diff options
Diffstat (limited to 'third_party/nix/src/libstore/references.cc')
-rw-r--r-- | third_party/nix/src/libstore/references.cc | 54 |
1 files changed, 36 insertions, 18 deletions
diff --git a/third_party/nix/src/libstore/references.cc b/third_party/nix/src/libstore/references.cc index 879f126f63ee..b70d282e8df8 100644 --- a/third_party/nix/src/libstore/references.cc +++ b/third_party/nix/src/libstore/references.cc @@ -13,21 +13,38 @@ namespace nix { static unsigned int refLength = 32; /* characters */ -static void search(const char* s, size_t len, StringSet& hashes, +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 + refLength <= len;) { - absl::string_view ref(s + i, refLength); - bool match = Hash::IsValidBase32(ref); + int j = 0; + bool match = true; + for (j = refLength - 1; j >= 0; --j) { + if (!isBase32[s[i + j]]) { + i += j + 1; + match = false; + break; + } + } if (!match) { continue; } - // TODO(kanepyork): convert StringSet to flat_hash_set, delay owned string - // conversion into the 'if' - std::string sref(ref); - if (hashes.find(sref) != hashes.end()) { + std::string ref(reinterpret_cast<const char*>(s) + i, refLength); + if (hashes.find(ref) != hashes.end()) { DLOG(INFO) << "found reference to '" << ref << "' at offset " << i; - seen.insert(sref); - hashes.erase(sref); + seen.insert(ref); + hashes.erase(ref); } ++i; } @@ -48,21 +65,22 @@ struct RefScanSink : Sink { void RefScanSink::operator()(const unsigned char* data, size_t len) { hashSink(data, len); - const char* data_ = reinterpret_cast<const char*>(data); - /* 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(data_, len > refLength ? refLength : len); - search(s.data(), s.size(), hashes, seen); + std::string s = tail + std::string(reinterpret_cast<const char*>(data), + len > refLength ? refLength : len); + search(reinterpret_cast<const unsigned char*>(s.data()), s.size(), hashes, + seen); - search(data_, len, hashes, seen); + search(data, len, hashes, seen); size_t tailLen = len <= refLength ? len : refLength; - tail = std::string(tail, tail.size() < refLength - tailLen - ? 0 - : tail.size() - (refLength - tailLen)) + - std::string(data_ + len - tailLen, tailLen); + tail = + std::string(tail, tail.size() < refLength - tailLen + ? 0 + : tail.size() - (refLength - tailLen)) + + std::string(reinterpret_cast<const char*>(data) + len - tailLen, tailLen); } PathSet scanForReferences(const std::string& path, const PathSet& refs, |