fix(users): rename zseri -> fogti

in accordnace with similar renaming on other sites
(e.g. GitHub, Exozyme, chaos.social)

My experience with exozyme tells me that fully applying
this change might require manual editing of gerrits database
anyways to fix broken references/patch ownerships.

Change-Id: I024ff264c09b25d8f854c489d93458d1fce7e9f4
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8919
Autosubmit: lukegb <lukegb@tvl.fyi>
Reviewed-by: tazjin <tazjin@tvl.su>
Tested-by: BuildkiteCI
Reviewed-by: zseri <zseri.devel@ytrizja.de>

users/fogti/store-ref-scanner/src/spec.rs

@@ -0,0 +1,40 @@
+use crate::hbm::HalfBytesMask;
+
+pub struct StoreSpec<'path> {
+    /// path to store without trailing slash
+    pub path_to_store: &'path str,
+
+    /// compressed map of allowed ASCII characters in hash part
+    pub valid_hashbytes: HalfBytesMask,
+
+    /// compressed map of allowed ASCII characters in part after hash
+    pub valid_restbytes: HalfBytesMask,
+
+    /// exact length of hash part of store paths
+    pub hashbytes_len: u8,
+}
+
+impl StoreSpec<'_> {
+    pub(crate) fn check_rest(&self, rest: &[u8]) -> bool {
+        let hbl = self.hashbytes_len.into();
+        rest.iter()
+            .take(hbl)
+            .take_while(|&&i| self.valid_hashbytes.contains(i))
+            .count()
+            == hbl
+    }
+
+    pub const DFL_NIX2: StoreSpec<'static> = StoreSpec {
+        path_to_store: "/nix/store",
+        valid_hashbytes: HalfBytesMask::B32_REVSHA256,
+        valid_restbytes: HalfBytesMask::DFL_REST,
+        hashbytes_len: 32,
+    };
+
+    pub const DFL_YZIX1: StoreSpec<'static> = StoreSpec {
+        path_to_store: "/yzixs",
+        valid_hashbytes: HalfBytesMask::B64_BLAKE2B256,
+        valid_restbytes: HalfBytesMask::DFL_REST,
+        hashbytes_len: 43,
+    };
+}