Lalit Maganti

tp: overhaul error handling and diagnostics for the shell and bundle (#6969) Issue: https://github.com/google/perfetto/issues/6927 `trace_processor bundle` (formerly `traceconv bundle`) gave cryptic or misleading feedback when things went wrong: - Traces with nothing to enrich (e.g. a pure atrace trace, or a function_graph trace recorded **with** `symbolize_ksyms`) failed with a bare `bundle: failed to create bundle.` and no explanation. - A function_graph trace recorded **without** `symbolize_ksyms` got no feedback at all, even though its kernel addresses can never be symbolized offline. - Unwritable output paths (missing parent dir, read-only, path-is-a-dir) crashed the whole process with a `PERFETTO_CHECK`. - Extra positional arguments were silently ignored/misparsed (e.g. passing each `--symbol-paths` directory as a separate argument). - Conversion failures produced double error messages (an internal `PERFETTO_ELOG` + a generic "conversion failed" wrapper), and several paths crashed with `PERFETTO_FATAL` on ordinary user error. ## Changes - **bundle** now always produces the bundle and explains what could not be enriched, with actionable hints. It detects function_graph traces recorded without `symbolize_ksyms`, fails gracefully (instead of crashing) on unwritable output paths, and reports reading/enrichment progress. - **CLI**: every fixed-arity subcommand (`bundle`, `convert`, `util`, `export`, `query`, `server`, `metrics`) now rejects extra positional arguments with a hint, instead of silently misinterpreting them. - **traceconv**: the conversion entry points (`TraceToJson`, `TraceToSystrace`, `TraceToText`, `TraceToProfile`, `TraceToFirefoxProfile`, `UnpackCompressedPackets`, `SymbolizeProfile`, `DeobfuscateProfile`) now return descriptive `base::Status` errors instead of int/bool returns paired with internal `PERFETTO_ELOG`/`FATAL`, so failures are reported once with the actual reason. - **TarWriter**: fails gracefully when the output path cannot be opened (also fixes the same crash in `util merge`). - **Parse errors**: no longer append a redundant "The trace file is corrupt." sentence; the UI error-dialog extraction is updated for the new message format.

tp: model trace types as importers, remove the TraceType enum (#6618) Today, all trace detection logic is centralized inside TP meaning it's impossible for plugins to register new formats and have them work without also changing the core code. As the number of formats has increased, this has gotten more and more unweildy Design it to instead be structured such that new trace types can be developed fully independently *without* making any changes to the core. This will be proved out in a followup change where perf text importer will be moved.

tp: add Arrow support for dataframes (#6827) Provide an Arrow serializer and deserializer for Dataframes using a standard Arrow file containing one record batch. Primitive columns map to Arrow numeric arrays, strings map to Utf8, nullable columns carry validity bitmaps, and sparse storage uses Arrow's logical row layout. The serializer computes metadata and variable-width sizes before streaming column contents with bounded scratch memory. The deserializer validates file framing, record batch metadata, and buffer extents before rebuilding column storage, null state, implicit Id columns, and strings in the target StringPool.

tp: add a batch execution pipeline (#7135) Trace processor moves rows one at a time through a cursor. That interface works well for callers, but upstream it costs a virtual call and bounds check per row and prevents operators from working over a run of values. Add a batch pipeline alongside the cursor. RowBatch holds column views over producer-owned storage, so filtering changes a selection instead of moving values. Operators hold only plan data; mutable execution state is owned separately, which makes plans safe to reuse. Values normally live until the producer's next pull. RowStore copies them into fixed-size chunks when an operator needs to keep them longer. Later changes add sources and operators on top of these primitives.

tp: memoize proto arg keys to avoid re-interning per field (#6348) ProtoToArgsParser rebuilt and re-interned the flat_key/key strings of every arg on every field of every message. The flat_key for a given proto field path is invariant, so give the parser a StringPool and a memo trie keyed by field number. The Delegate API now takes already-interned StringIds instead of Key strings, so delegates are pure value sinks and never re-intern keys. A new proto_to_args_parser_benchmark isolates the key path and shows ~1.7-2x; end-to-end trace load gains are ~1-2% as key interning is a small slice of ingestion.

perfetto_sql: add reusable semantic analysis (#7219)

tp: add streaming table export (#6839) Add a bounded-memory Export API for statically registered Trace Processor tables. ExportOutput is a virtual streaming interface with an optional file path alternative for formats which need direct random-access output later. Runtime SQL tables and views are deliberately outside this API. Support two explicit tar formats. kArrowTar is a stable, forwards-compatible, export-only archive containing standard Arrow files, including implicit ID columns and empty static tables for external consumers. kPerfetto is a version-coupled archive with an internal manifest which can restore tables into a compatible fresh Trace Processor instance; its representation carries no cross-version compatibility guarantee. Expose export through RPC, HTTP, the shell export subcommand, and Python. Keep the existing SQLite export path unchanged; moving it behind this API waits for the separate file-I/O abstraction work.

tp: rebuild flamegraphs from typed trees (#6942) Consume the core Tree representation directly and preserve typed values while merging top-down, bottom-up, pivot, and filtered flamegraph views. _{Stack created with <a href="https://github.com/github/gh-stack">GitHub Stacks CLI</a> • <a href="https://gh.io/stacks-feedback">Give Feedback 💬</a>}

tp: replace GetExtensionSlowly with SelectiveTracePacketDecoder (#6218) Introduce SelectiveTracePacketDecoder, a wrapper around protozero's SelectiveTypedProtoDecoder. An allowlist mask covers the TracePacket metadata fields the pipeline reads by name; the data field and out-of-tree extensions fall into unknown_fields(), which drives module dispatch in one pass per packet instead of one buffer re-scan per registered extension id. This deletes GetExtensionSlowly(). Module hooks now take an args struct and receive the dispatched field as a TypedProtoField, read via generated field constants. The allowlist must stay disjoint from module-registered ids (DCHECKed). Wall time is neutral to ~+1% across the test traces, but extension dispatch no longer scales with the number of registered extension modules.

tp: add C++ flamegraph computation library (#6851) A flamegraph is the trie of key-paths: every path through the input forest with the same sequence of merge keys collapses into one merged node. The library computes that trie and returns it as a tree plus a flat dataframe (id, parentId, depth, name and per-metric value columns). Presentation (sibling ordering, x layout) is deliberately absent: it is cheap to compute over the far smaller merged output and belongs to the consumer, which can also skip it entirely. The three views are one algorithm parameterized by anchors, the frames the merged trees grow from and re-root at: top-down anchors at the kept roots, bottom-up at every counted frame, pivot at frames matching the pivot pattern. Downward, one forward scan drives a cursor through an exact (parent node, key) hash map; upward, each anchor's caller chain is walked carrying the anchor's weight: its counted subtree total stopping at other anchors, which for bottom-up reduces to the frame's own values. Nodes whose subtree is zero on every metric are dropped, which is also what gives show-stack filters their effect on the output. Filters (show/hide-stack, show-from-frame, hide-frame and the pivot pattern) are regexes evaluated once per distinct frame name through the input's name dictionary, then folded into per-frame kept/counted flags and a nearest-kept-ancestor index in a single pass along the paths. Hidden frames fold their values into the nearest kept ancestor. Frames carry any number of metrics, flattened row-major with a constant stride; every accumulation is metric-wide. Each output node retains its constituent input frames, so consumers can aggregate arbitrary per-frame properties without the library knowing about them (the benchmark exercises a ONE_OR_SUMMARY aggregation this way). Input frames may arrive in any order: parents-before-children is detected and used directly, anything else costs one reverse-index and DFS pass. FlexVector gains reserve() for the pre-sized node columns. On 1M-frame callstack-shaped forests (see flamegraph_benchmark.cc), top-down computes in ~90ms, ~120ms including the dataframe; with filters ~77ms, bottom-up ~200ms, pivot ~18ms. At 100k frames every view is below 10ms.