#!/usr/bin/env python3 # Copyright (c) 2017 The Bitcoin Core developers # Distributed under the MIT software license, see the accompanying # file COPYING or http://www.opensource.org/licenses/mit-license.php. ''' This script will show the SHA512 tree has for a certain commit, or HEAD by default. Usage: treehash512.py [<commithash>] ''' import os from sys import stdin,stdout,stderr import sys import argparse import hashlib import subprocess # External tools (can be overridden using environment) GIT = os.getenv('GIT','git') def tree_sha512sum(commit='HEAD'): # request metadata for entire tree, recursively files = [] blob_by_name = {} for line in subprocess.check_output([GIT, 'ls-tree', '--full-tree', '-r', commit]).splitlines(): name_sep = line.index(b'\t') metadata = line[:name_sep].split() # perms, 'blob', blobid assert(metadata[1] == b'blob') name = line[name_sep+1:] files.append(name) blob_by_name[name] = metadata[2] files.sort() # open connection to git-cat-file in batch mode to request data for all blobs # this is much faster than launching it per file p = subprocess.Popen([GIT, 'cat-file', '--batch'], stdout=subprocess.PIPE, stdin=subprocess.PIPE) overall = hashlib.sha512() for f in files: blob = blob_by_name[f] # request blob p.stdin.write(blob + b'\n') p.stdin.flush() # read header: blob, "blob", size reply = p.stdout.readline().split() assert(reply[0] == blob and reply[1] == b'blob') size = int(reply[2]) # hash the blob data intern = hashlib.sha512() ptr = 0 while ptr < size: bs = min(65536, size - ptr) piece = p.stdout.read(bs) if len(piece) == bs: intern.update(piece) else: raise IOError('Premature EOF reading git cat-file output') ptr += bs dig = intern.hexdigest() assert(p.stdout.read(1) == b'\n') # ignore LF that follows blob data # update overall hash with file hash overall.update(dig.encode("utf-8")) overall.update(" ".encode("utf-8")) overall.update(f) overall.update("\n".encode("utf-8")) p.stdin.close() if p.wait(): raise IOError('Non-zero return value executing git cat-file') return overall.hexdigest() def main(): if len(sys.argv)>1: commit = sys.argv[1] else: commit = 'HEAD' print(tree_sha512sum(commit)) if __name__ == '__main__': main()