From 72c0ecc21f571bba38c889c57be0ba53aa72c015 Mon Sep 17 00:00:00 2001
From: Melody Horn <melody@boringcactus.com>
Date: Mon, 29 Mar 2021 18:55:08 -0600
Subject: implement crates.io

---
 repos/__init__.py  |  3 ++-
 repos/crates_io.py | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)
 create mode 100644 repos/crates_io.py

diff --git a/repos/__init__.py b/repos/__init__.py
index ab6aa76..7023071 100644
--- a/repos/__init__.py
+++ b/repos/__init__.py
@@ -1,6 +1,6 @@
 from typing import Mapping, List
 
-from . import alpine_linux, arch_linux
+from . import alpine_linux, arch_linux, crates_io
 from .base import Repository, Version
 
 __all__ = [
@@ -16,6 +16,7 @@ def repos_from(module):
 all_repos: List[Repository] = [
     *repos_from(alpine_linux),
     *repos_from(arch_linux),
+    *repos_from(crates_io),
 ]
 
 def get_versions(package: str) -> Mapping[str, Version]:
diff --git a/repos/crates_io.py b/repos/crates_io.py
new file mode 100644
index 0000000..95078e3
--- /dev/null
+++ b/repos/crates_io.py
@@ -0,0 +1,47 @@
+import csv
+from io import TextIOWrapper
+from pathlib import Path
+import tarfile
+from typing import Mapping
+
+from .base import Repository, Version
+
+__all__ = [
+    'crates',
+]
+
+csv.field_size_limit(69696969)
+
+def parse_cached(cached: Path) -> Mapping[str, Version]:
+    dump = tarfile.open(cached)
+    crate_name = dict()
+    crate_version = dict()
+    for archive_member in dump.getmembers():
+        if archive_member.name.endswith('crates.csv'):
+            reader = csv.DictReader(TextIOWrapper(dump.extractfile(archive_member), 'UTF-8'))
+            for crate in reader:
+                crate_name[crate['id']] = crate['name']
+        elif archive_member.name.endswith('versions.csv'):
+            reader = csv.DictReader(TextIOWrapper(dump.extractfile(archive_member), 'UTF-8'))
+            for version in reader:
+                if version['yanked'] == 't':
+                    continue
+                crate_id = version['crate_id']
+                version = version['num']
+                this_version = Version(version, version)
+                if crate_id in crate_version:
+                    if this_version < crate_version[crate_id]:
+                        continue
+                crate_version[crate_id] = this_version
+    result = dict()
+    for crate_id in set(crate_name.keys()).union(crate_version.keys()):
+        if crate_id in crate_name and crate_id in crate_version:
+            result[crate_name[crate_id]] = crate_version[crate_id]
+    return result
+
+crates = Repository(
+    family=None,
+    repo='crates.io',
+    index_url='https://static.crates.io/db-dump.tar.gz',
+    parse=parse_cached,
+)
-- 
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