pkgs/build-support/binary-cache/make-binary-cache.py

   1 from functools import partial
   2 import json
   3 from multiprocessing import Pool
   4 import os
   5 from pathlib import Path
   6 import subprocess
   7
   8
   9 def dropPrefix(path, nixPrefix):
  10     return path[len(nixPrefix + "/") :]
  11
  12
  13 def processItem(item, nixPrefix, outDir):
  14     narInfoHash = dropPrefix(item["path"], nixPrefix).split("-")[0]
  15
  16     xzFile = outDir / "nar" / f"{narInfoHash}.nar.xz"
  17     with open(xzFile, "wb") as f:
  18         subprocess.run(
  19             f"nix-store --dump {item['path']} | xz -c",
  20             stdout=f,
  21             shell=True,
  22             check=True,
  23         )
  24
  25     fileHash = (
  26         subprocess.run(
  27             ["nix-hash", "--base32", "--type", "sha256", "--flat", xzFile],
  28             capture_output=True,
  29             check=True,
  30         )
  31         .stdout.decode()
  32         .strip()
  33     )
  34     fileSize = os.path.getsize(xzFile)
  35
  36     finalXzFileName = Path("nar") / f"{fileHash}.nar.xz"
  37     os.rename(xzFile, outDir / finalXzFileName)
  38
  39     with open(outDir / f"{narInfoHash}.narinfo", "wt") as f:
  40         f.write(f"StorePath: {item['path']}\n")
  41         f.write(f"URL: {finalXzFileName}\n")
  42         f.write("Compression: xz\n")
  43         f.write(f"FileHash: sha256:{fileHash}\n")
  44         f.write(f"FileSize: {fileSize}\n")
  45         f.write(f"NarHash: {item['narHash']}\n")
  46         f.write(f"NarSize: {item['narSize']}\n")
  47         f.write(f"References: {' '.join(dropPrefix(ref, nixPrefix) for ref in item['references'])}\n")
  48
  49
  50 def main():
  51     outDir = Path(os.environ["out"])
  52     nixPrefix = os.environ["NIX_STORE"]
  53     numWorkers = int(os.environ.get("NIX_BUILD_CORES", "4"))
  54
  55     with open(os.environ["NIX_ATTRS_JSON_FILE"], "r") as f:
  56         closures = json.load(f)["closure"]
  57
  58     os.makedirs(outDir / "nar", exist_ok=True)
  59
  60     with open(outDir / "nix-cache-info", "w") as f:
  61         f.write(f"StoreDir: {nixPrefix}\n")
  62
  63     with Pool(processes=numWorkers) as pool:
  64         worker = partial(processItem, nixPrefix=nixPrefix, outDir=outDir)
  65         pool.map(worker, closures)
  66
  67
  68 if __name__ == "__main__":
  69     main()