ACE/ace/Read_Buffer.h

   1 // -*- C++ -*-
   2
   3 //==========================================================================
   4 /**
   5  *  @file    Read_Buffer.h
   6  *
   7  *  @author Douglas C. Schmidt <d.schmidt@vanderbilt.edu>
   8  *  @author Seth Widoff
   9  */
  10 //==========================================================================
  11
  12 #ifndef ACE_READ_BUFFER_H
  13 #define ACE_READ_BUFFER_H
  14
  15 #include /**/ "ace/pre.h"
  16
  17 #include /**/ "ace/ACE_export.h"
  18
  19 #if !defined (ACE_LACKS_PRAGMA_ONCE)
  20 # pragma once
  21 #endif /* ACE_LACKS_PRAGMA_ONCE */
  22
  23 #include "ace/Global_Macros.h"
  24 #include "ace/os_include/os_stdio.h"
  25
  26 ACE_BEGIN_VERSIONED_NAMESPACE_DECL
  27
  28 class ACE_Allocator;
  29
  30 /**
  31  * @class ACE_Read_Buffer
  32  *
  33  * @brief Efficiently reads an arbitrarily large buffer from an input
  34  * stream up to and including a termination character.  Also
  35  * performs search/replace on single occurrences a character in
  36  * the buffer using the principles of Integrated Layer
  37  * Processing.
  38  *
  39  * This implementation is optimized to do a single dynamic
  40  * allocation and make only one copy of the data. It uses
  41  * recursion and the run-time stack to accomplish this
  42  * efficiently.
  43  */
  44 class ACE_Export ACE_Read_Buffer
  45 {
  46 public:
  47   /// Read from a FILE *.
  48   ACE_Read_Buffer (FILE *fp,
  49                    bool close_on_delete = false,
  50                    ACE_Allocator * = 0);
  51
  52   /// Read from an open HANDLE.
  53   ACE_Read_Buffer (ACE_HANDLE handle,
  54                    bool close_on_delete = false,
  55                    ACE_Allocator * = 0);
  56
  57   /// Closes the FILE *.
  58   ~ACE_Read_Buffer ();
  59
  60   /**
  61    * Returns a pointer dynamically allocated with
  62    * ACE_Allocator::malloc() to data from the input stream up to (and
  63    * including) the @a terminator.  If @a search is >= 0 then all
  64    * occurrences of the @a search value are substituted with the
  65    * @a replace value.  The last of the byte of data is a 0, so that
  66    * @c strlen can be used on it.  The caller is responsible for
  67    * freeing the pointer returned from this method using the
  68    * ACE_Allocator::free().
  69    */
  70   char *read (int terminator = EOF,
  71               int search = '\n',
  72               int replace = '\0');
  73
  74   /// Returns the number of characters replaced during a @c read.
  75   size_t replaced () const;
  76
  77   /// Returns the size of the allocated buffer obtained during a
  78   /// @c read, not including the null terminator.
  79   size_t size () const;
  80
  81   /// Returns a pointer to its allocator.
  82   ACE_Allocator *alloc () const;
  83
  84   /// Dump the state of the object.
  85   void dump () const;
  86
  87 private:
  88   void operator= (const ACE_Read_Buffer &) = delete;
  89   ACE_Read_Buffer (const ACE_Read_Buffer &) = delete;
  90   void operator= (ACE_Read_Buffer &&) = delete;
  91   ACE_Read_Buffer (ACE_Read_Buffer &&) = delete;
  92
  93 private:
  94   /// Recursive helper method that does the work...
  95   char *rec_read (int term, int search, int replace);
  96
  97   /// The total number of characters in the buffer.
  98   size_t size_;
  99
 100   /// The total number of characters replaced.
 101   size_t occurrences_;
 102
 103   /// The stream we are reading from.
 104   FILE *stream_;
 105
 106   /// Keeps track of whether we should close the FILE in the
 107   /// destructor.
 108   bool const close_on_delete_;
 109
 110   /// Pointer to the allocator.
 111   ACE_Allocator *allocator_;
 112 };
 113
 114 ACE_END_VERSIONED_NAMESPACE_DECL
 115
 116 #if defined (__ACE_INLINE__)
 117 # include "ace/Read_Buffer.inl"
 118 #endif /* __ACE_INLINE__ */
 119
 120 #include /**/ "ace/post.h"
 121
 122 #endif /* ACE_READ_BUFFER_H */