feat(profiling): Add diagnostics mode to convert-jfr.sh script

Enhanced the conversion script with detailed diagnostic output showing:
- Input file sizes (individual and total)
- Output file size
- Wall-clock conversion time
- Compression ratio (output vs input size)
- Space savings (bytes and percentage)

Usage:
  ./convert-jfr.sh --diagnostics recording.jfr output.pb

Example output:
  [DIAG] Input: recording.jfr (89.3KB)
  [DIAG] Total input size: 89.3KB
  [DIAG] === Conversion Diagnostics ===
  [DIAG] Wall time: 127.3ms
  [DIAG] Output size: 45.2KB
  [DIAG] Size ratio: 50.6% of input
  [DIAG] Savings: 44.1KB (49.4% reduction)

Features:
- Cross-platform file size detection (macOS and Linux)
- Nanosecond-precision timing
- Human-readable size formatting (B, KB, MB, GB)
- Automatic compression ratio calculation
- Color-coded diagnostic output (cyan)

Updated CLI.md with:
- --diagnostics option documentation
- Example output showing diagnostic information
- Updated feature list

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: jbachorik

dd-java-agent/agent-profiling/profiling-otel/convert-jfr.sh

@@ -12,13 +12,14 @@
 #   --json              Output in JSON format instead of protobuf
 #   --pretty            Pretty-print JSON output (implies --json)
 #   --include-payload   Include original JFR payload in OTLP output
+#   --diagnostics       Show detailed diagnostics (file sizes, conversion time)
 #   --help              Show this help message
 #
 # Examples:
 #   ./convert-jfr.sh recording.jfr output.pb
 #   ./convert-jfr.sh --json recording.jfr output.json
 #   ./convert-jfr.sh --pretty recording.jfr output.json
-#   ./convert-jfr.sh file1.jfr file2.jfr combined.pb
+#   ./convert-jfr.sh --diagnostics file1.jfr file2.jfr combined.pb
 
 set -e
 
@@ -30,11 +31,65 @@ PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
 RED='\033[0;31m'
 GREEN='\033[0;32m'
 BLUE='\033[0;34m'
+YELLOW='\033[1;33m'
+CYAN='\033[0;36m'
 NC='\033[0m'
 
 log_info() { echo -e "${BLUE}[INFO]${NC} $1"; }
 log_success() { echo -e "${GREEN}[SUCCESS]${NC} $1"; }
 log_error() { echo -e "${RED}[ERROR]${NC} $1"; }
+log_diagnostic() { echo -e "${CYAN}[DIAG]${NC} $1"; }
+
+# Get file size in human-readable format
+get_file_size() {
+    local file="$1"
+    if [ -f "$file" ]; then
+        # Use du for cross-platform compatibility
+        du -h "$file" | cut -f1
+    else
+        echo "N/A"
+    fi
+}
+
+# Get file size in bytes
+get_file_size_bytes() {
+    local file="$1"
+    if [ -f "$file" ]; then
+        # Cross-platform file size in bytes
+        if [[ "$OSTYPE" == "darwin"* ]]; then
+            stat -f%z "$file"
+        else
+            stat -c%s "$file"
+        fi
+    else
+        echo "0"
+    fi
+}
+
+# Format bytes to human-readable
+format_bytes() {
+    local bytes=$1
+    if [ "$bytes" -lt 1024 ]; then
+        echo "${bytes}B"
+    elif [ "$bytes" -lt 1048576 ]; then
+        echo "$(awk "BEGIN {printf \"%.1f\", $bytes/1024}")KB"
+    elif [ "$bytes" -lt 1073741824 ]; then
+        echo "$(awk "BEGIN {printf \"%.1f\", $bytes/1048576}")MB"
+    else
+        echo "$(awk "BEGIN {printf \"%.1f\", $bytes/1073741824}")GB"
+    fi
+}
+
+# Calculate compression ratio
+calc_compression_ratio() {
+    local input_size=$1
+    local output_size=$2
+    if [ "$input_size" -eq 0 ]; then
+        echo "N/A"
+    else
+        awk "BEGIN {printf \"%.1f%%\", ($output_size / $input_size) * 100}"
+    fi
+}
 
 show_help() {
     cat << EOF
@@ -47,6 +102,7 @@ Options:
   --json              Output in JSON format instead of protobuf
   --pretty            Pretty-print JSON output (implies --json)
   --include-payload   Include original JFR payload in OTLP output
+  --diagnostics       Show detailed diagnostics (file sizes, conversion time)
   --help              Show this help message
 
 Examples:
@@ -65,10 +121,14 @@ Examples:
   # Combine multiple JFR files
   $(basename "$0") file1.jfr file2.jfr combined.pb
 
+  # Show detailed diagnostics
+  $(basename "$0") --diagnostics recording.jfr output.pb
+
 Notes:
   - Uses Gradle's convertJfr task under the hood
   - Automatically compiles if needed
   - Output format is detected from extension (.pb or .json)
+  - Use --diagnostics to see file sizes and conversion times
 
 EOF
 }
@@ -79,24 +139,99 @@ if [ $# -eq 0 ] || [ "$1" = "--help" ] || [ "$1" = "-h" ]; then
     exit 0
 fi
 
+# Check for diagnostics flag
+SHOW_DIAGNOSTICS=false
+CONVERTER_ARGS=()
+INPUT_FILES=()
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --diagnostics)
+            SHOW_DIAGNOSTICS=true
+            shift
+            ;;
+        --json|--pretty|--include-payload)
+            CONVERTER_ARGS+=("$1")
+            shift
+            ;;
+        *)
+            # Collect files
+            CONVERTER_ARGS+=("$1")
+            # If it's not the last arg and file exists, it's an input file
+            if [ $# -gt 1 ] && [ -f "$1" ]; then
+                INPUT_FILES+=("$1")
+            fi
+            shift
+            ;;
+    esac
+done
+
 # Convert all arguments to a space-separated string for Gradle --args
-ARGS="$*"
+ARGS="${CONVERTER_ARGS[*]}"
+
+# Calculate total input size if diagnostics enabled
+TOTAL_INPUT_SIZE=0
+if [ "$SHOW_DIAGNOSTICS" = true ]; then
+    for input_file in "${INPUT_FILES[@]}"; do
+        if [ -f "$input_file" ]; then
+            size=$(get_file_size_bytes "$input_file")
+            TOTAL_INPUT_SIZE=$((TOTAL_INPUT_SIZE + size))
+            log_diagnostic "Input: $input_file ($(format_bytes $size))"
+        fi
+    done
+    if [ ${#INPUT_FILES[@]} -gt 0 ]; then
+        log_diagnostic "Total input size: $(format_bytes $TOTAL_INPUT_SIZE)"
+    fi
+fi
 
 log_info "Converting JFR to OTLP format..."
-log_info "Arguments: $ARGS"
 
 cd "$PROJECT_ROOT"
 
+# Measure conversion time
+START_TIME=$(date +%s%N)
+START_CPU=$(ps -o cputime= -p $$ | tr -d ' :')
+
 # Run Gradle task with arguments
 if ./gradlew -q :dd-java-agent:agent-profiling:profiling-otel:convertJfr --args="$ARGS"; then
+    # Measure end time
+    END_TIME=$(date +%s%N)
+    END_CPU=$(ps -o cputime= -p $$ | tr -d ' :')
+
     # Extract output file (last argument)
-    OUTPUT_FILE="${!#}"
+    OUTPUT_FILE="${CONVERTER_ARGS[-1]}"
 
     log_success "Conversion completed successfully!"
 
     if [ -f "$OUTPUT_FILE" ]; then
-        SIZE=$(du -h "$OUTPUT_FILE" | cut -f1)
+        OUTPUT_SIZE=$(get_file_size_bytes "$OUTPUT_FILE")
+        SIZE=$(format_bytes $OUTPUT_SIZE)
         log_info "Output file: $OUTPUT_FILE ($SIZE)"
+
+        if [ "$SHOW_DIAGNOSTICS" = true ]; then
+            echo ""
+            log_diagnostic "=== Conversion Diagnostics ==="
+
+            # Calculate wall time
+            WALL_TIME_NS=$((END_TIME - START_TIME))
+            WALL_TIME_MS=$(awk "BEGIN {printf \"%.1f\", $WALL_TIME_NS/1000000}")
+            log_diagnostic "Wall time: ${WALL_TIME_MS}ms"
+
+            # Show size comparison
+            if [ ${#INPUT_FILES[@]} -gt 0 ]; then
+                RATIO=$(calc_compression_ratio $TOTAL_INPUT_SIZE $OUTPUT_SIZE)
+                log_diagnostic "Output size: $(format_bytes $OUTPUT_SIZE)"
+                log_diagnostic "Size ratio: $RATIO of input"
+
+                if [ "$OUTPUT_SIZE" -lt "$TOTAL_INPUT_SIZE" ]; then
+                    SAVINGS=$((TOTAL_INPUT_SIZE - OUTPUT_SIZE))
+                    SAVINGS_PCT=$(awk "BEGIN {printf \"%.1f%%\", (1 - $OUTPUT_SIZE/$TOTAL_INPUT_SIZE) * 100}")
+                    log_diagnostic "Savings: $(format_bytes $SAVINGS) ($SAVINGS_PCT reduction)"
+                fi
+            fi
+
+            echo ""
+        fi
     fi
 else
     EXIT_CODE=$?

dd-java-agent/agent-profiling/profiling-otel/doc/CLI.md

@@ -329,6 +329,7 @@ dd-java-agent/agent-profiling/profiling-otel/convert-jfr.sh
 - `--json` - Output in JSON format instead of protobuf
 - `--pretty` - Pretty-print JSON output (implies --json)
 - `--include-payload` - Include original JFR payload in OTLP output
+- `--diagnostics` - Show detailed diagnostics (file sizes, conversion time)
 - `--help` - Show help message
 
 ### Examples
@@ -358,12 +359,33 @@ Combine multiple files:
 ./convert-jfr.sh file1.jfr file2.jfr file3.jfr merged.pb
 ```
 
+Show detailed diagnostics:
+```bash
+./convert-jfr.sh --diagnostics recording.jfr output.pb
+```
+
+Output:
+```
+[INFO] Converting JFR to OTLP format...
+[DIAG] Input: recording.jfr (89.3KB)
+[DIAG] Total input size: 89.3KB
+[SUCCESS] Conversion completed successfully!
+[INFO] Output file: output.pb (45.2KB)
+
+[DIAG] === Conversion Diagnostics ===
+[DIAG] Wall time: 127.3ms
+[DIAG] Output size: 45.2KB
+[DIAG] Size ratio: 50.6% of input
+[DIAG] Savings: 44.1KB (49.4% reduction)
+```
+
 ### Features
 
 - **Automatic compilation**: Compiles code if needed before conversion
 - **Simplified interface**: No need to remember Gradle task paths
 - **Colored output**: Visual feedback for success/errors
 - **File size reporting**: Shows output file size after conversion
+- **Diagnostics mode**: Detailed metrics including input/output sizes, conversion time, and compression ratio
 - **Error handling**: Clear error messages if conversion fails
 
 ### Script Output