigation at `include/cmetrics/cmetrics.h`, the
+metric-specific public header, and its matching `src/cmt_*.c` implementation.
+For encoding or decoding, follow the corresponding `cmt_encode_*` or
+`cmt_decode_*` pair and its tests. See `docs/architecture.md` for the component
+map and `docs/dependencies.md` for repository boundaries.
+
+## Dependency boundaries
+
+Initialize submodules before building:
+
+```sh
+git submodule update --init --recursive
+```
+
+Changes owned by CFL or fluent-otel-proto should normally land in their source
+repository first, then update the CMetrics submodule revision separately.
+Validate CMetrics standalone before updating a downstream consumer such as
+Fluent Bit. See `docs/ai/cross-repository.md` and
+`docs/ai/dependency-update.md`.
+
+## Build and test
+
+The supported build system is CMake 3.20 or newer. Local builds require Git, a
+C compiler, and the initialized submodules. Flex 2 and Bison 3 enable the
+Prometheus text decoder and its tests; CMake omits that decoder if they are not
+found. A normal development build:
+
+```sh
+cmake -S . -B build/agent -DCMT_TESTS=On -DCMT_INSTALL_TARGETS=Off
+cmake --build build/agent
+ctest --test-dir build/agent --output-on-failure
+```
+
+Repository wrappers provide the same flow:
+
+```sh
+scripts/agent-build.sh
+scripts/agent-test.sh
+scripts/agent-verify.sh
+```
+
+Use `BUILD_DIR=/path` to select another build directory. Pass extra CMake
+configuration arguments to `agent-build.sh`. Pass a CTest regular expression
+to `agent-test.sh`, for example:
+
+```sh
+scripts/agent-test.sh '^cmt-test-opentelemetry$'
+```
+
+When making code changes, run the related unit test when one is available.
+Before handoff, run `scripts/agent-verify.sh` unless the change is documentation
+only or the environment cannot build the project; report any omitted check.
+
+There is no repository-defined C formatter or C static-lint command. Preserve
+the surrounding four-space, no-tab style. Shell changes must pass `sh -n`; CI
+also runs ShellCheck. Do not claim sanitizer coverage unless the binary was
+actually compiled and executed with the requested sanitizer.
+
+## Memory and ownership
+
+- Check every allocation and preserve cleanup for partial initialization.
+- Match allocation families (`malloc`/`free`, CFL SDS create/destroy, arena
+  lifetime) and make ownership transfers explicit in code structure.
+- Exercise failure and cleanup paths for codec and container changes.
+- Treat map mutation, metric indexing, expiration, and destruction as
+  concurrency-sensitive.
+- Use AddressSanitizer or Valgrind for ownership changes; follow
+  `docs/ai/memory-safety-review.md`.
+
+## Compatibility-sensitive changes
+
+- Public declarations under `include/cmetrics/` can affect source or ABI
+  compatibility. Avoid changing established public structure layout without
+  explicit review of downstream users.
+- Internal MessagePack, OTLP protobuf, Prometheus formats, and remote write are
+  wire-sensitive. Add round-trip and malformed-input coverage where relevant.
+- Preserve integer value types, timestamps, start timestamps, label ordering,
+  and metric identity unless the change intentionally revises their contract.
+- Decoders process untrusted lengths and values: prevent overflow, oversized
+  allocation from incomplete input, desynchronization, and partial-result leaks.
+
+## Generated and vendored content
+
+- Do not edit CMake-generated `include/cmetrics/cmt_info.h` or
+  `include/cmetrics/cmt_version.h`; edit their `.in` templates or CMake version.
+- Flex/Bison outputs are generated in the build directory from
+  `src/cmt_decode_prometheus.l` and `.y`; edit the grammar sources.
+- Files marked generated under `src/external/` and
+  `include/prometheus_remote_write/` must be regenerated from their source
+  schema/toolchain, not hand-edited.
+- Do not edit submodule contents as part of a CMetrics-only change. Make the
+  change in the owning repository and update the recorded revision.
+- Build outputs and generated payloads do not belong in commits unless an
+  existing tracked fixture is intentionally updated and reviewed.
+
+## Performance changes
+
+Build benchmarks with `CMT_BENCHMARKS=ON` and an optimized Release build. Use
+`benchmarks/run-perf.sh` for standard workloads and Linux hardware counters.
+Capture at least five before and five after runs on the same machine with
+identical compiler flags and workload parameters. Keep only repeatable gains
+with no relevant regression. See `docs/ai/performance-review.md`.
+
+## Change discipline and definition of done
+
+- Keep changes scoped; preserve unrelated user work and avoid drive-by cleanup.
+- Add a regression test for a bug when practical.
+- Verify every documented command against repository files before adding it.
+- Review error paths, compatibility, generated files, and dependency ownership.
+- Run targeted tests plus the strongest practical complete validation.
+- Report root cause or intent, files changed, exact checks, compatibility
+  impact, unresolved risks, and anything not validated.
+
+Detailed workflows:
+
+- `docs/ai/investigate.md`
+- `docs/ai/bug-fix.md`
+- `docs/ai/code-review.md`
+- `docs/ai/cross-repository.md`
+- `docs/ai/dependency-update.md`
+- `docs/ai/memory-safety-review.md`
+- `docs/ai/performance-review.md`

lib/cmetrics/CLAUDE.md

@@ -0,0 +1 @@
+@AGENTS.md

lib/cmetrics/CMakeLists.txt

@@ -6,7 +6,7 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 # CMetrics Version
 set(CMT_VERSION_MAJOR  2)
 set(CMT_VERSION_MINOR  2)
-set(CMT_VERSION_PATCH  0)
+set(CMT_VERSION_PATCH  1)
 set(CMT_VERSION_STR "${CMT_VERSION_MAJOR}.${CMT_VERSION_MINOR}.${CMT_VERSION_PATCH}")
 
 # Include helpers
@@ -63,17 +63,14 @@ if(NOT MSVC)
   set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall")
 endif()
 
-# Define __CMT_FILENAME__ consistently across Operating Systems
-if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Windows")
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D__CMT_FILENAME__='\"$$(subst ${CMAKE_SOURCE_DIR}/,,$$(abspath $$<))\"'")
-else()
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D__CMT_FILENAME__=__FILE__")
-endif()
+# Define __CMT_FILENAME__
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D__CMT_FILENAME__=__FILE__")
 
 # Configuration options
 option(CMT_DEV                       "Enable development mode"                    No)
 option(CMT_DEBUG                     "Enable debug mode"                          No)
 option(CMT_TESTS                     "Enable unit testing"                        No)
+option(CMT_BENCHMARKS                "Build performance benchmarks"               No)
 option(CMT_INSTALL_TARGETS           "Enable subdirectory library installations" Yes)
 option(CMT_PROMETHEUS_TEXT_DECODER   "Enable prometheus text format decoder (requires Flex/Bison)" Yes)
 
@@ -302,6 +299,10 @@ endif()
 add_subdirectory(include)
 add_subdirectory(src)
 
+if(CMT_BENCHMARKS)
+  add_subdirectory(benchmarks)
+endif()
+
 # Tests
 if(CMT_TESTS)
   enable_testing()

lib/cmetrics/README.md

@@ -141,6 +141,10 @@ CMetrics is heavily inspired by the Go Prometheus Client API design:
 
 - https://pkg.go.dev/github.com/prometheus/client_golang/prometheus#section-documentation
 
+Additional design notes:
+
+- [Long metric label handling](docs/label-value-handling.md)
+
 ## License
 
 This program is under the terms of the

lib/cmetrics/benchmarks/CMakeLists.txt

@@ -0,0 +1,6 @@
+add_executable(cmt-benchmark benchmark.c)
+target_link_libraries(cmt-benchmark cmetrics-static cfl-static fluent-otel-proto)
+
+if(NOT CMT_SYSTEM_WINDOWS)
+  target_link_libraries(cmt-benchmark pthread)
+endif()

lib/cmetrics/benchmarks/README.md

@@ -0,0 +1,38 @@
+# CMetrics benchmarks
+
+Benchmarks are opt-in and are intended for before/after comparisons on the
+same machine. Build an optimized binary:
+
+```sh
+cmake -S . -B build-perf \
+    -DCMT_BENCHMARKS=ON \
+    -DCMT_INSTALL_TARGETS=OFF \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DCMAKE_C_FLAGS_RELEASE='-O3 -DNDEBUG'
+cmake --build build-perf -j --target cmt-benchmark
+```
+
+Run the standard repeated workloads and Linux hardware counters:
+
+```sh
+REPETITIONS=5 benchmarks/run-perf.sh \
+    ./build-perf/benchmarks/cmt-benchmark
+```
+
+The executable also accepts individual workloads:
+
+```text
+cmt-benchmark lookup|update|prometheus|opentelemetry|opentelemetry-mixed CARDINALITY OPERATIONS
+```
+
+The `opentelemetry` workload repeatedly encodes a labeled counter with the
+requested number of series. The `opentelemetry-mixed` workload creates that
+many counter, gauge, and histogram series to exercise scalar and aggregate
+protobuf data points in the same request.
+
+Compare medians from at least five alternating before/after runs. Keep CPU
+frequency policy, compiler, flags, machine load, and input parameters fixed.
+Use the reported in-process `elapsed_ns` for the operation itself and `perf
+stat` for whole-process hardware counters. Whole-process counters include
+series construction and teardown by design, exposing setup complexity as well
+as steady-state behavior.