lix/src/nix-store/main.cc
Eelco Dolstra eb233e728f * `--min-age' flag in nix-store and nix-collect-garbage to only delete
unreachable paths that haven't been used for N hours.  For instance,
  `nix-collect-garbage --min-age 168' only deletes paths that haven't
  been accessed in the last week.

  This is useful for instance in the build farm where many derivations
  can be shared between consecutive builds, and we wouldn't want a
  garbage collect to throw them all away.  We could of course register
  them as roots, but then we'd to unregister them at some point, which
  would be a pain to manage.  The `--min-age' flag gives us a sort of
  MRU caching scheme.

  BUG: this really shouldn't be in gc.cc since that violates
  mechanism/policy separation.
2004-08-25 16:54:08 +00:00

391 lines
11 KiB
C++

#include <iostream>
#include <sstream>
#include "globals.hh"
#include "normalise.hh"
#include "gc.hh"
#include "archive.hh"
#include "shared.hh"
#include "dotgraph.hh"
#include "help.txt.hh"
typedef void (* Operation) (Strings opFlags, Strings opArgs);
void printHelp()
{
cout << string((char *) helpText, sizeof helpText);
}
/* Realise paths from the given store expressions. */
static void opRealise(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
{
Path nfPath = realiseStoreExpr(*i);
cout << format("%1%\n") % (string) nfPath;
}
}
/* Add paths to the Nix values directory and print the hashes of those
paths. */
static void opAdd(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
for (Strings::iterator i = opArgs.begin(); i != opArgs.end(); i++)
cout << format("%1%\n") % addToStore(*i);
}
Path maybeNormalise(const Path & ne, bool normalise, bool realise)
{
if (realise) {
Path ne2 = realiseStoreExpr(ne);
return normalise ? ne2 : ne;
} else
return normalise ? normaliseStoreExpr(ne) : ne;
}
/* Perform various sorts of queries. */
static void opQuery(Strings opFlags, Strings opArgs)
{
enum { qList, qRequisites, qPredecessors, qGraph
} query = qList;
bool normalise = false;
bool realise = false;
bool includeExprs = true;
bool includeSuccessors = false;
for (Strings::iterator i = opFlags.begin();
i != opFlags.end(); i++)
if (*i == "--list" || *i == "-l") query = qList;
else if (*i == "--requisites" || *i == "-R") query = qRequisites;
else if (*i == "--predecessors") query = qPredecessors;
else if (*i == "--graph") query = qGraph;
else if (*i == "--normalise" || *i == "-n") normalise = true;
else if (*i == "--force-realise" || *i == "-f") realise = true;
else if (*i == "--exclude-exprs") includeExprs = false;
else if (*i == "--include-successors") includeSuccessors = true;
else throw UsageError(format("unknown flag `%1%'") % *i);
switch (query) {
case qList: {
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
{
StringSet paths = storeExprRoots(
maybeNormalise(*i, normalise, realise));
for (StringSet::iterator j = paths.begin();
j != paths.end(); j++)
cout << format("%s\n") % *j;
}
break;
}
case qRequisites: {
StringSet paths;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
{
StringSet paths2 = storeExprRequisites(
maybeNormalise(*i, normalise, realise),
includeExprs, includeSuccessors);
paths.insert(paths2.begin(), paths2.end());
}
for (StringSet::iterator i = paths.begin();
i != paths.end(); i++)
cout << format("%s\n") % *i;
break;
}
case qPredecessors: {
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
{
Paths preds = queryPredecessors(*i);
for (Paths::iterator j = preds.begin();
j != preds.end(); j++)
cout << format("%s\n") % *j;
}
break;
}
case qGraph: {
PathSet roots;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
roots.insert(maybeNormalise(*i, normalise, realise));
printDotGraph(roots);
break;
}
default:
abort();
}
}
static void opSuccessor(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
if (opArgs.size() % 2) throw UsageError("expecting even number of arguments");
Transaction txn;
createStoreTransaction(txn);
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); )
{
Path path1 = *i++;
Path path2 = *i++;
registerSuccessor(txn, path1, path2);
}
txn.commit();
}
static void opSubstitute(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
if (!opArgs.empty())
throw UsageError("no arguments expected");
Transaction txn;
createStoreTransaction(txn);
while (1) {
Path srcPath;
Substitute sub;
getline(cin, srcPath);
if (cin.eof()) break;
getline(cin, sub.storeExpr);
getline(cin, sub.program);
string s;
getline(cin, s);
istringstream st(s);
int n;
st >> n;
if (!st) throw Error("number expected");
while (n--) {
getline(cin, s);
sub.args.push_back(s);
}
if (!cin || cin.eof()) throw Error("missing input");
registerSubstitute(txn, srcPath, sub);
}
txn.commit();
}
static void opValidPath(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
Transaction txn;
createStoreTransaction(txn);
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
registerValidPath(txn, *i);
txn.commit();
}
static void opIsValid(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); ++i)
if (!isValidPath(*i))
throw Error(format("path `%1%' is not valid") % *i);
}
static void opGC(Strings opFlags, Strings opArgs)
{
/* Do what? */
enum { soPrintLive, soPrintDead, soDelete } subOp;
time_t minAge = 0;
for (Strings::iterator i = opFlags.begin();
i != opFlags.end(); ++i)
if (*i == "--print-live") subOp = soPrintLive;
else if (*i == "--print-dead") subOp = soPrintDead;
else if (*i == "--delete") subOp = soDelete;
else if (*i == "--min-age") {
if (opArgs.size() == 0)
throw UsageError("`--min-age' requires an argument");
istringstream st(opArgs.front());
st >> minAge;
if (!st) throw Error("number expected");
}
else throw UsageError(format("bad sub-operation `%1%' in GC") % *i);
Paths roots;
while (1) {
Path root;
getline(cin, root);
if (cin.eof()) break;
roots.push_back(root);
}
PathSet live = findLivePaths(roots);
if (subOp == soPrintLive) {
for (PathSet::iterator i = live.begin(); i != live.end(); ++i)
cout << *i << endl;
return;
}
PathSet dead = findDeadPaths(live, minAge * 3600);
if (subOp == soPrintDead) {
for (PathSet::iterator i = dead.begin(); i != dead.end(); ++i)
cout << *i << endl;
return;
}
if (subOp == soDelete) {
/* !!! What happens if the garbage collector run is aborted
halfway through? In particular, dead paths can always
become live again (through re-instantiation), and might
then refer to deleted paths. => check instantiation
invariants */
for (PathSet::iterator i = dead.begin(); i != dead.end(); ++i) {
printMsg(lvlInfo, format("deleting `%1%'") % *i);
deleteFromStore(*i);
}
}
}
/* A sink that writes dump output to stdout. */
struct StdoutSink : DumpSink
{
virtual void operator ()
(const unsigned char * data, unsigned int len)
{
writeFull(STDOUT_FILENO, data, len);
}
};
/* Dump a path as a Nix archive. The archive is written to standard
output. */
static void opDump(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
if (opArgs.size() != 1) throw UsageError("only one argument allowed");
StdoutSink sink;
string path = *opArgs.begin();
dumpPath(path, sink);
}
/* A source that read restore intput to stdin. */
struct StdinSource : RestoreSource
{
virtual void operator () (unsigned char * data, unsigned int len)
{
readFull(STDIN_FILENO, data, len);
}
};
/* Restore a value from a Nix archive. The archive is written to
standard input. */
static void opRestore(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
if (opArgs.size() != 1) throw UsageError("only one argument allowed");
StdinSource source;
restorePath(*opArgs.begin(), source);
}
/* Initialise the Nix databases. */
static void opInit(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
if (!opArgs.empty())
throw UsageError("no arguments expected");
initDB();
}
/* Verify the consistency of the Nix environment. */
static void opVerify(Strings opFlags, Strings opArgs)
{
verifyStore();
}
/* Scan the arguments; find the operation, set global flags, put all
other flags in a list, and put all other arguments in another
list. */
void run(Strings args)
{
Strings opFlags, opArgs;
Operation op = 0;
for (Strings::iterator i = args.begin(); i != args.end(); ++i) {
string arg = *i;
Operation oldOp = op;
if (arg == "--realise" || arg == "-r")
op = opRealise;
else if (arg == "--add" || arg == "-A")
op = opAdd;
else if (arg == "--query" || arg == "-q")
op = opQuery;
else if (arg == "--successor")
op = opSuccessor;
else if (arg == "--substitute")
op = opSubstitute;
else if (arg == "--validpath")
op = opValidPath;
else if (arg == "--isvalid")
op = opIsValid;
else if (arg == "--gc")
op = opGC;
else if (arg == "--dump")
op = opDump;
else if (arg == "--restore")
op = opRestore;
else if (arg == "--init")
op = opInit;
else if (arg == "--verify")
op = opVerify;
else if (arg[0] == '-')
opFlags.push_back(arg);
else
opArgs.push_back(arg);
if (oldOp && oldOp != op)
throw UsageError("only one operation may be specified");
}
if (!op) throw UsageError("no operation specified");
if (op != opDump && op != opRestore) /* !!! hack */
openDB();
op(opFlags, opArgs);
}
string programId = "nix-store";