1 files changed, 152 insertions, 0 deletions
diff --git a/third_party/nix/src/nix/hash.cc b/third_party/nix/src/nix/hash.cc
new file mode 100644
index 0000000000..4fb262f1a8
--- /dev/null
+++ b/third_party/nix/src/nix/hash.cc
@@ -0,0 +1,152 @@
+#include "libutil/hash.hh"
+
+#include "libmain/shared.hh"
+#include "nix/command.hh"
+#include "nix/legacy.hh"
+
+namespace nix {
+struct CmdHash final : Command {
+  enum Mode { mFile, mPath };
+  Mode mode;
+  Base base = SRI;
+  bool truncate = false;
+  HashType ht = htSHA256;
+  std::vector<std::string> paths;
+
+  explicit CmdHash(Mode mode) : mode(mode) {
+    mkFlag(0, "sri", "print hash in SRI format", &base, SRI);
+    mkFlag(0, "base64", "print hash in base-64", &base, Base64);
+    mkFlag(0, "base32", "print hash in base-32 (Nix-specific)", &base, Base32);
+    mkFlag(0, "base16", "print hash in base-16", &base, Base16);
+    mkFlag().longName("type").mkHashTypeFlag(&ht);
+    expectArgs("paths", &paths);
+  }
+
+  std::string name() override {
+    return mode == mFile ? "hash-file" : "hash-path";
+  }
+
+  std::string description() override {
+    return mode == mFile
+               ? "print cryptographic hash of a regular file"
+               : "print cryptographic hash of the NAR serialisation of a path";
+  }
+
+  void run() override {
+    for (const auto& path : paths) {
+      Hash h = mode == mFile ? hashFile(ht, path) : hashPath(ht, path).first;
+      if (truncate && h.hashSize > nix::kStorePathHashSize) {
+        h = compressHash(h, nix::kStorePathHashSize);
+      }
+      std::cout << format("%1%\n") % h.to_string(base, base == SRI);
+    }
+  }
+};
+
+static RegisterCommand r1(make_ref<CmdHash>(CmdHash::mFile));
+static RegisterCommand r2(make_ref<CmdHash>(CmdHash::mPath));
+
+struct CmdToBase final : Command {
+  Base base;
+  HashType ht = htUnknown;
+  std::vector<std::string> args;
+
+  explicit CmdToBase(Base base) : base(base) {
+    mkFlag().longName("type").mkHashTypeFlag(&ht);
+    expectArgs("strings", &args);
+  }
+
+  std::string name() override {
+    return base == Base16   ? "to-base16"
+           : base == Base32 ? "to-base32"
+           : base == Base64 ? "to-base64"
+                            : "to-sri";
+  }
+
+  std::string description() override {
+    return fmt("convert a hash to %s representation",
+               base == Base16   ? "base-16"
+               : base == Base32 ? "base-32"
+               : base == Base64 ? "base-64"
+                                : "SRI");
+  }
+
+  void run() override {
+    for (const auto& s : args) {
+      auto hash_ = Hash::deserialize(s, ht);
+      if (hash_.ok()) {
+        std::cout << hash_->to_string(base, base == SRI) << "\n";
+      } else {
+        std::cerr << "failed to parse: " << hash_.status().ToString() << "\n";
+        // create a matching blank line, for scripting
+        std::cout << "\n";
+      }
+    }
+  }
+};
+
+static RegisterCommand r3(make_ref<CmdToBase>(Base16));
+static RegisterCommand r4(make_ref<CmdToBase>(Base32));
+static RegisterCommand r5(make_ref<CmdToBase>(Base64));
+static RegisterCommand r6(make_ref<CmdToBase>(SRI));
+
+/* Legacy nix-hash command. */
+static int compatNixHash(int argc, char** argv) {
+  HashType ht = htMD5;
+  bool flat = false;
+  bool base32 = false;
+  bool truncate = false;
+  enum { opHash, opTo32, opTo16 } op = opHash;
+  std::vector<std::string> ss;
+
+  parseCmdLine(argc, argv,
+               [&](Strings::iterator& arg, const Strings::iterator& end) {
+                 if (*arg == "--help") {
+                   showManPage("nix-hash");
+                 } else if (*arg == "--version") {
+                   printVersion("nix-hash");
+                 } else if (*arg == "--flat") {
+                   flat = true;
+                 } else if (*arg == "--base32") {
+                   base32 = true;
+                 } else if (*arg == "--truncate") {
+                   truncate = true;
+                 } else if (*arg == "--type") {
+                   std::string s = getArg(*arg, arg, end);
+                   ht = parseHashType(s);
+                   if (ht == htUnknown) {
+                     throw UsageError(format("unknown hash type '%1%'") % s);
+                   }
+                 } else if (*arg == "--to-base16") {
+                   op = opTo16;
+                 } else if (*arg == "--to-base32") {
+                   op = opTo32;
+                 } else if (*arg != "" && arg->at(0) == '-') {
+                   return false;
+                 } else {
+                   ss.push_back(*arg);
+                 }
+                 return true;
+               });
+
+  if (op == opHash) {
+    CmdHash cmd(flat ? CmdHash::mFile : CmdHash::mPath);
+    cmd.ht = ht;
+    cmd.base = base32 ? Base32 : Base16;
+    cmd.truncate = truncate;
+    cmd.paths = ss;
+    cmd.run();
+  }
+
+  else {
+    CmdToBase cmd(op == opTo32 ? Base32 : Base16);
+    cmd.args = ss;
+    cmd.ht = ht;
+    cmd.run();
+  }
+
+  return 0;
+}
+
+static RegisterLegacyCommand s1("nix-hash", compatNixHash);
+}  // namespace nix