chore(3p/nix): unvendor tvix 0.1 r/4098

Nothing is using this now, and we'll likely never pick this up again,
but we learned a lot in the process.

Every now and then this breaks in some bizarre way on channel bumps
and it's just a waste of time to maintain that.

Change-Id: Idcf2f5acd4ca7070ce18d7149cbfc0d967dc0a44
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5632
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: lukegb <lukegb@tvl.fyi>
Autosubmit: tazjin <tazjin@tvl.su>

1 files changed, 0 insertions, 296 deletions

diff --git a/third_party/nix/src/libstore/optimise-store.cc b/third_party/nix/src/libstore/optimise-store.cc
deleted file mode 100644
index eb24633c181c..000000000000
--- a/third_party/nix/src/libstore/optimise-store.cc
+++ /dev/null
@@ -1,296 +0,0 @@
-#include <cerrno>
-#include <cstdio>
-#include <cstdlib>
-#include <cstring>
-#include <regex>
-#include <utility>
-
-#include <glog/logging.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include "libstore/globals.hh"
-#include "libstore/local-store.hh"
-#include "libutil/util.hh"
-
-namespace nix {
-
-static void makeWritable(const Path& path) {
-  struct stat st;
-  if (lstat(path.c_str(), &st) != 0) {
-    throw SysError(format("getting attributes of path '%1%'") % path);
-  }
-  if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1) {
-    throw SysError(format("changing writability of '%1%'") % path);
-  }
-}
-
-struct MakeReadOnly {
-  Path path;
-  explicit MakeReadOnly(Path path) : path(std::move(path)) {}
-  ~MakeReadOnly() {
-    try {
-      /* This will make the path read-only. */
-      if (!path.empty()) {
-        canonicaliseTimestampAndPermissions(path);
-      }
-    } catch (...) {
-      ignoreException();
-    }
-  }
-};
-
-LocalStore::InodeHash LocalStore::loadInodeHash() {
-  DLOG(INFO) << "loading hash inodes in memory";
-  InodeHash inodeHash;
-
-  AutoCloseDir dir(opendir(linksDir.c_str()));
-  if (!dir) {
-    throw SysError(format("opening directory '%1%'") % linksDir);
-  }
-
-  struct dirent* dirent;
-  while (errno = 0, dirent = readdir(dir.get())) { /* sic */
-    checkInterrupt();
-    // We don't care if we hit non-hash files, anything goes
-    inodeHash.insert(dirent->d_ino);
-  }
-  if (errno) {
-    throw SysError(format("reading directory '%1%'") % linksDir);
-  }
-
-  DLOG(INFO) << "loaded " << inodeHash.size() << " hash inodes";
-
-  return inodeHash;
-}
-
-Strings LocalStore::readDirectoryIgnoringInodes(const Path& path,
-                                                const InodeHash& inodeHash) {
-  Strings names;
-
-  AutoCloseDir dir(opendir(path.c_str()));
-  if (!dir) {
-    throw SysError(format("opening directory '%1%'") % path);
-  }
-
-  struct dirent* dirent;
-  while (errno = 0, dirent = readdir(dir.get())) { /* sic */
-    checkInterrupt();
-
-    if (inodeHash.count(dirent->d_ino) != 0u) {
-      DLOG(WARNING) << dirent->d_name << " is already linked";
-      continue;
-    }
-
-    std::string name = dirent->d_name;
-    if (name == "." || name == "..") {
-      continue;
-    }
-    names.push_back(name);
-  }
-  if (errno) {
-    throw SysError(format("reading directory '%1%'") % path);
-  }
-
-  return names;
-}
-
-void LocalStore::optimisePath_(OptimiseStats& stats, const Path& path,
-                               InodeHash& inodeHash) {
-  checkInterrupt();
-
-  struct stat st;
-  if (lstat(path.c_str(), &st) != 0) {
-    throw SysError(format("getting attributes of path '%1%'") % path);
-  }
-
-  if (S_ISDIR(st.st_mode)) {
-    Strings names = readDirectoryIgnoringInodes(path, inodeHash);
-    for (auto& i : names) {
-      optimisePath_(stats, path + "/" + i, inodeHash);
-    }
-    return;
-  }
-
-  /* We can hard link regular files and maybe symlinks. */
-  if (!S_ISREG(st.st_mode)
-#if CAN_LINK_SYMLINK
-      && !S_ISLNK(st.st_mode)
-#endif
-  )
-    return;
-
-  /* Sometimes SNAFUs can cause files in the Nix store to be
-     modified, in particular when running programs as root under
-     NixOS (example: $fontconfig/var/cache being modified).  Skip
-     those files.  FIXME: check the modification time. */
-  if (S_ISREG(st.st_mode) && ((st.st_mode & S_IWUSR) != 0u)) {
-    LOG(WARNING) << "skipping suspicious writable file '" << path << "'";
-    return;
-  }
-
-  /* This can still happen on top-level files. */
-  if (st.st_nlink > 1 && (inodeHash.count(st.st_ino) != 0u)) {
-    DLOG(INFO) << path << " is already linked, with " << (st.st_nlink - 2)
-               << " other file(s)";
-    return;
-  }
-
-  /* Hash the file.  Note that hashPath() returns the hash over the
-     NAR serialisation, which includes the execute bit on the file.
-     Thus, executable and non-executable files with the same
-     contents *won't* be linked (which is good because otherwise the
-     permissions would be screwed up).
-
-     Also note that if `path' is a symlink, then we're hashing the
-     contents of the symlink (i.e. the result of readlink()), not
-     the contents of the target (which may not even exist). */
-  Hash hash = hashPath(htSHA256, path).first;
-  LOG(INFO) << path << " has hash " << hash.to_string();
-
-  /* Check if this is a known hash. */
-  Path linkPath = linksDir + "/" + hash.to_string(Base32, false);
-
-retry:
-  if (!pathExists(linkPath)) {
-    /* Nope, create a hard link in the links directory. */
-    if (link(path.c_str(), linkPath.c_str()) == 0) {
-      inodeHash.insert(st.st_ino);
-      return;
-    }
-
-    switch (errno) {
-      case EEXIST:
-        /* Fall through if another process created ‘linkPath’ before
-           we did. */
-        break;
-
-      case ENOSPC:
-        /* On ext4, that probably means the directory index is
-           full.  When that happens, it's fine to ignore it: we
-           just effectively disable deduplication of this
-           file.  */
-        LOG(WARNING) << "cannot link '" << linkPath << " to " << path << ": "
-                     << strerror(errno);
-
-        return;
-
-      default:
-        throw SysError("cannot link '%1%' to '%2%'", linkPath, path);
-    }
-  }
-
-  /* Yes!  We've seen a file with the same contents.  Replace the
-     current file with a hard link to that file. */
-  struct stat stLink;
-  if (lstat(linkPath.c_str(), &stLink) != 0) {
-    throw SysError(format("getting attributes of path '%1%'") % linkPath);
-  }
-
-  if (st.st_ino == stLink.st_ino) {
-    DLOG(INFO) << path << " is already linked to " << linkPath;
-    return;
-  }
-
-  if (st.st_size != stLink.st_size) {
-    LOG(WARNING) << "removing corrupted link '" << linkPath << "'";
-    unlink(linkPath.c_str());
-    goto retry;
-  }
-
-  DLOG(INFO) << "linking '" << path << "' to '" << linkPath << "'";
-
-  /* Make the containing directory writable, but only if it's not
-     the store itself (we don't want or need to mess with its
-     permissions). */
-  bool mustToggle = dirOf(path) != realStoreDir;
-  if (mustToggle) {
-    makeWritable(dirOf(path));
-  }
-
-  /* When we're done, make the directory read-only again and reset
-     its timestamp back to 0. */
-  MakeReadOnly makeReadOnly(mustToggle ? dirOf(path) : "");
-
-  Path tempLink =
-      (format("%1%/.tmp-link-%2%-%3%") % realStoreDir % getpid() % random())
-          .str();
-
-  if (link(linkPath.c_str(), tempLink.c_str()) == -1) {
-    if (errno == EMLINK) {
-      /* Too many links to the same file (>= 32000 on most file
-         systems).  This is likely to happen with empty files.
-         Just shrug and ignore. */
-      if (st.st_size != 0) {
-        LOG(WARNING) << linkPath << " has maximum number of links";
-      }
-      return;
-    }
-    throw SysError("cannot link '%1%' to '%2%'", tempLink, linkPath);
-  }
-
-  /* Atomically replace the old file with the new hard link. */
-  if (rename(tempLink.c_str(), path.c_str()) == -1) {
-    if (unlink(tempLink.c_str()) == -1) {
-      LOG(ERROR) << "unable to unlink '" << tempLink << "'";
-    }
-    if (errno == EMLINK) {
-      /* Some filesystems generate too many links on the rename,
-         rather than on the original link.  (Probably it
-         temporarily increases the st_nlink field before
-         decreasing it again.) */
-      DLOG(WARNING) << "'" << linkPath
-                    << "' has reached maximum number of links";
-      return;
-    }
-    throw SysError(format("cannot rename '%1%' to '%2%'") % tempLink % path);
-  }
-
-  stats.filesLinked++;
-  stats.bytesFreed += st.st_size;
-  stats.blocksFreed += st.st_blocks;
-}
-
-void LocalStore::optimiseStore(OptimiseStats& stats) {
-  PathSet paths = queryAllValidPaths();
-  InodeHash inodeHash = loadInodeHash();
-
-  uint64_t done = 0;
-
-  for (auto& i : paths) {
-    addTempRoot(i);
-    if (!isValidPath(i)) {
-      continue;
-    } /* path was GC'ed, probably */
-    {
-      LOG(INFO) << "optimising path '" << i << "'";
-      optimisePath_(stats, realStoreDir + "/" + baseNameOf(i), inodeHash);
-    }
-    done++;
-  }
-}
-
-static std::string showBytes(unsigned long long bytes) {
-  return (format("%.2f MiB") % (bytes / (1024.0 * 1024.0))).str();
-}
-
-void LocalStore::optimiseStore() {
-  OptimiseStats stats;
-
-  optimiseStore(stats);
-
-  LOG(INFO) << showBytes(stats.bytesFreed) << " freed by hard-linking "
-            << stats.filesLinked << " files";
-}
-
-void LocalStore::optimisePath(const Path& path) {
-  OptimiseStats stats;
-  InodeHash inodeHash;
-
-  if (settings.autoOptimiseStore) {
-    optimisePath_(stats, path, inodeHash);
-  }
-}
-
-}  // namespace nix