ACE/ace/Obstack_T.h

   1 // -*- C++ -*-
   2
   3 //=============================================================================
   4 /**
   5  *  @file    Obstack_T.h
   6  *
   7  *  @author Doug Schmidt <d.schmidt@vanderbilt.edu>
   8  *  @author Nanbor Wang <nanbor@cs.wustl.edu>
   9  */
  10 //=============================================================================
  11
  12 #ifndef ACE_OBSTACK_T_H
  13 #define ACE_OBSTACK_T_H
  14
  15 #include /**/ "ace/pre.h"
  16
  17 #include "ace/Obchunk.h"
  18
  19 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  20 # pragma once
  21 #endif /* ACE_LACKS_PRAGMA_ONCE */
  22
  23 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  24
  25 class ACE_Allocator;
  26
  27 /**
  28  * @class ACE_Obstack_T
  29  *
  30  * @brief Define a simple "mark and release" memory allocation utility.
  31  *
  32  * The implementation is similar to the GNU obstack utility,
  33  * which is used extensively in the GCC compiler.
  34  */
  35 template <class ACE_CHAR_T>
  36 class ACE_Obstack_T
  37 {
  38 public:
  39   ACE_Obstack_T (size_t size = (4096 * sizeof (ACE_CHAR_T)) - sizeof (ACE_Obchunk),
  40                  ACE_Allocator *allocator_strategy = 0);
  41   ~ACE_Obstack_T ();
  42
  43   /// Request Obstack to prepare a block at least @a len long for building
  44   /// a new string.  Return -1 if fail, 0 if success.
  45   int request (size_t len);
  46
  47   /// Inserting a new ACE_CHAR_T \a c into the current building block
  48   /// without freezing (null terminating) the block.  This function
  49   /// will create new chunk by checking the boundary of current
  50   /// Obchunk.  Return the location \a c gets inserted to, or 0 if
  51   /// error.
  52   ACE_CHAR_T *grow (ACE_CHAR_T c);
  53
  54   /// Inserting a new ACE_CHAR_T \a c into the current building
  55   /// block without freezing (null terminating) the block and without
  56   /// checking for out-of-bound error.
  57   void grow_fast (ACE_CHAR_T c);
  58
  59   /// Freeze the current building block by null terminating it.
  60   /// Return the starting address of the current building block, 0
  61   /// if error occurs.
  62   ACE_CHAR_T *freeze ();
  63
  64   /// Copy the data into the current Obchunk and freeze the current
  65   /// block.  Return the starting address of the current building
  66   /// block, 0 if error occurs.  @a len specify the string length,
  67   /// not the actually data size.
  68   ACE_CHAR_T *copy (const ACE_CHAR_T *data,
  69               size_t len);
  70
  71   /// Return the maximum @a size
  72   size_t size () const;
  73
  74   /// "Unwind" the stack. If @a obj is a null pointer, everything allocated
  75   /// in the stack is released. Otherwise, @a obj must be an address of an
  76   /// object allocated in the stack. In this case, @a obj is released along
  77   /// with everything allocated in the Obstack since @a obj.
  78   void unwind (void *obj);
  79
  80   /// "Release" the entire stack of Obchunks, putting it back on the free
  81   /// list.
  82   void release ();
  83
  84   /// Dump the state of an object.
  85   void dump () const;
  86
  87   /// Declare the dynamic allocation hooks.
  88   ACE_ALLOC_HOOK_DECLARE;
  89
  90 protected:
  91   class ACE_Obchunk *new_chunk ();
  92
  93   /// Search through the list of Obchunks and release them. Helper function
  94   /// used by unwind.
  95   void unwind_i (void *obj);
  96
  97   /// Pointer to the allocator used by this Obstack.
  98   ACE_Allocator *allocator_strategy_;
  99
 100   /// Current size of the Obstack;
 101   size_t size_;
 102
 103   // Don't change the order of the following two fields.
 104   /// Head of the Obchunk chain.
 105   class ACE_Obchunk *head_;
 106
 107   /// Pointer to the current Obchunk.
 108   class ACE_Obchunk *curr_;
 109 };
 110
 111 ACE_END_VERSIONED_NAMESPACE_DECL
 112
 113 #if defined (__ACE_INLINE__)
 114 #include "ace/Obstack_T.inl"
 115 #endif /* __ACE_INLINE__ */
 116
 117 #include "ace/Obstack_T.cpp"
 118
 119 #include /**/ "ace/post.h"
 120 #endif /* ACE_OBSTACK_T_H */