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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         4. Derivative works are permitted, but they must carry this notice
00027            in full and credit the original source.
00028 
00029 
00030                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
00031 
00032 
00033         @version        Initial version, October 2004      
00034         @author         Kris
00035 
00036 
00037 *******************************************************************************/
00038 
00039 module mango.io.ArrayAllocator;
00040 
00041 private import  mango.io.Reader;
00042 
00043 private import  mango.utils.HeapSlice;
00044 
00045 private import  mango.io.model.IBuffer,
00046                 mango.io.model.IReader;
00047 
00048 /*******************************************************************************
00049 
00050 *******************************************************************************/
00051 
00052 class SimpleAllocator : IArrayAllocator
00053 {
00054         private IReader reader;
00055 
00056         /***********************************************************************
00057         
00058         ***********************************************************************/
00059 
00060         void reset ()
00061         {
00062         }
00063 
00064         /***********************************************************************
00065         
00066         ***********************************************************************/
00067 
00068         void bind (IReader reader)
00069         {
00070                 this.reader = reader;
00071         }
00072 
00073         /***********************************************************************
00074         
00075         ***********************************************************************/
00076 
00077         bool isMutable (void* x)
00078         {
00079                 return true;
00080         }
00081         
00082         /***********************************************************************
00083         
00084         ***********************************************************************/
00085 
00086         void allocate (void[]* x, uint count, uint width, BufferDecoder decoder)
00087         {       
00088                 count *= width;
00089                 void[] tmp = new void [count];
00090                 *x = tmp [0 .. decoder (tmp, count) / width];
00091         }
00092 }
00093 
00094 
00095 /*******************************************************************************
00096 
00097 *******************************************************************************/
00098 
00099 class NativeAllocator : SimpleAllocator
00100 {
00101         private bool aliased;
00102 
00103         /***********************************************************************
00104         
00105         ***********************************************************************/
00106 
00107         this (bool aliased = true)
00108         {
00109                 this.aliased = aliased;
00110         }
00111 
00112         /***********************************************************************
00113         
00114         ***********************************************************************/
00115 
00116         bool isMutable (void* x)
00117         {
00118                 return !aliased;
00119         }
00120 
00121         /***********************************************************************
00122         
00123         ***********************************************************************/
00124 
00125         void allocate (void[]* x, uint count, uint width, BufferDecoder decoder)
00126         {      
00127                 void[] tmp = *x;
00128                 count *= width;
00129                 tmp.length = count;
00130                 *x = tmp [0 .. decoder (tmp, count) / width];
00131         }
00132 }
00133 
00134 
00135 /*******************************************************************************
00136 
00137 *******************************************************************************/
00138 
00139 class BufferAllocator : SimpleAllocator
00140 {
00141         private BufferDecoder raw;
00142         private uint          width;
00143 
00144         /***********************************************************************
00145         
00146         ***********************************************************************/
00147 
00148         this (int width = 0)
00149         {
00150                 this.width = width;
00151         }
00152 
00153         /***********************************************************************
00154         
00155         ***********************************************************************/
00156 
00157         void reset ()
00158         {
00159                 IBuffer buffer = reader.getBuffer;
00160 
00161                 // ensure there's enough room for another record
00162                 if (buffer.writable < width)
00163                     buffer.compress ();
00164         }
00165 
00166         /***********************************************************************
00167         
00168         ***********************************************************************/
00169 
00170         void bind (IReader reader)
00171         {
00172                 raw = &(cast(Reader) reader).read;
00173                 super.bind (reader);
00174         }
00175 
00176         /***********************************************************************
00177         
00178         ***********************************************************************/
00179 
00180         bool isMutable (void* x)
00181         {
00182                 void[] content = reader.getBuffer.getContent;
00183                 return (x < content || x >= &content[length]);
00184         }
00185 
00186         /***********************************************************************
00187         
00188         ***********************************************************************/
00189 
00190         void allocate (void[]* x, uint count, uint width, BufferDecoder decoder)
00191         {       
00192                 if (decoder == raw)
00193                     *x = reader.getBuffer.get (count * width) [0..length / width];
00194                 else
00195                    super.allocate (x, count, width, decoder);
00196         }
00197 }
00198 
00199 
00200 /*******************************************************************************
00201 
00202 *******************************************************************************/
00203 
00204 class SliceAllocator : HeapSlice, IArrayAllocator
00205 {
00206         private IReader reader;
00207 
00208         /***********************************************************************
00209         
00210         ***********************************************************************/
00211 
00212         this (int width)
00213         {
00214                 super (width);
00215         }
00216 
00217         /***********************************************************************
00218         
00219         ***********************************************************************/
00220 
00221         void reset ()
00222         {
00223                 super.reset ();
00224         }
00225 
00226         /***********************************************************************
00227         
00228         ***********************************************************************/
00229 
00230         void bind (IReader reader)
00231         {
00232                 this.reader = reader;
00233         }
00234 
00235         /***********************************************************************
00236         
00237         ***********************************************************************/
00238 
00239         bool isMutable (void* x)
00240         {
00241                 return false;
00242         }
00243 
00244         /***********************************************************************
00245         
00246         ***********************************************************************/
00247 
00248         void allocate (void[]* x, uint count, uint width, BufferDecoder decoder)
00249         {       
00250                 count *= width;
00251                 expand (count);
00252                 void[] tmp = slice (count);
00253                 *x = tmp [0 .. decoder (tmp, count) / width];
00254         }
00255 }
00256 
00257 
00258 /*******************************************************************************
00259 
00260 *******************************************************************************/
00261 
00262 class ReuseAllocator : SliceAllocator 
00263 {
00264         private uint count;
00265 
00266         /***********************************************************************
00267         
00268         ***********************************************************************/
00269 
00270         this (int width)
00271         {
00272                 super (width);
00273         }
00274 
00275         /***********************************************************************
00276         
00277         ***********************************************************************/
00278 
00279         void allocate (void[]* x, uint count, uint width, BufferDecoder decoder)
00280         {       
00281                 super.reset ();
00282                 super.allocate (x, count, width, decoder);
00283         }
00284 
00285 }
00286 
00287 

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