1 /*
   2  * Copyright © 2009  Red Hat, Inc.
   3  * Copyright © 2018  Google, Inc.
   4  *
   5  *  This is part of HarfBuzz, a text shaping library.
   6  *
   7  * Permission is hereby granted, without written agreement and without
   8  * license or royalty fees, to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose, provided that the
  10  * above copyright notice and the following two paragraphs appear in
  11  * all copies of this software.
  12  *
  13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  17  * DAMAGE.
  18  *
  19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  24  *
  25  * Red Hat Author(s): Behdad Esfahbod
  26  * Google Author(s): Behdad Esfahbod
  27  */
  28 
  29 #ifndef HB_BLOB_HH
  30 #define HB_BLOB_HH
  31 
  32 #include "hb.hh"
  33 
  34 
  35 /*
  36  * hb_blob_t
  37  */
  38 
  39 struct hb_blob_t
  40 {
  41   void fini_shallow () { destroy_user_data (); }
  42 
  43   void destroy_user_data ()
  44   {
  45     if (destroy)
  46     {
  47       destroy (user_data);
  48       user_data = nullptr;
  49       destroy = nullptr;
  50     }
  51   }
  52 
  53   HB_INTERNAL bool try_make_writable ();
  54   HB_INTERNAL bool try_make_writable_inplace ();
  55   HB_INTERNAL bool try_make_writable_inplace_unix ();
  56 
  57   template <typename Type>
  58   const Type* as () const
  59   {
  60     return length < hb_null_size (Type) ? &Null(Type) : reinterpret_cast<const Type *> (data);
  61   }
  62   hb_bytes_t as_bytes () const
  63   { return hb_bytes_t (data, length); }
  64 
  65   public:
  66   hb_object_header_t header;
  67 
  68   const char *data;
  69   unsigned int length;
  70   hb_memory_mode_t mode;
  71 
  72   void *user_data;
  73   hb_destroy_func_t destroy;
  74 };
  75 
  76 
  77 /*
  78  * hb_blob_ptr_t
  79  */
  80 
  81 template <typename P>
  82 struct hb_blob_ptr_t
  83 {
  84   typedef typename hb_remove_pointer (P) T;
  85 
  86   hb_blob_ptr_t (hb_blob_t *b_ = nullptr) : b (b_) {}
  87   hb_blob_t * operator = (hb_blob_t *b_) { return b = b_; }
  88   const T * operator -> () const { return get (); }
  89   const T & operator * () const  { return *get (); }
  90   template <typename C> operator const C * () const { return get (); }
  91   operator const char * () const { return (const char *) get (); }
  92   const T * get () const { return b->as<T> (); }
  93   hb_blob_t * get_blob () const { return b.get_raw (); }
  94   unsigned int get_length () const { return b.get ()->length; }
  95   void destroy () { hb_blob_destroy (b.get ()); b = nullptr; }
  96 
  97   hb_nonnull_ptr_t<hb_blob_t> b;
  98 };
  99 
 100 
 101 #endif /* HB_BLOB_HH */