# What does this PR do?

This PR backports the change buffer implementation required for dd-trace-js adoption of native spans. Follow-up of #2046.

The change buffer is a contiguous region of memory where span operations are encoded from the JS runtime, similar to a byte code. The implementation decode all those span events and reconstruct the corresponding span objects.

# Motivation

Required to land native spans dd-trace-js.

# How to test the change?

tests included.

Co-authored-by: yann.hamdaoui <[email protected]>

…ibdd-data-pipeline, libdd-li... (#2201)

# Release proposal for libdd-capabilities-impl, libdd-common,
libdd-data-pipeline, libdd-library-config, libdd-remote-config,
libdd-sampling, libdd-telemetry, libdd-tinybytes, libdd-trace-utils and
their dependencies

This PR contains version bumps based on public API changes and commits
since last release.

## libdd-capabilities
**Next version:** `2.1.0`
**Semver bump:** `minor`
**Tag:** `libdd-capabilities-v2.1.0`

### Commits

- feat(data-pipeline)!: add stdout log trace exporter (#2074)

## libdd-common
**Next version:** `5.1.0`
**Semver bump:** `minor`
**Tag:** `libdd-common-v5.1.0`

### Commits

- refactor(clippy): prefer core and alloc imports (#2196)
- fix: update rustls-webpki to 0.103.13 (#2187)
- fix: update anyhow for unsoundness (#2186)
- feat(machine id): Add helpers in ddcommon to fetch the machine UUID l…
(#2163)

## libdd-ddsketch
**Next version:** `1.1.0`
**Semver bump:** `minor`
**Tag:** `libdd-ddsketch-v1.1.0`

### Commits

- feat(data-pipeline)!: export client-computed span stats as OTLP trace
metrics (#2067)
- test(ddsketch): add microbenchmarks for add/encode/collapse (#2125)

## libdd-trace-protobuf
**Next version:** `4.0.0`
**Semver bump:** `major`
**Tag:** `libdd-trace-protobuf-v4.0.0`

### Commits

- chore!: update protobufs to be in sync with datadog-agent (#2180)
- feat(stats)!: add whole key cardinality limit (#2158)
- feat(remote-config)!: use the proto file from the agent (#2165)
- feat(data-pipeline): OTLP HTTP/protobuf trace export (#2115)

## libdd-capabilities-impl
**Next version:** `3.0.0`
**Semver bump:** `major`
**Tag:** `libdd-capabilities-impl-v3.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.1.0 → ^5.1.0

### Commits

- feat(data-pipeline)!: add stdout log trace exporter (#2074)

## libdd-library-config
**Next version:** `3.0.0`
**Semver bump:** `major`
**Tag:** `libdd-library-config-v3.0.0`

### ⚠️ major bump forced due to:

- `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0

### Commits

- refactor(clippy): prefer core and alloc imports (#2196)
- feat(library-config)!: caller-supplied threadlocal schema and extra
process-context attributes (#2162)
- fix(otel-thread-ctx): put the threadlocal attributes at the right
place in the context (#2167)

## libdd-remote-config
**Next version:** `2.0.0`
**Semver bump:** `major`
**Tag:** `libdd-remote-config-v2.0.0`

### ⚠️ major bump forced due to:

- `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0

### Commits

- refactor(libdd-remote-config)!: hide Target inner properties so they
are not leaked (#2182)
- feat(remote-config)!: use the proto file from the agent (#2165)
- refactor(rc): reexport Endpoint and Tag common types (#2147)

## libdd-trace-normalization
**Next version:** `3.0.0`
**Semver bump:** `major`
**Tag:** `libdd-trace-normalization-v3.0.0`

### ⚠️ major bump forced due to:

- `libdd-trace-protobuf`: ^3.0.1 → ^4.0.0

### Commits

- feat(data-pipeline)!: CSS Trace Filters (#1985)

## libdd-shared-runtime
**Next version:** `2.0.0`
**Semver bump:** `major`
**Tag:** `libdd-shared-runtime-v2.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.1.0 → ^5.1.0

### Commits

- feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061)
- feat(shared-runtime)!: use weak waker in trigger [APMSP-3371] (#2050)

## libdd-trace-utils
**Next version:** `9.0.0`
**Semver bump:** `major`
**Tag:** `libdd-trace-utils-v9.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.2.0 → ^5.1.0
- `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0

### Commits

- ci(miri): skip slow miri tests (#2188)
- chore!: update protobufs to be in sync with datadog-agent (#2180)
- feat(data-pipeline): add agentless export (#2081)
- feat(data-pipeline)!: add stdout log trace exporter (#2074)
- feat(data-pipeline): OTLP HTTP/protobuf trace export (#2115)
- feat(otlp)!: Export OTLP spans with attribute-level OTel compatibility
(#2091)
- test(trace-utils): add V05 msgpack decode microbenchmark (#2127)
- feat(data-pipeline)!: export client-computed span stats as OTLP trace
metrics (#2067)
- test(trace-utils): add VecMap microbenchmarks (#2126)
- chore(stats)!: submit p0 telemetry in stats (#2130)
- refactor(change-buffer)!: replace slot index with span_id, fix segment
isolation (#2105)
- feat(data-pipeline)!: CSS Trace Filters (#1985)
- feat(trace-exporter): add v1 span and its encoder (#2039)
- fix(trace-utils): mark decoded span maps as deduped (#2110)
- feat(trace-utils)!: change buffer implementation (#2055)
- feat(native-spans)!: change buffer foundation (#2046)
- refactor(span)!: use VecMap for `meta`, `metrics` and `meta_struct`
for v04 spans (#2043)
- test: fix timeouts on heavily contended scenarios (#2093)

## libdd-telemetry
**Next version:** `6.0.0`
**Semver bump:** `major`
**Tag:** `libdd-telemetry-v6.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.2.0 → ^5.1.0
- `libdd-shared-runtime`: ^1.0.0 → ^2.0.0

### Commits

- ci(miri): skip slow miri tests (#2188)
- refactor(libdd-telemetry)!: avoid leaking libdd-common types in the
public API (#2152)
- feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061)

## libdd-trace-obfuscation
**Next version:** `5.0.0`
**Semver bump:** `major`
**Tag:** `libdd-trace-obfuscation-v5.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.2.0 → ^5.1.0
- `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0
- `libdd-trace-utils`: ^8.0.0 → ^9.0.0

### Commits

- refactor(clippy): prefer core and alloc imports (#2196)
- ci(miri): skip slow miri tests (#2188)
- fix: update anyhow for unsoundness (#2186)

## libdd-trace-stats
**Next version:** `6.0.0`
**Semver bump:** `major`
**Tag:** `libdd-trace-stats-v6.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.2.0 → ^5.1.0
- `libdd-shared-runtime`: ^1.0.0 → ^2.0.0
- `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0
- `libdd-trace-utils`: ^8.0.0 → ^9.0.0

### Commits

- chore!: update protobufs to be in sync with datadog-agent (#2180)
- feat(stats)!: send telemetry for cardinality limits (#2159)
- feat(stats)!: add whole key cardinality limit (#2158)
- fix(trace-stats)!: add grpc_method to aggregation key (#2151)
- feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061)
- feat(data-pipeline)!: export client-computed span stats as OTLP trace
metrics (#2067)
- refactor(span)!: use VecMap for `meta`, `metrics` and `meta_struct`
for v04 spans (#2043)

## libdd-data-pipeline
**Next version:** `7.0.0`
**Semver bump:** `major`
**Tag:** `libdd-data-pipeline-v7.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.2.0 → ^5.1.0
- `libdd-shared-runtime`: ^1.0.0 → ^2.0.0
- `libdd-telemetry`: ^5.0.1 → ^6.0.0
- `libdd-trace-protobuf`: ^3.0.2 → ^4.0.0
- `libdd-trace-stats`: ^5.0.0 → ^6.0.0
- `libdd-trace-utils`: ^8.0.0 → ^9.0.0

### Commits

- feat(trace_exporter): enable telemetry in stats exporter (#2160)
- refactor(libdd-telemetry)!: avoid leaking libdd-common types in the
public API (#2152)
- feat(stats): emit canonical gRPC status name for OTLP
rpc.response.status_code (#2183)
- feat(data-pipeline): add agentless export (#2081)
- feat(stats)!: send telemetry for cardinality limits (#2159)
- feat(stats)!: add whole key cardinality limit (#2158)
- fix(trace-stats)!: add grpc_method to aggregation key (#2151)
- feat(data-pipeline)!: add stdout log trace exporter (#2074)
- feat(shared-runtime)!: SharedRuntime Borrowed & Owned mode (#2061)
- feat(data-pipeline): OTLP HTTP/protobuf trace export (#2115)
- feat(otlp)!: Export OTLP spans with attribute-level OTel compatibility
(#2091)
- feat(data-pipeline)!: export client-computed span stats as OTLP trace
metrics (#2067)
- chore(stats)!: submit p0 telemetry in stats (#2130)
- feat(data-pipeline)!: CSS Trace Filters (#1985)
- feat(shared-runtime)!: use weak waker in trigger [APMSP-3371] (#2050)
- refactor(span)!: use VecMap for `meta`, `metrics` and `meta_struct`
for v04 spans (#2043)
- feat(stats)!: add endpoint gating to client-side stats [APMSP-3361]
(#2040)

## libdd-dogstatsd-client
**Next version:** `4.0.0`
**Semver bump:** `major`
**Tag:** `libdd-dogstatsd-client-v4.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.1.0 → ^5.1.0


## libdd-sampling
**Next version:** `5.0.0`
**Semver bump:** `major`
**Tag:** `libdd-sampling-v5.0.0`

### ⚠️ major bump forced due to:

- `libdd-common`: ^4.2.0 → ^5.1.0
- `libdd-trace-utils`: ^8.0.0 → ^9.0.0


[APMSP-3371]:
https://datadoghq.atlassian.net/browse/APMSP-3371?atlOrigin=eyJpIjoiNWRkNTljNzYxNjVmNDY3MDlhMDU5Y2ZhYzA5YTRkZjUiLCJwIjoiZ2l0aHViLWNvbS1KU1cifQ

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: iunanua <[email protected]>