1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/netwerk/cache2/CacheFileUtils.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,290 @@
1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.7 +
1.8 +#include "CacheLog.h"
1.9 +#include "CacheFileUtils.h"
1.10 +#include "LoadContextInfo.h"
1.11 +#include "nsCOMPtr.h"
1.12 +#include "nsAutoPtr.h"
1.13 +#include "nsString.h"
1.14 +
1.15 +
1.16 +namespace mozilla {
1.17 +namespace net {
1.18 +namespace CacheFileUtils {
1.19 +
1.20 +namespace { // anon
1.21 +
1.22 +/**
1.23 + * A simple recursive descent parser for the mapping key.
1.24 + */
1.25 +class KeyParser
1.26 +{
1.27 +public:
1.28 + KeyParser(nsACString::const_iterator aCaret, nsACString::const_iterator aEnd)
1.29 + : caret(aCaret)
1.30 + , end(aEnd)
1.31 + // Initialize attributes to their default values
1.32 + , appId(nsILoadContextInfo::NO_APP_ID)
1.33 + , isPrivate(false)
1.34 + , isInBrowser(false)
1.35 + , isAnonymous(false)
1.36 + // Initialize the cache key to a zero length by default
1.37 + , cacheKey(aEnd)
1.38 + , lastTag(0)
1.39 + {
1.40 + }
1.41 +
1.42 +private:
1.43 + // Current character being parsed
1.44 + nsACString::const_iterator caret;
1.45 + // The end of the buffer
1.46 + nsACString::const_iterator const end;
1.47 +
1.48 + // Results
1.49 + uint32_t appId;
1.50 + bool isPrivate;
1.51 + bool isInBrowser;
1.52 + bool isAnonymous;
1.53 + nsCString idEnhance;
1.54 + // Position of the cache key, if present
1.55 + nsACString::const_iterator cacheKey;
1.56 +
1.57 + // Keeps the last tag name, used for alphabetical sort checking
1.58 + char lastTag;
1.59 +
1.60 + bool ParseTags()
1.61 + {
1.62 + // Expects to be at the tag name or at the end
1.63 + if (caret == end)
1.64 + return true;
1.65 +
1.66 + // 'Read' the tag name and move to the next char
1.67 + char const tag = *caret++;
1.68 + // Check the alphabetical order, hard-fail on disobedience
1.69 + if (!(lastTag < tag || tag == ':'))
1.70 + return false;
1.71 +
1.72 + lastTag = tag;
1.73 +
1.74 + switch (tag) {
1.75 + case ':':
1.76 + // last possible tag, when present there is the cacheKey following,
1.77 + // not terminated with ',' and no need to unescape.
1.78 + cacheKey = caret;
1.79 + caret = end;
1.80 + return true;
1.81 + case 'p':
1.82 + isPrivate = true;
1.83 + break;
1.84 + case 'b':
1.85 + isInBrowser = true;
1.86 + break;
1.87 + case 'a':
1.88 + isAnonymous = true;
1.89 + break;
1.90 + case 'i': {
1.91 + nsAutoCString appIdString;
1.92 + if (!ParseValue(&appIdString))
1.93 + return false;
1.94 +
1.95 + nsresult rv;
1.96 + int64_t appId64 = appIdString.ToInteger64(&rv);
1.97 + if (NS_FAILED(rv))
1.98 + return false; // appid value is mandatory
1.99 + if (appId64 < 0 || appId64 > PR_UINT32_MAX)
1.100 + return false; // not in the range
1.101 + appId = static_cast<uint32_t>(appId64);
1.102 +
1.103 + break;
1.104 + }
1.105 + case '~':
1.106 + if (!ParseValue(&idEnhance))
1.107 + return false;
1.108 + break;
1.109 + default:
1.110 + if (!ParseValue()) // skip any tag values, optional
1.111 + return false;
1.112 + break;
1.113 + }
1.114 +
1.115 + // Recurse to the next tag
1.116 + return ParseNextTagOrEnd();
1.117 + }
1.118 +
1.119 + bool ParseNextTagOrEnd()
1.120 + {
1.121 + // We expect a comma after every tag
1.122 + if (caret == end || *caret++ != ',')
1.123 + return false;
1.124 +
1.125 + // Go to another tag
1.126 + return ParseTags();
1.127 + }
1.128 +
1.129 + bool ParseValue(nsACString * result = nullptr)
1.130 + {
1.131 + // If at the end, fail since we expect a comma ; value may be empty tho
1.132 + if (caret == end)
1.133 + return false;
1.134 +
1.135 + // Remeber where the value starts
1.136 + nsACString::const_iterator val = caret;
1.137 + nsACString::const_iterator comma = end;
1.138 + bool escape = false;
1.139 + while (caret != end) {
1.140 + nsACString::const_iterator at = caret;
1.141 + ++caret; // we can safely break/continue the loop now
1.142 +
1.143 + if (*at == ',') {
1.144 + if (comma != end) {
1.145 + // another comma (we have found ",," -> escape)
1.146 + comma = end;
1.147 + escape = true;
1.148 + } else {
1.149 + comma = at;
1.150 + }
1.151 + continue;
1.152 + }
1.153 +
1.154 + if (comma != end) {
1.155 + // after a single comma
1.156 + break;
1.157 + }
1.158 + }
1.159 +
1.160 + // At this point |comma| points to the last and lone ',' we've hit.
1.161 + // If a lone comma was not found, |comma| is at the end of the buffer,
1.162 + // that is not expected and we return failure.
1.163 +
1.164 + caret = comma;
1.165 + if (result) {
1.166 + if (escape) {
1.167 + // No ReplaceSubstring on nsACString..
1.168 + nsAutoCString _result(Substring(val, caret));
1.169 + _result.ReplaceSubstring(NS_LITERAL_CSTRING(",,"), NS_LITERAL_CSTRING(","));
1.170 + result->Assign(_result);
1.171 + } else {
1.172 + result->Assign(Substring(val, caret));
1.173 + }
1.174 + }
1.175 +
1.176 + return caret != end;
1.177 + }
1.178 +
1.179 +public:
1.180 + already_AddRefed<LoadContextInfo> Parse()
1.181 + {
1.182 + nsRefPtr<LoadContextInfo> info;
1.183 + if (ParseTags())
1.184 + info = GetLoadContextInfo(isPrivate, appId, isInBrowser, isAnonymous);
1.185 +
1.186 + return info.forget();
1.187 + }
1.188 +
1.189 + void URISpec(nsACString &result)
1.190 + {
1.191 + // cacheKey is either pointing to end or the position where the cache key is.
1.192 + result.Assign(Substring(cacheKey, end));
1.193 + }
1.194 +
1.195 + void IdEnhance(nsACString &result)
1.196 + {
1.197 + result.Assign(idEnhance);
1.198 + }
1.199 +};
1.200 +
1.201 +} // anon
1.202 +
1.203 +already_AddRefed<nsILoadContextInfo>
1.204 +ParseKey(const nsCSubstring &aKey,
1.205 + nsCSubstring *aIdEnhance,
1.206 + nsCSubstring *aURISpec)
1.207 +{
1.208 + nsACString::const_iterator caret, end;
1.209 + aKey.BeginReading(caret);
1.210 + aKey.EndReading(end);
1.211 +
1.212 + KeyParser parser(caret, end);
1.213 + nsRefPtr<LoadContextInfo> info = parser.Parse();
1.214 +
1.215 + if (info) {
1.216 + if (aIdEnhance)
1.217 + parser.IdEnhance(*aIdEnhance);
1.218 + if (aURISpec)
1.219 + parser.URISpec(*aURISpec);
1.220 + }
1.221 +
1.222 + return info.forget();
1.223 +}
1.224 +
1.225 +void
1.226 +AppendKeyPrefix(nsILoadContextInfo* aInfo, nsACString &_retval)
1.227 +{
1.228 + /**
1.229 + * This key is used to salt file hashes. When form of the key is changed
1.230 + * cache entries will fail to find on disk.
1.231 + *
1.232 + * IMPORTANT NOTE:
1.233 + * Keep the attributes list sorted according their ASCII code.
1.234 + */
1.235 +
1.236 + if (aInfo->IsAnonymous()) {
1.237 + _retval.Append(NS_LITERAL_CSTRING("a,"));
1.238 + }
1.239 +
1.240 + if (aInfo->IsInBrowserElement()) {
1.241 + _retval.Append(NS_LITERAL_CSTRING("b,"));
1.242 + }
1.243 +
1.244 + if (aInfo->AppId() != nsILoadContextInfo::NO_APP_ID) {
1.245 + _retval.Append('i');
1.246 + _retval.AppendInt(aInfo->AppId());
1.247 + _retval.Append(',');
1.248 + }
1.249 +
1.250 + if (aInfo->IsPrivate()) {
1.251 + _retval.Append(NS_LITERAL_CSTRING("p,"));
1.252 + }
1.253 +}
1.254 +
1.255 +void
1.256 +AppendTagWithValue(nsACString & aTarget, char const aTag, nsCSubstring const & aValue)
1.257 +{
1.258 + aTarget.Append(aTag);
1.259 +
1.260 + // First check the value string to save some memory copying
1.261 + // for cases we don't need to escape at all (most likely).
1.262 + if (!aValue.IsEmpty()) {
1.263 + if (aValue.FindChar(',') == kNotFound) {
1.264 + // No need to escape
1.265 + aTarget.Append(aValue);
1.266 + } else {
1.267 + nsAutoCString escapedValue(aValue);
1.268 + escapedValue.ReplaceSubstring(
1.269 + NS_LITERAL_CSTRING(","), NS_LITERAL_CSTRING(",,"));
1.270 + aTarget.Append(escapedValue);
1.271 + }
1.272 + }
1.273 +
1.274 + aTarget.Append(',');
1.275 +}
1.276 +
1.277 +nsresult
1.278 +KeyMatchesLoadContextInfo(const nsACString &aKey, nsILoadContextInfo *aInfo,
1.279 + bool *_retval)
1.280 +{
1.281 + nsCOMPtr<nsILoadContextInfo> info = ParseKey(aKey);
1.282 +
1.283 + if (!info) {
1.284 + return NS_ERROR_FAILURE;
1.285 + }
1.286 +
1.287 + *_retval = info->Equals(aInfo);
1.288 + return NS_OK;
1.289 +}
1.290 +
1.291 +} // CacheFileUtils
1.292 +} // net
1.293 +} // mozilla
