From bec3c3160881fcedf226080f13739aee81adae1a Mon Sep 17 00:00:00 2001 From: Eelco Dolstra Date: Thu, 1 Oct 2015 16:47:43 +0200 Subject: nix-prefetch-url: Rewrite in C++ --- src/nix-prefetch-url/local.mk | 7 ++ src/nix-prefetch-url/nix-prefetch-url.cc | 132 +++++++++++++++++++++++++++++++ 2 files changed, 139 insertions(+) create mode 100644 src/nix-prefetch-url/local.mk create mode 100644 src/nix-prefetch-url/nix-prefetch-url.cc (limited to 'src/nix-prefetch-url') diff --git a/src/nix-prefetch-url/local.mk b/src/nix-prefetch-url/local.mk new file mode 100644 index 000000000000..3e7735406af0 --- /dev/null +++ b/src/nix-prefetch-url/local.mk @@ -0,0 +1,7 @@ +programs += nix-prefetch-url + +nix-prefetch-url_DIR := $(d) + +nix-prefetch-url_SOURCES := $(d)/nix-prefetch-url.cc + +nix-prefetch-url_LIBS = libmain libexpr libstore libutil libformat diff --git a/src/nix-prefetch-url/nix-prefetch-url.cc b/src/nix-prefetch-url/nix-prefetch-url.cc new file mode 100644 index 000000000000..bd52df1c74a3 --- /dev/null +++ b/src/nix-prefetch-url/nix-prefetch-url.cc @@ -0,0 +1,132 @@ +#include "hash.hh" +#include "shared.hh" +#include "download.hh" +#include "store-api.hh" +#include "eval.hh" +#include "eval-inline.hh" +#include "common-opts.hh" + +#include + +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 ", "."), 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->value); + + if (mirrorList->value->listSize() < 1) + throw Error(format("mirror URI ‘%1%’ did not expand to anything") % uri); + + string mirror = state.forceString(*mirrorList->value->listElems()[0]); + return mirror + (hasSuffix(mirror, "/") ? "" : "/") + string(s, p + 1); +} + + +int main(int argc, char * * argv) +{ + return handleExceptions(argv[0], [&]() { + initNix(); + initGC(); + + HashType ht = htSHA256; + std::vector args; + Strings searchPath; + + parseCmdLine(argc, argv, [&](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 (parseSearchPathArg(arg, end, searchPath)) + ; + else if (*arg != "" && arg->at(0) == '-') + return false; + else + args.push_back(*arg); + return true; + }); + + if (args.size() < 1 || args.size() > 2) + throw UsageError("nix-prefetch-url expects one argument"); + + store = openStore(); + + EvalState state(searchPath); + + /* Figure out a name in the Nix store. */ + auto uri = args[0]; + auto 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, expectedHash(ht); + Path storePath; + if (args.size() == 2) { + expectedHash = parseHash16or32(ht, args[1]); + storePath = makeFixedOutputPath(false, ht, expectedHash, name); + if (store->isValidPath(storePath)) + hash = expectedHash; + else + storePath.clear(); + } + + if (storePath.empty()) { + + auto actualUri = resolveMirrorUri(state, uri); + + if (uri != actualUri) + printMsg(lvlInfo, format("‘%1%’ expands to ‘%2%’") % uri % actualUri); + + /* Download the file. */ + auto result = downloadFile(actualUri); + + /* 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. */ + AutoDelete tmpDir(createTempDir(), true); + Path tmpFile = (Path) tmpDir + "/tmp"; + writeFile(tmpFile, result.data); + + /* FIXME: inefficient; addToStore() will also hash + this. */ + hash = hashString(ht, result.data); + + if (expectedHash != Hash(ht) && expectedHash != hash) + throw Error(format("hash mismatch for ‘%1%’") % uri); + + storePath = store->addToStore(name, tmpFile, false, ht); + } + + printMsg(lvlInfo, format("path is ‘%1%’") % storePath); + + std::cout << printHash16or32(hash) << std::endl; + if (getEnv("PRINT_PATH") != "") + std::cout << storePath << std::endl; + }); +} -- cgit 1.4.1