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ArrayAllocator.d

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00001 /*******************************************************************************
00002 
00003         @file ArrayAllocator.d
00004         
00005         Copyright (C) 2004 Kris Bell
00006         
00007         This software is provided 'as-is', without any express or implied
00008         warranty. In no event will the authors be held liable for damages
00009         of any kind arising from the use of this software.
00010         
00011         Permission is hereby granted to anyone to use this software for any 
00012         purpose, including commercial applications, and to alter it and/or 
00013         redistribute it freely, subject to the following restrictions:
00014         
00015         1. The origin of this software must not be misrepresented; you must 
00016            not claim that you wrote the original software. If you use this 
00017            software in a product, an acknowledgment within documentation of 
00018            said product would be appreciated but is not required.
00019 
00020         2. Altered source versions must be plainly marked as such, and must 
00021            not be misrepresented as being the original software.
00022 
00023         3. This notice may not be removed or altered from any distribution
00024            of the source.
00025 
00026 
00027                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
00028 
00029 
00030         @version        Initial version, October 2004      
00031         @author         Kris
00032 
00033 
00034 *******************************************************************************/
00035 
00036 module mango.io.ArrayAllocator;
00037 
00038 private import  mango.io.Reader;
00039 
00040 private import  mango.utils.HeapSlice;
00041 
00042 private import  mango.io.model.IBuffer,
00043                 mango.io.model.IReader;
00044 
00045 /*******************************************************************************
00046 
00047 *******************************************************************************/
00048 
00049 class SimpleAllocator : IArrayAllocator
00050 {
00051         private IReader reader;
00052 
00053         /***********************************************************************
00054         
00055         ***********************************************************************/
00056 
00057         this (IReader reader)
00058         {
00059                 this.reader = reader;
00060         }
00061 
00062         /***********************************************************************
00063         
00064         ***********************************************************************/
00065 
00066         void reset ()
00067         {
00068         }
00069 
00070         /***********************************************************************
00071         
00072         ***********************************************************************/
00073 
00074         bool isReadOnly (void* x)
00075         {
00076                 return false;
00077         }
00078 
00079         /***********************************************************************
00080         
00081         ***********************************************************************/
00082 
00083         void allocate (void[]* x, BufferConverter decoder)
00084         {       
00085                 uint len = reader.length;
00086                 *x = new void [len];
00087                 //printf ("allocated %d bytes\n", len);
00088                 decoder (*x, len);
00089         }
00090 }
00091 
00092 
00093 /*******************************************************************************
00094 
00095 *******************************************************************************/
00096 
00097 class BufferAllocator : IArrayAllocator
00098 {
00099         private BufferConverter raw;
00100         private uint            width;
00101         private IReader         reader;
00102 
00103         /***********************************************************************
00104         
00105         ***********************************************************************/
00106 
00107         this (IReader reader, int width = 0)
00108         {
00109                 this.width = width;
00110                 this.reader = reader;
00111                 raw = &(cast(Reader) reader).read;
00112         }
00113 
00114         /***********************************************************************
00115         
00116         ***********************************************************************/
00117 
00118         void reset ()
00119         {
00120                 IBuffer buffer = reader.getBuffer;
00121 
00122                 // ensure there's enough room for another record
00123                 if (buffer.writable < width)
00124                     buffer.compress ();
00125         }
00126 
00127         /***********************************************************************
00128         
00129         ***********************************************************************/
00130 
00131         bool isReadOnly (void* x)
00132         {
00133                 void[] buffer = reader.getBuffer.getContent;
00134                 return (x >= buffer && x <= cast(void*)buffer+buffer.length);
00135         }
00136 
00137         /***********************************************************************
00138         
00139         ***********************************************************************/
00140 
00141         void allocate (void[]* x, BufferConverter decoder)
00142         {       
00143                 uint len = reader.length;
00144 
00145                 if (decoder == raw)
00146                    {
00147                    *x = reader.getBuffer.get (len);
00148                    //printf ("sliced %d bytes from buffer\n", len);
00149                    }
00150                 else
00151                    {
00152                    *x = new void [len];
00153                    //printf ("allocated %d bytes\n", len);
00154                    decoder (*x, len);
00155                    }
00156         }
00157 }
00158 
00159 
00160 /*******************************************************************************
00161 
00162 *******************************************************************************/
00163 
00164 class SliceAllocator : HeapSlice, IArrayAllocator
00165 {
00166         private IReader reader;
00167 
00168         /***********************************************************************
00169         
00170         ***********************************************************************/
00171 
00172         this (IReader reader, int width)
00173         {
00174                 super (width);
00175                 this.reader = reader;
00176         }
00177 
00178         /***********************************************************************
00179         
00180         ***********************************************************************/
00181 
00182         void reset ()
00183         {
00184                 super.reset ();
00185         }
00186 
00187         /***********************************************************************
00188         
00189         ***********************************************************************/
00190 
00191         bool isReadOnly (void* x)
00192         {
00193                 return true;
00194         }
00195 
00196         /***********************************************************************
00197         
00198         ***********************************************************************/
00199 
00200         void allocate (void[]* x, BufferConverter decoder)
00201         {       
00202                 uint len = reader.length;
00203 
00204                 expand (len);
00205                 *x = slice (len);
00206                 //printf ("sliced %d bytes from heap\n", len);
00207                 decoder (*x, len);
00208         }
00209 }
00210 
00211 

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