xref: /aosp_15_r20/external/perfetto/python/perfetto/prebuilts/perfetto_prebuilts.py (revision 6dbdd20afdafa5e3ca9b8809fa73465d530080dc) 
1# Copyright (C) 2021 The Android Open Source Project
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7#      http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14"""
15Functions to fetch pre-pinned Perfetto prebuilts.
16
17This function is used in different places:
18- Into the //tools/{trace_processor, traceconv} scripts, which are just plain
19  wrappers around executables.
20- Into the //tools/{heap_profiler, record_android_trace} scripts, which contain
21  some other hand-written python code.
22
23The manifest argument looks as follows:
24TRACECONV_MANIFEST = [
25  {
26    'arch': 'mac-amd64',
27    'file_name': 'traceconv',
28    'file_size': 7087080,
29    'url': https://commondatastorage.googleapis.com/.../trace_to_text',
30    'sha256': 7d957c005b0dc130f5bd855d6cec27e060d38841b320d04840afc569f9087490',
31    'platform': 'darwin',
32    'machine': 'x86_64'
33  },
34  ...
35]
36
37The intended usage is:
38
39  from perfetto.prebuilts.manifests.traceconv import TRACECONV_MANIFEST
40  bin_path = get_perfetto_prebuilt(TRACECONV_MANIFEST)
41  subprocess.call(bin_path, ...)
42"""
43
44import hashlib
45import os
46import platform
47import random
48import subprocess
49import sys
50
51
52def download_or_get_cached(file_name, url, sha256):
53  """ Downloads a prebuilt or returns a cached version
54
55  The first time this is invoked, it downloads the |url| and caches it into
56  ~/.local/share/perfetto/prebuilts/$tool_name. On subsequent invocations it
57  just runs the cached version.
58  """
59  dir = os.path.join(
60      os.path.expanduser('~'), '.local', 'share', 'perfetto', 'prebuilts')
61  os.makedirs(dir, exist_ok=True)
62  bin_path = os.path.join(dir, file_name)
63  sha256_path = os.path.join(dir, file_name + '.sha256')
64  needs_download = True
65
66  # Avoid recomputing the SHA-256 on each invocation. The SHA-256 of the last
67  # download is cached into file_name.sha256, just check if that matches.
68  if os.path.exists(bin_path) and os.path.exists(sha256_path):
69    with open(sha256_path, 'rb') as f:
70      digest = f.read().decode()
71      if digest == sha256:
72        needs_download = False
73
74  if needs_download:  # The file doesn't exist or the SHA256 doesn't match.
75    # Use a unique random file to guard against concurrent executions.
76    # See https://github.com/google/perfetto/issues/786 .
77    tmp_path = '%s.%d.tmp' % (bin_path, random.randint(0, 100000))
78    print('Downloading ' + url)
79    subprocess.check_call(['curl', '-f', '-L', '-#', '-o', tmp_path, url])
80    with open(tmp_path, 'rb') as fd:
81      actual_sha256 = hashlib.sha256(fd.read()).hexdigest()
82    if actual_sha256 != sha256:
83      raise Exception('Checksum mismatch for %s (actual: %s, expected: %s)' %
84                      (url, actual_sha256, sha256))
85    os.chmod(tmp_path, 0o755)
86    os.replace(tmp_path, bin_path)
87    with open(tmp_path, 'w') as f:
88      f.write(sha256)
89    os.replace(tmp_path, sha256_path)
90  return bin_path
91
92
93def get_perfetto_prebuilt(manifest, soft_fail=False, arch=None):
94  """ Downloads the prebuilt, if necessary, and returns its path on disk. """
95  plat = sys.platform.lower()
96  machine = platform.machine().lower()
97  manifest_entry = None
98  for entry in manifest:
99    # If the caller overrides the arch, just match that (for Android prebuilts).
100    if arch:
101      if entry.get('arch') == arch:
102        manifest_entry = entry
103        break
104      continue
105    # Otherwise guess the local machine arch.
106    if entry.get('platform') == plat and machine in entry.get('machine', []):
107      manifest_entry = entry
108      break
109  if manifest_entry is None:
110    if soft_fail:
111      return None
112    raise Exception(
113        ('No prebuilts available for %s-%s\n' % (plat, machine)) +
114        'See https://perfetto.dev/docs/contributing/build-instructions')
115
116  return download_or_get_cached(
117      file_name=manifest_entry['file_name'],
118      url=manifest_entry['url'],
119      sha256=manifest_entry['sha256'])
120
121
122def run_perfetto_prebuilt(manifest):
123  bin_path = get_perfetto_prebuilt(manifest)
124  if sys.platform.lower() == 'win32':
125    sys.exit(subprocess.check_call([bin_path, *sys.argv[1:]]))
126  os.execv(bin_path, [bin_path] + sys.argv[1:])
127