lix/src/nix-store/main.cc
Eelco Dolstra 630ae0c9d7 * nix-build: use an indirection scheme to make it easier for users to
get rid of GC roots.  Nix-build places a symlink `result' in the
  current directory.  Previously, removing that symlink would not
  remove the store path being linked to as a GC root.  Now, the GC
  root created by nix-build is actually a symlink in
  `/nix/var/nix/gcroots/auto' to `result'.  So if that symlink is
  removed the GC root automatically becomes invalid (since it can no
  longer be resolved).  The root itself is not automatically removed -
  the garbage collector should delete dangling roots.
2005-02-01 13:48:46 +00:00

466 lines
13 KiB
C++

#include <iostream>
#include "globals.hh"
#include "build.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);
}
static Path gcRoot;
static int rootNr = 0;
static bool indirectRoot = false;
static Path findOutput(const Derivation & drv, string id)
{
for (DerivationOutputs::const_iterator i = drv.outputs.begin();
i != drv.outputs.end(); ++i)
if (i->first == id) return i->second.path;
throw Error(format("derivation has no output `%1%'") % id);
}
static Path followSymlinks(Path & path)
{
path = absPath(path);
while (!isStorePath(path)) {
if (!isLink(path)) return path;
string target = readLink(path);
path = canonPath(string(target, 0, 1) == "/"
? target
: path + "/" + target);
}
return path;
}
/* Realisation the given path. For a derivation that means build it;
for other paths it means ensure their validity. */
static Path realisePath(const Path & path)
{
if (isDerivation(path)) {
PathSet paths;
paths.insert(path);
buildDerivations(paths);
Path outPath = findOutput(derivationFromPath(path), "out");
if (gcRoot == "")
printGCWarning();
else
outPath = addPermRoot(outPath,
makeRootName(gcRoot, rootNr),
indirectRoot);
return outPath;
} else {
ensurePath(path);
return path;
}
}
/* Realise the given paths. */
static void opRealise(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
*i = followSymlinks(*i);
if (opArgs.size() > 1) {
PathSet drvPaths;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
if (isDerivation(*i))
drvPaths.insert(*i);
buildDerivations(drvPaths);
}
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
cout << format("%1%\n") % realisePath(*i);
}
/* Add files to the Nix values directory and print the resulting
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);
}
/* Place in `paths' the set of paths that are required to `realise'
the given store path, i.e., all paths necessary for valid
deployment of the path. For a derivation, this is the union of
requisites of the inputs, plus the derivation; for other store
paths, it is the set of paths in the FS closure of the path. If
`includeOutputs' is true, include the requisites of the output
paths of derivations as well.
Note that this function can be used to implement three different
deployment policies:
- Source deployment (when called on a derivation).
- Binary deployment (when called on an output path).
- Source/binary deployment (when called on a derivation with
`includeOutputs' set to true).
*/
static void storePathRequisites(const Path & storePath,
bool includeOutputs, PathSet & paths)
{
computeFSClosure(storePath, paths);
if (includeOutputs) {
for (PathSet::iterator i = paths.begin();
i != paths.end(); ++i)
if (isDerivation(*i)) {
Derivation drv = derivationFromPath(*i);
for (DerivationOutputs::iterator j = drv.outputs.begin();
j != drv.outputs.end(); ++j)
if (isValidPath(j->second.path))
computeFSClosure(j->second.path, paths);
}
}
}
static Path maybeUseOutput(const Path & storePath, bool useOutput, bool forceRealise)
{
if (forceRealise) realisePath(storePath);
if (useOutput && isDerivation(storePath)) {
Derivation drv = derivationFromPath(storePath);
return findOutput(drv, "out");
}
else return storePath;
}
static void printPathSet(const PathSet & paths)
{
for (PathSet::iterator i = paths.begin();
i != paths.end(); i++)
cout << format("%s\n") % *i;
}
/* Perform various sorts of queries. */
static void opQuery(Strings opFlags, Strings opArgs)
{
enum { qOutputs, qRequisites, qReferences, qReferers,
qReferersClosure, qGraph } query = qOutputs;
bool useOutput = false;
bool includeOutputs = false;
bool forceRealise = false;
for (Strings::iterator i = opFlags.begin();
i != opFlags.end(); i++)
if (*i == "--outputs") query = qOutputs;
else if (*i == "--requisites" || *i == "-R") query = qRequisites;
else if (*i == "--references") query = qReferences;
else if (*i == "--referers") query = qReferers;
else if (*i == "--referers-closure") query = qReferersClosure;
else if (*i == "--graph") query = qGraph;
else if (*i == "--use-output" || *i == "-u") useOutput = true;
else if (*i == "--force-realise" || *i == "-f") forceRealise = true;
else if (*i == "--include-outputs") includeOutputs = true;
else throw UsageError(format("unknown flag `%1%'") % *i);
switch (query) {
case qOutputs: {
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
{
*i = followSymlinks(*i);
if (forceRealise) realisePath(*i);
Derivation drv = derivationFromPath(*i);
cout << format("%1%\n") % findOutput(drv, "out");
}
break;
}
case qRequisites:
case qReferences:
case qReferers:
case qReferersClosure: {
PathSet paths;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
{
*i = followSymlinks(*i);
Path path = maybeUseOutput(*i, useOutput, forceRealise);
if (query == qRequisites)
storePathRequisites(path, includeOutputs, paths);
else if (query == qReferences) queryReferences(path, paths);
else if (query == qReferers) queryReferers(path, paths);
else if (query == qReferersClosure) computeFSClosure(path, paths, true);
}
printPathSet(paths);
break;
}
#if 0
case qGraph: {
PathSet roots;
for (Strings::iterator i = opArgs.begin();
i != opArgs.end(); i++)
roots.insert(maybeNormalise(*i, normalise, realise));
printDotGraph(roots);
break;
}
#endif
default:
abort();
}
}
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;
PathSet references;
getline(cin, srcPath);
if (cin.eof()) break;
getline(cin, sub.program);
string s;
int n;
getline(cin, s);
if (!string2Int(s, n)) throw Error("number expected");
while (n--) {
getline(cin, s);
sub.args.push_back(s);
}
getline(cin, s);
if (!string2Int(s, n)) throw Error("number expected");
while (n--) {
getline(cin, s);
references.insert(s);
}
if (!cin || cin.eof()) throw Error("missing input");
registerSubstitute(txn, srcPath, sub);
setReferences(txn, srcPath, references);
}
txn.commit();
}
static void opClearSubstitutes(Strings opFlags, Strings opArgs)
{
if (!opFlags.empty()) throw UsageError("unknown flag");
if (!opArgs.empty())
throw UsageError("no arguments expected");
clearSubstitutes();
}
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, hashPath(htSHA256, *i), PathSet());
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)
{
GCAction action;
/* Do what? */
for (Strings::iterator i = opFlags.begin();
i != opFlags.end(); ++i)
if (*i == "--print-live") action = gcReturnLive;
else if (*i == "--print-dead") action = gcReturnDead;
else if (*i == "--delete") action = gcDeleteDead;
else throw UsageError(format("bad sub-operation `%1%' in GC") % *i);
/* Read the roots. */
PathSet roots;
while (1) {
Path root;
getline(cin, root);
if (cin.eof()) break;
roots.insert(root);
}
PathSet result;
collectGarbage(roots, action, result);
if (action != gcDeleteDead) {
for (PathSet::iterator i = result.begin(); i != result.end(); ++i)
cout << *i << endl;
}
}
/* 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(); ) {
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 == "--substitute")
op = opSubstitute;
else if (arg == "--clear-substitutes")
op = opClearSubstitutes;
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 == "--add-root") {
if (i == args.end())
throw UsageError("`--add-root requires an argument");
gcRoot = absPath(*i++);
}
else if (arg == "--indirect")
indirectRoot = true;
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";