diff options
Diffstat (limited to 'indra/llfilesystem/lldiskcache.cpp')
| -rw-r--r-- | indra/llfilesystem/lldiskcache.cpp | 49 |
1 files changed, 22 insertions, 27 deletions
diff --git a/indra/llfilesystem/lldiskcache.cpp b/indra/llfilesystem/lldiskcache.cpp index 455e27221e..e2e50c775d 100644 --- a/indra/llfilesystem/lldiskcache.cpp +++ b/indra/llfilesystem/lldiskcache.cpp @@ -2,6 +2,12 @@ * @file lldiskcache.cpp * @brief The disk cache implementation. * + * Note: Rather than keep the top level function comments up + * to date in both the source and header files, I elected to + * only have explicit comments about each function and variable + * in the header - look there for details. The same is true for + * description of how this code is supposed to work. + * * $LicenseInfo:firstyear=2009&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2020, Linden Research, Inc. @@ -40,10 +46,8 @@ LLDiskCache::LLDiskCache(const std::string cache_dir, mMaxSizeBytes(max_size_bytes), mEnableCacheDebugInfo(enable_cache_debug_info) { - // the prefix used for cache filenames to disambiguate them from other files mCacheFilenamePrefix = "sl_cache"; - // create cache dir if it does not exist boost::filesystem::create_directory(cache_dir); } @@ -126,7 +130,7 @@ void LLDiskCache::purge() const std::string LLDiskCache::assetTypeToString(LLAssetType::EType at) { /** - * Make use of the C++17 (or is it 14) feature that allows + * Make use of the handy C++17 feature that allows * for inline initialization of an std::map<> */ typedef std::map<LLAssetType::EType, std::string> asset_type_to_name_t; @@ -190,20 +194,12 @@ const std::string LLDiskCache::metaDataToFilepath(const std::string id, return file_path.str(); } -/** - * Update the "last write time" of a file to "now". This must be called whenever a - * file in the cache is read (not written) so that the last time the file was - * accessed which is used in the mechanism for purging the cache, is up to date. - */ void LLDiskCache::updateFileAccessTime(const std::string file_path) { const std::time_t file_time = std::time(nullptr); boost::filesystem::last_write_time(file_path, file_time); } -/** - * - */ const std::string LLDiskCache::getCacheInfo() { std::ostringstream cache_info; @@ -219,14 +215,14 @@ const std::string LLDiskCache::getCacheInfo() return cache_info.str(); } -/** - * Clear the cache by removing all the files in the cache directory - * individually. It's important to maintain control of which directory - * if passed in and not let the user inadvertently (or maliciously) set - * it to an random location like your project source or OS system directory - */ void LLDiskCache::clearCache(const std::string cache_dir) { + /** + * See notes on performance in dirFileSize(..) - there may be + * a quicker way to do this by operating on the parent dir vs + * the component files but it's called infrequently so it's + * likely just fine + */ if (boost::filesystem::is_directory(cache_dir)) { for (auto& entry : boost::make_iterator_range(boost::filesystem::directory_iterator(cache_dir), {})) @@ -242,20 +238,19 @@ void LLDiskCache::clearCache(const std::string cache_dir) } } -/** - * Utility function to get the total filesize of all files in a directory. It - * used to test file extensions to only check cache files but that was removed. - * There may be a better way that works directly on the folder (similar to - * right clicking on a folder in the OS and asking for size vs right clicking - * on all files and adding up manually) but this is very fast - less than 100ms - * in my testing so, so long as it's not called frequently, it should be okay. - * Note that's it's only currently used for logging/debugging so if performance - * is ever an issue, optimizing this or removing it altogether, is an easy win. - */ uintmax_t LLDiskCache::dirFileSize(const std::string dir) { uintmax_t total_file_size = 0; + /** + * There may be a better way that works directly on the folder (similar to + * right clicking on a folder in the OS and asking for size vs right clicking + * on all files and adding up manually) but this is very fast - less than 100ms + * for 10,000 files in my testing so, so long as it's not called frequently, + * it should be okay. Note that's it's only currently used for logging/debugging + * so if performance is ever an issue, optimizing this or removing it altogether, + * is an easy win. + */ if (boost::filesystem::is_directory(dir)) { for (auto& entry : boost::make_iterator_range(boost::filesystem::directory_iterator(dir), {})) |