Introduce decodeme crate and start supporting old file format versions.

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## [10.0.0] - 2021-09-xx
+
+### Changed
+- `analyzeme`: Version-specific parts split out into `decodeme` crate. ([GH-181])
+- `analyzeme`: The crate now supports load both v7 and v8 of the file format. ([GH-181])
+
+## [9.2.0] - 2021-09-13
+### Changed
+- `analyzeme`: Makes a couple of methods in ProfilingData public. ([GH-180])
+
 ## [9.1.2] - 2021-05-21
 ### Added
 - `measureme`: Allow recording interval events without using the drop guard ([GH-159])
@@ -92,6 +102,7 @@
 
 ## [0.2.0] - 2019-04-10
 
+[9.2.0]: https://github.com/rust-lang/measureme/releases/tag/9.2.0
 [9.1.2]: https://github.com/rust-lang/measureme/releases/tag/9.1.2
 [9.1.1]: https://github.com/rust-lang/measureme/releases/tag/9.1.1
 [9.1.0]: https://github.com/rust-lang/measureme/releases/tag/9.1.0
@@ -143,3 +154,5 @@
 [GH-155]: https://github.com/rust-lang/measureme/pull/155
 [GH-156]: https://github.com/rust-lang/measureme/pull/156
 [GH-159]: https://github.com/rust-lang/measureme/pull/159
+[GH-180]: https://github.com/rust-lang/measureme/pull/180
+[GH-181]: https://github.com/rust-lang/measureme/pull/181

Cargo.toml

@@ -3,6 +3,7 @@
 members = [
     "analyzeme",
     "crox",
+    "decodeme",
     "flamegraph",
     "measureme",
     "mmview",

analyzeme/Cargo.toml

@@ -1,14 +1,19 @@
 [package]
 name = "analyzeme"
-version = "9.1.2"
+version = "10.0.0-alpha"
 authors = ["Wesley Wiser <wwiser@gmail.com>", "Michael Woerister <michaelwoerister@posteo>"]
 edition = "2018"
 license = "MIT OR Apache-2.0"
 
 [dependencies]
 byteorder = "1.2.7"
+decodeme = { path = "../decodeme" }
 memchr = "2"
 measureme = { path = "../measureme" }
 rustc-hash = "1.0.1"
 serde = { version = "1.0", features = [ "derive" ] }
 serde_json = "1.0"
+
+# Depending on older versions of this crate allows us to keep supporting older
+# file formats.
+analyzeme_9_2_0 = { package = "analyzeme", git = "https://github.com/rust-lang/measureme", tag = "9.2.0" }

analyzeme/src/file_formats/mod.rs

@@ -0,0 +1,15 @@
+use decodeme::{event::Event, lightweight_event::LightweightEvent, Metadata};
+use std::fmt::Debug;
+
+pub mod v7;
+pub mod v8;
+
+pub use v8 as current;
+
+/// The [EventDecoder] knows how to decode events for a specific file format.
+pub trait EventDecoder: Debug + Send + Sync {
+    fn num_events(&self) -> usize;
+    fn metadata(&self) -> &Metadata;
+    fn decode_full_event<'a>(&'a self, event_index: usize) -> Event<'a>;
+    fn decode_lightweight_event<'a>(&'a self, event_index: usize) -> LightweightEvent;
+}

analyzeme/src/file_formats/v7.rs

@@ -0,0 +1,78 @@
+//! This module implements file loading for the v7 file format used until
+//! crate version 9.2.0
+
+use std::error::Error;
+
+use analyzeme_9_2_0::ProfilingData;
+use decodeme::{
+    event::Event,
+    event_payload::{EventPayload, Timestamp},
+    lightweight_event::LightweightEvent,
+    Metadata,
+};
+
+pub const FILE_FORMAT: u32 = analyzeme_9_2_0::CURRENT_FILE_FORMAT_VERSION;
+
+#[derive(Debug)]
+pub struct EventDecoder {
+    legacy_profiling_data: ProfilingData,
+    metadata: Metadata,
+}
+
+impl EventDecoder {
+    pub fn new(entire_file_data: Vec<u8>) -> Result<EventDecoder, Box<dyn Error + Send + Sync>> {
+        let legacy_profiling_data = ProfilingData::from_paged_buffer(entire_file_data)?;
+
+        let metadata = Metadata {
+            start_time: legacy_profiling_data.metadata.start_time,
+            cmd: legacy_profiling_data.metadata.cmd.clone(),
+            process_id: legacy_profiling_data.metadata.process_id,
+        };
+
+        Ok(EventDecoder {
+            legacy_profiling_data,
+            metadata,
+        })
+    }
+}
+
+impl super::EventDecoder for EventDecoder {
+    fn num_events(&self) -> usize {
+        self.legacy_profiling_data.num_events()
+    }
+
+    fn metadata(&self) -> &Metadata {
+        &self.metadata
+    }
+
+    fn decode_full_event(&self, event_index: usize) -> Event<'_> {
+        let legacy_event = self.legacy_profiling_data.decode_full_event(event_index);
+        let timestamp = convert_timestamp(legacy_event.timestamp);
+
+        Event {
+            event_kind: legacy_event.event_kind,
+            label: legacy_event.label,
+            additional_data: legacy_event.additional_data,
+            thread_id: legacy_event.thread_id,
+            payload: EventPayload::Timestamp(timestamp),
+        }
+    }
+
+    fn decode_lightweight_event(&self, event_index: usize) -> LightweightEvent {
+        let legacy_event = self
+            .legacy_profiling_data
+            .decode_lightweight_event(event_index);
+        LightweightEvent {
+            event_index,
+            thread_id: legacy_event.thread_id,
+            payload: EventPayload::Timestamp(convert_timestamp(legacy_event.timestamp)),
+        }
+    }
+}
+
+fn convert_timestamp(legacy_timestamp: analyzeme_9_2_0::Timestamp) -> Timestamp {
+    match legacy_timestamp {
+        analyzeme_9_2_0::Timestamp::Interval { start, end } => Timestamp::Interval { start, end },
+        analyzeme_9_2_0::Timestamp::Instant(t) => Timestamp::Instant(t),
+    }
+}

analyzeme/src/file_formats/v8.rs

@@ -0,0 +1,26 @@
+//! This module implements file loading for the v8 file format used until
+//! crate version 10.0.0
+
+use crate::{Event, LightweightEvent};
+pub use decodeme::EventDecoder;
+use decodeme::Metadata;
+
+pub const FILE_FORMAT: u32 = decodeme::CURRENT_FILE_FORMAT_VERSION;
+
+impl super::EventDecoder for EventDecoder {
+    fn num_events(&self) -> usize {
+        self.num_events()
+    }
+
+    fn metadata(&self) -> &Metadata {
+        self.metadata()
+    }
+
+    fn decode_full_event(&self, event_index: usize) -> Event<'_> {
+        self.decode_full_event(event_index)
+    }
+
+    fn decode_lightweight_event(&self, event_index: usize) -> LightweightEvent {
+        self.decode_lightweight_event(event_index)
+    }
+}

analyzeme/src/lib.rs

@@ -10,17 +10,13 @@
 //! To retrieve an `Iterator` of all of the events in the file,
 //! call the [`ProfilingData::iter()`] method.
 
-mod event;
-mod event_payload;
-mod lightweight_event;
+mod file_formats;
 mod profiling_data;
 mod stack_collapse;
-mod stringtable;
 pub mod testing_common;
 
-pub use crate::event::Event;
-pub use crate::event_payload::{EventPayload, Timestamp};
-pub use crate::lightweight_event::LightweightEvent;
 pub use crate::profiling_data::{ProfilingData, ProfilingDataBuilder};
 pub use crate::stack_collapse::collapse_stacks;
-pub use crate::stringtable::{StringRef, StringTable};
+pub use decodeme::event::Event;
+pub use decodeme::event_payload::{EventPayload, Timestamp};
+pub use decodeme::lightweight_event::LightweightEvent;