michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "CacheLog.h"
michael@0: #include "CacheFileUtils.h"
michael@0: #include "LoadContextInfo.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsAutoPtr.h"
michael@0: #include "nsString.h"
michael@0: 
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace net {
michael@0: namespace CacheFileUtils {
michael@0: 
michael@0: namespace { // anon
michael@0: 
michael@0: /**
michael@0:  * A simple recursive descent parser for the mapping key.
michael@0:  */
michael@0: class KeyParser
michael@0: {
michael@0: public:
michael@0:   KeyParser(nsACString::const_iterator aCaret, nsACString::const_iterator aEnd)
michael@0:     : caret(aCaret)
michael@0:     , end(aEnd)
michael@0:     // Initialize attributes to their default values
michael@0:     , appId(nsILoadContextInfo::NO_APP_ID)
michael@0:     , isPrivate(false)
michael@0:     , isInBrowser(false)
michael@0:     , isAnonymous(false)
michael@0:     // Initialize the cache key to a zero length by default
michael@0:     , cacheKey(aEnd)
michael@0:     , lastTag(0)
michael@0:   {
michael@0:   }
michael@0: 
michael@0: private:
michael@0:   // Current character being parsed
michael@0:   nsACString::const_iterator caret;
michael@0:   // The end of the buffer
michael@0:   nsACString::const_iterator const end;
michael@0: 
michael@0:   // Results
michael@0:   uint32_t appId;
michael@0:   bool isPrivate;
michael@0:   bool isInBrowser;
michael@0:   bool isAnonymous;
michael@0:   nsCString idEnhance;
michael@0:   // Position of the cache key, if present
michael@0:   nsACString::const_iterator cacheKey;
michael@0: 
michael@0:   // Keeps the last tag name, used for alphabetical sort checking
michael@0:   char lastTag;
michael@0: 
michael@0:   bool ParseTags()
michael@0:   {
michael@0:     // Expects to be at the tag name or at the end
michael@0:     if (caret == end)
michael@0:       return true;
michael@0: 
michael@0:     // 'Read' the tag name and move to the next char
michael@0:     char const tag = *caret++;
michael@0:     // Check the alphabetical order, hard-fail on disobedience
michael@0:     if (!(lastTag < tag || tag == ':'))
michael@0:       return false;
michael@0: 
michael@0:     lastTag = tag;
michael@0: 
michael@0:     switch (tag) {
michael@0:     case ':':
michael@0:       // last possible tag, when present there is the cacheKey following,
michael@0:       // not terminated with ',' and no need to unescape.
michael@0:       cacheKey = caret;
michael@0:       caret = end;
michael@0:       return true;
michael@0:     case 'p':
michael@0:       isPrivate = true;
michael@0:       break;
michael@0:     case 'b':
michael@0:       isInBrowser = true;
michael@0:       break;
michael@0:     case 'a':
michael@0:       isAnonymous = true;
michael@0:       break;
michael@0:     case 'i': {
michael@0:       nsAutoCString appIdString;
michael@0:       if (!ParseValue(&appIdString))
michael@0:         return false;
michael@0: 
michael@0:       nsresult rv;
michael@0:       int64_t appId64 = appIdString.ToInteger64(&rv);
michael@0:       if (NS_FAILED(rv))
michael@0:         return false; // appid value is mandatory
michael@0:       if (appId64 < 0 || appId64 > PR_UINT32_MAX)
michael@0:         return false; // not in the range
michael@0:       appId = static_cast<uint32_t>(appId64);
michael@0: 
michael@0:       break;
michael@0:     }
michael@0:     case '~':
michael@0:       if (!ParseValue(&idEnhance))
michael@0:         return false;
michael@0:       break;
michael@0:     default:
michael@0:       if (!ParseValue()) // skip any tag values, optional
michael@0:         return false;
michael@0:       break;
michael@0:     }
michael@0: 
michael@0:     // Recurse to the next tag
michael@0:     return ParseNextTagOrEnd();
michael@0:   }
michael@0: 
michael@0:   bool ParseNextTagOrEnd()
michael@0:   {
michael@0:     // We expect a comma after every tag
michael@0:     if (caret == end || *caret++ != ',')
michael@0:       return false;
michael@0: 
michael@0:     // Go to another tag
michael@0:     return ParseTags();
michael@0:   }
michael@0: 
michael@0:   bool ParseValue(nsACString * result = nullptr)
michael@0:   {
michael@0:     // If at the end, fail since we expect a comma ; value may be empty tho
michael@0:     if (caret == end)
michael@0:       return false;
michael@0: 
michael@0:     // Remeber where the value starts
michael@0:     nsACString::const_iterator val = caret;
michael@0:     nsACString::const_iterator comma = end;
michael@0:     bool escape = false;
michael@0:     while (caret != end) {
michael@0:       nsACString::const_iterator at = caret;
michael@0:       ++caret; // we can safely break/continue the loop now
michael@0: 
michael@0:       if (*at == ',') {
michael@0:         if (comma != end) {
michael@0:           // another comma (we have found ",," -> escape)
michael@0:           comma = end;
michael@0:           escape = true;
michael@0:         } else {
michael@0:           comma = at;
michael@0:         }
michael@0:         continue;
michael@0:       }
michael@0: 
michael@0:       if (comma != end) {
michael@0:         // after a single comma
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // At this point |comma| points to the last and lone ',' we've hit.
michael@0:     // If a lone comma was not found, |comma| is at the end of the buffer,
michael@0:     // that is not expected and we return failure.
michael@0: 
michael@0:     caret = comma;
michael@0:     if (result) {
michael@0:       if (escape) {
michael@0:         // No ReplaceSubstring on nsACString..
michael@0:         nsAutoCString _result(Substring(val, caret));
michael@0:         _result.ReplaceSubstring(NS_LITERAL_CSTRING(",,"), NS_LITERAL_CSTRING(","));
michael@0:         result->Assign(_result);
michael@0:       } else {
michael@0:         result->Assign(Substring(val, caret));
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     return caret != end;
michael@0:   }
michael@0: 
michael@0: public:
michael@0:   already_AddRefed<LoadContextInfo> Parse()
michael@0:   {
michael@0:     nsRefPtr<LoadContextInfo> info;
michael@0:     if (ParseTags())
michael@0:       info = GetLoadContextInfo(isPrivate, appId, isInBrowser, isAnonymous);
michael@0: 
michael@0:     return info.forget();
michael@0:   }
michael@0: 
michael@0:   void URISpec(nsACString &result)
michael@0:   {
michael@0:     // cacheKey is either pointing to end or the position where the cache key is.
michael@0:     result.Assign(Substring(cacheKey, end));
michael@0:   }
michael@0: 
michael@0:   void IdEnhance(nsACString &result)
michael@0:   {
michael@0:     result.Assign(idEnhance);
michael@0:   }
michael@0: };
michael@0: 
michael@0: } // anon
michael@0: 
michael@0: already_AddRefed<nsILoadContextInfo>
michael@0: ParseKey(const nsCSubstring &aKey,
michael@0:          nsCSubstring *aIdEnhance,
michael@0:          nsCSubstring *aURISpec)
michael@0: {
michael@0:   nsACString::const_iterator caret, end;
michael@0:   aKey.BeginReading(caret);
michael@0:   aKey.EndReading(end);
michael@0: 
michael@0:   KeyParser parser(caret, end);
michael@0:   nsRefPtr<LoadContextInfo> info = parser.Parse();
michael@0: 
michael@0:   if (info) {
michael@0:     if (aIdEnhance)
michael@0:       parser.IdEnhance(*aIdEnhance);
michael@0:     if (aURISpec)
michael@0:       parser.URISpec(*aURISpec);
michael@0:   }
michael@0: 
michael@0:   return info.forget();
michael@0: }
michael@0: 
michael@0: void
michael@0: AppendKeyPrefix(nsILoadContextInfo* aInfo, nsACString &_retval)
michael@0: {
michael@0:   /**
michael@0:    * This key is used to salt file hashes.  When form of the key is changed
michael@0:    * cache entries will fail to find on disk.
michael@0:    *
michael@0:    * IMPORTANT NOTE:
michael@0:    * Keep the attributes list sorted according their ASCII code.
michael@0:    */
michael@0: 
michael@0:   if (aInfo->IsAnonymous()) {
michael@0:     _retval.Append(NS_LITERAL_CSTRING("a,"));
michael@0:   }
michael@0: 
michael@0:   if (aInfo->IsInBrowserElement()) {
michael@0:     _retval.Append(NS_LITERAL_CSTRING("b,"));
michael@0:   }
michael@0: 
michael@0:   if (aInfo->AppId() != nsILoadContextInfo::NO_APP_ID) {
michael@0:     _retval.Append('i');
michael@0:     _retval.AppendInt(aInfo->AppId());
michael@0:     _retval.Append(',');
michael@0:   }
michael@0: 
michael@0:   if (aInfo->IsPrivate()) {
michael@0:     _retval.Append(NS_LITERAL_CSTRING("p,"));
michael@0:   }
michael@0: }
michael@0: 
michael@0: void
michael@0: AppendTagWithValue(nsACString & aTarget, char const aTag, nsCSubstring const & aValue)
michael@0: {
michael@0:   aTarget.Append(aTag);
michael@0: 
michael@0:   // First check the value string to save some memory copying
michael@0:   // for cases we don't need to escape at all (most likely).
michael@0:   if (!aValue.IsEmpty()) {
michael@0:     if (aValue.FindChar(',') == kNotFound) {
michael@0:       // No need to escape
michael@0:       aTarget.Append(aValue);
michael@0:     } else {
michael@0:       nsAutoCString escapedValue(aValue);
michael@0:       escapedValue.ReplaceSubstring(
michael@0:         NS_LITERAL_CSTRING(","), NS_LITERAL_CSTRING(",,"));
michael@0:       aTarget.Append(escapedValue);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   aTarget.Append(',');
michael@0: }
michael@0: 
michael@0: nsresult
michael@0: KeyMatchesLoadContextInfo(const nsACString &aKey, nsILoadContextInfo *aInfo,
michael@0:                           bool *_retval)
michael@0: {
michael@0:   nsCOMPtr<nsILoadContextInfo> info = ParseKey(aKey);
michael@0: 
michael@0:   if (!info) {
michael@0:     return NS_ERROR_FAILURE;
michael@0:   }
michael@0: 
michael@0:   *_retval = info->Equals(aInfo);
michael@0:   return NS_OK;
michael@0: }
michael@0: 
michael@0: } // CacheFileUtils
michael@0: } // net
michael@0: } // mozilla