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Diffstat (limited to 'src/asm/scala/tools/asm/ByteVector.java')
-rw-r--r-- | src/asm/scala/tools/asm/ByteVector.java | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/asm/scala/tools/asm/ByteVector.java b/src/asm/scala/tools/asm/ByteVector.java new file mode 100644 index 0000000000..5081f0184b --- /dev/null +++ b/src/asm/scala/tools/asm/ByteVector.java @@ -0,0 +1,293 @@ +/*** + * ASM: a very small and fast Java bytecode manipulation framework + * Copyright (c) 2000-2011 INRIA, France Telecom + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF + * THE POSSIBILITY OF SUCH DAMAGE. + */ +package scala.tools.asm; + +/** + * A dynamically extensible vector of bytes. This class is roughly equivalent to + * a DataOutputStream on top of a ByteArrayOutputStream, but is more efficient. + * + * @author Eric Bruneton + */ +public class ByteVector { + + /** + * The content of this vector. + */ + byte[] data; + + /** + * Actual number of bytes in this vector. + */ + int length; + + /** + * Constructs a new {@link ByteVector ByteVector} with a default initial + * size. + */ + public ByteVector() { + data = new byte[64]; + } + + /** + * Constructs a new {@link ByteVector ByteVector} with the given initial + * size. + * + * @param initialSize the initial size of the byte vector to be constructed. + */ + public ByteVector(final int initialSize) { + data = new byte[initialSize]; + } + + /** + * Puts a byte into this byte vector. The byte vector is automatically + * enlarged if necessary. + * + * @param b a byte. + * @return this byte vector. + */ + public ByteVector putByte(final int b) { + int length = this.length; + if (length + 1 > data.length) { + enlarge(1); + } + data[length++] = (byte) b; + this.length = length; + return this; + } + + /** + * Puts two bytes into this byte vector. The byte vector is automatically + * enlarged if necessary. + * + * @param b1 a byte. + * @param b2 another byte. + * @return this byte vector. + */ + ByteVector put11(final int b1, final int b2) { + int length = this.length; + if (length + 2 > data.length) { + enlarge(2); + } + byte[] data = this.data; + data[length++] = (byte) b1; + data[length++] = (byte) b2; + this.length = length; + return this; + } + + /** + * Puts a short into this byte vector. The byte vector is automatically + * enlarged if necessary. + * + * @param s a short. + * @return this byte vector. + */ + public ByteVector putShort(final int s) { + int length = this.length; + if (length + 2 > data.length) { + enlarge(2); + } + byte[] data = this.data; + data[length++] = (byte) (s >>> 8); + data[length++] = (byte) s; + this.length = length; + return this; + } + + /** + * Puts a byte and a short into this byte vector. The byte vector is + * automatically enlarged if necessary. + * + * @param b a byte. + * @param s a short. + * @return this byte vector. + */ + ByteVector put12(final int b, final int s) { + int length = this.length; + if (length + 3 > data.length) { + enlarge(3); + } + byte[] data = this.data; + data[length++] = (byte) b; + data[length++] = (byte) (s >>> 8); + data[length++] = (byte) s; + this.length = length; + return this; + } + + /** + * Puts an int into this byte vector. The byte vector is automatically + * enlarged if necessary. + * + * @param i an int. + * @return this byte vector. + */ + public ByteVector putInt(final int i) { + int length = this.length; + if (length + 4 > data.length) { + enlarge(4); + } + byte[] data = this.data; + data[length++] = (byte) (i >>> 24); + data[length++] = (byte) (i >>> 16); + data[length++] = (byte) (i >>> 8); + data[length++] = (byte) i; + this.length = length; + return this; + } + + /** + * Puts a long into this byte vector. The byte vector is automatically + * enlarged if necessary. + * + * @param l a long. + * @return this byte vector. + */ + public ByteVector putLong(final long l) { + int length = this.length; + if (length + 8 > data.length) { + enlarge(8); + } + byte[] data = this.data; + int i = (int) (l >>> 32); + data[length++] = (byte) (i >>> 24); + data[length++] = (byte) (i >>> 16); + data[length++] = (byte) (i >>> 8); + data[length++] = (byte) i; + i = (int) l; + data[length++] = (byte) (i >>> 24); + data[length++] = (byte) (i >>> 16); + data[length++] = (byte) (i >>> 8); + data[length++] = (byte) i; + this.length = length; + return this; + } + + /** + * Puts an UTF8 string into this byte vector. The byte vector is + * automatically enlarged if necessary. + * + * @param s a String. + * @return this byte vector. + */ + public ByteVector putUTF8(final String s) { + int charLength = s.length(); + int len = length; + if (len + 2 + charLength > data.length) { + enlarge(2 + charLength); + } + byte[] data = this.data; + // optimistic algorithm: instead of computing the byte length and then + // serializing the string (which requires two loops), we assume the byte + // length is equal to char length (which is the most frequent case), and + // we start serializing the string right away. During the serialization, + // if we find that this assumption is wrong, we continue with the + // general method. + data[len++] = (byte) (charLength >>> 8); + data[len++] = (byte) charLength; + for (int i = 0; i < charLength; ++i) { + char c = s.charAt(i); + if (c >= '\001' && c <= '\177') { + data[len++] = (byte) c; + } else { + int byteLength = i; + for (int j = i; j < charLength; ++j) { + c = s.charAt(j); + if (c >= '\001' && c <= '\177') { + byteLength++; + } else if (c > '\u07FF') { + byteLength += 3; + } else { + byteLength += 2; + } + } + data[length] = (byte) (byteLength >>> 8); + data[length + 1] = (byte) byteLength; + if (length + 2 + byteLength > data.length) { + length = len; + enlarge(2 + byteLength); + data = this.data; + } + for (int j = i; j < charLength; ++j) { + c = s.charAt(j); + if (c >= '\001' && c <= '\177') { + data[len++] = (byte) c; + } else if (c > '\u07FF') { + data[len++] = (byte) (0xE0 | c >> 12 & 0xF); + data[len++] = (byte) (0x80 | c >> 6 & 0x3F); + data[len++] = (byte) (0x80 | c & 0x3F); + } else { + data[len++] = (byte) (0xC0 | c >> 6 & 0x1F); + data[len++] = (byte) (0x80 | c & 0x3F); + } + } + break; + } + } + length = len; + return this; + } + + /** + * Puts an array of bytes into this byte vector. The byte vector is + * automatically enlarged if necessary. + * + * @param b an array of bytes. May be <tt>null</tt> to put <tt>len</tt> + * null bytes into this byte vector. + * @param off index of the fist byte of b that must be copied. + * @param len number of bytes of b that must be copied. + * @return this byte vector. + */ + public ByteVector putByteArray(final byte[] b, final int off, final int len) + { + if (length + len > data.length) { + enlarge(len); + } + if (b != null) { + System.arraycopy(b, off, data, length, len); + } + length += len; + return this; + } + + /** + * Enlarge this byte vector so that it can receive n more bytes. + * + * @param size number of additional bytes that this byte vector should be + * able to receive. + */ + private void enlarge(final int size) { + int length1 = 2 * data.length; + int length2 = length + size; + byte[] newData = new byte[length1 > length2 ? length1 : length2]; + System.arraycopy(data, 0, newData, 0, length); + data = newData; + } +} |