#include "derivations.hh"
#include "fs-accessor.hh"
#include "globals.hh"
#include "istringstream_nocopy.hh"
#include "store-api.hh"
#include "util.hh"
#include "worker-protocol.hh"
namespace nix {
void DerivationOutput::parseHashInfo(bool& recursive, Hash& hash) const {
recursive = false;
string algo = hashAlgo;
if (string(algo, 0, 2) == "r:") {
recursive = true;
algo = string(algo, 2);
}
HashType hashType = parseHashType(algo);
if (hashType == htUnknown)
throw Error(format("unknown hash algorithm '%1%'") % algo);
hash = Hash(this->hash, hashType);
}
Path BasicDerivation::findOutput(const string& id) const {
auto i = outputs.find(id);
if (i == outputs.end())
throw Error(format("derivation has no output '%1%'") % id);
return i->second.path;
}
bool BasicDerivation::isBuiltin() const {
return string(builder, 0, 8) == "builtin:";
}
Path writeDerivation(ref<Store> store, const Derivation& drv,
const string& name, RepairFlag repair) {
PathSet references;
references.insert(drv.inputSrcs.begin(), drv.inputSrcs.end());
for (auto& 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 = drv.unparse();
return settings.readOnlyMode
? store->computeStorePathForText(suffix, contents, references)
: store->addTextToStore(suffix, contents, references, repair);
}
/* Read string `s' from stream `str'. */
static void expect(std::istream& str, const string& s) {
char s2[s.size()];
str.read(s2, s.size());
if (string(s2, s.size()) != s)
throw FormatError(format("expected string '%1%'") % s);
}
/* Read a C-style string from stream `str'. */
static string parseString(std::istream& str) {
string res;
expect(str, "\"");
int c;
while ((c = str.get()) != '"')
if (c == '\\') {
c = str.get();
if (c == 'n')
res += '\n';
else if (c == 'r')
res += '\r';
else if (c == 't')
res += '\t';
else
res += c;
} else
res += c;
return res;
}
static Path parsePath(std::istream& str) {
string s = parseString(str);
if (s.size() == 0 || s[0] != '/')
throw FormatError(format("bad path '%1%' in derivation") % s);
return s;
}
static bool endOfList(std::istream& str) {
if (str.peek() == ',') {
str.get();
return false;
}
if (str.peek() == ']') {
str.get();
return true;
}
return false;
}
static StringSet parseStrings(std::istream& str, bool arePaths) {
StringSet res;
while (!endOfList(str))
res.insert(arePaths ? parsePath(str) : parseString(str));
return res;
}
static Derivation parseDerivation(const string& s) {
Derivation drv;
istringstream_nocopy 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;
}
Derivation readDerivation(const Path& drvPath) {
try {
return parseDerivation(readFile(drvPath));
} catch (FormatError& e) {
throw Error(format("error parsing derivation '%1%': %2%") % drvPath %
e.msg());
}
}
Derivation Store::derivationFromPath(const Path& drvPath) {
assertStorePath(drvPath);
ensurePath(drvPath);
auto accessor = getFSAccessor();
try {
return parseDerivation(accessor->readFile(drvPath));
} catch (FormatError& e) {
throw Error(format("error parsing derivation '%1%': %2%") % drvPath %
e.msg());
}
}
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 <class ForwardIterator>
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 Derivation::unparse() const {
string s;
s.reserve(65536);
s += "Derive([";
bool first = true;
for (auto& i : 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;
for (auto& i : 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, inputSrcs.begin(), inputSrcs.end());
s += ',';
printString(s, platform);
s += ',';
printString(s, builder);
s += ',';
printStrings(s, args.begin(), args.end());
s += ",[";
first = true;
for (auto& i : 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 BasicDerivation::isFixedOutput() const {
return outputs.size() == 1 && outputs.begin()->first == "out" &&
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(Store& store, Derivation drv) {
/* Return a fixed hash for fixed-output derivations. */
if (drv.isFixedOutput()) {
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;
for (auto& i : drv.inputDrvs) {
Hash h = drvHashes[i.first];
if (!h) {
assert(store.isValidPath(i.first));
Derivation drv2 = readDerivation(store.toRealPath(i.first));
h = hashDerivationModulo(store, drv2);
drvHashes[i.first] = h;
}
inputs2[h.to_string(Base16, false)] = i.second;
}
drv.inputDrvs = inputs2;
return hashString(htSHA256, drv.unparse());
}
DrvPathWithOutputs parseDrvPathWithOutputs(const string& s) {
size_t n = s.find("!");
return n == s.npos ? DrvPathWithOutputs(s, std::set<string>())
: DrvPathWithOutputs(string(s, 0, n),
tokenizeString<std::set<string> >(
string(s, n + 1), ","));
}
Path makeDrvPathWithOutputs(const Path& drvPath,
const std::set<string>& outputs) {
return outputs.empty() ? drvPath
: drvPath + "!" + concatStringsSep(",", outputs);
}
bool wantOutput(const string& output, const std::set<string>& wanted) {
return wanted.empty() || wanted.find(output) != wanted.end();
}
PathSet BasicDerivation::outputPaths() const {
PathSet paths;
for (auto& i : outputs) paths.insert(i.second.path);
return paths;
}
Source& readDerivation(Source& in, Store& store, BasicDerivation& drv) {
drv.outputs.clear();
auto nr = readNum<size_t>(in);
for (size_t n = 0; n < nr; n++) {
auto name = readString(in);
DerivationOutput o;
in >> o.path >> o.hashAlgo >> o.hash;
store.assertStorePath(o.path);
drv.outputs[name] = o;
}
drv.inputSrcs = readStorePaths<PathSet>(store, in);
in >> drv.platform >> drv.builder;
drv.args = readStrings<Strings>(in);
nr = readNum<size_t>(in);
for (size_t n = 0; n < nr; n++) {
auto key = readString(in);
auto value = readString(in);
drv.env[key] = value;
}
return in;
}
Sink& operator<<(Sink& out, const BasicDerivation& drv) {
out << drv.outputs.size();
for (auto& i : drv.outputs)
out << i.first << i.second.path << i.second.hashAlgo << i.second.hash;
out << drv.inputSrcs << drv.platform << drv.builder << drv.args;
out << drv.env.size();
for (auto& i : drv.env) out << i.first << i.second;
return out;
}
std::string hashPlaceholder(const std::string& outputName) {
// FIXME: memoize?
return "/" + hashString(htSHA256, "nix-output:" + outputName)
.to_string(Base32, false);
}
} // namespace nix
