diff options
| -rw-r--r-- | ChangeLog | 8 | ||||
| -rw-r--r-- | java/io/DataOutputStream.java | 104 |
2 files changed, 77 insertions, 35 deletions
@@ -1,3 +1,11 @@ +2006-04-11 Bryce McKinlay <mckinlay@redhat.com> + + * java/io/DataOutputStream.java (writeUTF): Re-use fixed length byte + buffer. Loop only once to determine Utf8 length when possible. Make + the inner loop bounded by buf.length. + (getUTFlength): New private method. + (buf): New private field. + 2006-04-11 Lillian Angel <langel@redhat.com> * gnu/xml/dom/DomNodeIterator.java diff --git a/java/io/DataOutputStream.java b/java/io/DataOutputStream.java index 25178160d..fcaa97eec 100644 --- a/java/io/DataOutputStream.java +++ b/java/io/DataOutputStream.java @@ -63,6 +63,11 @@ public class DataOutputStream extends FilterOutputStream implements DataOutput protected int written; /** + * Utf8 byte buffer, used by writeUTF() + */ + private byte[] buf; + + /** * This method initializes an instance of <code>DataOutputStream</code> to * write its data to the specified underlying <code>OutputStream</code> * @@ -373,6 +378,37 @@ public class DataOutputStream extends FilterOutputStream implements DataOutput } /** + * Calculate the length, in bytes, of a <code>String</code> in Utf8 format. + * + * @param value The <code>String</code> to measure + * @param start String index at which to begin count + * @param sum Starting Utf8 byte count + * + * @throws UTFDataFormatException if result would exceed 65535 + */ + private int getUTFlength(String value, int start, int sum) + throws IOException + { + int len = value.length(); + + for (int i = start; i < len && sum <= 65535; ++i) + { + char c = value.charAt(i); + if (c >= '\u0001' && c <= '\u007f') + sum += 1; + else if (c == '\u0000' || (c >= '\u0080' && c <= '\u07ff')) + sum += 2; + else + sum += 3; + } + + if (sum > 65535) + throw new UTFDataFormatException (); + + return sum; + } + + /** * This method writes a Java <code>String</code> to the stream in a modified * UTF-8 format. First, two bytes are written to the stream indicating the * number of bytes to follow. Note that this is the number of bytes in the @@ -407,48 +443,46 @@ public class DataOutputStream extends FilterOutputStream implements DataOutput public final synchronized void writeUTF(String value) throws IOException { int len = value.length(); - int sum = 0; - - for (int i = 0; i < len && sum <= 65535; ++i) - { - char c = value.charAt(i); - if (c >= '\u0001' && c <= '\u007f') - sum += 1; - else if (c == '\u0000' || (c >= '\u0080' && c <= '\u07ff')) - sum += 2; - else - sum += 3; - } - - if (sum > 65535) - throw new UTFDataFormatException (); - + int i = 0; int pos = 0; - byte[] buf = new byte[sum]; + boolean lengthWritten = false; - for (int i = 0; i < len; ++i) + if (buf == null) + buf = new byte[512]; + + while (i < len) { - char c = value.charAt(i); - if (c >= '\u0001' && c <= '\u007f') - buf[pos++] = (byte) c; - else if (c == '\u0000' || (c >= '\u0080' && c <= '\u07ff')) + while (i < len && pos < buf.length - 3) { - buf[pos++] = (byte) (0xc0 | (0x1f & (c >> 6))); - buf[pos++] = (byte) (0x80 | (0x3f & c)); + char c = value.charAt(i++); + if (c >= '\u0001' && c <= '\u007f') + buf[pos++] = (byte) c; + else if (c == '\u0000' || (c >= '\u0080' && c <= '\u07ff')) + { + buf[pos++] = (byte) (0xc0 | (0x1f & (c >> 6))); + buf[pos++] = (byte) (0x80 | (0x3f & c)); + } + else + { + // JSL says the first byte should be or'd with 0xc0, but + // that is a typo. Unicode says 0xe0, and that is what is + // consistent with DataInputStream. + buf[pos++] = (byte) (0xe0 | (0x0f & (c >> 12))); + buf[pos++] = (byte) (0x80 | (0x3f & (c >> 6))); + buf[pos++] = (byte) (0x80 | (0x3f & c)); + } } - else + if (! lengthWritten) { - // JSL says the first byte should be or'd with 0xc0, but - // that is a typo. Unicode says 0xe0, and that is what is - // consistent with DataInputStream. - buf[pos++] = (byte) (0xe0 | (0x0f & (c >> 12))); - buf[pos++] = (byte) (0x80 | (0x3f & (c >> 6))); - buf[pos++] = (byte) (0x80 | (0x3f & c)); + if (i == len) + writeShort(pos); + else + writeShort(getUTFlength(value, i, pos)); + lengthWritten = true; } - } - - writeShort (sum); - write(buf, 0, sum); + write(buf, 0, pos); + pos = 0; + } } } // class DataOutputStream |