mirror of
https://github.com/NixOS/nix
synced 2024-09-20 23:28:26 -04:00
447089a5f6
Nix. This is to prevent Berkeley DB from becoming wedged. Unfortunately it is not possible to throw C++ exceptions from a signal handler. In fact, you can't do much of anything except change variables of type `volatile sig_atomic_t'. So we set an interrupt flag in the signal handler and check it at various strategic locations in the code (by calling checkInterrupt()). Since this is unlikely to cover all cases (e.g., (semi-)infinite loops), sometimes SIGTERM may now be required to kill Nix.
102 lines
2.4 KiB
C++
102 lines
2.4 KiB
C++
#include <cerrno>
|
|
#include <map>
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <unistd.h>
|
|
#include <dirent.h>
|
|
#include <fcntl.h>
|
|
|
|
#include "references.hh"
|
|
#include "hash.hh"
|
|
|
|
|
|
static void search(const string & s,
|
|
Strings & ids, Strings & seen)
|
|
{
|
|
for (Strings::iterator i = ids.begin();
|
|
i != ids.end(); )
|
|
{
|
|
checkInterrupt();
|
|
if (s.find(*i) == string::npos)
|
|
i++;
|
|
else {
|
|
debug(format("found reference to `%1%'") % *i);
|
|
seen.push_back(*i);
|
|
i = ids.erase(i);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
void checkPath(const string & path,
|
|
Strings & ids, Strings & seen)
|
|
{
|
|
checkInterrupt();
|
|
|
|
struct stat st;
|
|
if (lstat(path.c_str(), &st))
|
|
throw SysError(format("getting attributes of path `%1%'") % path);
|
|
|
|
if (S_ISDIR(st.st_mode)) {
|
|
Strings names = readDirectory(path);
|
|
for (Strings::iterator i = names.begin(); i != names.end(); i++) {
|
|
search(*i, ids, seen);
|
|
checkPath(path + "/" + *i, ids, seen);
|
|
}
|
|
}
|
|
|
|
else if (S_ISREG(st.st_mode)) {
|
|
|
|
debug(format("checking `%1%'") % path);
|
|
|
|
AutoCloseFD fd = open(path.c_str(), O_RDONLY);
|
|
if (fd == -1) throw SysError(format("opening file `%1%'") % path);
|
|
|
|
unsigned char * buf = new unsigned char[st.st_size];
|
|
|
|
readFull(fd, buf, st.st_size);
|
|
|
|
search(string((char *) buf, st.st_size), ids, seen);
|
|
|
|
delete buf; /* !!! autodelete */
|
|
}
|
|
|
|
else if (S_ISLNK(st.st_mode))
|
|
search(readLink(path), ids, seen);
|
|
|
|
else throw Error(format("unknown file type: %1%") % path);
|
|
}
|
|
|
|
|
|
Strings filterReferences(const string & path, const Strings & paths)
|
|
{
|
|
map<string, string> backMap;
|
|
Strings ids;
|
|
Strings seen;
|
|
|
|
/* For efficiency (and a higher hit rate), just search for the
|
|
hash part of the file name. (This assumes that all references
|
|
have the form `HASH-bla'). */
|
|
for (Strings::const_iterator i = paths.begin();
|
|
i != paths.end(); i++)
|
|
{
|
|
string s = string(baseNameOf(*i), 0, 32);
|
|
parseHash(s);
|
|
ids.push_back(s);
|
|
backMap[s] = *i;
|
|
}
|
|
|
|
checkPath(path, ids, seen);
|
|
|
|
Strings found;
|
|
for (Strings::iterator i = seen.begin(); i != seen.end(); i++)
|
|
{
|
|
map<string, string>::iterator j;
|
|
if ((j = backMap.find(*i)) == backMap.end()) abort();
|
|
found.push_back(j->second);
|
|
}
|
|
|
|
return found;
|
|
}
|