hphp/runtime/base/zend-pack.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    | Copyright (c) 1998-2010 Zend Technologies Ltd. (http://www.zend.com) |
   7    +----------------------------------------------------------------------+
   8    | This source file is subject to version 2.00 of the Zend license,     |
   9    | that is bundled with this package in the file LICENSE, and is        |
  10    | available through the world-wide-web at the following url:           |
  11    | http://www.zend.com/license/2_00.txt.                                |
  12    | If you did not receive a copy of the Zend license and are unable to  |
  13    | obtain it through the world-wide-web, please send a note to          |
  14    | license@zend.com so we can mail you a copy immediately.              |
  15    +----------------------------------------------------------------------+
  16 */
  17
  18 #ifndef incl_HPHP_ZEND_PACK_H_
  19 #define incl_HPHP_ZEND_PACK_H_
  20
  21 #include <cstdint>
  22
  23 namespace HPHP {
  24 ///////////////////////////////////////////////////////////////////////////////
  25 // pack/unpack
  26
  27 struct Variant;
  28 struct String;
  29 struct Array;
  30
  31 /**
  32  * Implemented formats are A, a, h, H, c, C, s, S, i, I, l, L, n, N, f, d,
  33  * x, X, Z and @.
  34  */
  35 struct ZendPack {
  36   ZendPack();
  37
  38   /**
  39    * Takes one or more arguments and packs them into a binary string according
  40    * to the format argument. pack() idea stolen from Perl (implemented formats
  41    * behave the same as there).
  42    */
  43   Variant pack(const String& fmt, const Array& argv);
  44
  45   /**
  46    * Unpack binary string into named array elements according to format
  47    * argument.
  48    *
  49    * unpack() is based on Perl's unpack(), but is modified a bit from there.
  50    * Rather than depending on error-prone ordered lists or syntactically
  51    * unpleasant pass-by-reference, we return an object with named parameters
  52    * (like *_fetch_object()). Syntax is "f[repeat]name/...", where "f" is the
  53    * formatter char (like pack()), "[repeat]" is the optional repeater
  54    * argument, and "name" is the name of the variable to use.
  55    * Example: "c2chars/nints" will return an object with fields
  56    * chars1, chars2, and ints.
  57    * Numeric pack types will return numbers, a and A will return strings,
  58    * f and d will return doubles.
  59    */
  60   Variant unpack(const String& fmt, const String& data);
  61
  62 private:
  63   // Whether machine is little endian
  64   char machine_little_endian;
  65
  66   // Mapping of byte from char (8bit) to int32 for machine endian
  67   int64_t byte_map[1];
  68
  69   // Mappings of bytes from int (machine dependent) to int for machine endian
  70   int64_t int_map[sizeof(int)];
  71
  72   // Mappings of bytes from shorts (16bit) for all endian environments
  73   int64_t machine_endian_short_map[2];
  74   int64_t big_endian_short_map[2];
  75   int64_t little_endian_short_map[2];
  76
  77   // Mappings of bytes from int32s (32bit) for all endian environments
  78   int64_t machine_endian_int32_map[4];
  79   int64_t big_endian_int32_map[4];
  80   int64_t little_endian_int32_map[4];
  81
  82   /* Mappings of bytes from int64s (64bit) for all endian environments */
  83   int64_t machine_endian_int64_map[8];
  84   int64_t big_endian_int64_map[8];
  85   int64_t little_endian_int64_map[8];
  86
  87   void pack(const Variant& val, int64_t size, int64_t *map, char *output);
  88   int64_t unpack(const char *data, int64_t size, int issigned, int64_t *map);
  89 };
  90
  91 ///////////////////////////////////////////////////////////////////////////////
  92 }
  93
  94 #endif // incl_HPHP_ZEND_PACK_H_