tvl-depot/src/nix-env/user-env.cc
Eelco Dolstra b83801f8b3 Optimize small lists
The value pointers of lists with 1 or 2 elements are now stored in the
list value itself. In particular, this makes the "concatMap (x: if
cond then [(f x)] else [])" idiom cheaper.
2015-07-23 22:05:09 +02:00

151 lines
5.2 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 "user-env.hh"
#include "util.hh"
#include "derivations.hh"
#include "store-api.hh"
#include "globals.hh"
#include "shared.hh"
#include "eval.hh"
#include "eval-inline.hh"
#include "profiles.hh"
namespace nix {
DrvInfos queryInstalled(EvalState & state, const Path & userEnv)
{
DrvInfos elems;
Path manifestFile = userEnv + "/manifest.nix";
if (pathExists(manifestFile)) {
Value v;
state.evalFile(manifestFile, v);
Bindings & bindings(*state.allocBindings(0));
getDerivations(state, v, "", bindings, elems, false);
}
return elems;
}
bool createUserEnv(EvalState & state, DrvInfos & elems,
const Path & profile, bool keepDerivations,
const string & lockToken)
{
/* Build the components in the user environment, if they don't
exist already. */
PathSet drvsToBuild;
for (auto & i : elems)
if (i.queryDrvPath() != "")
drvsToBuild.insert(i.queryDrvPath());
debug(format("building user environment dependencies"));
store->buildPaths(drvsToBuild, state.repair ? bmRepair : bmNormal);
/* Construct the whole top level derivation. */
PathSet references;
Value manifest;
state.mkList(manifest, elems.size());
unsigned int n = 0;
for (auto & i : elems) {
/* Create a pseudo-derivation containing the name, system,
output paths, and optionally the derivation path, as well
as the meta attributes. */
Path drvPath = keepDerivations ? i.queryDrvPath() : "";
Value & v(*state.allocValue());
manifest.listElems()[n++] = &v;
state.mkAttrs(v, 16);
mkString(*state.allocAttr(v, state.sType), "derivation");
mkString(*state.allocAttr(v, state.sName), i.name);
if (!i.system.empty())
mkString(*state.allocAttr(v, state.sSystem), i.system);
mkString(*state.allocAttr(v, state.sOutPath), i.queryOutPath());
if (drvPath != "")
mkString(*state.allocAttr(v, state.sDrvPath), i.queryDrvPath());
// Copy each output.
DrvInfo::Outputs outputs = i.queryOutputs();
Value & vOutputs = *state.allocAttr(v, state.sOutputs);
state.mkList(vOutputs, outputs.size());
unsigned int m = 0;
for (auto & j : outputs) {
mkString(*(vOutputs.listElems()[m++] = state.allocValue()), j.first);
Value & vOutputs = *state.allocAttr(v, state.symbols.create(j.first));
state.mkAttrs(vOutputs, 2);
mkString(*state.allocAttr(vOutputs, state.sOutPath), j.second);
/* This is only necessary when installing store paths, e.g.,
`nix-env -i /nix/store/abcd...-foo'. */
store->addTempRoot(j.second);
store->ensurePath(j.second);
references.insert(j.second);
}
// Copy the meta attributes.
Value & vMeta = *state.allocAttr(v, state.sMeta);
state.mkAttrs(vMeta, 16);
StringSet metaNames = i.queryMetaNames();
for (auto & j : metaNames) {
Value * v = i.queryMeta(j);
if (!v) continue;
vMeta.attrs->push_back(Attr(state.symbols.create(j), v));
}
vMeta.attrs->sort();
v.attrs->sort();
if (drvPath != "") references.insert(drvPath);
}
/* Also write a copy of the list of user environment elements to
the store; we need it for future modifications of the
environment. */
Path manifestFile = store->addTextToStore("env-manifest.nix",
(format("%1%") % manifest).str(), references);
/* Get the environment builder expression. */
Value envBuilder;
state.evalFile(state.findFile("nix/buildenv.nix"), envBuilder);
/* Construct a Nix expression that calls the user environment
builder with the manifest as argument. */
Value args, topLevel;
state.mkAttrs(args, 3);
mkString(*state.allocAttr(args, state.symbols.create("manifest")),
manifestFile, singleton<PathSet>(manifestFile));
args.attrs->push_back(Attr(state.symbols.create("derivations"), &manifest));
args.attrs->sort();
mkApp(topLevel, envBuilder, args);
/* Evaluate it. */
debug("evaluating user environment builder");
state.forceValue(topLevel);
PathSet context;
Attr & aDrvPath(*topLevel.attrs->find(state.sDrvPath));
Path topLevelDrv = state.coerceToPath(aDrvPath.pos ? *(aDrvPath.pos) : noPos, *(aDrvPath.value), context);
Attr & aOutPath(*topLevel.attrs->find(state.sOutPath));
Path topLevelOut = state.coerceToPath(aOutPath.pos ? *(aOutPath.pos) : noPos, *(aOutPath.value), context);
/* Realise the resulting store expression. */
debug("building user environment");
store->buildPaths(singleton<PathSet>(topLevelDrv), state.repair ? bmRepair : bmNormal);
/* Switch the current user environment to the output path. */
PathLocks lock;
lockProfile(lock, profile);
Path lockTokenCur = optimisticLockProfile(profile);
if (lockToken != lockTokenCur) {
printMsg(lvlError, format("profile %1% changed while we were busy; restarting") % profile);
return false;
}
debug(format("switching to new user environment"));
Path generation = createGeneration(profile, topLevelOut);
switchLink(profile, generation);
return true;
}
}