Optimization
This commit is contained in:
Andrea Cavalli
parent
40d7f35a8e
commit
4ff1eb0179
|
|
@ -1,13 +1,11 @@
|
|||
package it.cavallium.buffer;
|
||||
|
||||
import static it.cavallium.stream.SafeDataOutputStream.strLen;
|
||||
import static it.cavallium.stream.SafeDataOutputStream.utfLen;
|
||||
|
||||
import it.cavallium.stream.SafeByteArrayOutputStream;
|
||||
import it.cavallium.stream.SafeDataOutput;
|
||||
import it.cavallium.stream.SafeDataOutputStream;
|
||||
import it.unimi.dsi.fastutil.Arrays;
|
||||
import java.io.IOException;
|
||||
import java.nio.charset.StandardCharsets;
|
||||
import java.util.Objects;
|
||||
import org.jetbrains.annotations.NotNull;
|
||||
|
||||
|
|
@ -205,11 +203,13 @@ public class BufDataOutput implements SafeDataOutput {
|
|||
|
||||
@Override
|
||||
public void writeUTF(@NotNull String str) {
|
||||
var strlen = strLen(str);
|
||||
var utflen = utfLen(str, strlen);
|
||||
var bytes = Short.BYTES + utflen;
|
||||
checkOutOfBounds(bytes);
|
||||
dOut.writeUTF(strlen, utflen, str);
|
||||
var out = str.getBytes(StandardCharsets.UTF_8);
|
||||
if (out.length > Short.MAX_VALUE) {
|
||||
throw new IndexOutOfBoundsException("String too long: " + out.length + " bytes");
|
||||
}
|
||||
checkOutOfBounds(Short.BYTES + out.length);
|
||||
dOut.writeShort(out.length);
|
||||
dOut.write(out);
|
||||
}
|
||||
|
||||
public Buf asList() {
|
||||
|
|
|
|||
|
|
@ -26,6 +26,7 @@
|
|||
package it.cavallium.stream;
|
||||
|
||||
import java.io.DataOutputStream;
|
||||
import java.nio.charset.StandardCharsets;
|
||||
|
||||
/**
|
||||
* A data output stream lets an application write primitive Java data
|
||||
|
|
@ -326,102 +327,15 @@ public class SafeDataOutputStream extends SafeFilterOutputStream implements Safe
|
|||
* @see #writeChars(String)
|
||||
*/
|
||||
public final void writeUTF(String str) {
|
||||
writeUTF(str, this);
|
||||
}
|
||||
|
||||
public final void writeUTF(int strlen, int utflen, String str) {
|
||||
writeUTF(strlen, utflen, str, this);
|
||||
}
|
||||
|
||||
/**
|
||||
* Writes a string to the specified DataOutput using
|
||||
* <a href="DataInput.html#modified-utf-8">modified UTF-8</a>
|
||||
* encoding in a machine-independent manner.
|
||||
* <p>
|
||||
* First, two bytes are written to out as if by the {@code writeShort}
|
||||
* method giving the number of bytes to follow. This value is the number of
|
||||
* bytes actually written out, not the length of the string. Following the
|
||||
* length, each character of the string is output, in sequence, using the
|
||||
* modified UTF-8 encoding for the character. If no exception is thrown, the
|
||||
* counter {@code written} is incremented by the total number of
|
||||
* bytes written to the output stream. This will be at least two
|
||||
* plus the length of {@code str}, and at most two plus
|
||||
* thrice the length of {@code str}.
|
||||
*
|
||||
* @param str a string to be written.
|
||||
* @param out destination to write to
|
||||
* @return The number of bytes written out.
|
||||
*/
|
||||
static int writeUTF(String str, SafeDataOutput out) {
|
||||
int strlen = strLen(str);
|
||||
int utflen = utfLen(str, strlen);
|
||||
return writeUTF(strlen, utflen, str, out);
|
||||
}
|
||||
|
||||
public static int strLen(String str) {
|
||||
return str.length();
|
||||
}
|
||||
|
||||
public static int utfLen(String str, int strLen) {
|
||||
int utflen = strLen; // optimized for ASCII
|
||||
|
||||
for (int i = 0; i < strLen; i++) {
|
||||
int c = str.charAt(i);
|
||||
if (c >= 0x80 || c == 0)
|
||||
utflen += (c >= 0x800) ? 2 : 1;
|
||||
var outString = str.getBytes(StandardCharsets.UTF_8);
|
||||
if (outString.length > Short.MAX_VALUE) {
|
||||
throw new IndexOutOfBoundsException("String too long: " + outString.length + " bytes");
|
||||
}
|
||||
|
||||
if (utflen > 65535 || /* overflow */ utflen < strLen)
|
||||
throw new IllegalArgumentException(tooLongMsg(str, utflen));
|
||||
return utflen;
|
||||
}
|
||||
|
||||
static int writeUTF(int strlen, int utflen, String str, SafeDataOutput out) {
|
||||
final byte[] bytearr;
|
||||
if (out instanceof SafeDataOutputStream dos) {
|
||||
if (dos.bytearr == null || (dos.bytearr.length < (utflen + 2)))
|
||||
dos.bytearr = new byte[(utflen*2) + 2];
|
||||
bytearr = dos.bytearr;
|
||||
} else {
|
||||
bytearr = new byte[utflen + 2];
|
||||
}
|
||||
|
||||
int count = 0;
|
||||
bytearr[count++] = (byte) ((utflen >>> 8) & 0xFF);
|
||||
bytearr[count++] = (byte) ((utflen) & 0xFF);
|
||||
|
||||
int i;
|
||||
for (i = 0; i < strlen; i++) { // optimized for initial run of ASCII
|
||||
int c = str.charAt(i);
|
||||
if (c >= 0x80 || c == 0) break;
|
||||
bytearr[count++] = (byte) c;
|
||||
}
|
||||
|
||||
for (; i < strlen; i++) {
|
||||
int c = str.charAt(i);
|
||||
if (c < 0x80 && c != 0) {
|
||||
bytearr[count++] = (byte) c;
|
||||
} else if (c >= 0x800) {
|
||||
bytearr[count++] = (byte) (0xE0 | ((c >> 12) & 0x0F));
|
||||
bytearr[count++] = (byte) (0x80 | ((c >> 6) & 0x3F));
|
||||
bytearr[count++] = (byte) (0x80 | ((c) & 0x3F));
|
||||
} else {
|
||||
bytearr[count++] = (byte) (0xC0 | ((c >> 6) & 0x1F));
|
||||
bytearr[count++] = (byte) (0x80 | ((c) & 0x3F));
|
||||
}
|
||||
}
|
||||
out.write(bytearr, 0, utflen + 2);
|
||||
return utflen + 2;
|
||||
}
|
||||
|
||||
private static String tooLongMsg(String s, int bits32) {
|
||||
int slen = s.length();
|
||||
String head = s.substring(0, 8);
|
||||
String tail = s.substring(slen - 8, slen);
|
||||
// handle int overflow with max 3x expansion
|
||||
long actualLength = (long)slen + Integer.toUnsignedLong(bits32 - slen);
|
||||
return "encoded string (" + head + "..." + tail + ") too long: "
|
||||
+ actualLength + " bytes";
|
||||
var v = outString.length;
|
||||
out.write((v >>> 8) & 0xFF);
|
||||
out.write((v) & 0xFF);
|
||||
out.write(outString);
|
||||
incCount(2 + outString.length);
|
||||
}
|
||||
|
||||
/**
|
||||
|
|
|
|||
Loading…
Reference in New Issue