Add per-request benchmarking and collection script

Motivation

Provide optional, in‑pipeline latency logging in HTTPResponsivenessServer and a straightforward way to gather end‑to‑end percentile metrics.
Modifications

    main.swift

        Imported Foundation for DispatchTime.
        Added PerformanceMeasurementHandler (logs “Request handled in XX ms”) and PingHandler (/ping endpoint).
        Extended channelInitializer and CLI with a --collect-benchmarks flag to insert these handlers only when requested.

    Examples/collect_benchmarks.sh

        New Bash script that reads the server’s logs, collects a user‑specified number of samples, uses Python/NumPy to compute
        p0/p25/p50/p75/p90/p99/p100, and prints a Unicode table.

Result

Users can now opt in to per‑request latency logging via --collect-benchmarks, and run a one‑step script to produce full percentile reports.

Author: RaghavRoy145

http-responsiveness-server/Examples/ping-benchmarks/collect_benchmarks.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+#
+# collect_benchmarks.sh
+#
+# Description:
+#   Reads “Request handled in XX ms” lines from a SwiftNIO HTTPResponsivenessServer
+#   log file (produced when started with --collect-benchmarks) and computes
+#   p0, p25, p50, p75, p90, p99 and p100 statistics.
+#   
+#   Called from run_benchmarks.sh
+#
+#
+
+set -euo pipefail
+
+if [ $# -ne 3 ]; then
+  echo "Usage: $0 <LOGFILE> <ENDPOINT> <SAMPLES>" >&2
+  exit 1
+fi
+
+LOGFILE="$1"
+ENDPOINT="$2"
+SAMPLES="$3"
+
+# extract exactly the first N timings
+mapfile -t times < <(
+  grep "Request handled in" "$LOGFILE" \
+    | head -n "$SAMPLES" \
+    | sed -E 's/.*Request handled in ([0-9]+(\.[0-9]+)?) ms/\1/'
+)
+
+if [ "${#times[@]}" -lt "$SAMPLES" ]; then
+  echo "ERROR: only found ${#times[@]} samples in $LOGFILE" >&2
+  exit 1
+fi
+
+# compute percentiles in Python
+python3 - "$ENDPOINT" "${times[@]}" << 'PYCODE'
+import sys, numpy as np
+
+# parse float timings from command-line args (skip the first entry which is '-')
+data = [float(x) for x in sys.argv[2:]]
+arr  = np.array(data)
+
+# compute percentiles
+pcts = [ np.percentile(arr, p) for p in (0, 25, 50, 75, 90, 99, 100) ]
+samples = arr.size
+metric = sys.argv[1]
+
+# nice Unicode table
+print("╒═══════════════════════╤══════════╤══════════╤══════════╤══════════╤══════════╤══════════╤══════════╤══════════╕")
+print("│ Metric                │     p0   │    p25   │    p50   │    p75   │    p90   │    p99   │   p100   │ Samples  │")
+print("╞═══════════════════════╪══════════╪══════════╪══════════╪══════════╪══════════╪══════════╪══════════╪══════════╡")
+print(f"│ {metric:20s}  │ " +
+      " │ ".join(f"{v:7.6f}" for v in pcts) +
+      f" │ {samples:7d}  │")
+print("╘═══════════════════════╧══════════╧══════════╧══════════╧══════════╧══════════╧══════════╧══════════╧══════════╛")
+PYCODE

http-responsiveness-server/Examples/ping-benchmarks/run_benchmarks.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+#
+# run_benchmarks.sh
+#
+# Description:
+# Sends HTTP GETs to a running HTTPResponsivenessServer (started with --collect-benchmarks)
+# then invokes collect-benchmarks.sh on its log.
+#
+# Prerequisites:
+#   1. Build your server with benchmarking support:
+#        swift build -c release
+#
+#   2. Start it in the background, redirecting stdout+stderr to a log:
+#        .build/release/HTTPResponsivenessServer \
+#          --host 127.0.0.1 \
+#          --insecure-port 8080 \
+#          --collect-benchmarks \
+#        > server.log 2>&1 &
+#
+# Usage:
+#   In the root directory of this App
+#
+#   Examples/ping-benchmarks/run_benchmarks.sh \
+#     --host 127.0.0.1 \
+#     --port 8080 \
+#     --endpoint /ping \
+#     --samples 100 \
+#     --logfile server.log
+#
+
+set -euo pipefail
+
+# --- parse args ---
+while [[ $# -gt 0 ]]; do
+  case $1 in
+    --host)      HOST="$2";     shift 2 ;;
+    --port)      PORT="$2";     shift 2 ;;
+    --endpoint)  ENDPOINT="$2"; shift 2 ;;
+    --samples)   SAMPLES="$2";  shift 2 ;;
+    --logfile)   LOGFILE="$2";  shift 2 ;;
+    *) echo "Unknown argument: $1" >&2; exit 1 ;;
+  esac
+done
+
+echo "→ Sending $SAMPLES requests to http://$HOST:$PORT$ENDPOINT"
+for i in $(seq 1 "$SAMPLES"); do
+  curl -s "http://$HOST:$PORT$ENDPOINT" > /dev/null
+done
+
+# give the server a moment to flush
+sleep 0.1
+
+# hand off to the collector
+Examples/ping-benchmarks/collect_benchmarks.sh "$LOGFILE" "$ENDPOINT" "$SAMPLES"