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* Get rid of identifiers since they are redundant now. This greatly

Browse source 
simplifies stuff.

* The format of Nix expressions and the database schema changed
  because of this, so it's best to delete old Nix installations.
This commit is contained in:
Eelco Dolstra 2003-10-08 15:06:59 +00:00
parent b9f4942bd2
commit 6baa2c4420
23 changed files with 485 additions and 631 deletions
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208
src/store.cc
View file

@ -8,7 +8,6 @@
#include "db.hh"
#include "archive.hh"
#include "pathlocks.hh"
#include "normalise.hh"
struct CopySink : DumpSink
@ -31,7 +30,7 @@ struct CopySource : RestoreSource
};
void copyPath(string src, string dst)
void copyPath(const Path & src, const Path & dst)
{
debug(format("copying `%1%' to `%2%'") % src % dst);
@ -82,7 +81,7 @@ void copyPath(string src, string dst)
}
void registerSubstitute(const FSId & srcId, const FSId & subId)
void registerSubstitute(const Path & srcPath, const Path & subPath)
{
#if 0
Strings subs;
@ -98,202 +97,89 @@ void registerSubstitute(const FSId & srcId, const FSId & subId)
/* For now, accept only one substitute per id. */
Strings subs;
subs.push_back(subId);
subs.push_back(subPath);
Transaction txn(nixDB);
nixDB.setStrings(txn, dbSubstitutes, srcId, subs);
nixDB.setStrings(txn, dbSubstitutes, srcPath, subs);
txn.commit();
}
void registerPath(const Transaction & txn,
const string & _path, const FSId & id)
void registerValidPath(const Transaction & txn, const Path & _path)
{
string path(canonPath(_path));
debug(format("registering path `%1%' with id %2%")
% path % (string) id);
string oldId;
if (nixDB.queryString(txn, dbPath2Id, path, oldId)) {
if (id != parseHash(oldId))
throw Error(format("path `%1%' already contains id %2%")
% path % oldId);
return;
}
nixDB.setString(txn, dbPath2Id, path, id);
Strings paths;
nixDB.queryStrings(txn, dbId2Paths, id, paths); /* non-existence = ok */
paths.push_back(path);
nixDB.setStrings(txn, dbId2Paths, id, paths);
Path path(canonPath(_path));
debug(format("registering path `%1%'") % path);
nixDB.setString(txn, dbValidPaths, path, "");
}
void unregisterPath(const string & _path)
bool isValidPath(const Path & path)
{
string path(canonPath(_path));
string s;
return nixDB.queryString(noTxn, dbValidPaths, path, s);
}
void unregisterValidPath(const Path & _path)
{
Path path(canonPath(_path));
Transaction txn(nixDB);
debug(format("unregistering path `%1%'") % path);
string _id;
if (!nixDB.queryString(txn, dbPath2Id, path, _id)) {
txn.abort();
return;
}
FSId id(parseHash(_id));
nixDB.delPair(txn, dbPath2Id, path);
Strings paths, paths2;
nixDB.queryStrings(txn, dbId2Paths, id, paths); /* non-existence = ok */
for (Strings::iterator it = paths.begin();
it != paths.end(); it++)
if (*it != path) paths2.push_back(*it);
nixDB.setStrings(txn, dbId2Paths, id, paths2);
nixDB.delPair(txn, dbValidPaths, path);
txn.commit();
}
bool queryPathId(const string & path, FSId & id)
{
string s;
if (!nixDB.queryString(noTxn, dbPath2Id, absPath(path), s)) return false;
id = parseHash(s);
return true;
}
bool isInPrefix(const string & path, const string & _prefix)
static bool isInPrefix(const string & path, const string & _prefix)
{
string prefix = canonPath(_prefix + "/");
return string(path, 0, prefix.size()) == prefix;
}
string expandId(const FSId & id, const string & target,
const string & prefix, FSIdSet pending, bool ignoreSubstitutes)
{
Nest nest(lvlDebug, format("expanding %1%") % (string) id);
Strings paths;
if (!target.empty() && !isInPrefix(target, prefix))
abort();
nixDB.queryStrings(noTxn, dbId2Paths, id, paths);
/* Pick one equal to `target'. */
if (!target.empty()) {
for (Strings::iterator i = paths.begin();
i != paths.end(); i++)
{
string path = *i;
if (path == target && pathExists(path))
return path;
}
}
/* Arbitrarily pick the first one that exists and isn't stale. */
for (Strings::iterator it = paths.begin();
it != paths.end(); it++)
{
string path = *it;
if (isInPrefix(path, prefix) && pathExists(path)) {
if (target.empty())
return path;
else {
/* Acquire a lock on the target path. */
Strings lockPaths;
lockPaths.push_back(target);
PathLocks outputLock(lockPaths);
/* Copy. */
copyPath(path, target);
/* Register the target path. */
Transaction txn(nixDB);
registerPath(txn, target, id);
txn.commit();
return target;
}
}
}
if (!ignoreSubstitutes) {
if (pending.find(id) != pending.end())
throw Error(format("id %1% already being expanded") % (string) id);
pending.insert(id);
/* Try to realise the substitutes, but only if this id is not
already being realised by a substitute. */
Strings subs;
nixDB.queryStrings(noTxn, dbSubstitutes, id, subs); /* non-existence = ok */
for (Strings::iterator it = subs.begin(); it != subs.end(); it++) {
FSId subId = parseHash(*it);
debug(format("trying substitute %1%") % (string) subId);
realiseClosure(normaliseNixExpr(subId, pending), pending);
return expandId(id, target, prefix, pending);
}
}
throw Error(format("cannot expand id `%1%'") % (string) id);
}
void addToStore(string srcPath, string & dstPath, FSId & id,
bool deterministicName)
Path addToStore(const Path & _srcPath)
{
Path srcPath(absPath(_srcPath));
debug(format("adding `%1%' to the store") % srcPath);
srcPath = absPath(srcPath);
id = hashPath(srcPath);
Hash h = hashPath(srcPath);
string baseName = baseNameOf(srcPath);
dstPath = canonPath(nixStore + "/" + (string) id + "-" + baseName);
Path dstPath = canonPath(nixStore + "/" + (string) h + "-" + baseName);
try {
dstPath = expandId(id, deterministicName ? dstPath : "",
nixStore, FSIdSet(), true);
return;
} catch (...) {
if (!isValidPath(dstPath)) {
/* The first check above is an optimisation to prevent
unnecessary lock acquisition. */
PathSet lockPaths;
lockPaths.insert(dstPath);
PathLocks outputLock(lockPaths);
if (!isValidPath(dstPath)) {
copyPath(srcPath, dstPath);
Transaction txn(nixDB);
registerValidPath(txn, dstPath);
txn.commit();
}
}
Strings lockPaths;
lockPaths.push_back(dstPath);
PathLocks outputLock(lockPaths);
copyPath(srcPath, dstPath);
Transaction txn(nixDB);
registerPath(txn, dstPath, id);
txn.commit();
return dstPath;
}
void deleteFromStore(const string & path)
void deleteFromStore(const Path & _path)
{
string prefix = + "/";
if (!isInPrefix(path, nixStore))
throw Error(format("path %1% is not in the store") % path);
Path path(canonPath(_path));
unregisterPath(path);
if (!isInPrefix(path, nixStore))
throw Error(format("path `%1%' is not in the store") % path);
unregisterValidPath(path);
deletePath(path);
}
@ -305,6 +191,7 @@ void verifyStore()
/* !!! verify that the result is consistent */
#if 0
Strings paths;
nixDB.enumTable(txn, dbPath2Id, paths);
@ -421,6 +308,7 @@ void verifyStore()
}
}
}
#endif
txn.commit();
}