diff options
Diffstat (limited to 'third_party/nix/src/libstore/references.cc')
-rw-r--r-- | third_party/nix/src/libstore/references.cc | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/third_party/nix/src/libstore/references.cc b/third_party/nix/src/libstore/references.cc deleted file mode 100644 index f120439c1060..000000000000 --- a/third_party/nix/src/libstore/references.cc +++ /dev/null @@ -1,126 +0,0 @@ -#include "libstore/references.hh" - -#include <cstdlib> -#include <map> - -#include <glog/logging.h> - -#include "libutil/archive.hh" -#include "libutil/hash.hh" -#include "libutil/util.hh" - -namespace nix { - -constexpr unsigned int kRefLength = 32; /* characters */ - -static void search(const unsigned char* s, size_t len, StringSet& hashes, - StringSet& seen) { - static bool initialised = false; - static bool isBase32[256]; - if (!initialised) { - for (bool& i : isBase32) { - i = false; - } - for (char base32Char : base32Chars) { - isBase32[static_cast<unsigned char>(base32Char)] = true; - } - initialised = true; - } - - for (size_t i = 0; i + kRefLength <= len;) { - int j = 0; - bool match = true; - for (j = kRefLength - 1; j >= 0; --j) { - if (!isBase32[s[i + j]]) { - i += j + 1; - match = false; - break; - } - } - if (!match) { - continue; - } - std::string ref(reinterpret_cast<const char*>(s) + i, kRefLength); - if (hashes.find(ref) != hashes.end()) { - DLOG(INFO) << "found reference to '" << ref << "' at offset " << i; - seen.insert(ref); - hashes.erase(ref); - } - ++i; - } -} - -struct RefScanSink : Sink { - HashSink hashSink; - StringSet hashes; - StringSet seen; - - std::string tail; - - RefScanSink() : hashSink(htSHA256) {} - - void operator()(const unsigned char* data, size_t len) override; -}; - -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. */ - std::string s = tail + std::string(reinterpret_cast<const char*>(data), - len > kRefLength ? kRefLength : len); - search(reinterpret_cast<const unsigned char*>(s.data()), s.size(), hashes, - seen); - - search(data, len, hashes, seen); - - size_t tailLen = len <= kRefLength ? len : kRefLength; - tail = - std::string(tail, tail.size() < kRefLength - tailLen - ? 0 - : tail.size() - (kRefLength - tailLen)) + - std::string(reinterpret_cast<const char*>(data) + len - tailLen, tailLen); -} - -PathSet scanForReferences(const std::string& path, const PathSet& refs, - HashResult& hash) { - RefScanSink sink; - std::map<std::string, Path> 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'). */ - for (auto& i : refs) { - std::string baseName = baseNameOf(i); - std::string::size_type pos = baseName.find('-'); - if (pos == std::string::npos) { - throw Error(format("bad reference '%1%'") % i); - } - std::string s = std::string(baseName, 0, pos); - assert(s.size() == kRefLength); - 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; - for (auto& i : sink.seen) { - std::map<std::string, Path>::iterator j; - if ((j = backMap.find(i)) == backMap.end()) { - abort(); - } - found.insert(j->second); - } - - hash = sink.hashSink.finish(); - - return found; -} - -} // namespace nix |