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ACE_Read_Buffer Class Reference

Efficiently reads an artibrarily large buffer from an input stream up to and including a termination character. Also performs search/replace on single occurrences a character in the buffer using the principles of Integrated Layer Processing. More...

#include <Read_Buffer.h>

Collaboration diagram for ACE_Read_Buffer:

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List of all members.

Public Methods

 ACE_Read_Buffer (FILE *fp, int close_on_delete=0, ACE_Allocator *=0)
 Read from a FILE *. More...

 ACE_Read_Buffer (ACE_HANDLE handle, int close_on_delete=0, ACE_Allocator *=0)
 Read from an open HANDLE. More...

 ~ACE_Read_Buffer (void)
 Closes the FILE *. More...

char * read (int terminator=EOF, int search='\n', int replace='\0')
size_t replaced (void) const
 Returns the number of characters replaced during a <read>. More...

size_t size (void) const
 Returns the size of the allocated buffer obtained during a <read>, not including the null terminator. More...

ACE_Allocator * alloc (void) const
 Returns a pointer to its allocator. More...

void dump (void) const
 Dump the state of the object. More...


Private Methods

char * rec_read (int term, int search, int replace)
 Recursive helper method that does the work... More...

void operator= (const ACE_Read_Buffer &)
 ACE_Read_Buffer (const ACE_Read_Buffer &)

Private Attributes

size_t size_
 The total number of characters in the buffer. More...

size_t occurrences_
 The total number of characters replaced. More...

FILE * stream_
 The stream we are reading from. More...

int close_on_delete_
 Keeps track of whether we should close the FILE in the destructor. More...

ACE_Allocator * allocator_
 Pointer to the allocator. More...

Detailed Description

Efficiently reads an artibrarily large buffer from an input stream up to and including a termination character. Also performs search/replace on single occurrences a character in the buffer using the principles of Integrated Layer Processing.

This implementation is optimized to do a single dynamic allocation and make only one copy of the data. It uses recursion and the run-time stack to accomplish this efficiently.

Definition at line 43 of file Read_Buffer.h.

Constructor & Destructor Documentation

ACE_Read_Buffer::ACE_Read_Buffer (  FILE *    fp,
int    close_on_delete = 0,
ACE_Allocator *    = 0
) 
 

Read from a FILE *.

Definition at line 27 of file Read_Buffer.cpp.

References ACE_TRACE, allocator_, and ACE_Allocator::instance. 

00030   : stream_ (fp),
00031     close_on_delete_ (close_on_delete),
00032     allocator_ (alloc)
00033 {
00034   ACE_TRACE ("ACE_Read_Buffer::ACE_Read_Buffer");
00035   if (this->allocator_ == 0)
00036     this->allocator_ = ACE_Allocator::instance ();
00037 }

ACE_Read_Buffer::ACE_Read_Buffer (  ACE_HANDLE    handle,
int    close_on_delete = 0,
ACE_Allocator *    = 0
) 
 

Read from an open HANDLE.

Definition at line 40 of file Read_Buffer.cpp.

References ACE_LIB_TEXT, ACE_TRACE, allocator_, and ACE_Allocator::instance. 

00043   : stream_ (ACE_OS::fdopen (handle, ACE_LIB_TEXT ("r"))),
00044     close_on_delete_ (close_on_delete),
00045     allocator_ (alloc)
00046 {
00047   ACE_TRACE ("ACE_Read_Buffer::ACE_Read_Buffer");
00048 
00049   if (this->allocator_ == 0)
00050     this->allocator_ = ACE_Allocator::instance ();
00051 }

ACE_Read_Buffer::~ACE_Read_Buffer (  void    ) 
 

Closes the FILE *.

Definition at line 54 of file Read_Buffer.cpp.

References ACE_TRACE, close_on_delete_, and ACE_OS::fclose. 

00055 {
00056   ACE_TRACE ("ACE_Read_Buffer::~ACE_Read_Buffer");
00057 
00058   if (this->close_on_delete_)
00059     ACE_OS::fclose (this->stream_);
00060 }

ACE_Read_Buffer::ACE_Read_Buffer (  const ACE_Read_Buffer &    )  [private]
 

Member Function Documentation

ACE_INLINE ACE_Allocator * ACE_Read_Buffer::alloc (  void    )  const
 

Returns a pointer to its allocator.

Definition at line 23 of file Read_Buffer.i.

References ACE_TRACE, and allocator_. 

00024 {
00025   ACE_TRACE ("ACE_Read_Buffer::alloc");
00026   return this->allocator_;
00027 }

void ACE_Read_Buffer::dump (  void    )  const
 

Dump the state of the object.

Definition at line 16 of file Read_Buffer.cpp.

References ACE_BEGIN_DUMP, ACE_DEBUG, ACE_END_DUMP, ACE_LIB_TEXT, ACE_TRACE, and LM_DEBUG. 

00017 {
00018   ACE_TRACE ("ACE_Read_Buffer::dump");
00019   ACE_DEBUG ((LM_DEBUG, ACE_BEGIN_DUMP, this));
00020   ACE_DEBUG ((LM_DEBUG,  ACE_LIB_TEXT ("size_ = %d"), this->size_));
00021   ACE_DEBUG ((LM_DEBUG,  ACE_LIB_TEXT ("\noccurrences_ = %d"), this->occurrences_));
00022   ACE_DEBUG ((LM_DEBUG,  ACE_LIB_TEXT ("\nstream_ = %x"), this->stream_));
00023   ACE_DEBUG ((LM_DEBUG,  ACE_LIB_TEXT ("\nallocator_ = %x"), this->allocator_));
00024   ACE_DEBUG ((LM_DEBUG, ACE_END_DUMP));
00025 }

void ACE_Read_Buffer::operator= (  const ACE_Read_Buffer &    )  [private]
 

char * ACE_Read_Buffer::read (  int    terminator = EOF,
int    search = '\n',
int    replace = '\0'
) 
 

Returns a pointer dynamically allocated with <ACE_Allocator::malloc> to data from the input stream up to (and including) the <terminator>. If <search> is >= 0 then all occurrences of the <search> value are substituted with the <replace> value. The last of the byte of data is a 0, so that <strlen> can be used on it. The caller is responsible for freeing the pointer returned from this method using the <ACE_Allocator::free>.

Definition at line 69 of file Read_Buffer.cpp.

References ACE_TRACE, occurrences_, rec_read, and size_. 

00070 {
00071   ACE_TRACE ("ACE_Read_Buffer::read");
00072   this->occurrences_ = 0;
00073   this->size_ = 0;
00074   return this->rec_read (term, search, replace);
00075 }

char * ACE_Read_Buffer::rec_read (  int    term,
int    search,
int    replace
)  [private]
 

Recursive helper method that does the work...

Definition at line 89 of file Read_Buffer.cpp.

References ACE_TRACE, allocator_, ACE_Allocator::malloc, occurrences_, and size_.

Referenced by read. 

00090 {
00091   ACE_TRACE ("ACE_Read_Buffer::rec_read");
00092   // This is our temporary workspace.
00093   char buf[BUFSIZ];
00094 
00095   int c = EOF;
00096   size_t slot = 0;
00097   int done = 0;
00098 
00099   // Read in the file char by char
00100   while (slot < BUFSIZ)
00101     {
00102       c = getc (this->stream_);
00103 
00104       // Don't insert EOF into the buffer...
00105       if (c == EOF)
00106         {
00107           ungetc (c, this->stream_);
00108           break;
00109         }
00110       else if (c == term)
00111         done = 1;
00112 
00113       // Check for possible substitutions.
00114       if (c == search)
00115         {
00116           this->occurrences_++;
00117 
00118           if (replace >= 0)
00119             c = replace;
00120         }
00121 
00122       buf[slot++] = (char) c;
00123 
00124       // Substitutions must be made before checking for termination.
00125       if (done)
00126         break;
00127     }
00128 
00129   // Increment the number of bytes.
00130   this->size_ += slot;
00131 
00132   // Don't bother going any farther if the total size is 0.
00133   if (this->size_ == 0)
00134     return 0;
00135 
00136   char *result;
00137 
00138   // Recurse, when the recursion bottoms out, allocate the result
00139   // buffer.
00140   if (done || c == EOF)
00141     {
00142       // Use the allocator to acquire the memory.  The + 1 allows
00143       // space for the null terminator.
00144       result = (char *) this->allocator_->malloc (this->size_ + 1);
00145 
00146       if (result == 0)
00147         {
00148           errno = ENOMEM;
00149           return 0;
00150         }
00151       result += this->size_;
00152 
00153       // Null terminate the buffer.
00154       *result = '\0';
00155     }
00156   else if ((result = this->rec_read (term, search, replace)) == 0)
00157     return 0;
00158 
00159   // Copy buf into the appropriate location starting from end of
00160   // buffer.  Peter says this is confusing and that we should use
00161   // memcpy() ;-)
00162   for (size_t j = slot; j > 0; j--)
00163     *--result = buf[j - 1];
00164 
00165   return result;
00166 }

ACE_INLINE size_t ACE_Read_Buffer::replaced (  void    )  const
 

Returns the number of characters replaced during a <read>.

Definition at line 16 of file Read_Buffer.i.

References ACE_TRACE, and occurrences_. 

00017 {
00018   ACE_TRACE ("ACE_Read_Buffer::replaced");
00019   return this->occurrences_;
00020 }

ACE_INLINE size_t ACE_Read_Buffer::size (  void    )  const
 

Returns the size of the allocated buffer obtained during a <read>, not including the null terminator.

Definition at line 7 of file Read_Buffer.i.

References ACE_TRACE, and size_. 

00008 {
00009   ACE_TRACE ("ACE_Read_Buffer::size");
00010   return this->size_;
00011 }

Member Data Documentation

ACE_Allocator* ACE_Read_Buffer::allocator_ [private]
 

Pointer to the allocator.

Definition at line 109 of file Read_Buffer.h.

Referenced by ACE_Read_Buffer, alloc, and rec_read.

int ACE_Read_Buffer::close_on_delete_ [private]
 

Keeps track of whether we should close the FILE in the destructor.

Definition at line 106 of file Read_Buffer.h.

Referenced by ~ACE_Read_Buffer.

size_t ACE_Read_Buffer::occurrences_ [private]
 

The total number of characters replaced.

Definition at line 99 of file Read_Buffer.h.

Referenced by read, rec_read, and replaced.

size_t ACE_Read_Buffer::size_ [private]
 

The total number of characters in the buffer.

Definition at line 96 of file Read_Buffer.h.

Referenced by read, rec_read, and size.

FILE* ACE_Read_Buffer::stream_ [private]
 

The stream we are reading from.

Definition at line 102 of file Read_Buffer.h.

The documentation for this class was generated from the following files:
Generated on Mon Jun 16 12:54:55 2003 for ACE by doxygen1.2.14 written by Dimitri van Heesch, © 1997-2002