Use SourcePath in more places

Now that SourcePath uses a SourceAccessor instead of an InputAccessor,
we can use it in function signatures instead of passing a
SourceAccessor and CanonPath separately.

src/libutil/archive.cc

@@ -8,6 +8,7 @@
 #include "archive.hh"
 #include "config.hh"
 #include "posix-source-accessor.hh"
+#include "source-path.hh"
 #include "file-system.hh"
 #include "signals.hh"
 
@@ -110,9 +111,9 @@ void SourceAccessor::dumpPath(
 
 time_t dumpPathAndGetMtime(const Path & path, Sink & sink, PathFilter & filter)
 {
-    auto [accessor, canonPath] = PosixSourceAccessor::createAtRoot(path);
-    accessor.dumpPath(canonPath, sink, filter);
-    return accessor.mtime;
+    auto path2 = PosixSourceAccessor::createAtRoot(path);
+    path2.dumpPath(sink, filter);
+    return path2.accessor.dynamic_pointer_cast<PosixSourceAccessor>()->mtime;
 }
 
 void dumpPath(const Path & path, Sink & sink, PathFilter & filter)

src/libutil/file-content-address.cc

@@ -1,6 +1,7 @@
 #include "file-content-address.hh"
 #include "archive.hh"
 #include "git.hh"
+#include "source-path.hh"
 
 namespace nix {
 
@@ -68,17 +69,17 @@ std::string_view renderFileIngestionMethod(FileIngestionMethod method)
 
 
 void dumpPath(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     Sink & sink,
     FileSerialisationMethod method,
     PathFilter & filter)
 {
     switch (method) {
     case FileSerialisationMethod::Flat:
-        accessor.readFile(path, sink);
+        path.readFile(sink);
         break;
     case FileSerialisationMethod::Recursive:
-        accessor.dumpPath(path, sink, filter);
+        path.dumpPath(sink, filter);
         break;
     }
 }
@@ -101,27 +102,27 @@ void restorePath(
 
 
 HashResult hashPath(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     FileSerialisationMethod method, HashAlgorithm ha,
     PathFilter & filter)
 {
     HashSink sink { ha };
-    dumpPath(accessor, path, sink, method, filter);
+    dumpPath(path, sink, method, filter);
     return sink.finish();
 }
 
 
 Hash hashPath(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     FileIngestionMethod method, HashAlgorithm ht,
     PathFilter & filter)
 {
     switch (method) {
     case FileIngestionMethod::Flat:
     case FileIngestionMethod::Recursive:
-        return hashPath(accessor, path, (FileSerialisationMethod) method, ht, filter).first;
+        return hashPath(path, (FileSerialisationMethod) method, ht, filter).first;
     case FileIngestionMethod::Git:
-        return git::dumpHash(ht, accessor, path, filter).hash;
+        return git::dumpHash(ht, path, filter).hash;
     }
     assert(false);
 }

src/libutil/file-content-address.hh

@@ -7,6 +7,8 @@
 
 namespace nix {
 
+struct SourcePath;
+
 /**
  * An enumeration of the ways we can serialize file system
  * objects.
@@ -45,7 +47,7 @@ std::string_view renderFileSerialisationMethod(FileSerialisationMethod method);
  * Dump a serialization of the given file system object.
  */
 void dumpPath(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     Sink & sink,
     FileSerialisationMethod method,
     PathFilter & filter = defaultPathFilter);
@@ -72,7 +74,7 @@ void restorePath(
  * ```
  */
 HashResult hashPath(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     FileSerialisationMethod method, HashAlgorithm ha,
     PathFilter & filter = defaultPathFilter);
 
@@ -138,7 +140,7 @@ std::string_view renderFileIngestionMethod(FileIngestionMethod method);
  * useful defined for a merkle format.
  */
 Hash hashPath(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     FileIngestionMethod method, HashAlgorithm ha,
     PathFilter & filter = defaultPathFilter);
 

src/libutil/git.cc

@@ -8,7 +8,6 @@
 #include "signals.hh"
 #include "config.hh"
 #include "hash.hh"
-#include "posix-source-accessor.hh"
 
 #include "git.hh"
 #include "serialise.hh"
@@ -269,18 +268,18 @@ void dumpTree(const Tree & entries, Sink & sink,
 
 
 Mode dump(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     Sink & sink,
     std::function<DumpHook> hook,
     PathFilter & filter,
     const ExperimentalFeatureSettings & xpSettings)
 {
-    auto st = accessor.lstat(path);
+    auto st = path.lstat();
 
     switch (st.type) {
     case SourceAccessor::tRegular:
     {
-        accessor.readFile(path, sink, [&](uint64_t size) {
+        path.readFile(sink, [&](uint64_t size) {
             dumpBlobPrefix(size, sink, xpSettings);
         });
         return st.isExecutable
@@ -291,9 +290,9 @@ Mode dump(
     case SourceAccessor::tDirectory:
     {
         Tree entries;
-        for (auto & [name, _] : accessor.readDirectory(path)) {
+        for (auto & [name, _] : path.readDirectory()) {
             auto child = path / name;
-            if (!filter(child.abs())) continue;
+            if (!filter(child.path.abs())) continue;
 
             auto entry = hook(child);
 
@@ -309,7 +308,7 @@ Mode dump(
 
     case SourceAccessor::tSymlink:
     {
-        auto target = accessor.readLink(path);
+        auto target = path.readLink();
         dumpBlobPrefix(target.size(), sink, xpSettings);
         sink(target);
         return Mode::Symlink;
@@ -323,13 +322,14 @@ Mode dump(
 
 
 TreeEntry dumpHash(
-        HashAlgorithm ha,
-        SourceAccessor & accessor, const CanonPath & path, PathFilter & filter)
+    HashAlgorithm ha,
+    const SourcePath & path,
+    PathFilter & filter)
 {
     std::function<DumpHook> hook;
-    hook = [&](const CanonPath & path) -> TreeEntry {
+    hook = [&](const SourcePath & path) -> TreeEntry {
         auto hashSink = HashSink(ha);
-        auto mode = dump(accessor, path, hashSink, hook, filter);
+        auto mode = dump(path, hashSink, hook, filter);
         auto hash = hashSink.finish().first;
         return {
             .mode = mode,

src/libutil/git.hh

@@ -8,7 +8,7 @@
 #include "types.hh"
 #include "serialise.hh"
 #include "hash.hh"
-#include "source-accessor.hh"
+#include "source-path.hh"
 #include "fs-sink.hh"
 
 namespace nix::git {
@@ -125,7 +125,7 @@ std::optional<Mode> convertMode(SourceAccessor::Type type);
  * Given a `Hash`, return a `SourceAccessor` and `CanonPath` pointing to
  * the file system object with that path.
  */
-using RestoreHook = std::pair<SourceAccessor *, CanonPath>(Hash);
+using RestoreHook = SourcePath(Hash);
 
 /**
  * Wrapper around `parse` and `RestoreSink`
@@ -157,10 +157,10 @@ void dumpTree(
  * Note that if the child is a directory, its child in must also be so
  * processed in order to compute this information.
  */
-using DumpHook = TreeEntry(const CanonPath & path);
+using DumpHook = TreeEntry(const SourcePath & path);
 
 Mode dump(
-    SourceAccessor & accessor, const CanonPath & path,
+    const SourcePath & path,
     Sink & sink,
     std::function<DumpHook> hook,
     PathFilter & filter = defaultPathFilter,
@@ -172,9 +172,9 @@ Mode dump(
  * A smaller wrapper around `dump`.
  */
 TreeEntry dumpHash(
-            HashAlgorithm ha,
-            SourceAccessor & accessor, const CanonPath & path,
-            PathFilter & filter = defaultPathFilter);
+    HashAlgorithm ha,
+    const SourcePath & path,
+    PathFilter & filter = defaultPathFilter);
 
 /**
  * A line from the output of `git ls-remote --symref`.

src/libutil/posix-source-accessor.cc

@@ -1,4 +1,5 @@
 #include "posix-source-accessor.hh"
+#include "source-path.hh"
 #include "signals.hh"
 #include "sync.hh"
 
@@ -17,11 +18,11 @@ PosixSourceAccessor::PosixSourceAccessor()
     : PosixSourceAccessor(std::filesystem::path {})
 { }
 
-std::pair<PosixSourceAccessor, CanonPath> PosixSourceAccessor::createAtRoot(const std::filesystem::path & path)
+SourcePath PosixSourceAccessor::createAtRoot(const std::filesystem::path & path)
 {
     std::filesystem::path path2 = absPath(path.string());
     return {
-        PosixSourceAccessor { path2.root_path() },
+        make_ref<PosixSourceAccessor>(path2.root_path()),
         CanonPath { path2.relative_path().string() },
     };
 }

src/libutil/posix-source-accessor.hh

@@ -4,6 +4,8 @@
 
 namespace nix {
 
+struct SourcePath;
+
 /**
  * A source accessor that uses the Unix filesystem.
  */
@@ -53,7 +55,7 @@ struct PosixSourceAccessor : virtual SourceAccessor
      * and
      * [`std::filesystem::path::relative_path`](https://en.cppreference.com/w/cpp/filesystem/path/relative_path).
      */
-    static std::pair<PosixSourceAccessor, CanonPath> createAtRoot(const std::filesystem::path & path);
+    static SourcePath createAtRoot(const std::filesystem::path & path);
 
 private:
 

src/libutil/source-path.hh

@@ -41,6 +41,11 @@ struct SourcePath
      */
     std::string readFile() const;
 
+    void readFile(
+        Sink & sink,
+        std::function<void(uint64_t)> sizeCallback = [](uint64_t size){}) const
+    { return accessor->readFile(path, sink, sizeCallback); }
+
     /**
      * Return whether this `SourcePath` denotes a file (of any type)
      * that exists