From 36457566f9917dc7c0c348d012816a2ca333ef1b Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Wed, 17 Dec 2014 23:00:42 +0100 Subject: Merge branch 'nix' into 'master'. --- nix/libstore/derivations.cc | 278 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 278 insertions(+) create mode 100644 nix/libstore/derivations.cc (limited to 'nix/libstore/derivations.cc') diff --git a/nix/libstore/derivations.cc b/nix/libstore/derivations.cc new file mode 100644 index 0000000000..d91e42784c --- /dev/null +++ b/nix/libstore/derivations.cc @@ -0,0 +1,278 @@ +#include "derivations.hh" +#include "store-api.hh" +#include "globals.hh" +#include "util.hh" +#include "misc.hh" + + +namespace nix { + + +void DerivationOutput::parseHashInfo(bool & recursive, HashType & hashType, Hash & hash) const +{ + recursive = false; + string algo = hashAlgo; + + if (string(algo, 0, 2) == "r:") { + recursive = true; + algo = string(algo, 2); + } + + hashType = parseHashType(algo); + if (hashType == htUnknown) + throw Error(format("unknown hash algorithm `%1%'") % algo); + + hash = parseHash(hashType, this->hash); +} + + +Path writeDerivation(StoreAPI & store, + const Derivation & drv, const string & name, bool repair) +{ + PathSet references; + references.insert(drv.inputSrcs.begin(), drv.inputSrcs.end()); + foreach (DerivationInputs::const_iterator, i, drv.inputDrvs) + references.insert(i->first); + /* Note that the outputs of a derivation are *not* references + (that can be missing (of course) and should not necessarily be + held during a garbage collection). */ + string suffix = name + drvExtension; + string contents = unparseDerivation(drv); + return settings.readOnlyMode + ? computeStorePathForText(suffix, contents, references) + : store.addTextToStore(suffix, contents, references, repair); +} + + +static Path parsePath(std::istream & str) +{ + string s = parseString(str); + if (s.size() == 0 || s[0] != '/') + throw Error(format("bad path `%1%' in derivation") % s); + return s; +} + + +static StringSet parseStrings(std::istream & str, bool arePaths) +{ + StringSet res; + while (!endOfList(str)) + res.insert(arePaths ? parsePath(str) : parseString(str)); + return res; +} + + +Derivation parseDerivation(const string & s) +{ + Derivation drv; + std::istringstream str(s); + expect(str, "Derive(["); + + /* Parse the list of outputs. */ + while (!endOfList(str)) { + DerivationOutput out; + expect(str, "("); string id = parseString(str); + expect(str, ","); out.path = parsePath(str); + expect(str, ","); out.hashAlgo = parseString(str); + expect(str, ","); out.hash = parseString(str); + expect(str, ")"); + drv.outputs[id] = out; + } + + /* Parse the list of input derivations. */ + expect(str, ",["); + while (!endOfList(str)) { + expect(str, "("); + Path drvPath = parsePath(str); + expect(str, ",["); + drv.inputDrvs[drvPath] = parseStrings(str, false); + expect(str, ")"); + } + + expect(str, ",["); drv.inputSrcs = parseStrings(str, true); + expect(str, ","); drv.platform = parseString(str); + expect(str, ","); drv.builder = parseString(str); + + /* Parse the builder arguments. */ + expect(str, ",["); + while (!endOfList(str)) + drv.args.push_back(parseString(str)); + + /* Parse the environment variables. */ + expect(str, ",["); + while (!endOfList(str)) { + expect(str, "("); string name = parseString(str); + expect(str, ","); string value = parseString(str); + expect(str, ")"); + drv.env[name] = value; + } + + expect(str, ")"); + return drv; +} + + +static void printString(string & res, const string & s) +{ + res += '"'; + for (const char * i = s.c_str(); *i; i++) + if (*i == '\"' || *i == '\\') { res += "\\"; res += *i; } + else if (*i == '\n') res += "\\n"; + else if (*i == '\r') res += "\\r"; + else if (*i == '\t') res += "\\t"; + else res += *i; + res += '"'; +} + + +template +static void printStrings(string & res, ForwardIterator i, ForwardIterator j) +{ + res += '['; + bool first = true; + for ( ; i != j; ++i) { + if (first) first = false; else res += ','; + printString(res, *i); + } + res += ']'; +} + + +string unparseDerivation(const Derivation & drv) +{ + string s; + s.reserve(65536); + s += "Derive(["; + + bool first = true; + foreach (DerivationOutputs::const_iterator, i, drv.outputs) { + if (first) first = false; else s += ','; + s += '('; printString(s, i->first); + s += ','; printString(s, i->second.path); + s += ','; printString(s, i->second.hashAlgo); + s += ','; printString(s, i->second.hash); + s += ')'; + } + + s += "],["; + first = true; + foreach (DerivationInputs::const_iterator, i, drv.inputDrvs) { + if (first) first = false; else s += ','; + s += '('; printString(s, i->first); + s += ','; printStrings(s, i->second.begin(), i->second.end()); + s += ')'; + } + + s += "],"; + printStrings(s, drv.inputSrcs.begin(), drv.inputSrcs.end()); + + s += ','; printString(s, drv.platform); + s += ','; printString(s, drv.builder); + s += ','; printStrings(s, drv.args.begin(), drv.args.end()); + + s += ",["; + first = true; + foreach (StringPairs::const_iterator, i, drv.env) { + if (first) first = false; else s += ','; + s += '('; printString(s, i->first); + s += ','; printString(s, i->second); + s += ')'; + } + + s += "])"; + + return s; +} + + +bool isDerivation(const string & fileName) +{ + return hasSuffix(fileName, drvExtension); +} + + +bool isFixedOutputDrv(const Derivation & drv) +{ + return drv.outputs.size() == 1 && + drv.outputs.begin()->first == "out" && + drv.outputs.begin()->second.hash != ""; +} + + +DrvHashes drvHashes; + + +/* Returns the hash of a derivation modulo fixed-output + subderivations. A fixed-output derivation is a derivation with one + output (`out') for which an expected hash and hash algorithm are + specified (using the `outputHash' and `outputHashAlgo' + attributes). We don't want changes to such derivations to + propagate upwards through the dependency graph, changing output + paths everywhere. + + For instance, if we change the url in a call to the `fetchurl' + function, we do not want to rebuild everything depending on it + (after all, (the hash of) the file being downloaded is unchanged). + So the *output paths* should not change. On the other hand, the + *derivation paths* should change to reflect the new dependency + graph. + + That's what this function does: it returns a hash which is just the + hash of the derivation ATerm, except that any input derivation + paths have been replaced by the result of a recursive call to this + function, and that for fixed-output derivations we return a hash of + its output path. */ +Hash hashDerivationModulo(StoreAPI & store, Derivation drv) +{ + /* Return a fixed hash for fixed-output derivations. */ + if (isFixedOutputDrv(drv)) { + DerivationOutputs::const_iterator i = drv.outputs.begin(); + return hashString(htSHA256, "fixed:out:" + + i->second.hashAlgo + ":" + + i->second.hash + ":" + + i->second.path); + } + + /* For other derivations, replace the inputs paths with recursive + calls to this function.*/ + DerivationInputs inputs2; + foreach (DerivationInputs::const_iterator, i, drv.inputDrvs) { + Hash h = drvHashes[i->first]; + if (h.type == htUnknown) { + assert(store.isValidPath(i->first)); + Derivation drv2 = parseDerivation(readFile(i->first)); + h = hashDerivationModulo(store, drv2); + drvHashes[i->first] = h; + } + inputs2[printHash(h)] = i->second; + } + drv.inputDrvs = inputs2; + + return hashString(htSHA256, unparseDerivation(drv)); +} + + +DrvPathWithOutputs parseDrvPathWithOutputs(const string & s) +{ + size_t n = s.find("!"); + return n == s.npos + ? DrvPathWithOutputs(s, std::set()) + : DrvPathWithOutputs(string(s, 0, n), tokenizeString >(string(s, n + 1), ",")); +} + + +Path makeDrvPathWithOutputs(const Path & drvPath, const std::set & outputs) +{ + return outputs.empty() + ? drvPath + : drvPath + "!" + concatStringsSep(",", outputs); +} + + +bool wantOutput(const string & output, const std::set & wanted) +{ + return wanted.empty() || wanted.find(output) != wanted.end(); +} + + +} -- cgit 1.4.1