#include "references.hh" #include "hash.hh" #include "util.hh" #include "archive.hh" #include #include namespace nix { static unsigned int refLength = 32; /* characters */ static void search(const unsigned char * s, unsigned int len, StringSet & hashes, StringSet & seen) { static bool initialised = false; static bool isBase32[256]; if (!initialised) { for (unsigned int i = 0; i < 256; ++i) isBase32[i] = false; for (unsigned int i = 0; i < base32Chars.size(); ++i) isBase32[(unsigned char) base32Chars[i]] = true; initialised = true; } for (unsigned int i = 0; i + refLength <= len; ) { int j; bool match = true; for (j = refLength - 1; j >= 0; --j) if (!isBase32[(unsigned char) s[i + j]]) { i += j + 1; match = false; break; } if (!match) continue; string ref((const char *) s + i, refLength); if (hashes.find(ref) != hashes.end()) { debug(format("found reference to `%1%' at offset `%2%'") % ref % i); seen.insert(ref); hashes.erase(ref); } ++i; } } struct RefScanSink : Sink { HashSink hashSink; StringSet hashes; StringSet seen; string tail; RefScanSink() : hashSink(htSHA256) { } void operator () (const unsigned char * data, size_t len); }; void RefScanSink::operator () (const unsigned char * data, size_t len) { hashSink(data, len); /* It's possible that a reference spans the previous and current fragment, so search in the concatenation of the tail of the previous fragment and the start of the current fragment. */ string s = tail + string((const char *) data, len > refLength ? refLength : len); search((const unsigned char *) s.data(), s.size(), hashes, seen); search(data, len, hashes, seen); unsigned int tailLen = len <= refLength ? len : refLength; tail = string(tail, tail.size() < refLength - tailLen ? 0 : tail.size() - (refLength - tailLen)) + string((const char *) data + len - tailLen, tailLen); } PathSet scanForReferences(const string & path, const PathSet & refs, HashResult & hash) { RefScanSink sink; std::map backMap; /* 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'). */ foreach (PathSet::const_iterator, i, refs) { string baseName = baseNameOf(*i); string::size_type pos = baseName.find('-'); if (pos == string::npos) throw Error(format("bad reference `%1%'") % *i); string s = string(baseName, 0, pos); assert(s.size() == refLength); assert(backMap.find(s) == backMap.end()); // parseHash(htSHA256, s); sink.hashes.insert(s); backMap[s] = *i; } /* Look for the hashes in the NAR dump of the path. */ dumpPath(path, sink); /* Map the hashes found back to their store paths. */ PathSet found; foreach (StringSet::iterator, i, sink.seen) { std::map::iterator j; if ((j = backMap.find(*i)) == backMap.end()) abort(); found.insert(j->second); } hash = sink.hashSink.finish(); return found; } } ng guix pull): Document it. * doc/contributing.texi (Running Guix Before It Is Installed): Remove footnote about abusing ~/.config/guix/latest. Ludovic Courtès 2018-01-28guix: Let Emacs detect “scripts/guix.in” appropriate mode....Mathieu Lirzin 2018-01-23guix: Refactor script....Mathieu Lirzin 2018-01-23build: Expand ‘scripts/guix’ at Make time....Mathieu Lirzin 2017-03-20build: Install .go files to $libdir/guile/X.Y....Ludovic Courtès 2016-04-06challenge: Really exit with non-zero upon hash mismatch....Ludovic Courtès