henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2004 The WebRTC Project Authors. All rights reserved. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license |
| 5 | * that can be found in the LICENSE file in the root of the source |
| 6 | * tree. An additional intellectual property rights grant can be found |
| 7 | * in the file PATENTS. All contributing project authors may |
| 8 | * be found in the AUTHORS file in the root of the source tree. |
| 9 | */ |
| 10 | |
| 11 | #include <time.h> |
| 12 | |
| 13 | #if defined(WEBRTC_WIN) |
| 14 | #include "webrtc/base/win32.h" |
| 15 | #endif |
| 16 | |
andresp@webrtc.org | ff689be | 2015-02-12 11:54:26 +0000 | [diff] [blame] | 17 | #include <algorithm> |
tfarina | 5237aaf | 2015-11-10 23:44:30 -0800 | [diff] [blame] | 18 | #include "webrtc/base/arraysize.h" |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 19 | #include "webrtc/base/common.h" |
| 20 | #include "webrtc/base/diskcache.h" |
| 21 | #include "webrtc/base/fileutils.h" |
| 22 | #include "webrtc/base/pathutils.h" |
| 23 | #include "webrtc/base/stream.h" |
| 24 | #include "webrtc/base/stringencode.h" |
| 25 | #include "webrtc/base/stringutils.h" |
| 26 | |
tfarina | a41ab93 | 2015-10-30 16:08:48 -0700 | [diff] [blame] | 27 | #if !defined(NDEBUG) |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 28 | #define TRANSPARENT_CACHE_NAMES 1 |
tfarina | a41ab93 | 2015-10-30 16:08:48 -0700 | [diff] [blame] | 29 | #else |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 30 | #define TRANSPARENT_CACHE_NAMES 0 |
tfarina | a41ab93 | 2015-10-30 16:08:48 -0700 | [diff] [blame] | 31 | #endif |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 32 | |
| 33 | namespace rtc { |
| 34 | |
| 35 | class DiskCache; |
| 36 | |
| 37 | /////////////////////////////////////////////////////////////////////////////// |
| 38 | // DiskCacheAdapter |
| 39 | /////////////////////////////////////////////////////////////////////////////// |
| 40 | |
| 41 | class DiskCacheAdapter : public StreamAdapterInterface { |
| 42 | public: |
| 43 | DiskCacheAdapter(const DiskCache* cache, const std::string& id, size_t index, |
| 44 | StreamInterface* stream) |
| 45 | : StreamAdapterInterface(stream), cache_(cache), id_(id), index_(index) |
| 46 | { } |
kwiberg@webrtc.org | 67186fe | 2015-03-09 22:21:53 +0000 | [diff] [blame] | 47 | ~DiskCacheAdapter() override { |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 48 | Close(); |
| 49 | cache_->ReleaseResource(id_, index_); |
| 50 | } |
| 51 | |
| 52 | private: |
| 53 | const DiskCache* cache_; |
| 54 | std::string id_; |
| 55 | size_t index_; |
| 56 | }; |
| 57 | |
| 58 | /////////////////////////////////////////////////////////////////////////////// |
| 59 | // DiskCache |
| 60 | /////////////////////////////////////////////////////////////////////////////// |
| 61 | |
| 62 | DiskCache::DiskCache() : max_cache_(0), total_size_(0), total_accessors_(0) { |
| 63 | } |
| 64 | |
| 65 | DiskCache::~DiskCache() { |
| 66 | ASSERT(0 == total_accessors_); |
| 67 | } |
| 68 | |
| 69 | bool DiskCache::Initialize(const std::string& folder, size_t size) { |
| 70 | if (!folder_.empty() || !Filesystem::CreateFolder(folder)) |
| 71 | return false; |
| 72 | |
| 73 | folder_ = folder; |
| 74 | max_cache_ = size; |
| 75 | ASSERT(0 == total_size_); |
| 76 | |
| 77 | if (!InitializeEntries()) |
| 78 | return false; |
| 79 | |
| 80 | return CheckLimit(); |
| 81 | } |
| 82 | |
| 83 | bool DiskCache::Purge() { |
| 84 | if (folder_.empty()) |
| 85 | return false; |
| 86 | |
| 87 | if (total_accessors_ > 0) { |
| 88 | LOG_F(LS_WARNING) << "Cache files open"; |
| 89 | return false; |
| 90 | } |
| 91 | |
| 92 | if (!PurgeFiles()) |
| 93 | return false; |
| 94 | |
| 95 | map_.clear(); |
| 96 | return true; |
| 97 | } |
| 98 | |
| 99 | bool DiskCache::LockResource(const std::string& id) { |
| 100 | Entry* entry = GetOrCreateEntry(id, true); |
| 101 | if (LS_LOCKED == entry->lock_state) |
| 102 | return false; |
| 103 | if ((LS_UNLOCKED == entry->lock_state) && (entry->accessors > 0)) |
| 104 | return false; |
| 105 | if ((total_size_ > max_cache_) && !CheckLimit()) { |
| 106 | LOG_F(LS_WARNING) << "Cache overfull"; |
| 107 | return false; |
| 108 | } |
| 109 | entry->lock_state = LS_LOCKED; |
| 110 | return true; |
| 111 | } |
| 112 | |
| 113 | StreamInterface* DiskCache::WriteResource(const std::string& id, size_t index) { |
| 114 | Entry* entry = GetOrCreateEntry(id, false); |
| 115 | if (LS_LOCKED != entry->lock_state) |
| 116 | return NULL; |
| 117 | |
| 118 | size_t previous_size = 0; |
| 119 | std::string filename(IdToFilename(id, index)); |
| 120 | FileStream::GetSize(filename, &previous_size); |
| 121 | ASSERT(previous_size <= entry->size); |
| 122 | if (previous_size > entry->size) { |
| 123 | previous_size = entry->size; |
| 124 | } |
| 125 | |
| 126 | scoped_ptr<FileStream> file(new FileStream); |
| 127 | if (!file->Open(filename, "wb", NULL)) { |
| 128 | LOG_F(LS_ERROR) << "Couldn't create cache file"; |
| 129 | return NULL; |
| 130 | } |
| 131 | |
andresp@webrtc.org | ff689be | 2015-02-12 11:54:26 +0000 | [diff] [blame] | 132 | entry->streams = std::max(entry->streams, index + 1); |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 133 | entry->size -= previous_size; |
| 134 | total_size_ -= previous_size; |
| 135 | |
| 136 | entry->accessors += 1; |
| 137 | total_accessors_ += 1; |
| 138 | return new DiskCacheAdapter(this, id, index, file.release()); |
| 139 | } |
| 140 | |
| 141 | bool DiskCache::UnlockResource(const std::string& id) { |
| 142 | Entry* entry = GetOrCreateEntry(id, false); |
| 143 | if (LS_LOCKED != entry->lock_state) |
| 144 | return false; |
| 145 | |
| 146 | if (entry->accessors > 0) { |
| 147 | entry->lock_state = LS_UNLOCKING; |
| 148 | } else { |
| 149 | entry->lock_state = LS_UNLOCKED; |
| 150 | entry->last_modified = time(0); |
| 151 | CheckLimit(); |
| 152 | } |
| 153 | return true; |
| 154 | } |
| 155 | |
| 156 | StreamInterface* DiskCache::ReadResource(const std::string& id, |
| 157 | size_t index) const { |
| 158 | const Entry* entry = GetEntry(id); |
| 159 | if (LS_UNLOCKED != entry->lock_state) |
| 160 | return NULL; |
| 161 | if (index >= entry->streams) |
| 162 | return NULL; |
| 163 | |
| 164 | scoped_ptr<FileStream> file(new FileStream); |
| 165 | if (!file->Open(IdToFilename(id, index), "rb", NULL)) |
| 166 | return NULL; |
| 167 | |
| 168 | entry->accessors += 1; |
| 169 | total_accessors_ += 1; |
| 170 | return new DiskCacheAdapter(this, id, index, file.release()); |
| 171 | } |
| 172 | |
| 173 | bool DiskCache::HasResource(const std::string& id) const { |
| 174 | const Entry* entry = GetEntry(id); |
| 175 | return (NULL != entry) && (entry->streams > 0); |
| 176 | } |
| 177 | |
| 178 | bool DiskCache::HasResourceStream(const std::string& id, size_t index) const { |
| 179 | const Entry* entry = GetEntry(id); |
| 180 | if ((NULL == entry) || (index >= entry->streams)) |
| 181 | return false; |
| 182 | |
| 183 | std::string filename = IdToFilename(id, index); |
| 184 | |
| 185 | return FileExists(filename); |
| 186 | } |
| 187 | |
| 188 | bool DiskCache::DeleteResource(const std::string& id) { |
| 189 | Entry* entry = GetOrCreateEntry(id, false); |
| 190 | if (!entry) |
| 191 | return true; |
| 192 | |
| 193 | if ((LS_UNLOCKED != entry->lock_state) || (entry->accessors > 0)) |
| 194 | return false; |
| 195 | |
| 196 | bool success = true; |
| 197 | for (size_t index = 0; index < entry->streams; ++index) { |
| 198 | std::string filename = IdToFilename(id, index); |
| 199 | |
| 200 | if (!FileExists(filename)) |
| 201 | continue; |
| 202 | |
| 203 | if (!DeleteFile(filename)) { |
| 204 | LOG_F(LS_ERROR) << "Couldn't remove cache file: " << filename; |
| 205 | success = false; |
| 206 | } |
| 207 | } |
| 208 | |
| 209 | total_size_ -= entry->size; |
| 210 | map_.erase(id); |
| 211 | return success; |
| 212 | } |
| 213 | |
| 214 | bool DiskCache::CheckLimit() { |
tfarina | a41ab93 | 2015-10-30 16:08:48 -0700 | [diff] [blame] | 215 | #if !defined(NDEBUG) |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 216 | // Temporary check to make sure everything is working correctly. |
| 217 | size_t cache_size = 0; |
| 218 | for (EntryMap::iterator it = map_.begin(); it != map_.end(); ++it) { |
| 219 | cache_size += it->second.size; |
| 220 | } |
| 221 | ASSERT(cache_size == total_size_); |
tfarina | a41ab93 | 2015-10-30 16:08:48 -0700 | [diff] [blame] | 222 | #endif |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 223 | |
| 224 | // TODO: Replace this with a non-brain-dead algorithm for clearing out the |
| 225 | // oldest resources... something that isn't O(n^2) |
| 226 | while (total_size_ > max_cache_) { |
| 227 | EntryMap::iterator oldest = map_.end(); |
| 228 | for (EntryMap::iterator it = map_.begin(); it != map_.end(); ++it) { |
| 229 | if ((LS_UNLOCKED != it->second.lock_state) || (it->second.accessors > 0)) |
| 230 | continue; |
| 231 | oldest = it; |
| 232 | break; |
| 233 | } |
| 234 | if (oldest == map_.end()) { |
| 235 | LOG_F(LS_WARNING) << "All resources are locked!"; |
| 236 | return false; |
| 237 | } |
| 238 | for (EntryMap::iterator it = oldest++; it != map_.end(); ++it) { |
| 239 | if (it->second.last_modified < oldest->second.last_modified) { |
| 240 | oldest = it; |
| 241 | } |
| 242 | } |
| 243 | if (!DeleteResource(oldest->first)) { |
| 244 | LOG_F(LS_ERROR) << "Couldn't delete from cache!"; |
| 245 | return false; |
| 246 | } |
| 247 | } |
| 248 | return true; |
| 249 | } |
| 250 | |
| 251 | std::string DiskCache::IdToFilename(const std::string& id, size_t index) const { |
| 252 | #ifdef TRANSPARENT_CACHE_NAMES |
| 253 | // This escapes colons and other filesystem characters, so the user can't open |
| 254 | // special devices (like "COM1:"), or access other directories. |
| 255 | size_t buffer_size = id.length()*3 + 1; |
| 256 | char* buffer = new char[buffer_size]; |
| 257 | encode(buffer, buffer_size, id.data(), id.length(), |
| 258 | unsafe_filename_characters(), '%'); |
| 259 | // TODO: ASSERT(strlen(buffer) < FileSystem::MaxBasenameLength()); |
| 260 | #else // !TRANSPARENT_CACHE_NAMES |
| 261 | // We might want to just use a hash of the filename at some point, both for |
| 262 | // obfuscation, and to avoid both filename length and escaping issues. |
| 263 | ASSERT(false); |
| 264 | #endif // !TRANSPARENT_CACHE_NAMES |
| 265 | |
| 266 | char extension[32]; |
tfarina | 5237aaf | 2015-11-10 23:44:30 -0800 | [diff] [blame] | 267 | sprintfn(extension, arraysize(extension), ".%u", index); |
henrike@webrtc.org | f048872 | 2014-05-13 18:00:26 +0000 | [diff] [blame] | 268 | |
| 269 | Pathname pathname; |
| 270 | pathname.SetFolder(folder_); |
| 271 | pathname.SetBasename(buffer); |
| 272 | pathname.SetExtension(extension); |
| 273 | |
| 274 | #ifdef TRANSPARENT_CACHE_NAMES |
| 275 | delete [] buffer; |
| 276 | #endif // TRANSPARENT_CACHE_NAMES |
| 277 | |
| 278 | return pathname.pathname(); |
| 279 | } |
| 280 | |
| 281 | bool DiskCache::FilenameToId(const std::string& filename, std::string* id, |
| 282 | size_t* index) const { |
| 283 | Pathname pathname(filename); |
| 284 | unsigned tempdex; |
| 285 | if (1 != sscanf(pathname.extension().c_str(), ".%u", &tempdex)) |
| 286 | return false; |
| 287 | |
| 288 | *index = static_cast<size_t>(tempdex); |
| 289 | |
| 290 | size_t buffer_size = pathname.basename().length() + 1; |
| 291 | char* buffer = new char[buffer_size]; |
| 292 | decode(buffer, buffer_size, pathname.basename().data(), |
| 293 | pathname.basename().length(), '%'); |
| 294 | id->assign(buffer); |
| 295 | delete [] buffer; |
| 296 | return true; |
| 297 | } |
| 298 | |
| 299 | DiskCache::Entry* DiskCache::GetOrCreateEntry(const std::string& id, |
| 300 | bool create) { |
| 301 | EntryMap::iterator it = map_.find(id); |
| 302 | if (it != map_.end()) |
| 303 | return &it->second; |
| 304 | if (!create) |
| 305 | return NULL; |
| 306 | Entry e; |
| 307 | e.lock_state = LS_UNLOCKED; |
| 308 | e.accessors = 0; |
| 309 | e.size = 0; |
| 310 | e.streams = 0; |
| 311 | e.last_modified = time(0); |
| 312 | it = map_.insert(EntryMap::value_type(id, e)).first; |
| 313 | return &it->second; |
| 314 | } |
| 315 | |
| 316 | void DiskCache::ReleaseResource(const std::string& id, size_t index) const { |
| 317 | const Entry* entry = GetEntry(id); |
| 318 | if (!entry) { |
| 319 | LOG_F(LS_WARNING) << "Missing cache entry"; |
| 320 | ASSERT(false); |
| 321 | return; |
| 322 | } |
| 323 | |
| 324 | entry->accessors -= 1; |
| 325 | total_accessors_ -= 1; |
| 326 | |
| 327 | if (LS_UNLOCKED != entry->lock_state) { |
| 328 | // This is safe, because locked resources only issue WriteResource, which |
| 329 | // is non-const. Think about a better way to handle it. |
| 330 | DiskCache* this2 = const_cast<DiskCache*>(this); |
| 331 | Entry* entry2 = this2->GetOrCreateEntry(id, false); |
| 332 | |
| 333 | size_t new_size = 0; |
| 334 | std::string filename(IdToFilename(id, index)); |
| 335 | FileStream::GetSize(filename, &new_size); |
| 336 | entry2->size += new_size; |
| 337 | this2->total_size_ += new_size; |
| 338 | |
| 339 | if ((LS_UNLOCKING == entry->lock_state) && (0 == entry->accessors)) { |
| 340 | entry2->last_modified = time(0); |
| 341 | entry2->lock_state = LS_UNLOCKED; |
| 342 | this2->CheckLimit(); |
| 343 | } |
| 344 | } |
| 345 | } |
| 346 | |
| 347 | /////////////////////////////////////////////////////////////////////////////// |
| 348 | |
| 349 | } // namespace rtc |