/* This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ #include "CacheIndex.h" #include "CacheLog.h" #include "CacheFileUtils.h" #include "LoadContextInfo.h" #include "mozilla/Tokenizer.h" #include "nsCOMPtr.h" #include "nsAutoPtr.h" #include "nsString.h" #include <algorithm> #include "mozilla/Unused.h" namespace mozilla { namespace net { namespace CacheFileUtils { // This designates the format for the "alt-data" metadata. // When the format changes we need to update the version. static uint32_t const kAltDataVersion = 1; const char *kAltDataKey = "alt-data"; namespace { /** * A simple recursive descent parser for the mapping key. */ class KeyParser : protected Tokenizer { public: explicit KeyParser(nsACString const& aInput) : Tokenizer(aInput) // Initialize attributes to their default values , originAttribs(0, false) , isAnonymous(false) // Initialize the cache key to a zero length by default , lastTag(0) { } private: // Results NeckoOriginAttributes originAttribs; bool isAnonymous; nsCString idEnhance; nsDependentCSubstring cacheKey; // Keeps the last tag name, used for alphabetical sort checking char lastTag; // Classifier for the 'tag' character valid range static bool TagChar(const char aChar) { return aChar >= ' ' && aChar <= '~'; } bool ParseTags() { // Expects to be at the tag name or at the end if (CheckEOF()) { return true; } char tag; if (!ReadChar(&TagChar, &tag)) { return false; } // Check the alphabetical order, hard-fail on disobedience if (!(lastTag < tag || tag == ':')) { return false; } lastTag = tag; switch (tag) { case ':': // last possible tag, when present there is the cacheKey following, // not terminated with ',' and no need to unescape. cacheKey.Rebind(mCursor, mEnd - mCursor); return true; case 'O': { nsAutoCString originSuffix; if (!ParseValue(&originSuffix) || !originAttribs.PopulateFromSuffix(originSuffix)) { return false; } break; } case 'p': originAttribs.SyncAttributesWithPrivateBrowsing(true); break; case 'b': // Leaving to be able to read and understand oldformatted entries originAttribs.mInIsolatedMozBrowser = true; break; case 'a': isAnonymous = true; break; case 'i': { // Leaving to be able to read and understand oldformatted entries if (!ReadInteger(&originAttribs.mAppId)) { return false; // not a valid 32-bit integer } break; } case '~': if (!ParseValue(&idEnhance)) { return false; } break; default: if (!ParseValue()) { // skip any tag values, optional return false; } break; } // We expect a comma after every tag if (!CheckChar(',')) { return false; } // Recurse to the next tag return ParseTags(); } bool ParseValue(nsACString *result = nullptr) { // If at the end, fail since we expect a comma ; value may be empty tho if (CheckEOF()) { return false; } Token t; while (Next(t)) { if (!Token::Char(',').Equals(t)) { if (result) { result->Append(t.Fragment()); } continue; } if (CheckChar(',')) { // Two commas in a row, escaping if (result) { result->Append(','); } continue; } // We must give the comma back since the upper calls expect it Rollback(); return true; } return false; } public: already_AddRefed<LoadContextInfo> Parse() { RefPtr<LoadContextInfo> info; if (ParseTags()) { info = GetLoadContextInfo(isAnonymous, originAttribs); } return info.forget(); } void URISpec(nsACString &result) { result.Assign(cacheKey); } void IdEnhance(nsACString &result) { result.Assign(idEnhance); } }; } // namespace already_AddRefed<nsILoadContextInfo> ParseKey(const nsCSubstring &aKey, nsCSubstring *aIdEnhance, nsCSubstring *aURISpec) { KeyParser parser(aKey); RefPtr<LoadContextInfo> info = parser.Parse(); if (info) { if (aIdEnhance) parser.IdEnhance(*aIdEnhance); if (aURISpec) parser.URISpec(*aURISpec); } return info.forget(); } void AppendKeyPrefix(nsILoadContextInfo* aInfo, nsACString &_retval) { /** * This key is used to salt file hashes. When form of the key is changed * cache entries will fail to find on disk. * * IMPORTANT NOTE: * Keep the attributes list sorted according their ASCII code. */ NeckoOriginAttributes const *oa = aInfo->OriginAttributesPtr(); nsAutoCString suffix; oa->CreateSuffix(suffix); if (!suffix.IsEmpty()) { AppendTagWithValue(_retval, 'O', suffix); } if (aInfo->IsAnonymous()) { _retval.AppendLiteral("a,"); } if (aInfo->IsPrivate()) { _retval.AppendLiteral("p,"); } } void AppendTagWithValue(nsACString & aTarget, char const aTag, nsCSubstring const & aValue) { aTarget.Append(aTag); // First check the value string to save some memory copying // for cases we don't need to escape at all (most likely). if (!aValue.IsEmpty()) { if (!aValue.Contains(',')) { // No need to escape aTarget.Append(aValue); } else { nsAutoCString escapedValue(aValue); escapedValue.ReplaceSubstring( NS_LITERAL_CSTRING(","), NS_LITERAL_CSTRING(",,")); aTarget.Append(escapedValue); } } aTarget.Append(','); } nsresult KeyMatchesLoadContextInfo(const nsACString &aKey, nsILoadContextInfo *aInfo, bool *_retval) { nsCOMPtr<nsILoadContextInfo> info = ParseKey(aKey); if (!info) { return NS_ERROR_FAILURE; } *_retval = info->Equals(aInfo); return NS_OK; } ValidityPair::ValidityPair(uint32_t aOffset, uint32_t aLen) : mOffset(aOffset), mLen(aLen) {} ValidityPair& ValidityPair::operator=(const ValidityPair& aOther) { mOffset = aOther.mOffset; mLen = aOther.mLen; return *this; } bool ValidityPair::CanBeMerged(const ValidityPair& aOther) const { // The pairs can be merged into a single one if the start of one of the pairs // is placed anywhere in the validity interval of other pair or exactly after // its end. return IsInOrFollows(aOther.mOffset) || aOther.IsInOrFollows(mOffset); } bool ValidityPair::IsInOrFollows(uint32_t aOffset) const { return mOffset <= aOffset && mOffset + mLen >= aOffset; } bool ValidityPair::LessThan(const ValidityPair& aOther) const { if (mOffset < aOther.mOffset) { return true; } if (mOffset == aOther.mOffset && mLen < aOther.mLen) { return true; } return false; } void ValidityPair::Merge(const ValidityPair& aOther) { MOZ_ASSERT(CanBeMerged(aOther)); uint32_t offset = std::min(mOffset, aOther.mOffset); uint32_t end = std::max(mOffset + mLen, aOther.mOffset + aOther.mLen); mOffset = offset; mLen = end - offset; } void ValidityMap::Log() const { LOG(("ValidityMap::Log() - number of pairs: %u", mMap.Length())); for (uint32_t i=0; i<mMap.Length(); i++) { LOG((" (%u, %u)", mMap[i].Offset() + 0, mMap[i].Len() + 0)); } } uint32_t ValidityMap::Length() const { return mMap.Length(); } void ValidityMap::AddPair(uint32_t aOffset, uint32_t aLen) { ValidityPair pair(aOffset, aLen); if (mMap.Length() == 0) { mMap.AppendElement(pair); return; } // Find out where to place this pair into the map, it can overlap only with // one preceding pair and all subsequent pairs. uint32_t pos = 0; for (pos = mMap.Length(); pos > 0; ) { --pos; if (mMap[pos].LessThan(pair)) { // The new pair should be either inserted after pos or merged with it. if (mMap[pos].CanBeMerged(pair)) { // Merge with the preceding pair mMap[pos].Merge(pair); } else { // They don't overlap, element must be placed after pos element ++pos; if (pos == mMap.Length()) { mMap.AppendElement(pair); } else { mMap.InsertElementAt(pos, pair); } } break; } if (pos == 0) { // The new pair should be placed in front of all existing pairs. mMap.InsertElementAt(0, pair); } } // pos now points to merged or inserted pair, check whether it overlaps with // subsequent pairs. while (pos + 1 < mMap.Length()) { if (mMap[pos].CanBeMerged(mMap[pos + 1])) { mMap[pos].Merge(mMap[pos + 1]); mMap.RemoveElementAt(pos + 1); } else { break; } } } void ValidityMap::Clear() { mMap.Clear(); } size_t ValidityMap::SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const { return mMap.ShallowSizeOfExcludingThis(mallocSizeOf); } ValidityPair& ValidityMap::operator[](uint32_t aIdx) { return mMap.ElementAt(aIdx); } void FreeBuffer(void *aBuf) { #ifndef NS_FREE_PERMANENT_DATA if (CacheObserver::ShuttingDown()) { return; } #endif free(aBuf); } nsresult ParseAlternativeDataInfo(const char *aInfo, int64_t *_offset, nsACString *_type) { // The format is: "1;12345,javascript/binary" // <version>;<offset>,<type> mozilla::Tokenizer p(aInfo, nullptr, "/"); uint32_t altDataVersion = 0; int64_t altDataOffset = -1; // The metadata format has a wrong version number. if (!p.ReadInteger(&altDataVersion) || altDataVersion != kAltDataVersion) { LOG(("ParseAlternativeDataInfo() - altDataVersion=%u, " "expectedVersion=%u", altDataVersion, kAltDataVersion)); return NS_ERROR_NOT_AVAILABLE; } if (!p.CheckChar(';') || !p.ReadInteger(&altDataOffset) || !p.CheckChar(',')) { return NS_ERROR_NOT_AVAILABLE; } // The requested alt-data representation is not available if (altDataOffset < 0) { return NS_ERROR_NOT_AVAILABLE; } *_offset = altDataOffset; if (_type) { mozilla::Unused << p.ReadUntil(Tokenizer::Token::EndOfFile(), *_type); } return NS_OK; } void BuildAlternativeDataInfo(const char *aInfo, int64_t aOffset, nsACString &_retval) { _retval.Truncate(); _retval.AppendInt(kAltDataVersion); _retval.Append(';'); _retval.AppendInt(aOffset); _retval.Append(','); _retval.Append(aInfo); } } // namespace CacheFileUtils } // namespace net } // namespace mozilla