* Allow the output/expression id to be forced to a certain

value; this potentially dangerous feature enables better 
  sharing for those paths for which the content is known in 
  advance (e.g., because a content hash is given).
* Fast builds: if we can expand all output paths of a derive 
  expression, we don't have to build.
This commit is contained in:
Eelco Dolstra 2003-07-21 20:07:12 +00:00
parent 49231fbe41
commit 249988a787
6 changed files with 23 additions and 17 deletions

View file

@ -4,6 +4,7 @@ Function(["url", "md5"],
, ("url", Var("url"))
, ("md5", Var("md5"))
, ("name", BaseName(Var("url")))
, ("id", Var("md5"))
]
)
)

View file

@ -4,9 +4,7 @@ echo "downloading $url into $out..."
wget "$url" -O "$out" || exit 1
actual=$(md5sum -b $out | cut -c1-32)
if ! test "$md5" == "ignore"; then
if ! test "$actual" == "$md5"; then
if ! test "$actual" == "$md5"; then
echo "hash is $actual, expected $md5"
exit 1
fi
fi

View file

@ -153,8 +153,10 @@ static Expr evalExpr2(EvalState & state, Expr e)
fs.slice.roots.push_back(id);
fs.slice.elems.push_back(elem);
return ATmake("FSId(<str>)",
((string) writeTerm(unparseFState(fs), "")).c_str());
FSId termId = hashString("producer-" + (string) id
+ "-" + dstPath);
writeTerm(unparseFState(fs), "", termId);
return ATmake("FSId(<str>)", ((string) termId).c_str());
}
/* Packages are transformed into Derive fstate expressions. */
@ -176,6 +178,7 @@ static Expr evalExpr2(EvalState & state, Expr e)
fs.type = FState::fsDerive;
fs.derive.platform = SYSTEM;
string name;
FSId outId;
bnds = ATempty;
for (map<string, ATerm>::iterator it = bndMap.begin();
@ -195,6 +198,7 @@ static Expr evalExpr2(EvalState & state, Expr e)
}
else if (ATmatch(value, "<str>", &s1)) {
if (key == "name") name = s1;
if (key == "id") outId = parseHash(s1);
fs.derive.env.push_back(StringPair(key, s1));
}
else throw badTerm("invalid package argument", value);
@ -211,7 +215,8 @@ static Expr evalExpr2(EvalState & state, Expr e)
/* Hash the fstate-expression with no outputs to produce a
unique but deterministic path name for this package. */
Hash outId = hashTerm(unparseFState(fs));
if (outId == FSId())
outId = hashTerm(unparseFState(fs));
string outPath =
canonPath(nixStore + "/" + ((string) outId).c_str() + "-" + name);
fs.derive.env.push_back(StringPair("out", outPath));
@ -219,8 +224,10 @@ static Expr evalExpr2(EvalState & state, Expr e)
debug(format("%1%: %2%") % (string) outId % name);
/* Write the resulting term into the Nix store directory. */
return ATmake("FSId(<str>)",
((string) writeTerm(unparseFState(fs), "-d-" + name)).c_str());
FSId termId = hashString("producer-" + (string) outId
+ "-" + outPath);
writeTerm(unparseFState(fs), "-d-" + name, termId);
return ATmake("FSId(<str>)", ((string) termId).c_str());
}
/* BaseName primitive function. */

View file

@ -31,9 +31,10 @@ ATerm termFromId(const FSId & id)
}
FSId writeTerm(ATerm t, const string & suffix)
FSId writeTerm(ATerm t, const string & suffix, FSId id)
{
FSId id = hashTerm(t);
/* By default, the id of a term is its hash. */
if (id == FSId()) id = hashTerm(t);
string path = canonPath(nixStore + "/" +
(string) id + suffix + ".nix");

View file

@ -63,7 +63,7 @@ Hash hashTerm(ATerm t);
ATerm termFromId(const FSId & id);
/* Write an aterm to the Nix store directory, and return its hash. */
FSId writeTerm(ATerm t, const string & suffix);
FSId writeTerm(ATerm t, const string & suffix, FSId id = FSId());
/* Parse an fstate-expression. */
FState parseFState(ATerm t);

View file

@ -88,19 +88,18 @@ Slice normaliseFState(FSId id)
/* We can skip running the builder if we can expand all output
paths from their ids. */
bool fastBuild = false;
#if 0
bool fastBuild = true;
for (OutPaths::iterator i = outPaths.begin();
i != outPaths.end(); i++)
{
try {
expandId(i->second, i->first);
} catch (...) {
} catch (Error & e) {
debug(format("fast build failed: %1%") % e.what());
fastBuild = false;
break;
}
}
#endif
if (!fastBuild) {