Display potential build time savings in experiment summaries

components/fetch-build-scan-data-cmdline-tool/src/main/java/com/gradle/enterprise/cli/Fields.java

@@ -33,6 +33,7 @@ public enum Fields {
     EXECUTED_NOT_CACHEABLE_DURATION("Executed not cacheable duration", d -> totalDuration(d, "executed_not_cacheable")),
     EFFECTIVE_TASK_EXECUTION_DURATION("Effective task execution duration", d -> String.valueOf(d.getEffectiveTaskExecutionDuration().toMillis())),
     SERIALIZATION_FACTOR("Serialization factor", d -> formatBigDecimal(d.getSerializationFactor())),
+    EXECUTED_CACHEABLE_DURATION_MILLISECONDS("Executed cacheable duration milliseconds", d -> totalDurationMillis(d, "executed_cacheable")),
     ;
 
     public final String label;
@@ -77,6 +78,15 @@ private static String totalDuration(BuildValidationData data, String avoidanceOu
         );
     }
 
+    private static String totalDurationMillis(BuildValidationData data, String avoidanceOutcome) {
+        return String.valueOf(
+            data.getTasksByAvoidanceOutcome()
+                .getOrDefault(avoidanceOutcome, TaskExecutionSummary.ZERO)
+                .totalDuration()
+                .toMillis()
+        );
+    }
+
     private static String formatDuration(Duration duration) {
         long hours = duration.toHours();
         long minutes = duration.minusHours(hours).toMinutes();

components/scripts/lib/build-scan-parse.sh

@@ -28,6 +28,7 @@ executed_not_cacheable_duration=()
 # Build duration metrics
 effective_task_execution_duration=()
 serialization_factors=()
+executed_cacheable_duration_milliseconds=()
 
 parse_build_scan_csv() {
   # This isn't the most robust way to read a CSV,
@@ -46,7 +47,7 @@ parse_build_scan_csv() {
   idx=0
 
   # shellcheck disable=SC2034 # not all scripts use all of the fetched data
-  while IFS=, read -r field_1 field_2 field_3 field_4 field_5 field_6 field_7 field_8 field_9 field_10 field_11 field_12 field_13 field_14 field_15 field_16 field_17 field_18 field_19 field_20 field_21; do
+  while IFS=, read -r field_1 field_2 field_3 field_4 field_5 field_6 field_7 field_8 field_9 field_10 field_11 field_12 field_13 field_14 field_15 field_16 field_17 field_18 field_19 field_20 field_21 field_22; do
     if [[ "$header_row_read" == "false" ]]; then
       header_row_read=true
       continue;
@@ -86,6 +87,10 @@ parse_build_scan_csv() {
       serialization_factors[idx]="${field_21}"
     fi
 
+    if [[ -n "$field_22" ]]; then
+      executed_cacheable_duration_milliseconds[idx]="${field_22}"
+    fi
+
     ((idx++))
     done <<< "${build_scan_csv}"
 }

components/scripts/lib/info.sh

@@ -140,6 +140,8 @@ print_performance_characteristics() {
 
   print_realized_build_time_savings
 
+  print_potential_build_time_savings
+
   print_build_caching_leverage_metrics
 
   print_serialization_factor
@@ -172,6 +174,35 @@ print_realized_build_time_savings() {
   fi
 }
 
+print_potential_build_time_savings() {
+  local build_1_effective_execution_duration="${effective_task_execution_duration[0]}"
+
+  local build_2_effective_execution_duration="${effective_task_execution_duration[1]}"
+  local build_2_executed_cacheable_duration="${executed_cacheable_duration_milliseconds[1]}"
+  local build_2_serialization_factor="${serialization_factors[1]}"
+
+  # Do not print potential build time savings at all if these values do not exist
+  # This can happen since build-scan-support-tool does not yet support these fields
+  if [[ -z "${build_1_effective_execution_duration}" || -z "${build_2_effective_execution_duration}" || -z "${build_2_executed_cacheable_duration}" || -z "${build_2_serialization_factor}" ]]; then
+    return 0
+  fi
+
+  local value
+  value=""
+  # Only calculate realized build time savings when these have valid values
+  # These values can be returned as zero when an error occurs processing the Build Scan data
+  if [[ "${build_1_effective_execution_duration}" && "${build_2_effective_execution_duration}" && -n "${build_2_serialization_factor}" ]]; then
+    local first_build second_build potential_build_duration potential_savings
+    first_build=$(format_duration "${effective_task_execution_duration[0]}")
+    # shellcheck disable=SC2034 # it's used on the next few lines
+    potential_build_duration=$(echo "${build_2_effective_execution_duration}-(${build_2_executed_cacheable_duration}/${build_2_serialization_factor})" | bc)
+    potential_savings=$(format_duration build_1_effective_execution_duration-potential_build_duration)
+    second_build=$(format_duration potential_build_duration)
+    value="${potential_savings} wall-clock time (from ${first_build} to ${second_build})"
+  fi
+  summary_row "Potential build time savings:" "${value}"
+}
+
 print_build_caching_leverage_metrics() {
   local task_count_padding
   task_count_padding=$(max_length "${avoided_from_cache_num_tasks[1]}" "${executed_cacheable_num_tasks[1]}" "${executed_not_cacheable_num_tasks[1]}")