1 files changed, 102 insertions, 0 deletions
diff --git a/tools/tryselect/selectors/preview.py b/tools/tryselect/selectors/preview.py
new file mode 100644
index 0000000000..1d232af9e0
--- /dev/null
+++ b/tools/tryselect/selectors/preview.py
@@ -0,0 +1,102 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+"""This script is intended to be called through fzf as a preview formatter."""
+
+
+import argparse
+import os
+import sys
+
+here = os.path.abspath(os.path.dirname(__file__))
+sys.path.insert(0, os.path.join(os.path.dirname(here), "util"))
+from estimates import duration_summary
+
+
+def process_args():
+    """Process preview arguments."""
+    argparser = argparse.ArgumentParser()
+    argparser.add_argument(
+        "-s",
+        "--show-estimates",
+        action="store_true",
+        help="Show task duration estimates (default: False)",
+    )
+    argparser.add_argument(
+        "-g",
+        "--graph-cache",
+        type=str,
+        default=None,
+        help="Filename of task graph dependencies",
+    )
+    argparser.add_argument(
+        "-c",
+        "--cache_dir",
+        type=str,
+        default=None,
+        help="Path to cache directory containing task durations",
+    )
+    argparser.add_argument(
+        "-t",
+        "--tasklist",
+        type=str,
+        default=None,
+        help="Path to temporary file containing the selected tasks",
+    )
+    return argparser.parse_args()
+
+
+def plain_display(taskfile):
+    """Original preview window display."""
+    with open(taskfile) as f:
+        tasklist = [line.strip() for line in f]
+    print("\n".join(sorted(tasklist)))
+
+
+def duration_display(graph_cache_file, taskfile, cache_dir):
+    """Preview window display with task durations + metadata."""
+    with open(taskfile) as f:
+        tasklist = [line.strip() for line in f]
+
+    durations = duration_summary(graph_cache_file, tasklist, cache_dir)
+    output = ""
+    max_columns = int(os.environ["FZF_PREVIEW_COLUMNS"])
+
+    output += "\nSelected tasks take {}\n".format(durations["selected_duration"])
+    output += "+{} dependencies, total {}\n".format(
+        durations["dependency_count"],
+        durations["selected_duration"] + durations["dependency_duration"],
+    )
+
+    if durations.get("percentile"):
+        output += "This is in the top {}% of requests\n".format(
+            100 - durations["percentile"]
+        )
+
+    output += "Estimated finish in {} at {}".format(
+        durations["wall_duration_seconds"], durations["eta_datetime"].strftime("%H:%M")
+    )
+
+    duration_width = 5  # show five numbers at most.
+    output += "{:>{width}}\n".format("Duration", width=max_columns)
+    for task in tasklist:
+        duration = durations["task_durations"].get(task, 0.0)
+        output += "{:{align}{width}} {:{nalign}{nwidth}}s\n".format(
+            task,
+            duration,
+            align="<",
+            width=max_columns - (duration_width + 2),  # 2: space and 's'
+            nalign=">",
+            nwidth=duration_width,
+        )
+
+    print(output)
+
+
+if __name__ == "__main__":
+    args = process_args()
+    if args.show_estimates and os.path.isdir(args.cache_dir):
+        duration_display(args.graph_cache, args.tasklist, args.cache_dir)
+    else:
+        plain_display(args.tasklist)