69 }
70
71 // public methods --------------------------------------------------------
72
73 /**
74 * Loads an ICU binary data file and returns it as a ByteBuffer.
75 * The buffer contents is normally read-only, but its position etc. can be modified.
76 *
77 * @param itemPath Relative ICU data item path, for example "root.res" or "coll/ucadata.icu".
78 * @return The data as a read-only ByteBuffer.
79 */
80 public static ByteBuffer getRequiredData(String itemPath) {
81 final Class<ICUBinary> root = ICUBinary.class;
82
83 try (InputStream is = AccessController.doPrivileged(new PrivilegedAction<InputStream>() {
84 public InputStream run() {
85 return root.getResourceAsStream(itemPath);
86 }
87 })) {
88
89 BufferedInputStream b=new BufferedInputStream(is, 4096 /* data buffer size */);
90 DataInputStream inputStream = new DataInputStream(b);
91 byte[] bb = new byte[130000];
92 int n = inputStream.read(bb);
93 ByteBuffer bytes = ByteBuffer.wrap(bb, 0, n);
94 return bytes;
95 }
96 catch (IOException e) {
97 throw new UncheckedIOException(e);
98 }
99 }
100
101 /**
102 * Same as readHeader(), but returns a VersionInfo rather than a compact int.
103 */
104 public static VersionInfo readHeaderAndDataVersion(ByteBuffer bytes,
105 int dataFormat,
106 Authenticate authenticate)
107 throws IOException {
108 return getVersionInfoFromCompactInt(readHeader(bytes, dataFormat, authenticate));
109 }
110
111 private static final byte BIG_ENDIAN_ = 1;
112 public static final byte[] readHeader(InputStream inputStream,
113 byte dataFormatIDExpected[],
114 Authenticate authenticate)
|
69 }
70
71 // public methods --------------------------------------------------------
72
73 /**
74 * Loads an ICU binary data file and returns it as a ByteBuffer.
75 * The buffer contents is normally read-only, but its position etc. can be modified.
76 *
77 * @param itemPath Relative ICU data item path, for example "root.res" or "coll/ucadata.icu".
78 * @return The data as a read-only ByteBuffer.
79 */
80 public static ByteBuffer getRequiredData(String itemPath) {
81 final Class<ICUBinary> root = ICUBinary.class;
82
83 try (InputStream is = AccessController.doPrivileged(new PrivilegedAction<InputStream>() {
84 public InputStream run() {
85 return root.getResourceAsStream(itemPath);
86 }
87 })) {
88
89 // is.available() may return 0, or 1, or the total number of bytes in the stream,
90 // or some other number.
91 // Do not try to use is.available() == 0 to find the end of the stream!
92 byte[] bytes;
93 int avail = is.available();
94 if (avail > 32) {
95 // There are more bytes available than just the ICU data header length.
96 // With luck, it is the total number of bytes.
97 bytes = new byte[avail];
98 } else {
99 bytes = new byte[128]; // empty .res files are even smaller
100 }
101 // Call is.read(...) until one returns a negative value.
102 int length = 0;
103 for(;;) {
104 if (length < bytes.length) {
105 int numRead = is.read(bytes, length, bytes.length - length);
106 if (numRead < 0) {
107 break; // end of stream
108 }
109 length += numRead;
110 } else {
111 // See if we are at the end of the stream before we grow the array.
112 int nextByte = is.read();
113 if (nextByte < 0) {
114 break;
115 }
116 int capacity = 2 * bytes.length;
117 if (capacity < 128) {
118 capacity = 128;
119 } else if (capacity < 0x4000) {
120 capacity *= 2; // Grow faster until we reach 16kB.
121 }
122 // TODO Java 6 replace new byte[] and arraycopy(): bytes = Arrays.copyOf(bytes, capacity);
123 byte[] newBytes = new byte[capacity];
124 System.arraycopy(bytes, 0, newBytes, 0, length);
125 bytes = newBytes;
126 bytes[length++] = (byte) nextByte;
127 }
128 }
129 return ByteBuffer.wrap(bytes, 0, length);
130 }
131 catch (IOException e) {
132 throw new UncheckedIOException(e);
133 }
134 }
135
136 /**
137 * Same as readHeader(), but returns a VersionInfo rather than a compact int.
138 */
139 public static VersionInfo readHeaderAndDataVersion(ByteBuffer bytes,
140 int dataFormat,
141 Authenticate authenticate)
142 throws IOException {
143 return getVersionInfoFromCompactInt(readHeader(bytes, dataFormat, authenticate));
144 }
145
146 private static final byte BIG_ENDIAN_ = 1;
147 public static final byte[] readHeader(InputStream inputStream,
148 byte dataFormatIDExpected[],
149 Authenticate authenticate)
|