From 753fc1661d9b5275ee7048353872f10bcd9c2953 Mon Sep 17 00:00:00 2001
From: John Ericson <John.Ericson@Obsidian.Systems>
Date: Tue, 9 May 2023 13:05:38 -0400
Subject: [PATCH] Cleanups to content address types

---
 src/libstore/content-address.cc | 14 +++++++++-----
 src/libstore/content-address.hh | 23 ++++++++++++++++++++---
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/src/libstore/content-address.cc b/src/libstore/content-address.cc
index 167f7af6c..b62818e11 100644
--- a/src/libstore/content-address.cc
+++ b/src/libstore/content-address.cc
@@ -21,7 +21,8 @@ std::string makeFileIngestionPrefix(FileIngestionMethod m)
     }
 }
 
-std::string ContentAddressMethod::renderPrefix() const {
+std::string ContentAddressMethod::renderPrefix() const
+{
     return std::visit(overloaded {
         [](TextIngestionMethod) -> std::string { return "text:"; },
         [](FileIngestionMethod m2) {
@@ -113,7 +114,8 @@ static std::pair<ContentAddressMethod, HashType> parseContentAddressMethodPrefix
         throw UsageError("content address prefix '%s' is unrecognized. Recogonized prefixes are 'text' or 'fixed'", prefix);
 }
 
-ContentAddress ContentAddress::parse(std::string_view rawCa) {
+ContentAddress ContentAddress::parse(std::string_view rawCa)
+{
     auto rest = rawCa;
 
     auto [caMethod, hashType_] = parseContentAddressMethodPrefix(rest);
@@ -155,7 +157,7 @@ std::string renderContentAddress(std::optional<ContentAddress> ca)
 }
 
 ContentAddress ContentAddress::fromParts(
-    ContentAddressMethod method, Hash hash)
+    ContentAddressMethod method, Hash hash) noexcept
 {
     return std::visit(overloaded {
         [&](TextIngestionMethod _) -> ContentAddress {
@@ -196,7 +198,8 @@ const Hash & ContentAddress::getHash() const
     }, raw);
 }
 
-std::string ContentAddress::printMethodAlgo() const {
+std::string ContentAddress::printMethodAlgo() const
+{
     return getMethod().renderPrefix()
         + printHashType(getHash().type);
 }
@@ -211,7 +214,8 @@ size_t StoreReferences::size() const
     return (self ? 1 : 0) + others.size();
 }
 
-ContentAddressWithReferences ContentAddressWithReferences::withoutRefs(const ContentAddress & ca) {
+ContentAddressWithReferences ContentAddressWithReferences::withoutRefs(const ContentAddress & ca) noexcept
+{
     return std::visit(overloaded {
         [&](const TextHash & h) -> ContentAddressWithReferences {
             return TextInfo {
diff --git a/src/libstore/content-address.hh b/src/libstore/content-address.hh
index 4183ac1e7..03a2e2a23 100644
--- a/src/libstore/content-address.hh
+++ b/src/libstore/content-address.hh
@@ -81,17 +81,30 @@ struct ContentAddressMethod
      * Parse the prefix tag which indicates how the files
      * were ingested, with the fixed output case not prefixed for back
      * compat.
+     *
+     * @param [in] m A string that should begin with the prefix.
+     * @param [out] m The remainder of the string after the prefix.
      */
     static ContentAddressMethod parsePrefix(std::string_view & m);
 
+    /**
+     * Render the prefix tag which indicates how the files wre ingested.
+     *
+     * The rough inverse of `parsePrefix()`.
+     */
     std::string renderPrefix() const;
 
     /**
-     * Parse and pretty print a content addressing method and hash type in a
-     * nicer way, prefixing both cases.
+     * Parse a content addressing method and hash type.
      */
     static std::pair<ContentAddressMethod, HashType> parse(std::string_view rawCaMethod);
 
+    /**
+     * Render a content addressing method and hash type in a
+     * nicer way, prefixing both cases.
+     *
+     * The rough inverse of `parse()`.
+     */
     std::string render(HashType ht) const;
 };
 
@@ -178,7 +191,7 @@ struct ContentAddress
      * @param hash Hash of ingested file system data.
      */
     static ContentAddress fromParts(
-        ContentAddressMethod method, Hash hash);
+        ContentAddressMethod method, Hash hash) noexcept;
 
     ContentAddressMethod getMethod() const;
 
@@ -187,6 +200,10 @@ struct ContentAddress
     std::string printMethodAlgo() const;
 };
 
+/**
+ * Render the `ContentAddress` if it exists to a string, return empty
+ * string otherwise.
+ */
 std::string renderContentAddress(std::optional<ContentAddress> ca);