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Date:   Wed,  4 Jan 2023 19:04:34 -0800
Message-Id: <20230105030434.255603-1-irogers@google.com>
Mime-Version: 1.0
Subject: [PATCH v1] perf script flamegraph: Avoid d3-flame-graph package dependency
From:   Ian Rogers <irogers@google.com>
To:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        996839@bugs.debian.org, Andreas Gerstmayr <agerstmayr@redhat.com>,
        Martin Spier <mspier@netflix.com>,
        Brendan Gregg <brendan@intel.com>
Cc:     Ian Rogers <irogers@google.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Currently flame graph generation requires a d3-flame-graph template to
be installed. Unfortunately this is hard to come by for things like
Debian [1]. If the template isn't installed warn and download it from
jsdelivr CDN. If downloading fails generate a minimal flame graph
again with the javascript coming from jsdelivr CDN.

[1] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=996839

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/scripts/python/flamegraph.py | 63 ++++++++++++++++++-------
 1 file changed, 45 insertions(+), 18 deletions(-)

diff --git a/tools/perf/scripts/python/flamegraph.py b/tools/perf/scripts/python/flamegraph.py
index b6af1dd5f816..808b0e1c9be5 100755
--- a/tools/perf/scripts/python/flamegraph.py
+++ b/tools/perf/scripts/python/flamegraph.py
@@ -25,6 +25,27 @@ import io
 import argparse
 import json
 import subprocess
+import urllib.request
+
+minimal_html = """<head>
+  <link rel="stylesheet" type="text/css" href="https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/d3-flamegraph.css">
+</head>
+<body>
+  <div id="chart"></div>
+  <script type="text/javascript" src="https://d3js.org/d3.v7.js"></script>
+  <script type="text/javascript" src="https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/d3-flamegraph.min.js"></script>
+  <script type="text/javascript">
+  const stacks = [/** @flamegraph_json **/];
+  // Note, options is unused.
+  const options = [/** @options_json **/];
+
+  var chart = flamegraph();
+  d3.select("#chart")
+        .datum(stacks[0])
+        .call(chart);
+  </script>
+</body>
+"""
 
 # pylint: disable=too-few-public-methods
 class Node:
@@ -50,15 +71,18 @@ class FlameGraphCLI:
         self.args = args
         self.stack = Node("all", "root")
 
-        if self.args.format == "html" and \
-                not os.path.isfile(self.args.template):
-            print("Flame Graph template {} does not exist. Please install "
-                  "the js-d3-flame-graph (RPM) or libjs-d3-flame-graph (deb) "
-                  "package, specify an existing flame graph template "
-                  "(--template PATH) or another output format "
-                  "(--format FORMAT).".format(self.args.template),
-                  file=sys.stderr)
-            sys.exit(1)
+        if self.args.format == "html":
+            if os.path.isfile(self.args.template):
+                self.template = f"file://{self.args.template}"
+            else:
+                print(f"""
+Warning: Flame Graph template '{self.args.template}'
+does not exist, a template will be downloaded via http. To avoid this
+please install a package such as the js-d3-flame-graph or
+libjs-d3-flame-graph, specify an existing flame graph template
+(--template PATH) or another output format (--format FORMAT).
+""", file=sys.stderr)
+            self.template = "https://cdn.jsdelivr.net/npm/d3-flame-graph@4.1.3/dist/templates/d3-flamegraph-base.html"
 
     @staticmethod
     def get_libtype_from_dso(dso):
@@ -129,15 +153,18 @@ class FlameGraphCLI:
             options_json = json.dumps(options)
 
             try:
-                with io.open(self.args.template, encoding="utf-8") as template:
-                    output_str = (
-                        template.read()
-                        .replace("/** @options_json **/", options_json)
-                        .replace("/** @flamegraph_json **/", stacks_json)
-                    )
-            except IOError as err:
-                print("Error reading template file: {}".format(err), file=sys.stderr)
-                sys.exit(1)
+                with urllib.request.urlopen(self.template) as template:
+                    output_str = '\n'.join([
+                        l.decode('utf-8') for l in template.readlines()
+                    ])
+            except Exception as err:
+                print(f"Error reading template {self.template}: {err}\n"
+                      "a minimal flame graph will be generated", file=sys.stderr)
+                output_str = minimal_html
+
+            output_str = output_str.replace("/** @options_json **/", options_json)
+            output_str = output_str.replace("/** @flamegraph_json **/", stacks_json)
+
             output_fn = self.args.output or "flamegraph.html"
         else:
             output_str = stacks_json
-- 
2.39.0.314.g84b9a713c41-goog