rust: event file read and write using JSON only

rust/bear/src/bin/bear.rs

@@ -1,10 +1,6 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 
-use bear::input::EventFileReader;
-use bear::modes::recognition::Recognition;
-use bear::modes::transformation::Transformation;
 use bear::modes::{All, Intercept, Mode, Semantic};
-use bear::output::OutputWriter;
 use bear::{args, config};
 use std::env;
 use std::process::ExitCode;
@@ -53,38 +49,15 @@ impl Application {
         match args.mode {
             args::Mode::Intercept { input, output } => {
                 log::debug!("Mode: intercept");
-                let intercept_config = config.intercept;
-                let mode = Intercept::new(input, output, intercept_config);
-                Ok(Application::Intercept(mode))
+                Intercept::from(input, output, config).map(Application::Intercept)
             }
             args::Mode::Semantic { input, output } => {
                 log::debug!("Mode: semantic analysis");
-                let event_source = EventFileReader::try_from(input)?;
-                let semantic_recognition = Recognition::try_from(&config)?;
-                let semantic_transform = Transformation::from(&config.output);
-                let output_writer = OutputWriter::configure(&output, &config.output)?;
-                let mode = Semantic::new(
-                    event_source,
-                    semantic_recognition,
-                    semantic_transform,
-                    output_writer,
-                );
-                Ok(Application::Semantic(mode))
+                Semantic::from(input, output, config).map(Application::Semantic)
             }
             args::Mode::All { input, output } => {
                 log::debug!("Mode: intercept and semantic analysis");
-                let semantic_recognition = Recognition::try_from(&config)?;
-                let semantic_transform = Transformation::from(&config.output);
-                let output_writer = OutputWriter::configure(&output, &config.output)?;
-                let intercept_config = config.intercept;
-                let mode = All::new(
-                    input,
-                    intercept_config,
-                    semantic_recognition,
-                    semantic_transform,
-                    output_writer,
-                );
-                Ok(Application::All(mode))
+                All::from(input, output, config).map(Application::All)
             }
         }
     }

rust/bear/src/bin/wrapper.rs

@@ -21,7 +21,7 @@ use anyhow::{Context, Result};
 use bear::ipc::tcp::ReporterOnTcp;
 use bear::ipc::Reporter;
 use bear::ipc::{Event, Execution, ProcessId};
-use bear::modes::intercept::KEY_DESTINATION;
+use bear::modes::KEY_DESTINATION;
 use std::path::{Path, PathBuf};
 
 /// Implementation of the wrapper process.

rust/bear/src/ipc/tcp.rs

@@ -14,7 +14,7 @@ use rand::random;
 
 /// Implements convenient methods for the `Envelope` type.
 impl Envelope {
-    pub fn new(rid: &ReporterId, event: Event) -> Self {
+    fn new(rid: &ReporterId, event: Event) -> Self {
         let timestamp = Utc::now().timestamp_millis() as u64;
         Envelope {
             rid: rid.clone(),
@@ -27,7 +27,7 @@ impl Envelope {
     ///
     /// The envelope is serialized using JSON and the length of the JSON
     /// is written as a 4 byte big-endian integer before the JSON.
-    pub fn read_from(reader: &mut impl Read) -> Result<Self, anyhow::Error> {
+    fn read_from(reader: &mut impl Read) -> Result<Self, anyhow::Error> {
         let mut length_bytes = [0; 4];
         reader.read_exact(&mut length_bytes)?;
         let length = u32::from_be_bytes(length_bytes) as usize;
@@ -43,7 +43,7 @@ impl Envelope {
     ///
     /// The envelope is serialized using JSON and the length of the JSON
     /// is written as a 4 byte big-endian integer before the JSON.
-    pub fn write_into(&self, writer: &mut impl Write) -> Result<u32, anyhow::Error> {
+    fn write_into(&self, writer: &mut impl Write) -> Result<u32, anyhow::Error> {
         let serialized_envelope = serde_json::to_string(&self)?;
         let bytes = serialized_envelope.into_bytes();
         let length = bytes.len() as u32;

rust/bear/src/lib.rs

@@ -3,7 +3,6 @@
 pub mod args;
 pub mod config;
 mod fixtures;
-pub mod input;
 pub mod ipc;
 pub mod modes;
 pub mod output;

rust/bear/src/modes/input.rs

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+use anyhow::Context;
+use serde_json::de::IoRead;
+use serde_json::{Error, StreamDeserializer};
+use std::fs::OpenOptions;
+use std::io::BufReader;
+use std::path::PathBuf;
+
+use crate::args;
+use crate::ipc::{Envelope, Execution};
+
+/// Responsible for reading the build events from the intercept mode.
+///
+/// The file syntax is defined by the `events` module, and the parsing logic is implemented there.
+/// Here we only handle the file opening and the error handling.
+pub struct EventFileReader {
+    stream: Box<dyn Iterator<Item = Result<Envelope, Error>>>,
+}
+
+impl TryFrom<args::BuildEvents> for EventFileReader {
+    type Error = anyhow::Error;
+
+    /// Open the file and create a new instance of the event file reader.
+    ///
+    /// If the file cannot be opened, the error will be logged and escalated.
+    fn try_from(value: args::BuildEvents) -> Result<Self, Self::Error> {
+        let file_name = PathBuf::from(value.file_name);
+        let file = OpenOptions::new()
+            .read(true)
+            .open(file_name.as_path())
+            .map(BufReader::new)
+            .with_context(|| format!("Failed to open input file: {:?}", file_name))?;
+        let stream = Box::new(StreamDeserializer::new(IoRead::new(file)));
+
+        Ok(EventFileReader { stream })
+    }
+}
+
+impl EventFileReader {
+    /// Generate the build events from the file.
+    ///
+    /// Returns an iterator over the build events. Any error during the reading
+    /// of the file will be logged and the failed entries will be skipped.
+    pub fn generate(self) -> impl Iterator<Item = Execution> {
+        self.stream.filter_map(|result| match result {
+            Ok(value) => Some(value.event.execution),
+            Err(error) => {
+                log::error!("Failed to read event: {:?}", error);
+                None
+            }
+        })
+    }
+}