hphp/util/cache/cache-data.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-2016 Facebook, Inc. (http://www.facebook.com)     |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16
  17 // Individual in-memory component of the cache.
  18 // Usually normal files (web static resources).
  19
  20 #ifndef incl_HPHP_CACHE_DATA_H_
  21 #define incl_HPHP_CACHE_DATA_H_
  22
  23 #include <cstdint>
  24 #include <string>
  25
  26 namespace HPHP {
  27
  28 struct CacheSaver;
  29 struct MmapFile;
  30
  31 struct CacheData {
  32   CacheData();
  33   ~CacheData();
  34
  35   CacheData(const CacheData&) = delete;
  36   CacheData& operator=(const CacheData&) = delete;
  37
  38   // --- Creation functions: call at most one of these per instance.
  39
  40   // Create a named entry with contents of regular file at <path>.
  41   bool loadFromFile(const std::string& name, uint64_t id,
  42                     const std::string& path);
  43
  44   // Create a named entry without any contents.
  45   void createEmpty(const std::string& name, uint64_t id);
  46
  47   // Create a named directory entry.
  48   void createDirectory(const std::string& name, uint64_t id);
  49
  50   // Point into an existing cache file on disk.  Populates name on success.
  51   bool loadFromMmap(MmapFile* mmap_file, std::string* name);
  52
  53   // --- End creation functions.
  54
  55   // Push the internal data for this instance to CacheSaver for serialization.
  56   bool save(CacheSaver* cs) const;
  57
  58   bool isRegularFile() const;
  59   bool isDirectory() const;
  60   bool isCompressed() const;
  61   bool isEmpty() const;
  62
  63   uint64_t fileSize() const;
  64
  65   // Access contents if possible.  Populates all three arguments on success.
  66   bool getDataPointer(const char** data, uint64_t* datalen,
  67                               bool* compressed) const;
  68
  69   // Make a decompressed copy of the data.  Only works if actually compressed.
  70   // Returns false if data is not compressed, or on any other error.
  71   bool getDecompressedData(std::string* data) const;
  72
  73   void dump() const;
  74
  75  private:
  76   static const int kFlag_Compressed  = 0x00000001;
  77
  78   static const int kFlag_RegularFile = 0x00010000;
  79   static const int kFlag_EmptyEntry  = 0x00020000;
  80   static const int kFlag_Directory   = 0x00040000;
  81
  82   uint64_t createChecksum() const;
  83   bool sufficientlyCompressed(uint64_t orig_size, uint64_t new_size) const;
  84
  85   uint64_t id_;
  86   uint64_t flags_;
  87   uint64_t mtime_;
  88   uint64_t checksum_;
  89
  90   // It might be something we malloced, or something we got via mmap...
  91   const char* file_data_;
  92   uint64_t file_data_length_;
  93
  94   // ... hence this bool.
  95   bool should_free_;
  96
  97   std::string name_;
  98 };
  99
 100 }  // namespace HPHP
 101
 102 #endif  // incl_HPHP_CACHE_DATA_H_