nix3-profile: make element names stable

Based off of commit 6268a45b650f563bae2360e0540920a2959bdd40

Upstream-PR: https://github.com/NixOS/nix/pull/9656
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Change-Id: I0fcf069a8537c61ad6fc4eee1f3c193a708ea1c4

4 files changed, 91 insertions, 73 deletions

diff --git a/src/libcmd/cmd-profiles.cc b/src/libcmd/cmd-profiles.cc
index 5fa7f902c..4b17d60c6 100644
--- a/src/libcmd/cmd-profiles.cc
+++ b/src/libcmd/cmd-profiles.cc
@@ -6,6 +6,7 @@
 #include "logging.hh"
 #include "names.hh"
 #include "store-api.hh"
+#include "url-name.hh"
 
 namespace nix
 {
@@ -109,8 +110,6 @@ ProfileManifest::ProfileManifest(EvalState & state, const Path & profile)
 
     if (pathExists(manifestPath)) {
         auto json = nlohmann::json::parse(readFile(manifestPath));
-        // Keep track of already found names so we can prevent duplicates.
-        std::set<std::string> foundNames;
 
         auto version = json.value("version", 0);
         std::string sUrl;
@@ -121,6 +120,8 @@ ProfileManifest::ProfileManifest(EvalState & state, const Path & profile)
             sOriginalUrl = "originalUri";
             break;
         case 2:
+            [[fallthrough]];
+        case 3:
             sUrl = "url";
             sOriginalUrl = "originalUrl";
             break;
@@ -128,7 +129,10 @@ ProfileManifest::ProfileManifest(EvalState & state, const Path & profile)
             throw Error("profile manifest '%s' has unsupported version %d", manifestPath, version);
         }
 
-        for (auto & e : json["elements"]) {
+        auto elems = json["elements"];
+
+        for (auto & elem : elems.items()) {
+            auto & e = elem.value();
             ProfileElement element;
             for (auto & p : e["storePaths"]) {
                 element.storePaths.insert(state.store->parseStorePath((std::string) p));
@@ -145,26 +149,17 @@ ProfileManifest::ProfileManifest(EvalState & state, const Path & profile)
                     e["outputs"].get<ExtendedOutputsSpec>()};
             }
 
-            std::string nameCandidate(element.identifier());
-
-            if (e.contains("name")) {
-                nameCandidate = e["name"];
-            } else if (element.source) {
-                auto const url = parseURL(element.source->to_string());
-                auto const name = getNameFromURL(url);
-                if (name) {
-                    nameCandidate = *name;
-                }
-            }
-
-            auto finalName = nameCandidate;
-            for (unsigned appendedIndex = 1; foundNames.contains(finalName); ++appendedIndex) {
-                finalName = nameCandidate + std::to_string(appendedIndex);
-            }
-            element.name = finalName;
-            foundNames.insert(element.name);
-
-            elements.emplace_back(std::move(element));
+            // TODO(Qyriad): holy crap this chain of ternaries needs cleanup.
+            std::string name =
+                elems.is_object()
+                ? elem.key()
+                : e.contains("name")
+                ? static_cast<std::string>(e["name"])
+                : element.source
+                ? getNameFromURL(parseURL(element.source->to_string())).value_or(element.identifier())
+                : element.identifier();
+
+            addElement(name, std::move(element));
         }
     } else if (pathExists(profile + "/manifest.nix")) {
         // FIXME: needed because of pure mode; ugly.
@@ -176,16 +171,37 @@ ProfileManifest::ProfileManifest(EvalState & state, const Path & profile)
         for (auto & drvInfo : drvInfos) {
             ProfileElement element;
             element.storePaths = {drvInfo.queryOutPath()};
-            element.name = element.identifier();
-            elements.emplace_back(std::move(element));
+            addElement(std::move(element));
         }
     }
 }
 
+void ProfileManifest::addElement(std::string_view nameCandidate, ProfileElement element)
+{
+    std::string finalName(nameCandidate);
+
+    for (unsigned i = 1; elements.contains(finalName); ++i) {
+        finalName = nameCandidate + "-" + std::to_string(i);
+    }
+
+    elements.insert_or_assign(finalName, std::move(element));
+}
+
+void ProfileManifest::addElement(ProfileElement element)
+{
+    auto name =
+        element.source
+        ? getNameFromURL(parseURL(element.source->to_string()))
+        : std::nullopt;
+
+    auto finalName = name.value_or(element.identifier());
+    addElement(finalName, std::move(element));
+}
+
 nlohmann::json ProfileManifest::toJSON(Store & store) const
 {
-    auto array = nlohmann::json::array();
-    for (auto & element : elements) {
+    auto es = nlohmann::json::object();
+    for (auto & [name, element] : elements) {
         auto paths = nlohmann::json::array();
         for (auto & path : element.storePaths) {
             paths.push_back(store.printStorePath(path));
@@ -200,11 +216,11 @@ nlohmann::json ProfileManifest::toJSON(Store & store) const
             obj["attrPath"] = element.source->attrPath;
             obj["outputs"] = element.source->outputs;
         }
-        array.push_back(obj);
+        es[name] = obj;
     }
     nlohmann::json json;
-    json["version"] = 2;
-    json["elements"] = array;
+    json["version"] = 3;
+    json["elements"] = es;
     return json;
 }
 
@@ -215,7 +231,7 @@ StorePath ProfileManifest::build(ref<Store> store)
     StorePathSet references;
 
     Packages pkgs;
-    for (auto & element : elements) {
+    for (auto & [name, element] : elements) {
         for (auto & path : element.storePaths) {
             if (element.active) {
                 pkgs.emplace_back(store->printStorePath(path), true, element.priority);
@@ -261,35 +277,29 @@ void ProfileManifest::printDiff(
     const ProfileManifest & prev, const ProfileManifest & cur, std::string_view indent
 )
 {
-    auto prevElems = prev.elements;
-    std::sort(prevElems.begin(), prevElems.end());
-
-    auto curElems = cur.elements;
-    std::sort(curElems.begin(), curElems.end());
-
-    auto i = prevElems.begin();
-    auto j = curElems.begin();
+    auto prevElemIt = prev.elements.begin();
+    auto curElemIt = cur.elements.begin();
 
     bool changes = false;
 
-    while (i != prevElems.end() || j != curElems.end()) {
-        if (j != curElems.end() && (i == prevElems.end() || i->identifier() > j->identifier())) {
-            logger->cout("%s%s: ∅ -> %s", indent, j->identifier(), j->versions());
+    while (prevElemIt != prev.elements.end() || curElemIt != cur.elements.end()) {
+        if (curElemIt != cur.elements.end() && (prevElemIt == prev.elements.end() || prevElemIt->first > curElemIt->first)) {
+            logger->cout("%s%s: ∅ -> %s", indent, curElemIt->second.identifier(), curElemIt->second.versions());
             changes = true;
-            ++j;
-        } else if (i != prevElems.end() && (j == curElems.end() || i->identifier() < j->identifier())) {
-            logger->cout("%s%s: %s -> ∅", indent, i->identifier(), i->versions());
+            ++curElemIt;
+        } else if (prevElemIt != prev.elements.end() && (curElemIt == cur.elements.end() || prevElemIt->first < curElemIt->first)) {
+            logger->cout("%s%s: %s -> ∅", indent, prevElemIt->second.identifier(), prevElemIt->second.versions());
             changes = true;
-            ++i;
+            ++prevElemIt;
         } else {
-            auto v1 = i->versions();
-            auto v2 = j->versions();
+            auto v1 = prevElemIt->second.versions();
+            auto v2 = curElemIt->second.versions();
             if (v1 != v2) {
-                logger->cout("%s%s: %s -> %s", indent, i->identifier(), v1, v2);
+                logger->cout("%s%s: %s -> %s", indent, prevElemIt->second.identifier(), v1, v2);
                 changes = true;
             }
-            ++i;
-            ++j;
+            ++prevElemIt;
+            ++curElemIt;
         }
     }
 
diff --git a/src/libcmd/cmd-profiles.hh b/src/libcmd/cmd-profiles.hh
index 7f2c8a76f..2185daa34 100644
--- a/src/libcmd/cmd-profiles.hh
+++ b/src/libcmd/cmd-profiles.hh
@@ -35,7 +35,6 @@ constexpr int DEFAULT_PRIORITY = 5;
 struct ProfileElement
 {
     StorePathSet storePaths;
-    std::string name;
     std::optional<ProfileElementSource> source;
     bool active = true;
     int priority = DEFAULT_PRIORITY;
@@ -57,7 +56,7 @@ struct ProfileElement
 
 struct ProfileManifest
 {
-    std::vector<ProfileElement> elements;
+    std::map<std::string, ProfileElement> elements;
 
     ProfileManifest() { }
 
@@ -67,6 +66,9 @@ struct ProfileManifest
 
     StorePath build(ref<Store> store);
 
+    void addElement(std::string_view nameCandidate, ProfileElement element);
+    void addElement(ProfileElement element);
+
     static void printDiff(const ProfileManifest & prev, const ProfileManifest & cur, std::string_view indent);
 };
 
diff --git a/src/nix/profile.cc b/src/nix/profile.cc
index 131abb258..401d5bd77 100644
--- a/src/nix/profile.cc
+++ b/src/nix/profile.cc
@@ -105,7 +105,7 @@ struct CmdProfileInstall : InstallablesCommand, MixDefaultProfile
 
             element.updateStorePaths(getEvalStore(), store, res);
 
-            manifest.elements.push_back(std::move(element));
+            manifest.addElement(std::move(element));
         }
 
         try {
@@ -115,7 +115,7 @@ struct CmdProfileInstall : InstallablesCommand, MixDefaultProfile
             //       See https://github.com/NixOS/nix/compare/3efa476c5439f8f6c1968a6ba20a31d1239c2f04..1fe5d172ece51a619e879c4b86f603d9495cc102
             auto findRefByFilePath = [&]<typename Iterator>(Iterator begin, Iterator end) {
                 for (auto it = begin; it != end; it++) {
-                    auto profileElement = *it;
+                    auto & profileElement = it->second;
                     for (auto & storePath : profileElement.storePaths) {
                         if (conflictError.fileA.starts_with(store->printStorePath(storePath))) {
                             return std::pair(conflictError.fileA, profileElement.toInstallables(*store));
@@ -202,13 +202,19 @@ public:
         return res;
     }
 
-    bool matches(const Store & store, const ProfileElement & element, const std::vector<Matcher> & matchers)
+    bool matches(
+        Store const & store,
+        // regex_match doesn't take a string_view lol
+        std::string const & name,
+        ProfileElement const & element,
+        std::vector<Matcher> const & matchers
+    )
     {
         for (auto & matcher : matchers) {
             if (auto path = std::get_if<Path>(&matcher)) {
                 if (element.storePaths.count(store.parseStorePath(*path))) return true;
             } else if (auto regex = std::get_if<RegexPattern>(&matcher)) {
-                if (std::regex_match(element.name, regex->reg)) {
+                if (std::regex_match(name, regex->reg)) {
                     return true;
                 }
             }
@@ -240,10 +246,9 @@ struct CmdProfileRemove : virtual EvalCommand, MixDefaultProfile, MixProfileElem
 
         ProfileManifest newManifest;
 
-        for (size_t i = 0; i < oldManifest.elements.size(); ++i) {
-            auto & element(oldManifest.elements[i]);
-            if (!matches(*store, element, matchers)) {
-                newManifest.elements.push_back(std::move(element));
+        for (auto & [name, element] : oldManifest.elements) {
+            if (!matches(*store, name, element, matchers)) {
+                newManifest.elements.insert_or_assign(name, std::move(element));
             } else {
                 notice("removing '%s'", element.identifier());
             }
@@ -289,14 +294,13 @@ struct CmdProfileUpgrade : virtual SourceExprCommand, MixDefaultProfile, MixProf
         auto matchers = getMatchers(store);
 
         Installables installables;
-        std::vector<size_t> indices;
+        std::vector<ProfileElement *> elems;
 
         auto matchedCount = 0;
         auto upgradedCount = 0;
 
-        for (size_t i = 0; i < manifest.elements.size(); ++i) {
-            auto & element(manifest.elements[i]);
-            if (!matches(*store, element, matchers)) {
+        for (auto & [name, element] : manifest.elements) {
+            if (!matches(*store, name, element, matchers)) {
                 continue;
             }
 
@@ -368,7 +372,7 @@ struct CmdProfileUpgrade : virtual SourceExprCommand, MixDefaultProfile, MixProf
             };
 
             installables.push_back(installable);
-            indices.push_back(i);
+            elems.push_back(&element);
 
         }
 
@@ -393,7 +397,7 @@ struct CmdProfileUpgrade : virtual SourceExprCommand, MixDefaultProfile, MixProf
 
         for (size_t i = 0; i < installables.size(); ++i) {
             auto & installable = installables.at(i);
-            auto & element = manifest.elements[indices.at(i)];
+            auto & element = *elems.at(i);
             element.updateStorePaths(
                 getEvalStore(),
                 store,
@@ -425,14 +429,14 @@ struct CmdProfileList : virtual EvalCommand, virtual StoreCommand, MixDefaultPro
         if (json) {
             std::cout << manifest.toJSON(*store).dump() << "\n";
         } else {
-            for (size_t i = 0; i < manifest.elements.size(); ++i) {
-                auto & element(manifest.elements[i]);
+            for (auto const & [i, nameElemPair] : enumerate(manifest.elements)) {
+                auto & [name, element] = nameElemPair;
                 if (i) {
                     logger->cout("");
                 }
                 logger->cout(
                     "Name:               " ANSI_BOLD "%s" ANSI_NORMAL "%s",
-                    element.name,
+                    name,
                     element.active ? "" : " " ANSI_RED "(inactive)" ANSI_NORMAL
                 );
                 if (element.source) {
diff --git a/src/nix/upgrade-nix.cc b/src/nix/upgrade-nix.cc
index 31a051246..ca8080f88 100644
--- a/src/nix/upgrade-nix.cc
+++ b/src/nix/upgrade-nix.cc
@@ -208,7 +208,8 @@ struct CmdUpgradeNix : MixDryRun, EvalCommand
         // Find which profile element has Nix in it.
         // It should be impossible to *not* have Nix, since we grabbed this
         // store path by looking for things with bin/nix-env in them anyway.
-        auto findNix = [&](ProfileElement const & elem) -> bool {
+        auto findNix = [&](std::pair<std::string, ProfileElement> const & nameElemPair) -> bool {
+            auto const & [name, elem] = nameElemPair;
             for (auto const & ePath : elem.storePaths) {
                 auto const nixEnv = store->printStorePath(ePath) + "/bin/nix-env";
                 if (pathExists(nixEnv)) {
@@ -226,14 +227,15 @@ struct CmdUpgradeNix : MixDryRun, EvalCommand
         // *Should* be impossible...
         assert(elemWithNix != std::end(manifest.elements));
 
+        auto const nixElemName = elemWithNix->first;
+
         // Now create a new profile element for the new Nix version...
         ProfileElement elemForNewNix = {
             .storePaths = {newNix},
         };
 
         // ...and splork it into the manifest where the old profile element was.
-        // (Remember, elemWithNix is an iterator)
-        *elemWithNix = elemForNewNix;
+        manifest.elements.at(nixElemName) = elemForNewNix;
 
         // Build the new profile, and switch to it.
         StorePath const newProfile = manifest.build(store);