lix/src/libstore/derivations.cc
Eelco Dolstra e6a61b8da7
Fix S3BinaryCacheStore
It failed with

   AWS error uploading ‘6gaxphsyhg66mz0a00qghf9nqf7majs2.ls.xz’: Unable to parse ExceptionName: MissingContentLength Message: You must provide the Content-Length HTTP header.

possibly because the istringstream_nocopy introduced in
0d2ebb4373 doesn't supply the seek
method that the AWS library expects. So bring back the old version,
but only for S3BinaryCacheStore.
2016-12-08 15:31:27 +01:00

445 lines
12 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#include "derivations.hh"
#include "store-api.hh"
#include "globals.hh"
#include "util.hh"
#include "worker-protocol.hh"
#include "fs-accessor.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 = parseHash(hashType, this->hash);
}
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::willBuildLocally() const
{
return get(env, "preferLocalBuild") == "1" && canBuildLocally();
}
bool BasicDerivation::substitutesAllowed() const
{
return get(env, "allowSubstitutes", "1") == "1";
}
bool BasicDerivation::isBuiltin() const
{
return string(builder, 0, 8) == "builtin:";
}
bool BasicDerivation::canBuildLocally() const
{
return platform == settings.thisSystem
|| isBuiltin()
#if __linux__
|| (platform == "i686-linux" && settings.thisSystem == "x86_64-linux")
|| (platform == "armv6l-linux" && settings.thisSystem == "armv7l-linux")
|| (platform == "armv5tel-linux" && (settings.thisSystem == "armv7l-linux" || settings.thisSystem == "armv6l-linux"))
#elif __FreeBSD__
|| (platform == "i686-linux" && settings.thisSystem == "x86_64-freebsd")
|| (platform == "i686-linux" && settings.thisSystem == "i686-freebsd")
#endif
;
}
Path writeDerivation(ref<Store> store,
const Derivation & drv, const string & name, bool 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;
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;
}
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(i.first);
h = hashDerivationModulo(store, drv2);
drvHashes[i.first] = h;
}
inputs2[printHash(h)] = 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 = readInt(in);
for (unsigned int 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 = readInt(in);
for (unsigned int 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 "/" + printHash32(hashString(htSHA256, "nix-output:" + outputName));
}
}