* Revert r19650 (implement gc-keep-outputs by looking for derivations

with the same name as the output) and instead use the
  DerivationOutputs table in the database, which is the correct way to
  to do things.
This commit is contained in:
Eelco Dolstra 2010-02-22 11:44:17 +00:00
parent 299ff64812
commit 103cfee056
5 changed files with 34 additions and 74 deletions

View file

@ -416,12 +416,7 @@ struct LocalStore::GCState
PathSet busy;
bool gcKeepOutputs;
bool gcKeepDerivations;
bool drvsIndexed;
typedef std::multimap<string, Path> DrvsByName;
DrvsByName drvsByName; // derivation paths hashed by name attribute
GCState(GCResults & results_) : results(results_), drvsIndexed(false)
GCState(GCResults & results_) : results(results_)
{
}
};
@ -441,42 +436,6 @@ bool LocalStore::isActiveTempFile(const GCState & state,
&& state.tempRoots.find(string(path, 0, path.size() - suffix.size())) != state.tempRoots.end();
}
/* Return all the derivations in the Nix store that have `path' as an
output. This function assumes that derivations have the same name
as their outputs. */
PathSet LocalStore::findDerivers(GCState & state, const Path & path)
{
PathSet derivers;
Path deriver = queryDeriver(path);
if (deriver != "") derivers.insert(deriver);
if (!state.drvsIndexed) {
Paths entries = readDirectory(nixStore);
foreach (Paths::iterator, i, entries)
if (isDerivation(*i))
state.drvsByName.insert(std::pair<string, Path>(
getNameOfStorePath(*i), nixStore + "/" + *i));
state.drvsIndexed = true;
}
string name = getNameOfStorePath(path);
// Urgh, I should have used Haskell...
std::pair<GCState::DrvsByName::iterator, GCState::DrvsByName::iterator> range =
state.drvsByName.equal_range(name);
for (GCState::DrvsByName::iterator i = range.first; i != range.second; ++i)
if (isValidPath(i->second)) {
Derivation drv = derivationFromPath(i->second);
foreach (DerivationOutputs::iterator, j, drv.outputs)
if (j->second.path == path) derivers.insert(i->second);
}
return derivers;
}
bool LocalStore::tryToDelete(GCState & state, const Path & path)
{
@ -522,18 +481,9 @@ bool LocalStore::tryToDelete(GCState & state, const Path & path)
if (!pathExists(path)) return true;
/* If gc-keep-outputs is set, then don't delete this path if
its deriver is not garbage. !!! Nix does not reliably
store derivers, so we have to look at all derivations to
determine which of them derive `path'. Since this makes
the garbage collector very slow to start on large Nix
stores, here we just look for all derivations that have the
same name as `path' (where the name is the part of the
filename after the hash, i.e. the `name' attribute of the
derivation). This is somewhat hacky: currently, the
deriver of a path always has the same name as the output,
but this might change in the future. */
there are derivers of this path that are not garbage. */
if (state.gcKeepOutputs) {
PathSet derivers = findDerivers(state, path);
PathSet derivers = queryValidDerivers(path);
foreach (PathSet::iterator, deriver, derivers) {
/* Break an infinite recursion if gc-keep-derivations
and gc-keep-outputs are both set by tentatively

View file

@ -297,6 +297,8 @@ void LocalStore::prepareStatements()
"select time from FailedPaths where path = ?;");
stmtAddDerivationOutput.create(db,
"insert or replace into DerivationOutputs (drv, id, path) values (?, ?, ?);");
stmtQueryValidDerivers.create(db,
"select v.id, v.path from DerivationOutputs d join ValidPaths v on d.drv = v.id where d.path = ?;");
}
@ -599,6 +601,28 @@ Path LocalStore::queryDeriver(const Path & path)
}
PathSet LocalStore::queryValidDerivers(const Path & path)
{
assertStorePath(path);
SQLiteStmtUse use(stmtQueryValidDerivers);
stmtQueryValidDerivers.bind(path);
PathSet derivers;
int r;
while ((r = sqlite3_step(stmtQueryValidDerivers)) == SQLITE_ROW) {
const char * s = (const char *) sqlite3_column_text(stmtQueryValidDerivers, 1);
assert(s);
derivers.insert(s);
}
if (r != SQLITE_DONE)
throw SQLiteError(db, format("error getting valid derivers of `%1%'") % path);
return derivers;
}
void LocalStore::startSubstituter(const Path & substituter, RunningSubstituter & run)
{
if (run.pid != -1) return;

View file

@ -103,6 +103,12 @@ public:
void queryReferrers(const Path & path, PathSet & referrers);
Path queryDeriver(const Path & path);
/* Return all currently valid derivations that have `path' as an
output. (Note that the result of `queryDeriver()' is the
derivation that was actually used to produce `path', which may
not exist anymore.) */
PathSet queryValidDerivers(const Path & path);
PathSet querySubstitutablePaths();
@ -199,6 +205,7 @@ private:
SQLiteStmt stmtRegisterFailedPath;
SQLiteStmt stmtHasPathFailed;
SQLiteStmt stmtAddDerivationOutput;
SQLiteStmt stmtQueryValidDerivers;
int getSchema();
@ -228,8 +235,6 @@ private:
bool tryToDelete(GCState & state, const Path & path);
PathSet findDerivers(GCState & state, const Path & path);
bool isActiveTempFile(const GCState & state,
const Path & path, const string & suffix);

View file

@ -1,7 +1,6 @@
#include "store-api.hh"
#include "globals.hh"
#include "util.hh"
#include "derivations.hh"
#include <limits.h>
@ -53,18 +52,6 @@ Path toStorePath(const Path & path)
}
string getNameOfStorePath(const Path & path)
{
Path::size_type slash = path.rfind('/');
string p = slash == Path::npos ? path : string(path, slash + 1);
Path::size_type dash = p.find('-');
assert(dash != Path::npos);
string p2 = string(p, dash + 1);
if (isDerivation(p2)) p2 = string(p2, 0, p2.size() - 4);
return p2;
}
Path followLinksToStore(const Path & _path)
{
Path path = absPath(_path);

View file

@ -243,12 +243,6 @@ void checkStoreName(const string & name);
Path toStorePath(const Path & path);
/* Get the "name" part of a store path, that is, the part after the
hash and the dash, and with any ".drv" suffix removed
(e.g. /nix/store/<hash>-foo-1.2.3.drv => foo-1.2.3). */
string getNameOfStorePath(const Path & path);
/* Follow symlinks until we end up with a path in the Nix store. */
Path followLinksToStore(const Path & path);