| 1 | package com.hammurapi.extract.scripting; |
| 2 | |
| 3 | import java.util.Arrays; |
| 4 | import java.util.Map; |
| 5 | import java.util.Set; |
| 6 | import java.util.TreeSet; |
| 7 | |
| 8 | import javax.script.ScriptEngine; |
| 9 | import javax.script.ScriptEngineFactory; |
| 10 | import javax.script.ScriptException; |
| 11 | |
| 12 | import com.hammurapi.extract.Extractor; |
| 13 | import com.hammurapi.extract.ExtractorBase; |
| 14 | import com.hammurapi.extract.ExtractorException; |
| 15 | import com.hammurapi.extract.ExtractorFactory; |
| 16 | |
| 17 | class ScriptingExtractor<T, V, C> extends ExtractorBase<T, V, C> { |
| 18 | |
| 19 | private boolean doArgs = true; |
| 20 | private Set<Integer> parameterIndices = new TreeSet<Integer>(); |
| 21 | private String[] parameterNames; |
| 22 | private ScriptEngineFactory sef; |
| 23 | private String code; |
| 24 | |
| 25 | public ScriptingExtractor(String code, ScriptEngineFactory sef, String[] parameterNames) { |
| 26 | super(0, null); // TODO cost from the factory? |
| 27 | for (String pn: parameterNames) { |
| 28 | if (pn!=null) { |
| 29 | doArgs = false; |
| 30 | } |
| 31 | } |
| 32 | |
| 33 | for (int i=0; i<parameterNames.length; ++i) { |
| 34 | if (doArgs || parameterNames[i]!=null) { |
| 35 | parameterIndices.add(i); |
| 36 | } |
| 37 | } |
| 38 | this.parameterNames = parameterNames; |
| 39 | this.sef = sef; |
| 40 | this.code = code; |
| 41 | } |
| 42 | |
| 43 | public boolean isContextDependent() { |
| 44 | return true; |
| 45 | } |
| 46 | |
| 47 | public Set<Integer> parameterIndices() { |
| 48 | return parameterIndices; |
| 49 | } |
| 50 | |
| 51 | ThreadLocal<ScriptEngine> setl = new ThreadLocal<ScriptEngine>() { |
| 52 | |
| 53 | @Override |
| 54 | protected ScriptEngine initialValue() { |
| 55 | return sef.getScriptEngine(); |
| 56 | } |
| 57 | }; |
| 58 | |
| 59 | @SuppressWarnings("unchecked") |
| 60 | @Override |
| 61 | protected V extractInternal(C context, Map<C, Map<Extractor<T, ? super V, C>, ? super V>> cache, T... obj) { |
| 62 | ScriptEngine engine = setl.get(); // Engine is requested once per thread. sef.getScriptEngine(); |
| 63 | if (doArgs) { |
| 64 | engine.put(ExtractorFactory.ARGS_BINDING, obj); |
| 65 | } else { |
| 66 | for (int i=0, l=Math.min(parameterNames.length, obj.length); i<l; ++i) { |
| 67 | if (parameterNames[i]!=null) { |
| 68 | engine.put(parameterNames[i], obj[i]); |
| 69 | } |
| 70 | } |
| 71 | } |
| 72 | engine.put(ExtractorFactory.CONTEXT_BINDING, context); |
| 73 | try { |
| 74 | return (V) engine.eval(code); |
| 75 | } catch (ScriptException e) { |
| 76 | throw new ExtractorException("Error evaluating '"+code+"'", e); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | @Override |
| 81 | public int hashCode() { |
| 82 | final int prime = 31; |
| 83 | int result = 1; |
| 84 | result = prime * result + ((code == null) ? 0 : code.hashCode()); |
| 85 | result = prime * result + (doArgs ? 1231 : 1237); |
| 86 | result = prime |
| 87 | * result |
| 88 | + ((parameterIndices == null) ? 0 : parameterIndices.hashCode()); |
| 89 | result = prime * result + Arrays.hashCode(parameterNames); |
| 90 | result = prime * result + ((sef == null) ? 0 : sef.hashCode()); |
| 91 | return result; |
| 92 | } |
| 93 | |
| 94 | @Override |
| 95 | public boolean equals(Object obj) { |
| 96 | if (this == obj) |
| 97 | return true; |
| 98 | |
| 99 | if (obj == null) |
| 100 | return false; |
| 101 | |
| 102 | if (getClass() != obj.getClass()) |
| 103 | return false; |
| 104 | |
| 105 | ScriptingExtractor other = (ScriptingExtractor) obj; |
| 106 | |
| 107 | if (code == null) { |
| 108 | if (other.code != null) |
| 109 | return false; |
| 110 | } else if (!code.equals(other.code)) |
| 111 | return false; |
| 112 | |
| 113 | if (doArgs != other.doArgs) |
| 114 | return false; |
| 115 | |
| 116 | if (parameterIndices == null) { |
| 117 | if (other.parameterIndices != null) |
| 118 | return false; |
| 119 | } else if (!parameterIndices.equals(other.parameterIndices)) |
| 120 | return false; |
| 121 | |
| 122 | if (!Arrays.equals(parameterNames, other.parameterNames)) |
| 123 | return false; |
| 124 | |
| 125 | if (sef == null) { |
| 126 | if (other.sef != null) |
| 127 | return false; |
| 128 | } else if (!sef.equals(other.sef)) { |
| 129 | return sef.getClass().equals(other.sef.getClass()) |
| 130 | && equal(sef.getEngineName(), other.sef.getEngineName()) |
| 131 | && equal(sef.getEngineVersion(), other.sef.getEngineVersion()); |
| 132 | } |
| 133 | return true; |
| 134 | } |
| 135 | |
| 136 | private boolean equal(String s1, String s2) { |
| 137 | return (s1==null && s2==null) || (s1!=null && s2!=null && s1.equals(s2)); |
| 138 | } |
| 139 | |
| 140 | @Override |
| 141 | public String toString() { |
| 142 | return getClass().getName()+"("+sef.getEngineName()+" v. "+sef.getEngineVersion()+", code '"+code+"', parameter indices "+parameterIndices+")"; |
| 143 | } |
| 144 | } |