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-rw-r--r--third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc252
1 files changed, 252 insertions, 0 deletions
diff --git a/third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc b/third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc
new file mode 100644
index 000000000000..fa88dc9bc67e
--- /dev/null
+++ b/third_party/nix/src/nix-prefetch-url/nix-prefetch-url.cc
@@ -0,0 +1,252 @@
+#include <iostream>
+
+#include <fcntl.h>
+#include <glog/logging.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "attr-path.hh"
+#include "common-eval-args.hh"
+#include "download.hh"
+#include "eval-inline.hh"
+#include "eval.hh"
+#include "finally.hh"
+#include "hash.hh"
+#include "legacy.hh"
+#include "shared.hh"
+#include "store-api.hh"
+
+using namespace nix;
+
+/* If ‘uri’ starts with ‘mirror://’, then resolve it using the list of
+   mirrors defined in Nixpkgs. */
+string resolveMirrorUri(EvalState& state, string uri) {
+  if (string(uri, 0, 9) != "mirror://") {
+    return uri;
+  }
+
+  string s(uri, 9);
+  auto p = s.find('/');
+  if (p == string::npos) {
+    throw Error("invalid mirror URI");
+  }
+  string mirrorName(s, 0, p);
+
+  Value vMirrors;
+  state.eval(
+      state.parseExprFromString(
+          "import <nixpkgs/pkgs/build-support/fetchurl/mirrors.nix>", "."),
+      vMirrors);
+  state.forceAttrs(vMirrors);
+
+  auto mirrorList = vMirrors.attrs->find(state.symbols.Create(mirrorName));
+  if (mirrorList == vMirrors.attrs->end()) {
+    throw Error(format("unknown mirror name '%1%'") % mirrorName);
+  }
+  state.forceList(*mirrorList->second.value);
+
+  if (mirrorList->second.value->listSize() < 1) {
+    throw Error(format("mirror URI '%1%' did not expand to anything") % uri);
+  }
+
+  string mirror = state.forceString(*mirrorList->second.value->listElems()[0]);
+  return mirror + (hasSuffix(mirror, "/") ? "" : "/") + string(s, p + 1);
+}
+
+static int _main(int argc, char** argv) {
+  {
+    HashType ht = htSHA256;
+    std::vector<string> args;
+    bool printPath = !getEnv("PRINT_PATH").empty();
+    bool fromExpr = false;
+    string attrPath;
+    bool unpack = false;
+    string name;
+
+    struct MyArgs : LegacyArgs, MixEvalArgs {
+      using LegacyArgs::LegacyArgs;
+    };
+
+    MyArgs myArgs(baseNameOf(argv[0]),
+                  [&](Strings::iterator& arg, const Strings::iterator& end) {
+                    if (*arg == "--help") {
+                      showManPage("nix-prefetch-url");
+                    } else if (*arg == "--version") {
+                      printVersion("nix-prefetch-url");
+                    } else if (*arg == "--type") {
+                      string s = getArg(*arg, arg, end);
+                      ht = parseHashType(s);
+                      if (ht == htUnknown) {
+                        throw UsageError(format("unknown hash type '%1%'") % s);
+                      }
+                    } else if (*arg == "--print-path") {
+                      printPath = true;
+                    } else if (*arg == "--attr" || *arg == "-A") {
+                      fromExpr = true;
+                      attrPath = getArg(*arg, arg, end);
+                    } else if (*arg == "--unpack") {
+                      unpack = true;
+                    } else if (*arg == "--name") {
+                      name = getArg(*arg, arg, end);
+                    } else if (*arg != "" && arg->at(0) == '-') {
+                      return false;
+                    } else {
+                      args.push_back(*arg);
+                    }
+                    return true;
+                  });
+
+    myArgs.parseCmdline(argvToStrings(argc, argv));
+
+    initPlugins();
+
+    if (args.size() > 2) {
+      throw UsageError("too many arguments");
+    }
+
+    auto store = openStore();
+    auto state = std::make_unique<EvalState>(myArgs.searchPath, store);
+
+    Bindings& autoArgs = *myArgs.getAutoArgs(*state);
+
+    /* If -A is given, get the URI from the specified Nix
+       expression. */
+    string uri;
+    if (!fromExpr) {
+      if (args.empty()) {
+        throw UsageError("you must specify a URI");
+      }
+      uri = args[0];
+    } else {
+      Path path =
+          resolveExprPath(lookupFileArg(*state, args.empty() ? "." : args[0]));
+      Value vRoot;
+      state->evalFile(path, vRoot);
+      Value& v(*findAlongAttrPath(*state, attrPath, autoArgs, vRoot));
+      state->forceAttrs(v);
+
+      /* Extract the URI. */
+      auto attr = v.attrs->find(state->symbols.Create("urls"));
+      if (attr == v.attrs->end()) {
+        throw Error("attribute set does not contain a 'urls' attribute");
+      }
+      state->forceList(*attr->second.value);
+      if (attr->second.value->listSize() < 1) {
+        throw Error("'urls' list is empty");
+      }
+      uri = state->forceString(*attr->second.value->listElems()[0]);
+
+      /* Extract the hash mode. */
+      attr = v.attrs->find(state->symbols.Create("outputHashMode"));
+      if (attr == v.attrs->end()) {
+        LOG(WARNING) << "this does not look like a fetchurl call";
+      } else {
+        unpack = state->forceString(*attr->second.value) == "recursive";
+      }
+
+      /* Extract the name. */
+      if (name.empty()) {
+        attr = v.attrs->find(state->symbols.Create("name"));
+        if (attr != v.attrs->end()) {
+          name = state->forceString(*attr->second.value);
+        }
+      }
+    }
+
+    /* Figure out a name in the Nix store. */
+    if (name.empty()) {
+      name = baseNameOf(uri);
+    }
+    if (name.empty()) {
+      throw Error(format("cannot figure out file name for '%1%'") % uri);
+    }
+
+    /* If an expected hash is given, the file may already exist in
+       the store. */
+    Hash hash;
+    Hash expectedHash(ht);
+    Path storePath;
+    if (args.size() == 2) {
+      expectedHash = Hash(args[1], ht);
+      storePath = store->makeFixedOutputPath(unpack, expectedHash, name);
+      if (store->isValidPath(storePath)) {
+        hash = expectedHash;
+      } else {
+        storePath.clear();
+      }
+    }
+
+    if (storePath.empty()) {
+      auto actualUri = resolveMirrorUri(*state, uri);
+
+      AutoDelete tmpDir(createTempDir(), true);
+      Path tmpFile = (Path)tmpDir + "/tmp";
+
+      /* Download the file. */
+      {
+        AutoCloseFD fd =
+            open(tmpFile.c_str(), O_WRONLY | O_CREAT | O_EXCL, 0600);
+        if (!fd) {
+          throw SysError("creating temporary file '%s'", tmpFile);
+        }
+
+        FdSink sink(fd.get());
+
+        DownloadRequest req(actualUri);
+        req.decompress = false;
+        getDownloader()->download(std::move(req), sink);
+      }
+
+      /* Optionally unpack the file. */
+      if (unpack) {
+        LOG(INFO) << "unpacking...";
+        Path unpacked = (Path)tmpDir + "/unpacked";
+        createDirs(unpacked);
+        if (hasSuffix(baseNameOf(uri), ".zip")) {
+          runProgram("unzip", true, {"-qq", tmpFile, "-d", unpacked});
+        } else {
+          // FIXME: this requires GNU tar for decompression.
+          runProgram("tar", true, {"xf", tmpFile, "-C", unpacked});
+        }
+
+        /* If the archive unpacks to a single file/directory, then use
+           that as the top-level. */
+        auto entries = readDirectory(unpacked);
+        if (entries.size() == 1) {
+          tmpFile = unpacked + "/" + entries[0].name;
+        } else {
+          tmpFile = unpacked;
+        }
+      }
+
+      /* FIXME: inefficient; addToStore() will also hash
+         this. */
+      hash = unpack ? hashPath(ht, tmpFile).first : hashFile(ht, tmpFile);
+
+      if (expectedHash != Hash(ht) && expectedHash != hash) {
+        throw Error(format("hash mismatch for '%1%'") % uri);
+      }
+
+      /* Copy the file to the Nix store. FIXME: if RemoteStore
+         implemented addToStoreFromDump() and downloadFile()
+         supported a sink, we could stream the download directly
+         into the Nix store. */
+      storePath = store->addToStore(name, tmpFile, unpack, ht);
+
+      assert(storePath == store->makeFixedOutputPath(unpack, hash, name));
+    }
+
+    if (!printPath) {
+      LOG(INFO) << "path is '" << storePath << "'";
+    }
+
+    std::cout << printHash16or32(hash) << std::endl;
+    if (printPath) {
+      std::cout << storePath << std::endl;
+    }
+
+    return 0;
+  }
+}
+
+static RegisterLegacyCommand s1("nix-prefetch-url", _main);