lix/src/normalise.cc
Eelco Dolstra 49231fbe41 * Changes to the command line syntax of Nix.
* A function to find all Nix expressions whose output ids are
  completely contained in some set.  Useful for uploading relevant Nix
  expressions to a shared cache.
2003-07-21 14:46:01 +00:00

305 lines
8.2 KiB
C++

#include <map>
#include "normalise.hh"
#include "references.hh"
#include "db.hh"
#include "exec.hh"
#include "globals.hh"
void registerSuccessor(const FSId & id1, const FSId & id2)
{
setDB(nixDB, dbSuccessors, id1, id2);
}
static FSId storeSuccessor(const FSId & id1, ATerm sc)
{
FSId id2 = writeTerm(sc, "-s-" + (string) id1);
registerSuccessor(id1, id2);
return id2;
}
typedef set<FSId> FSIdSet;
Slice normaliseFState(FSId id)
{
debug(format("normalising fstate %1%") % (string) id);
Nest nest(true);
/* Try to substitute $id$ by any known successors in order to
speed up the rewrite process. */
string idSucc;
while (queryDB(nixDB, dbSuccessors, id, idSucc)) {
debug(format("successor %1% -> %2%") % (string) id % idSucc);
id = parseHash(idSucc);
}
/* Get the fstate expression. */
FState fs = parseFState(termFromId(id));
/* It this is a normal form (i.e., a slice) we are done. */
if (fs.type == FState::fsSlice) return fs.slice;
/* Otherwise, it's a derivation. */
/* Right platform? */
if (fs.derive.platform != thisSystem)
throw Error(format("a `%1%' is required, but I am a `%2%'")
% fs.derive.platform % thisSystem);
/* Realise inputs (and remember all input paths). */
typedef map<string, SliceElem> ElemMap;
ElemMap inMap;
for (FSIds::iterator i = fs.derive.inputs.begin();
i != fs.derive.inputs.end(); i++) {
Slice slice = normaliseFState(*i);
realiseSlice(slice);
for (SliceElems::iterator j = slice.elems.begin();
j != slice.elems.end(); j++)
inMap[j->path] = *j;
}
Strings inPaths;
for (ElemMap::iterator i = inMap.begin(); i != inMap.end(); i++)
inPaths.push_back(i->second.path);
/* Build the environment. */
Environment env;
for (StringPairs::iterator i = fs.derive.env.begin();
i != fs.derive.env.end(); i++)
env[i->first] = i->second;
/* Parse the outputs. */
typedef map<string, FSId> OutPaths;
OutPaths outPaths;
for (DeriveOutputs::iterator i = fs.derive.outputs.begin();
i != fs.derive.outputs.end(); i++)
{
debug(format("building %1% in %2%") % (string) i->second % i->first);
outPaths[i->first] = i->second;
inPaths.push_back(i->first);
}
/* We can skip running the builder if we can expand all output
paths from their ids. */
bool fastBuild = false;
#if 0
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
{
try {
expandId(i->second, i->first);
} catch (...) {
fastBuild = false;
break;
}
}
#endif
if (!fastBuild) {
/* Check that none of the outputs exist. */
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
if (pathExists(i->first))
throw Error(format("path `%1%' exists") % i->first);
/* Run the builder. */
debug(format("building..."));
runProgram(fs.derive.builder, env);
debug(format("build completed"));
} else
debug(format("skipping build"));
/* Check whether the output paths were created, and register each
one. */
FSIdSet used;
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
{
string path = i->first;
if (!pathExists(path))
throw Error(format("path `%1%' does not exist") % path);
registerPath(path, i->second);
fs.slice.roots.push_back(i->second);
Strings refs = filterReferences(path, inPaths);
SliceElem elem;
elem.path = path;
elem.id = i->second;
for (Strings::iterator j = refs.begin(); j != refs.end(); j++) {
ElemMap::iterator k;
OutPaths::iterator l;
if ((k = inMap.find(*j)) != inMap.end()) {
elem.refs.push_back(k->second.id);
used.insert(k->second.id);
for (FSIds::iterator m = k->second.refs.begin();
m != k->second.refs.end(); m++)
used.insert(*m);
} else if ((l = outPaths.find(*j)) != outPaths.end()) {
elem.refs.push_back(l->second);
used.insert(l->second);
} else
throw Error(format("unknown referenced path `%1%'") % *j);
}
fs.slice.elems.push_back(elem);
}
for (ElemMap::iterator i = inMap.begin();
i != inMap.end(); i++)
{
FSIdSet::iterator j = used.find(i->second.id);
if (j == used.end())
debug(format("NOT referenced: `%1%'") % i->second.path);
else {
debug(format("referenced: `%1%'") % i->second.path);
fs.slice.elems.push_back(i->second);
}
}
fs.type = FState::fsSlice;
ATerm nf = unparseFState(fs);
debug(format("normal form: %1%") % printTerm(nf));
storeSuccessor(id, nf);
return fs.slice;
}
void realiseSlice(const Slice & slice)
{
debug(format("realising slice"));
Nest nest(true);
/* Perhaps all paths already contain the right id? */
bool missing = false;
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
{
SliceElem elem = *i;
string id;
if (!queryDB(nixDB, dbPath2Id, elem.path, id)) {
if (pathExists(elem.path))
throw Error(format("path `%1%' obstructed") % elem.path);
missing = true;
break;
}
if (parseHash(id) != elem.id)
throw Error(format("path `%1%' obstructed") % elem.path);
}
if (!missing) {
debug(format("already installed"));
return;
}
/* For each element, expand its id at its path. */
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
{
SliceElem elem = *i;
debug(format("expanding %1% in %2%") % (string) elem.id % elem.path);
expandId(elem.id, elem.path);
}
}
Strings fstatePaths(const FSId & id, bool normalise)
{
Strings paths;
FState fs;
if (normalise) {
fs.slice = normaliseFState(id);
fs.type = FState::fsSlice;
} else
fs = parseFState(termFromId(id));
if (fs.type == FState::fsSlice) {
/* !!! fix complexity */
for (FSIds::const_iterator i = fs.slice.roots.begin();
i != fs.slice.roots.end(); i++)
for (SliceElems::const_iterator j = fs.slice.elems.begin();
j != fs.slice.elems.end(); j++)
if (*i == j->id) paths.push_back(j->path);
}
else if (fs.type == FState::fsDerive) {
for (DeriveOutputs::iterator i = fs.derive.outputs.begin();
i != fs.derive.outputs.end(); i++)
paths.push_back(i->first);
}
else abort();
return paths;
}
Strings fstateRefs(const FSId & id)
{
Strings paths;
Slice slice = normaliseFState(id);
for (SliceElems::const_iterator i = slice.elems.begin();
i != slice.elems.end(); i++)
paths.push_back(i->path);
return paths;
}
FSIds findGenerators(const FSIds & _ids)
{
FSIdSet ids(_ids.begin(), _ids.end());
FSIds generators;
/* !!! hack; for performance, we just look at the rhs of successor
mappings, since we know that those are Nix expressions. */
Strings sucs;
enumDB(nixDB, dbSuccessors, sucs);
for (Strings::iterator i = sucs.begin();
i != sucs.end(); i++)
{
string s;
queryDB(nixDB, dbSuccessors, *i, s);
FSId id = parseHash(s);
FState fs;
try {
/* !!! should substitutes be used? */
fs = parseFState(termFromId(id));
} catch (...) { /* !!! only catch parse errors */
continue;
}
if (fs.type != FState::fsSlice) continue;
bool okay = true;
for (SliceElems::const_iterator i = fs.slice.elems.begin();
i != fs.slice.elems.end(); i++)
if (ids.find(i->id) == ids.end()) {
okay = false;
break;
}
if (!okay) continue;
generators.push_back(id);
}
return generators;
}