From 0328598e3b643edd0a2033ca97c607f596dfb092 Mon Sep 17 00:00:00 2001
From: Bryan Newbold <bnewbold@archive.org>
Date: Tue, 30 Nov 2021 15:29:41 -0800
Subject: add CDX sha1hex lookup/fetch helper script

---
 python/scripts/fetch_cdx_sha1hex.py | 170 ++++++++++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)
 create mode 100755 python/scripts/fetch_cdx_sha1hex.py

(limited to 'python/scripts')

diff --git a/python/scripts/fetch_cdx_sha1hex.py b/python/scripts/fetch_cdx_sha1hex.py
new file mode 100755
index 0000000..2eb56cb
--- /dev/null
+++ b/python/scripts/fetch_cdx_sha1hex.py
@@ -0,0 +1,170 @@
+#!/usr/bin/env python3
+
+"""
+This is a helper script to take fatcat file entities with partial metadata (eg,
+missing SHA256) and try to find one or more CDX record where the file may be
+found in wayback.
+
+This script uses the sandcrawler library and should be run like:
+
+    head file_export.json | python -m scripts.fetch_cdx_sha1hex > results.json
+"""
+
+import base64
+import json
+import sys
+from typing import List, Optional
+
+import requests
+from requests.adapters import HTTPAdapter
+from requests.packages.urllib3.util.retry import Retry  # pylint: disable=import-error
+
+from sandcrawler.ia import CdxApiClient, cdx_to_dict
+
+
+def requests_retry_session(
+    retries: int = 10,
+    backoff_factor: int = 3,
+    status_forcelist: List[int] = [500, 502, 504],
+    session: requests.Session = None,
+) -> requests.Session:
+    """
+    From: https://www.peterbe.com/plog/best-practice-with-retries-with-requests
+    """
+    session = session or requests.Session()
+    retry = Retry(
+        total=retries,
+        read=retries,
+        connect=retries,
+        backoff_factor=backoff_factor,
+        status_forcelist=status_forcelist,
+    )
+    adapter = HTTPAdapter(max_retries=retry)
+    session.mount("http://", adapter)
+    session.mount("https://", adapter)
+    return session
+
+
+def b32_hex(s: str) -> str:
+    """
+    Converts a base32-encoded SHA-1 checksum into hex-encoded
+
+    base32 checksums are used by, eg, heritrix and in wayback CDX files
+    """
+    s = s.strip().split()[0].lower()
+    if s.startswith("sha1:"):
+        s = s[5:]
+    if len(s) != 32:
+        if len(s) == 40:
+            return s
+        raise ValueError("not a base-32 encoded SHA-1 hash: {}".format(s))
+    return base64.b16encode(base64.b32decode(s.upper())).lower().decode("utf-8")
+
+
+SANDCRAWLER_POSTGREST_URL = "http://wbgrp-svc506.us.archive.org:3030"
+
+
+def get_db_cdx(sha1hex: str, http_session) -> List[dict]:
+    resp = http_session.get(
+        SANDCRAWLER_POSTGREST_URL + "/cdx", params=dict(sha1hex="eq." + sha1hex)
+    )
+    resp.raise_for_status()
+    rows = resp.json()
+    return rows or []
+
+
+CDX_API_URL = "https://web.archive.org/cdx/search/cdx"
+
+
+def get_api_cdx(url: str, sha1hex: str, cdx_api) -> Optional[dict]:
+
+    params = {
+        "url": url,
+        "output": "json",
+        "matchType": "exact",
+        "limit": 20,
+        # TODO: group-by digest/checksum?
+        # can't filter status because might be warc/revisit
+        # "filter": "statuscode:200",
+    }
+    rows = cdx_api._query_api(params)
+    if not rows:
+        return None
+    for row in rows:
+        if row.sha1hex == sha1hex:
+            return row
+    return None
+
+
+def process_file(fe, session, cdx_api) -> dict:
+    status = "unknown"
+
+    # simple CDX db lookup first
+    cdx_row_list = get_db_cdx(fe["sha1"], http_session=session)
+    if cdx_row_list:
+        return dict(
+            file_entity=fe,
+            cdx_rows=cdx_row_list,
+            status="success-db",
+        )
+
+    original_urls = []
+    for pair in fe["urls"]:
+        u = pair["url"]
+        if not "://web.archive.org/web/" in u:
+            continue
+        seg = u.split("/")
+        assert seg[2] == "web.archive.org"
+        assert seg[3] == "web"
+        if not seg[4].isdigit():
+            continue
+        original_url = "/".join(seg[5:])
+        original_urls.append(original_url)
+
+    if len(original_urls) == 0:
+        return dict(file_entity=fe, status="skip-no-urls")
+
+    found_cdx_rows = []
+    for url in list(set(original_urls)):
+
+        cdx_record = None
+        try:
+            cdx_record = get_api_cdx(original_url, sha1hex=fe["sha1"], cdx_api=cdx_api)
+        except requests.exceptions.HTTPError as e:
+            if e.response.status_code == 403:
+                return dict(file_entity=fe, status="fail-cdx-403")
+            else:
+                raise
+        if cdx_record and cdx_record.sha1hex == fe["sha1"]:
+            found_cdx_rows.append(cdx_to_dict(cdx_record))
+
+    if found_cdx_rows:
+        return dict(
+            file_entity=fe,
+            cdx_rows=found_cdx_rows,
+            status="success-api",
+        )
+
+    return dict(
+        file_entity=fe,
+        status="fail-not-found",
+    )
+
+
+def main():
+    session = requests_retry_session()
+    session.headers.update(
+        {
+            "User-Agent": "Mozilla/5.0 fatcat.CdxFixupBot",
+        }
+    )
+    cdx_api = CdxApiClient()
+    for line in sys.stdin:
+        if not line.strip():
+            continue
+        fe = json.loads(line)
+        print(json.dumps(process_file(fe, session=session, cdx_api=cdx_api)))
+
+
+if __name__ == "__main__":
+    main()
-- 
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