用python实现git blob对象的创建和查询

来源：互联网发布：重庆cnc编程最新招聘编辑：程序博客网时间：2024/05/19 13:14

Pro Git第九章用ruby创建了一个blob对象，按照其中介绍的步骤，用python实现了一遍。

import hashlibimport zlibimport osimport os.pathdef calc_git_blob_obj(blob_content):    blob_header = 'blob ' + str(len(blob_content)) + '\0'    blob_store = blob_header + blob_content    blob_sha1 = hashlib.sha1(blob_store).hexdigest()    blob_compressed_content = zlib.compress(blob_store)    return blob_sha1, blob_compressed_contentdef gen_git_blob_file(objects_dir, blob_sha1, blob_compressed_content):    blob_dir = objects_dir + '/' + blob_sha1[:2]    blob_file = blob_dir + '/' + blob_sha1[2:]    if not os.path.exists(blob_dir):        os.mkdir(blob_dir)    open(blob_file, 'w').write(blob_compressed_content)def gen_git_blob_obj(objects_dir, blob_content):    blob_sha1, blob_compressed_content = calc_git_blob_obj(blob_content)    gen_git_blob_file(objects_dir, blob_sha1, blob_compressed_content)def get_git_blob_obj(blob_file):    return zlib.decompress(open(blob_file, 'r').read())gen_git_blob_obj('git/objects', 'what is up, doc?')print get_git_blob_obj('git/objects/bd/9dbf5aae1a3862dd1526723246b20206e5fc37')

除了直接用zlib，还有更简化的方法，用str的encode和decode方法，还不用import zlib：

    #下面两条语句是等价的    #blob_compressed_content = zlib.compress(blob_store)    blob_compressed_content = blob_store.encode('zip')

    #下面两条语句也是等价的    #return zlib.decompress(open(blob_file, 'r').read())    return open(blob_file, 'r').read().decode('zip')

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