From ac42aedc1188e3136e4692f871e43b6a8bf3ad17 Mon Sep 17 00:00:00 2001
From: Patrice Billaut <57354406+pbillaut@users.noreply.github.com>
Date: Tue, 24 Sep 2024 22:17:10 +0200
Subject: [PATCH] chore(memory-profiling): add option for macos (#18)

---
 Makefile.toml | 25 +++++++++++++++++++++++--
 README.md     | 31 +++++++++++++++++++++++++++++--
 src/main.rs   | 11 ++++++++++-
 3 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/Makefile.toml b/Makefile.toml
index 25561dd..46fa39d 100644
--- a/Makefile.toml
+++ b/Makefile.toml
@@ -11,7 +11,8 @@ command = "cargo"
 args = ["build", "--profile", "${BUILD_PROFILE_PERF}"]
 
 [tasks.heaptrack]
-description = "Run heaptrack"
+description = "Profile memory usage with heaptrack (Linux)"
+condition = { platforms = ["linux"] }
 dependencies = ["build-perf"]
 script = '''
 SIZE="${1:-10K}"
@@ -41,5 +42,25 @@ fi
 OUTPUT_FILE="${CARGO_MAKE_WORKING_DIRECTORY}/heaptrack.${CARGO_MAKE_CRATE_NAME}.${SIZE}.${TAG}"
 BINARY="${CARGO_MAKE_CRATE_TARGET_DIRECTORY}/${BUILD_PROFILE_PERF}/${CARGO_MAKE_CRATE_NAME}"
 
-heaptrack --output "${OUTPUT_FILE}" "${BINARY}" "${SAMPLE_FILE}"
+heaptrack --output "${OUTPUT_FILE}" "${BINARY}" --silent "${SAMPLE_FILE}"
 '''
+
+[tasks.instruments]
+description = "Profile memory usage with instruments (macOS)"
+condition = { platforms = ["mac"] }
+script = '''
+SIZE="${1:-10K}"
+SAMPLE_FILE="${BENCHES_DATA_DIR}/activities_${SIZE}.csv"
+if [ ! -f "$SAMPLE_FILE" ]; then
+  echo "ERROR: File '${SAMPLE_FILE}' does not exist."
+  echo
+  echo "Available sample files in '${DATA_DIR}':"
+  for file in ${BENCHES_DATA_DIR}/activities_*.csv; do
+    echo "• $(basename "$file")"
+  done
+  echo
+  exit 1
+fi
+
+cargo instruments --profile perf -t Allocations -- --silent "${SAMPLE_FILE}"
+'''
\ No newline at end of file
diff --git a/README.md b/README.md
index 04a7f91..f2f570f 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,28 @@
 
 A simple toy payment processor.
 
+## Profiling
+
+### Memory
+
+#### Linux
+
+To profile memory usage on Linux with [heaptrack][tool:heaptrack], run
+
+```shell
+cargo make heaptrack [1K|10K]
+```
+
+#### macOS
+
+To profile memory usage on macOS with [Instruments][tool:instruments],
+install [cargo-instruments][tool:cargo-instruments] and
+run
+
+```shell
+cargo make instruments [1K|10K]
+```
+
 ## A Note on Parsing
 
 In parsing a CSV file containing different types of records, such as transactions and dispute events, using separate
@@ -49,9 +71,14 @@ As above, since no specific performance target has been set, there is no strong
 that rely on native floating-point types. The advantages provided by [`rust_decimal`][crate:rust_decimal], particularly
 in terms of precision and error avoidance, outweigh the potential performance gains from using floats.
 
-[type:decimal]: https://docs.rs/rust_decimal/latest/rust_decimal/struct.Decimal.html
-
 [crate:csv]: https://docs.rs/csv/latest
 
 [crate:rust_decimal]: https://docs.rs/rust_decimal/latest
 
+[tool:cargo-instruments]: https://crates.io/crates/cargo-instruments
+
+[tool:heaptrack]: https://github.com/KDE/heaptrack
+
+[tool:instruments]: https://help.apple.com/instruments/mac/current
+
+[type:decimal]: https://docs.rs/rust_decimal/latest/rust_decimal/struct.Decimal.html
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index d3268f1..1a3160d 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,7 @@ use anyhow::Context;
 use clap::{Parser, ValueHint};
 use payment_processor::processor::Processor;
 use payment_processor::processors::csv::CsvProcessor;
+use std::io::Write;
 use std::{fs::File, io, path::PathBuf};
 use tracing_subscriber::EnvFilter;
 
@@ -13,6 +14,14 @@ struct Cli {
     /// Supported file formats: CSV
     #[arg(value_hint = ValueHint::FilePath)]
     path: PathBuf,
+
+    /// Whether to suppress printing the results to stdout.
+    #[clap(long, action)]
+    silent: bool,
+}
+
+fn output(silent: bool) -> Box<dyn Write> {
+    if silent { Box::new(io::sink()) } else { Box::new(io::stdout()) }
 }
 
 fn main() -> Result<(), anyhow::Error> {
@@ -24,6 +33,6 @@ fn main() -> Result<(), anyhow::Error> {
     let cli = Cli::parse();
     let file = File::open(&cli.path).context("unable to open file input file")?;
 
-    let mut processor = CsvProcessor::try_new(file, io::stdout())?;
+    let mut processor = CsvProcessor::try_new(file, output(cli.silent))?;
     processor.process().context("processing input file failed")
 }