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1 | package be.nikiroo.utils; |
2 | ||
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3 | import java.io.ByteArrayInputStream; |
4 | import java.io.Closeable; | |
5 | import java.io.File; | |
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6 | import java.io.IOException; |
7 | import java.io.InputStream; | |
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8 | import java.io.OutputStream; |
9 | import java.io.Serializable; | |
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11 | import be.nikiroo.utils.streams.MarkableFileInputStream; |
12 | ||
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13 | /** |
14 | * This class represents an image data. | |
15 | * | |
16 | * @author niki | |
17 | */ | |
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18 | public class Image implements Closeable, Serializable { |
19 | static private final long serialVersionUID = 1L; | |
20 | ||
82fcfcde | 21 | static private File tempRoot; |
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22 | static private TempFiles tmpRepository; |
23 | static private long count = 0; | |
24 | static private Object lock = new Object(); | |
25 | ||
26 | private File data; | |
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27 | |
28 | /** | |
29 | * Do not use -- for serialisation purposes only. | |
30 | */ | |
31 | @SuppressWarnings("unused") | |
32 | private Image() { | |
33 | } | |
34 | ||
35 | /** | |
36 | * Create a new {@link Image} with the given data. | |
37 | * | |
38 | * @param data | |
39 | * the data | |
40 | */ | |
41 | public Image(byte[] data) { | |
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42 | ByteArrayInputStream in = new ByteArrayInputStream(data); |
43 | try { | |
44 | this.data = getTemporaryFile(); | |
45 | IOUtils.write(in, this.data); | |
46 | } catch (IOException e) { | |
47 | throw new RuntimeException(e); | |
48 | } finally { | |
49 | try { | |
50 | in.close(); | |
51 | } catch (IOException e) { | |
52 | throw new RuntimeException(e); | |
53 | } | |
54 | } | |
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55 | } |
56 | ||
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57 | /** |
58 | * Create a new {@link Image} from a stream. | |
59 | * | |
60 | * @param in | |
61 | * the stream | |
62 | * | |
63 | * @throws IOException | |
64 | * in case of I/O error | |
65 | */ | |
66 | public Image(InputStream in) throws IOException { | |
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67 | data = getTemporaryFile(); |
68 | IOUtils.write(in, data); | |
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69 | } |
70 | ||
7b42695f | 71 | /** |
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72 | * Generate an {@link InputStream} that you can {@link InputStream#reset()} |
73 | * for this {@link Image}. | |
7b42695f NR |
74 | * <p> |
75 | * This {@link InputStream} will (always) be a new one, and <b>you</b> are | |
76 | * responsible for it. | |
77 | * <p> | |
78 | * Note: take care that the {@link InputStream} <b>must not</b> live past | |
79 | * the {@link Image} life time! | |
80 | * | |
81 | * @return the stream | |
82 | * | |
83 | * @throws IOException | |
84 | * in case of I/O error | |
85 | */ | |
86 | public InputStream newInputStream() throws IOException { | |
7194ac50 | 87 | return new MarkableFileInputStream(data); |
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88 | } |
89 | ||
80500544 | 90 | /** |
59864f77 | 91 | * <b>Read</b> the actual image data, as a byte array. |
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92 | * <p> |
93 | * Note: if possible, prefer the {@link Image#newInputStream()} method, as | |
94 | * it can be more efficient. | |
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95 | * |
96 | * @return the image data | |
97 | */ | |
98 | public byte[] getData() { | |
59864f77 | 99 | try { |
7b42695f | 100 | InputStream in = newInputStream(); |
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101 | try { |
102 | return IOUtils.toByteArray(in); | |
103 | } finally { | |
104 | in.close(); | |
105 | } | |
106 | } catch (IOException e) { | |
107 | throw new RuntimeException(e); | |
108 | } | |
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109 | } |
110 | ||
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111 | /** |
112 | * Closing the {@link Image} will delete the associated temporary file on | |
113 | * disk. | |
114 | * <p> | |
115 | * Note that even if you don't, the program will still <b>try</b> to delete | |
116 | * all the temporary files at JVM termination. | |
117 | */ | |
118 | @Override | |
119 | public void close() throws IOException { | |
120 | data.delete(); | |
121 | synchronized (lock) { | |
122 | count--; | |
123 | if (count <= 0) { | |
124 | count = 0; | |
125 | tmpRepository.close(); | |
126 | tmpRepository = null; | |
127 | } | |
128 | } | |
129 | } | |
130 | ||
131 | @Override | |
132 | protected void finalize() throws Throwable { | |
133 | try { | |
134 | close(); | |
135 | } finally { | |
136 | super.finalize(); | |
137 | } | |
138 | } | |
139 | ||
140 | /** | |
141 | * Return a newly created temporary file to work on. | |
142 | * | |
143 | * @return the file | |
144 | * | |
145 | * @throws IOException | |
146 | * in case of I/O error | |
147 | */ | |
148 | private File getTemporaryFile() throws IOException { | |
149 | synchronized (lock) { | |
150 | if (tmpRepository == null) { | |
82fcfcde | 151 | tmpRepository = new TempFiles(tempRoot, "images"); |
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152 | count = 0; |
153 | } | |
154 | ||
155 | count++; | |
156 | ||
157 | return tmpRepository.createTempFile("image"); | |
158 | } | |
159 | } | |
82fcfcde | 160 | |
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161 | /** |
162 | * Write this {@link Image} for serialization purposes; that is, write the | |
163 | * content of the backing temporary file. | |
164 | * | |
165 | * @param out | |
166 | * the {@link OutputStream} to write to | |
167 | * | |
168 | * @throws IOException | |
169 | * in case of I/O error | |
170 | */ | |
171 | private void writeObject(java.io.ObjectOutputStream out) throws IOException { | |
172 | InputStream in = newInputStream(); | |
173 | try { | |
174 | IOUtils.write(in, out); | |
175 | } finally { | |
176 | in.close(); | |
177 | } | |
178 | } | |
179 | ||
180 | /** | |
181 | * Read an {@link Image} written by | |
182 | * {@link Image#writeObject(java.io.ObjectOutputStream)}; that is, create a | |
183 | * new temporary file with the saved content. | |
184 | * | |
185 | * @param in | |
186 | * the {@link InputStream} to read from | |
187 | * @throws IOException | |
188 | * in case of I/O error | |
189 | * @throws ClassNotFoundException | |
190 | * will not be thrown by this method | |
191 | */ | |
192 | @SuppressWarnings("unused") | |
193 | private void readObject(java.io.ObjectInputStream in) throws IOException, | |
194 | ClassNotFoundException { | |
195 | data = getTemporaryFile(); | |
196 | IOUtils.write(in, data); | |
197 | } | |
198 | ||
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199 | /** |
200 | * Change the temporary root directory used by the program. | |
201 | * <p> | |
202 | * Caution: the directory will be <b>owned</b> by the system, all its files | |
203 | * now belong to us (and will most probably be deleted). | |
204 | * <p> | |
205 | * Note: it may take some time until the new temporary root is used, we | |
206 | * first need to make sure the previous one is not used anymore (i.e., we | |
207 | * must reach a point where no unclosed {@link Image} remains in memory) to | |
208 | * switch the temporary root. | |
209 | * | |
210 | * @param root | |
211 | * the new temporary root, which will be <b>owned</b> by the | |
212 | * system | |
213 | */ | |
214 | public static void setTemporaryFilesRoot(File root) { | |
215 | tempRoot = root; | |
216 | } | |
80500544 | 217 | } |