hunt.sql.visitor.functions.Unhex source code

1 /*
2  * Copyright 2015-2018 HuntLabs.cn
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 module hunt.sql.visitor.functions.Unhex;
17 
18 // import hunt.sql.visitor.SQLEvalVisitor.EVAL_EXPR;
19 // import hunt.sql.visitor.SQLEvalVisitor.EVAL_VALUE;
20 
21 
22 import hunt.sql.ast.SQLExpr;
23 import hunt.sql.ast.expr.SQLMethodInvokeExpr;
24 import hunt.sql.visitor.SQLEvalVisitor;
25 import hunt.sql.util.HexBin;
26 import hunt.sql.visitor.functions.Function;
27 //import hunt.lang;
28 import hunt.String;
29 import hunt.String;
30 import hunt.collection;
31 import std.conv;
32 import std.uni;
33 import hunt.text;
34 
35 import std.concurrency : initOnce;
36 
37 public class Unhex : Function {
38 
39     static Unhex instance() {
40         __gshared Unhex inst;
41         return initOnce!inst(new Unhex());
42     } 
43     
44     // public  static Unhex instance;
45 
46     // static this()
47     // {
48     //     instance = new Unhex();
49     // }
50 
51     public Object eval(SQLEvalVisitor visitor, SQLMethodInvokeExpr x) {
52         if (x.getParameters().size() != 1) {
53             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
54         }
55 
56         SQLExpr param0 = x.getParameters().get(0);
57 
58         if (cast(SQLMethodInvokeExpr)(param0) !is null) {
59             SQLMethodInvokeExpr paramMethodExpr = cast(SQLMethodInvokeExpr) param0;
60             if (paramMethodExpr.getMethodName().equalsIgnoreCase("hex")) {
61                 SQLExpr subParamExpr = paramMethodExpr.getParameters().get(0);
62                 subParamExpr.accept(visitor);
63 
64                 Object param0Value = subParamExpr.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
65                 if (param0Value is null) {
66                     x.putAttribute(SQLEvalVisitor.EVAL_EXPR,cast(Object)subParamExpr);
67                     return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
68                 }
69 
70                 return param0Value;
71             }
72         }
73 
74         param0.accept(visitor);
75 
76         Object param0Value = param0.getAttributes().get(SQLEvalVisitor.EVAL_VALUE);
77         if (param0Value is null) {
78             return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
79         }
80 
81         if (cast(String)(param0Value) !is null) {
82             byte[] bytes = HexBin.decode((cast(String) param0Value).value());
83             if (bytes is null) {
84                 return cast(Object)(SQLEvalVisitor.EVAL_VALUE_NULL);
85             }
86             
87             string result;
88             try {
89                 result = cast(string)(bytes);
90             } catch (Exception e) {
91                 throw new Exception(e.msg, e);
92             }
93             return new String(result);
94         }
95 
96         return cast(Object)(SQLEvalVisitor.EVAL_ERROR);
97     }
98 }