/[escript]/branches/schroedinger/escript/src/DataLazy.h
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Revision 1926 - (hide annotations)
Fri Oct 24 05:54:08 2008 UTC (11 years, 7 months ago) by jfenwick
File MIME type: text/plain
File size: 7034 byte(s)
Branch commit.
Changed some text so it doesn't mention DataArrayView.
Added some tests for DataLazy.
Factored common code in the Data tests (will add tests against lazy 
later).


1 jfenwick 1865
2     /*******************************************************
3     *
4     * Copyright (c) 2003-2008 by University of Queensland
5     * Earth Systems Science Computational Center (ESSCC)
6     * http://www.uq.edu.au/esscc
7     *
8     * Primary Business: Queensland, Australia
9     * Licensed under the Open Software License version 3.0
10     * http://www.opensource.org/licenses/osl-3.0.php
11     *
12     *******************************************************/
13    
14    
15     #if !defined escript_DataLazy_20081008_H
16     #define escript_DataLazy_20081008_H
17     #include "system_dep.h"
18    
19     #include "DataAbstract.h"
20    
21     #include <string>
22 jfenwick 1868 #include <functional>
23 jfenwick 1865
24 jfenwick 1879 #include "LocalOps.h" // for tensor_binary_op
25    
26 jfenwick 1865 namespace escript {
27    
28 jfenwick 1926 // For the purposes of unit testing and maintaining sanity, it is important that this enum be contiguous
29 jfenwick 1865 enum ES_optype
30     {
31     UNKNOWNOP=0,
32 jfenwick 1868 IDENTITY=1,
33     ADD=2,
34     SUB=3,
35     MUL=4,
36 jfenwick 1886 DIV=5,
37 jfenwick 1910 POW=6,
38     SIN=POW+1,
39     COS=SIN+1,
40     TAN=SIN+2,
41     ASIN=SIN+3,
42     ACOS=SIN+4,
43     ATAN=SIN+5,
44     SINH=SIN+6,
45     COSH=SIN+7,
46     TANH=SIN+8,
47     ERF=SIN+9,
48     ASINH=SIN+10,
49     ACOSH=SIN+11,
50     ATANH=SIN+12,
51     LOG10=ATANH+1,
52     LOG=LOG10+1,
53     SIGN=LOG10+2,
54     ABS=LOG10+3,
55     NEG=LOG10+4,
56     POS=LOG10+5,
57     EXP=LOG10+6,
58     SQRT=LOG10+7,
59     RECIP=LOG10+8,
60     GZ=RECIP+1,
61     LZ=GZ+1,
62     GEZ=GZ+2,
63     LEZ=GZ+3
64 jfenwick 1865 };
65    
66     const std::string&
67     opToString(ES_optype op);
68    
69     /**
70     \class escript::DataLazy
71     \brief Wraps an expression tree of other DataObjects.
72 jfenwick 1903 The data will be evaluated when required.
73 jfenwick 1879
74 jfenwick 1903
75 jfenwick 1879 NOTE: This class assumes that the Data being pointed at are immutable.
76 jfenwick 1865 */
77    
78 jfenwick 1879 class DataLazy;
79    
80     typedef POINTER_WRAPPER_CLASS(DataLazy) DataLazy_ptr;
81     typedef POINTER_WRAPPER_CLASS(const DataLazy) const_DataLazy_ptr;
82    
83 jfenwick 1865 class DataLazy : public DataAbstract
84     {
85    
86     typedef DataAbstract parent;
87     typedef DataTypes::ValueType ValueType;
88     typedef DataTypes::ShapeType ShapeType;
89    
90     public:
91 jfenwick 1899 /**
92     \brief Create an IDENTITY DataLazy for the given DataAbstract.
93     \param p DataAbstract to be wrapped.
94     \throws DataException if p is lazy data or it is not constant, tagged or expanded.
95     */
96 jfenwick 1865 ESCRIPT_DLL_API
97     DataLazy(DataAbstract_ptr p);
98    
99 jfenwick 1899
100     /**
101     \brief Produce a DataLazy for a unary operation.
102     \param left DataAbstract to be operated on.
103     \param op unary operation to perform.
104     \throws DataException if op is not a unary operation or if p cannot be converted to a DataLazy.
105     Note that IDENTITY is not considered a unary operation.
106     */
107 jfenwick 1865 ESCRIPT_DLL_API
108 jfenwick 1886 DataLazy(DataAbstract_ptr left, ES_optype op);
109    
110 jfenwick 1899 /**
111     \brief Produce a DataLazy for a binary operation.
112     \param left left operand
113     \param right right operand
114     \param op unary operation to perform.
115     \throws DataException if op is not a binary operation or if left or right cannot be converted to a DataLazy.
116     */
117 jfenwick 1886 ESCRIPT_DLL_API
118 jfenwick 1865 DataLazy(DataAbstract_ptr left, DataAbstract_ptr right, ES_optype op);
119    
120     ESCRIPT_DLL_API
121     ~DataLazy();
122    
123     /**
124 jfenwick 1899 \brief Evaluate the lazy expression.
125     \return A DataReady with the value of the lazy expresion.
126 jfenwick 1865 */
127     ESCRIPT_DLL_API
128 jfenwick 1879 DataReady_ptr
129     resolve();
130 jfenwick 1865
131     ESCRIPT_DLL_API
132     std::string
133     toString() const;
134    
135     ESCRIPT_DLL_API
136     DataAbstract*
137     deepCopy();
138    
139    
140     /**
141     \brief
142     Return the number of doubles that would be stored for this Data object if it were resolved.
143     */
144     ESCRIPT_DLL_API
145     ValueType::size_type
146     getLength() const;
147    
148    
149     ESCRIPT_DLL_API
150     DataAbstract*
151     getSlice(const DataTypes::RegionType& region) const;
152    
153    
154     DataTypes::ValueType::size_type
155     getPointOffset(int sampleNo,
156     int dataPointNo) const;
157    
158 jfenwick 1879
159 jfenwick 1899 /**
160     \return the number of samples which need to be stored to evaluate the expression.
161     */
162 jfenwick 1879 ESCRIPT_DLL_API
163     int
164     getBuffsRequired() const;
165    
166 jfenwick 1901 /**
167     \brief Produces an IDENTITY DataLazy containing zero.
168     The result will have the same shape and functionspace as before.
169     */
170     ESCRIPT_DLL_API
171     virtual void
172     setToZero();
173 jfenwick 1889
174 jfenwick 1865 private:
175 jfenwick 1899 DataReady_ptr m_id; // For IDENTITY nodes, stores a wrapped value.
176     DataLazy_ptr m_left, m_right; // operands for operation.
177     ES_optype m_op; // operation to perform.
178 jfenwick 1879 size_t m_length; // number of values represented by the operation
179    
180 jfenwick 1899 int m_buffsRequired; // how many samples are required to evaluate this expression
181 jfenwick 1879 size_t m_samplesize; // number of values required to store a sample
182    
183 jfenwick 1899 char m_readytype; // E for expanded, T for tagged, C for constant
184 jfenwick 1879
185 jfenwick 1889
186 jfenwick 1899 /**
187     Does the work for toString.
188     */
189 jfenwick 1886 void
190     intoString(std::ostringstream& oss) const;
191    
192 jfenwick 1899 /**
193     \brief Converts the DataLazy into an IDENTITY storing the value of the expression.
194     This method uses the original methods on the Data class to evaluate the expressions.
195     For this reason, it should not be used on DataExpanded instances. (To do so would defeat
196     the purpose of using DataLazy in the first place).
197     */
198 jfenwick 1889 void
199     collapse(); // converts the node into an IDENTITY node
200    
201 jfenwick 1899
202     /**
203     \brief Evaluates the expression using methods on Data.
204     This does the work for the collapse method.
205     For reasons of efficiency do not call this method on DataExpanded nodes.
206     */
207 jfenwick 1889 DataReady_ptr
208     collapseToReady();
209    
210 jfenwick 1899 /**
211     \brief Compute the value of the expression for the given sample.
212     \return Vector which stores the value of the subexpression for the given sample.
213     \param v A vector to store intermediate results.
214     \param offset Index in v to begin storing results.
215     \param sampleNo Sample number to evaluate.
216     \param roffset (output parameter) the offset in the return vector where the result begins.
217 jfenwick 1889
218 jfenwick 1899 The return value will be an existing vector so do not deallocate it.
219     */
220     const ValueType*
221     resolveSample(ValueType& v, size_t offset ,int sampleNo, size_t& roffset);
222 jfenwick 1889
223 jfenwick 1899 /**
224     \brief Compute the value of the expression (binary operation) for the given sample.
225     \return Vector which stores the value of the subexpression for the given sample.
226     \param v A vector to store intermediate results.
227     \param offset Index in v to begin storing results.
228     \param sampleNo Sample number to evaluate.
229     \param roffset (output parameter) the offset in the return vector where the result begins.
230    
231     The return value will be an existing vector so do not deallocate it.
232     If the result is stored in v it should be stored at the offset given.
233     Everything from offset to the end of v should be considered available for this method to use.
234     */
235 jfenwick 1898 ValueType*
236     resolveUnary(ValueType& v, size_t offset,int sampleNo, size_t& roffset) const;
237 jfenwick 1889
238 jfenwick 1899 /**
239     \brief Compute the value of the expression (binary operation) for the given sample.
240     \return Vector which stores the value of the subexpression for the given sample.
241     \param v A vector to store intermediate results.
242     \param offset Index in v to begin storing results.
243     \param sampleNo Sample number to evaluate.
244     \param roffset (output parameter) the offset in the return vector where the result begins.
245    
246     The return value will be an existing vector so do not deallocate it.
247     If the result is stored in v it should be stored at the offset given.
248     Everything from offset to the end of v should be considered available for this method to use.
249     */
250 jfenwick 1898 ValueType*
251     resolveBinary(ValueType& v, size_t offset,int sampleNo, size_t& roffset) const;
252    
253 jfenwick 1865 };
254    
255     }
256     #endif

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