Factor out StoreDirConfig

More progress on #5729.

src/libstore/path.cc

@@ -1,4 +1,4 @@
-#include "store-api.hh"
+#include "store-dir-config.hh"
 
 #include <sodium.h>
 
@@ -54,7 +54,7 @@ StorePath StorePath::random(std::string_view name)
     return StorePath(hash, name);
 }
 
-StorePath Store::parseStorePath(std::string_view path) const
+StorePath StoreDirConfig::parseStorePath(std::string_view path) const
 {
     auto p = canonPath(std::string(path));
     if (dirOf(p) != storeDir)
@@ -62,7 +62,7 @@ StorePath Store::parseStorePath(std::string_view path) const
     return StorePath(baseNameOf(p));
 }
 
-std::optional<StorePath> Store::maybeParseStorePath(std::string_view path) const
+std::optional<StorePath> StoreDirConfig::maybeParseStorePath(std::string_view path) const
 {
     try {
         return parseStorePath(path);
@@ -71,24 +71,24 @@ std::optional<StorePath> Store::maybeParseStorePath(std::string_view path) const
     }
 }
 
-bool Store::isStorePath(std::string_view path) const
+bool StoreDirConfig::isStorePath(std::string_view path) const
 {
     return (bool) maybeParseStorePath(path);
 }
 
-StorePathSet Store::parseStorePathSet(const PathSet & paths) const
+StorePathSet StoreDirConfig::parseStorePathSet(const PathSet & paths) const
 {
     StorePathSet res;
     for (auto & i : paths) res.insert(parseStorePath(i));
     return res;
 }
 
-std::string Store::printStorePath(const StorePath & path) const
+std::string StoreDirConfig::printStorePath(const StorePath & path) const
 {
     return (storeDir + "/").append(path.to_string());
 }
 
-PathSet Store::printStorePathSet(const StorePathSet & paths) const
+PathSet StoreDirConfig::printStorePathSet(const StorePathSet & paths) const
 {
     PathSet res;
     for (auto & i : paths) res.insert(printStorePath(i));

src/libstore/store-api.cc

@@ -23,13 +23,13 @@ using json = nlohmann::json;
 namespace nix {
 
 
-bool Store::isInStore(PathView path) const
+bool StoreDirConfig::isInStore(PathView path) const
 {
     return isInDir(path, storeDir);
 }
 
 
-std::pair<StorePath, Path> Store::toStorePath(PathView path) const
+std::pair<StorePath, Path> StoreDirConfig::toStorePath(PathView path) const
 {
     if (!isInStore(path))
         throw Error("path '%1%' is not in the Nix store", path);
@@ -143,7 +143,7 @@ StorePath Store::followLinksToStorePath(std::string_view path) const
 */
 
 
-StorePath Store::makeStorePath(std::string_view type,
+StorePath StoreDirConfig::makeStorePath(std::string_view type,
     std::string_view hash, std::string_view name) const
 {
     /* e.g., "source:sha256:1abc...:/nix/store:foo.tar.gz" */
@@ -154,14 +154,14 @@ StorePath Store::makeStorePath(std::string_view type,
 }
 
 
-StorePath Store::makeStorePath(std::string_view type,
+StorePath StoreDirConfig::makeStorePath(std::string_view type,
     const Hash & hash, std::string_view name) const
 {
     return makeStorePath(type, hash.to_string(HashFormat::Base16, true), name);
 }
 
 
-StorePath Store::makeOutputPath(std::string_view id,
+StorePath StoreDirConfig::makeOutputPath(std::string_view id,
     const Hash & hash, std::string_view name) const
 {
     return makeStorePath("output:" + std::string { id }, hash, outputPathName(name, id));
@@ -172,7 +172,7 @@ StorePath Store::makeOutputPath(std::string_view id,
    hacky, but we can't put them in, say, <s2> (per the grammar above)
    since that would be ambiguous. */
 static std::string makeType(
-    const Store & store,
+    const StoreDirConfig & store,
     std::string && type,
     const StoreReferences & references)
 {
@@ -185,7 +185,7 @@ static std::string makeType(
 }
 
 
-StorePath Store::makeFixedOutputPath(std::string_view name, const FixedOutputInfo & info) const
+StorePath StoreDirConfig::makeFixedOutputPath(std::string_view name, const FixedOutputInfo & info) const
 {
     if (info.hash.type == htSHA256 && info.method == FileIngestionMethod::Recursive) {
         return makeStorePath(makeType(*this, "source", info.references), info.hash, name);
@@ -201,7 +201,7 @@ StorePath Store::makeFixedOutputPath(std::string_view name, const FixedOutputInf
 }
 
 
-StorePath Store::makeTextPath(std::string_view name, const TextInfo & info) const
+StorePath StoreDirConfig::makeTextPath(std::string_view name, const TextInfo & info) const
 {
     assert(info.hash.type == htSHA256);
     return makeStorePath(
@@ -214,7 +214,7 @@ StorePath Store::makeTextPath(std::string_view name, const TextInfo & info) cons
 }
 
 
-StorePath Store::makeFixedOutputPathFromCA(std::string_view name, const ContentAddressWithReferences & ca) const
+StorePath StoreDirConfig::makeFixedOutputPathFromCA(std::string_view name, const ContentAddressWithReferences & ca) const
 {
     // New template
     return std::visit(overloaded {
@@ -228,7 +228,7 @@ StorePath Store::makeFixedOutputPathFromCA(std::string_view name, const ContentA
 }
 
 
-std::pair<StorePath, Hash> Store::computeStorePathFromDump(
+std::pair<StorePath, Hash> StoreDirConfig::computeStorePathFromDump(
     Source & dump,
     std::string_view name,
     FileIngestionMethod method,
@@ -247,7 +247,7 @@ std::pair<StorePath, Hash> Store::computeStorePathFromDump(
 }
 
 
-StorePath Store::computeStorePathForText(
+StorePath StoreDirConfig::computeStorePathForText(
     std::string_view name,
     std::string_view s,
     const StorePathSet & references) const
@@ -1315,7 +1315,7 @@ std::optional<ValidPathInfo> decodeValidPathInfo(const Store & store, std::istre
 }
 
 
-std::string Store::showPaths(const StorePathSet & paths)
+std::string StoreDirConfig::showPaths(const StorePathSet & paths)
 {
     std::string s;
     for (auto & i : paths) {

src/libstore/store-api.hh

@@ -14,6 +14,7 @@
 #include "config.hh"
 #include "path-info.hh"
 #include "repair-flag.hh"
+#include "store-dir-config.hh"
 
 #include <nlohmann/json_fwd.hpp>
 #include <atomic>
@@ -64,7 +65,6 @@ MakeError(InvalidPath, Error);
 MakeError(Unsupported, Error);
 MakeError(SubstituteGone, Error);
 MakeError(SubstituterDisabled, Error);
-MakeError(BadStorePath, Error);
 
 MakeError(InvalidStoreURI, Error);
 
@@ -97,11 +97,11 @@ struct KeyedBuildResult;
 
 typedef std::map<StorePath, std::optional<ContentAddress>> StorePathCAMap;
 
-struct StoreConfig : public Config
+struct StoreConfig : public StoreDirConfig
 {
     typedef std::map<std::string, std::string> Params;
 
-    using Config::Config;
+    using StoreDirConfig::StoreDirConfig;
 
     StoreConfig() = delete;
 
@@ -131,15 +131,6 @@ struct StoreConfig : public Config
         return std::nullopt;
     }
 
-    const PathSetting storeDir_{this, settings.nixStore,
-        "store",
-        R"(
-          Logical location of the Nix store, usually
-          `/nix/store`. Note that you can only copy store paths
-          between stores if they have the same `store` setting.
-        )"};
-    const Path storeDir = storeDir_;
-
     const Setting<int> pathInfoCacheSize{this, 65536, "path-info-cache-size",
         "Size of the in-memory store path metadata cache."};
 
@@ -224,45 +215,6 @@ public:
 
     virtual std::string getUri() = 0;
 
-    StorePath parseStorePath(std::string_view path) const;
-
-    std::optional<StorePath> maybeParseStorePath(std::string_view path) const;
-
-    std::string printStorePath(const StorePath & path) const;
-
-    /**
-     * Deprecated
-     *
-     * \todo remove
-     */
-    StorePathSet parseStorePathSet(const PathSet & paths) const;
-
-    PathSet printStorePathSet(const StorePathSet & path) const;
-
-    /**
-     * Display a set of paths in human-readable form (i.e., between quotes
-     * and separated by commas).
-     */
-    std::string showPaths(const StorePathSet & paths);
-
-    /**
-     * @return true if ‘path’ is in the Nix store (but not the Nix
-     * store itself).
-     */
-    bool isInStore(PathView path) const;
-
-    /**
-     * @return true if ‘path’ is a store path, i.e. a direct child of the
-     * Nix store.
-     */
-    bool isStorePath(std::string_view path) const;
-
-    /**
-     * Split a path like /nix/store/<hash>-<name>/<bla> into
-     * /nix/store/<hash>-<name> and /<bla>.
-     */
-    std::pair<StorePath, Path> toStorePath(PathView path) const;
-
     /**
      * Follow symlinks until we end up with a path in the Nix store.
      */
@@ -274,55 +226,6 @@ public:
      */
     StorePath followLinksToStorePath(std::string_view path) const;
 
-    /**
-     * Constructs a unique store path name.
-     */
-    StorePath makeStorePath(std::string_view type,
-        std::string_view hash, std::string_view name) const;
-    StorePath makeStorePath(std::string_view type,
-        const Hash & hash, std::string_view name) const;
-
-    StorePath makeOutputPath(std::string_view id,
-        const Hash & hash, std::string_view name) const;
-
-    StorePath makeFixedOutputPath(std::string_view name, const FixedOutputInfo & info) const;
-
-    StorePath makeTextPath(std::string_view name, const TextInfo & info) const;
-
-    StorePath makeFixedOutputPathFromCA(std::string_view name, const ContentAddressWithReferences & ca) const;
-
-    /**
-     * Read-only variant of addToStoreFromDump(). It returns the store
-     * path to which a NAR or flat file would be written.
-     */
-    std::pair<StorePath, Hash> computeStorePathFromDump(
-        Source & dump,
-        std::string_view name,
-        FileIngestionMethod method = FileIngestionMethod::Recursive,
-        HashType hashAlgo = htSHA256,
-        const StorePathSet & references = {}) const;
-
-    /**
-     * Preparatory part of addTextToStore().
-     *
-     * !!! Computation of the path should take the references given to
-     * addTextToStore() into account, otherwise we have a (relatively
-     * minor) security hole: a caller can register a source file with
-     * bogus references.  If there are too many references, the path may
-     * not be garbage collected when it has to be (not really a problem,
-     * the caller could create a root anyway), or it may be garbage
-     * collected when it shouldn't be (more serious).
-     *
-     * Hashing the references would solve this (bogus references would
-     * simply yield a different store path, so other users wouldn't be
-     * affected), but it has some backwards compatibility issues (the
-     * hashing scheme changes), so I'm not doing that for now.
-     */
-    StorePath computeStorePathForText(
-        std::string_view name,
-        std::string_view s,
-        const StorePathSet & references) const;
-
     /**
      * Check whether a path is valid.
      */

src/libstore/store-dir-config.hh

@@ -0,0 +1,126 @@
+#pragma once
+
+#include "path.hh"
+#include "hash.hh"
+#include "content-address.hh"
+#include "globals.hh"
+#include "config.hh"
+
+#include <map>
+#include <string>
+#include <variant>
+
+
+namespace nix {
+
+MakeError(BadStorePath, Error);
+
+struct StoreDirConfig : public Config
+{
+    using Config::Config;
+
+    StoreDirConfig() = delete;
+
+    virtual ~StoreDirConfig() = default;
+
+    const PathSetting storeDir_{this, settings.nixStore,
+        "store",
+        R"(
+          Logical location of the Nix store, usually
+          `/nix/store`. Note that you can only copy store paths
+          between stores if they have the same `store` setting.
+        )"};
+    const Path storeDir = storeDir_;
+
+    // pure methods
+
+    StorePath parseStorePath(std::string_view path) const;
+
+    std::optional<StorePath> maybeParseStorePath(std::string_view path) const;
+
+    std::string printStorePath(const StorePath & path) const;
+
+    /**
+     * Deprecated
+     *
+     * \todo remove
+     */
+    StorePathSet parseStorePathSet(const PathSet & paths) const;
+
+    PathSet printStorePathSet(const StorePathSet & path) const;
+
+    /**
+     * Display a set of paths in human-readable form (i.e., between quotes
+     * and separated by commas).
+     */
+    std::string showPaths(const StorePathSet & paths);
+
+    /**
+     * @return true if ‘path’ is in the Nix store (but not the Nix
+     * store itself).
+     */
+    bool isInStore(PathView path) const;
+
+    /**
+     * @return true if ‘path’ is a store path, i.e. a direct child of the
+     * Nix store.
+     */
+    bool isStorePath(std::string_view path) const;
+
+    /**
+     * Split a path like /nix/store/<hash>-<name>/<bla> into
+     * /nix/store/<hash>-<name> and /<bla>.
+     */
+    std::pair<StorePath, Path> toStorePath(PathView path) const;
+
+    /**
+     * Constructs a unique store path name.
+     */
+    StorePath makeStorePath(std::string_view type,
+        std::string_view hash, std::string_view name) const;
+    StorePath makeStorePath(std::string_view type,
+        const Hash & hash, std::string_view name) const;
+
+    StorePath makeOutputPath(std::string_view id,
+        const Hash & hash, std::string_view name) const;
+
+    StorePath makeFixedOutputPath(std::string_view name, const FixedOutputInfo & info) const;
+
+    StorePath makeTextPath(std::string_view name, const TextInfo & info) const;
+
+    StorePath makeFixedOutputPathFromCA(std::string_view name, const ContentAddressWithReferences & ca) const;
+
+    /**
+     * Read-only variant of addToStoreFromDump(). It returns the store
+     * path to which a NAR or flat file would be written.
+     */
+    std::pair<StorePath, Hash> computeStorePathFromDump(
+        Source & dump,
+        std::string_view name,
+        FileIngestionMethod method = FileIngestionMethod::Recursive,
+        HashType hashAlgo = htSHA256,
+        const StorePathSet & references = {}) const;
+
+    /**
+     * Preparatory part of addTextToStore().
+     *
+     * !!! Computation of the path should take the references given to
+     * addTextToStore() into account, otherwise we have a (relatively
+     * minor) security hole: a caller can register a source file with
+     * bogus references.  If there are too many references, the path may
+     * not be garbage collected when it has to be (not really a problem,
+     * the caller could create a root anyway), or it may be garbage
+     * collected when it shouldn't be (more serious).
+     *
+     * Hashing the references would solve this (bogus references would
+     * simply yield a different store path, so other users wouldn't be
+     * affected), but it has some backwards compatibility issues (the
+     * hashing scheme changes), so I'm not doing that for now.
+     */
+    StorePath computeStorePathForText(
+        std::string_view name,
+        std::string_view s,
+        const StorePathSet & references) const;
+};
+
+}