Remove dead code

Most of the code in `git.{cc,hh}` is dead, so get rid of it.

src/libutil/git.hh

@@ -5,160 +5,8 @@
 #include <string_view>
 #include <optional>
 
-#include "types.hh"
-#include "serialise.hh"
-#include "hash.hh"
-#include "source-accessor.hh"
-#include "fs-sink.hh"
-
 namespace nix::git {
 
-enum struct ObjectType {
-    Blob,
-    Tree,
-    //Commit,
-    //Tag,
-};
-
-using RawMode = uint32_t;
-
-enum struct Mode : RawMode {
-    Directory = 0040000,
-    Regular = 0100644,
-    Executable = 0100755,
-    Symlink = 0120000,
-};
-
-std::optional<Mode> decodeMode(RawMode m);
-
-/**
- * An anonymous Git tree object entry (no name part).
- */
-struct TreeEntry
-{
-    Mode mode;
-    Hash hash;
-
-    GENERATE_CMP(TreeEntry, me->mode, me->hash);
-};
-
-/**
- * A Git tree object, fully decoded and stored in memory.
- *
- * Directory names must end in a `/` for sake of sorting. See
- * https://github.com/mirage/irmin/issues/352
- */
-using Tree = std::map<std::string, TreeEntry>;
-
-/**
- * Callback for processing a child hash with `parse`
- *
- * The function should
- *
- * 1. Obtain the file system objects denoted by `gitHash`
- *
- * 2. Ensure they match `mode`
- *
- * 3. Feed them into the same sink `parse` was called with
- *
- * Implementations may seek to memoize resources (bandwidth, storage,
- * etc.) for the same Git hash.
- */
-using SinkHook = void(const Path & name, TreeEntry entry);
-
-/**
- * Parse the "blob " or "tree " prefix.
- *
- * @throws if prefix not recognized
- */
-ObjectType parseObjectType(
-    Source & source,
-    const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-
-void parseBlob(
-    FileSystemObjectSink & sink, const Path & sinkPath,
-    Source & source,
-    bool executable,
-    const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-
-void parseTree(
-    FileSystemObjectSink & sink, const Path & sinkPath,
-    Source & source,
-    std::function<SinkHook> hook,
-    const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-
-/**
- * Helper putting the previous three `parse*` functions together.
- */
-void parse(
-    FileSystemObjectSink & sink, const Path & sinkPath,
-    Source & source,
-    bool executable,
-    std::function<SinkHook> hook,
-    const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-
-/**
- * Assists with writing a `SinkHook` step (2).
- */
-std::optional<Mode> convertMode(SourceAccessor::Type type);
-
-/**
- * Simplified version of `SinkHook` for `restore`.
- *
- * Given a `Hash`, return a `SourceAccessor` and `CanonPath` pointing to
- * the file system object with that path.
- */
-using RestoreHook = std::pair<SourceAccessor *, CanonPath>(Hash);
-
-/**
- * Wrapper around `parse` and `RestoreSink`
- */
-void restore(FileSystemObjectSink & sink, Source & source, std::function<RestoreHook> hook);
-
-/**
- * Dumps a single file to a sink
- *
- * @param xpSettings for testing purposes
- */
-void dumpBlobPrefix(
-    uint64_t size, Sink & sink,
-    const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-
-/**
- * Dumps a representation of a git tree to a sink
- */
-void dumpTree(
-    const Tree & entries, Sink & sink,
-    const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-
-/**
- * Callback for processing a child with `dump`
- *
- * The function should return the Git hash and mode of the file at the
- * given path in the accessor passed to `dump`.
- *
- * 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);
-
-Mode dump(
-    SourceAccessor & accessor, const CanonPath & path,
-    Sink & sink,
-    std::function<DumpHook> hook,
-    PathFilter & filter = defaultPathFilter,
-    const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
-
-/**
- * Recursively dumps path, hashing as we go.
- *
- * A smaller wrapper around `dump`.
- */
-TreeEntry dumpHash(
-            HashAlgorithm ha,
-            SourceAccessor & accessor, const CanonPath & path,
-            PathFilter & filter = defaultPathFilter);
-
 /**
  * A line from the output of `git ls-remote --symref`.
  *