updateFabric.py

from meta.common.json import dump, dumps, load, loads
import os
import zipfile
from concurrent.futures import ThreadPoolExecutor
from datetime import datetime

import requests
from cachecontrol import CacheControl
from cachecontrol.caches import FileCache

from meta.common import upstream_path, ensure_upstream_dir, transform_maven_key
from meta.common.fabric import JARS_DIR, INSTALLER_INFO_DIR, META_DIR, DATETIME_FORMAT_HTTP
from meta.model.fabric import FabricJarInfo

UPSTREAM_DIR = upstream_path()

ensure_upstream_dir(JARS_DIR)
ensure_upstream_dir(INSTALLER_INFO_DIR)
ensure_upstream_dir(META_DIR)

forever_cache = FileCache('caches/http_cache', forever=True)


# each thread worker has its own session
def make_session():
    return CacheControl(requests.Session(), forever_cache)


def filehash(filename, hashtype, blocksize=65536):
    h = hashtype()
    with open(filename, "rb") as f:
        for block in iter(lambda: f.read(blocksize), b""):
            h.update(block)
    return h.hexdigest()


def get_maven_url(maven_key, server, ext):
    parts = maven_key.split(":", 3)
    maven_ver_url = server + parts[0].replace(".", "/") + "/" + parts[1] + "/" + parts[2] + "/"
    maven_url = maven_ver_url + parts[1] + "-" + parts[2] + ext
    return maven_url


def get_json_file(path, url, sess):
    with open(path, 'w', encoding='utf-8') as f:
        r = sess.get(url)
        r.raise_for_status()
        version_json = r.json()
        dump(version_json, f, sort_keys=True, indent=4)
        return version_json


def head_file(url, sess):
    r = sess.head(url)
    r.raise_for_status()
    return r.headers


def get_binary_file(path, url, sess):
    with open(path, 'wb') as f:
        r = sess.get(url)
        r.raise_for_status()
        for chunk in r.iter_content(chunk_size=8192):
            f.write(chunk)


def compute_jar_file(path, url, sess):
    # These two approaches should result in the same metadata, except for the timestamp which might be a few minutes
    # off for the fallback method
    try:
        # Let's not download a Jar file if we don't need to.
        headers = head_file(url, sess)
        tstamp = datetime.strptime(headers["Last-Modified"], DATETIME_FORMAT_HTTP)
    except requests.HTTPError:
        # Just in case something changes in the future
        print(f"Falling back to downloading jar for {url}")

        jar_path = path + ".jar"
        get_binary_file(jar_path, url, sess)
        tstamp = datetime.fromtimestamp(0)
        with zipfile.ZipFile(jar_path) as jar:
            allinfo = jar.infolist()
            for info in allinfo:
                tstamp_new = datetime(*info.date_time)
                if tstamp_new > tstamp:
                    tstamp = tstamp_new

    data = FabricJarInfo(release_time=tstamp)
    data.write(path + ".json")


def process_version(it, component, sess):
    print(f"Processing {component} {it['version']}")
    jar_maven_url = get_maven_url(it["maven"], "https://maven.fabricmc.net/", ".jar")
    compute_jar_file(os.path.join(UPSTREAM_DIR, JARS_DIR, transform_maven_key(it["maven"])), jar_maven_url, sess)


def process_loader(it, sess):
    print(f"Downloading JAR info for loader {it['version']}")
    maven_url = get_maven_url(it["maven"], "https://maven.fabricmc.net/", ".json")
    get_json_file(os.path.join(UPSTREAM_DIR, INSTALLER_INFO_DIR, f"{it['version']}.json"), maven_url, sess)


def main():
    # get the version list for each component we are interested in
    for component in ["intermediary", "loader"]:
        index = get_json_file(os.path.join(UPSTREAM_DIR, META_DIR, f"{component}.json"),
                              "https://meta.fabricmc.net/v2/versions/" + component, make_session())

        with ThreadPoolExecutor(max_workers=16) as executor:
            futures = []
            for it in index:
                futures.append(executor.submit(process_version, it, component, make_session()))
            for future in futures:
                future.result()

    # for each loader, download installer JSON file from maven
    with open(os.path.join(UPSTREAM_DIR, META_DIR, "loader.json"), 'r', encoding='utf-8') as loaderVersionIndexFile:
        loader_version_index = load(loaderVersionIndexFile)

        with ThreadPoolExecutor(max_workers=16) as executor:
            futures = []
            for it in loader_version_index:
                # preserve ordering
                futures.append(executor.submit(process_loader, it, make_session()))
            for future in futures:
                future.result()


if __name__ == '__main__':
    main()