brancher: pre-generate deltas when creating a branch

Since we batch patches for testing when something fails we need
to figure out what went wrong. Instead of having to fetch the branches
locally and manually run cidiff just generate the output after creating
each branch. Link to it from the status page. Hardcoding part of the URL
isn't nice but not sure what to do about that. We could put the link
to the cidiff in the branch manifest. But it feels a little auxiliary.

Signed-off-by: Jakub Kicinski <[email protected]>

contest/cidiff

@@ -15,6 +15,15 @@ if [ x$BRANCH1$BRANCH2 == x ]; then
     BRANCH1=${branches[0]}
     BRANCH2=${branches[1]}
 
+    echo "  " $BRANCH1
+    echo "  " $BRANCH2
+    echo
+elif [ x$BRANCH2 == x ]; then
+    echo "Single branch specified, using that and the previous one:"
+    branches=( $(git branch -a | grep -B1 "$1") )
+    BRANCH1=${branches[0]}
+    BRANCH2=${branches[1]}
+
     echo "  " $BRANCH1
     echo "  " $BRANCH2
     echo

pw_brancher.py

@@ -6,6 +6,7 @@
 import json
 import os
 import psycopg2
+import subprocess
 import time
 from typing import List, Tuple
 import uuid
@@ -32,6 +33,7 @@
 [output]
 branches=branches.json
 info=branches-info.json
+deltas=/path/to/dir/
 [db]
 db=db-name
 """
@@ -190,6 +192,18 @@ def db_insert(config, state, name):
         cur.execute("INSERT INTO branches VALUES " + arg.decode('utf-8'))
 
 
+def generate_deltas(config, name):
+    outdir = config.get("output", "deltas", fallback=None)
+    if not outdir:
+        return
+
+    outfile = os.path.join(outdir, name)
+    cidiff = os.path.join(os.path.dirname(__file__), "contest", "cidiff")
+
+    with open(outfile, 'w') as fp:
+        subprocess.run([cidiff, name], stdout=fp, check=True)
+
+
 def create_new(pw, config, state, tree, tgt_remote) -> None:
     now = datetime.datetime.now(datetime.UTC)
     pfx = config.get("target", "branch_pfx")
@@ -235,6 +249,10 @@ def create_new(pw, config, state, tree, tgt_remote) -> None:
     tree.git_push(tgt_remote, "HEAD:" + branch_name)
     log_end_sec()
 
+    log_open_sec("Generate deltas")
+    generate_deltas(config, branch_name)
+    log_end_sec()
+
 
 def state_delete_branch(state, br):
     del state["branches"][br]

ui/status.js

@@ -693,7 +693,7 @@ function load_result_table_one(data_raw, table, reported, avgs)
 		br_pull = " (pull: " + v.pull_status + ")";
 	    branch.innerHTML = a + v.branch + "</a>" + br_pull;
 	    branch.setAttribute("colspan", "2");
-	    res.innerHTML = "";
+	    res.innerHTML = "<a href=\"static/nipa/branch_deltas/" + v.branch + "\">cidiff</a>";
 	    row.setAttribute("class", "end-row");
 	}
     });