org.postgresql.util.PGbytea Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jdbc-yugabytedb Show documentation
Show all versions of jdbc-yugabytedb Show documentation
Java JDBC 4.2 (JRE 8+) driver for YugaByte SQL database
The newest version!
/*
* Copyright (c) 2003, PostgreSQL Global Development Group
* See the LICENSE file in the project root for more information.
*/
package org.postgresql.util;
import org.checkerframework.checker.nullness.qual.PolyNull;
import java.sql.SQLException;
/**
* Converts to and from the postgresql bytea datatype used by the backend.
*/
public class PGbytea {
private static final int MAX_3_BUFF_SIZE = 2 * 1024 * 1024;
/**
* Lookup table for each of the valid ascii code points (offset by {@code '0'})
* to the 4 bit numeric value.
*/
private static final int[] HEX_VALS = new int['f' + 1 - '0'];
static {
for (int i = 0; i < 10; i++) {
HEX_VALS[i] = (byte) i;
}
for (int i = 0; i < 6; i++) {
HEX_VALS['A' + i - '0'] = (byte) (10 + i);
HEX_VALS['a' + i - '0'] = (byte) (10 + i);
}
}
/*
* Converts a PG bytea raw value (i.e. the raw binary representation of the bytea data type) into
* a java byte[]
*/
public static byte @PolyNull [] toBytes(byte @PolyNull[] s) throws SQLException {
if (s == null) {
return null;
}
// Starting with PG 9.0, a new hex format is supported
// that starts with "\x". Figure out which format we're
// dealing with here.
//
if (s.length < 2 || s[0] != '\\' || s[1] != 'x') {
return toBytesOctalEscaped(s);
}
return toBytesHexEscaped(s);
}
private static byte[] toBytesHexEscaped(byte[] s) {
// first 2 bytes of s indicate the byte[] is hex encoded
// so they need to be ignored here
final int realLength = s.length - 2;
byte[] output = new byte[realLength >>> 1];
for (int i = 0; i < realLength; i += 2) {
int val = getHex(s[2 + i]) << 4;
val |= getHex(s[3 + i]);
output[i >>> 1] = (byte) val;
}
return output;
}
private static int getHex(byte b) {
return HEX_VALS[b - '0'];
}
private static byte[] toBytesOctalEscaped(byte[] s) {
final int slength = s.length;
byte[] buf = null;
int correctSize = slength;
if (slength > MAX_3_BUFF_SIZE) {
// count backslash escapes, they will be either
// backslashes or an octal escape \\ or \003
//
for (int i = 0; i < slength; i++) {
byte current = s[i];
if (current == '\\') {
byte next = s[++i];
if (next == '\\') {
--correctSize;
} else {
correctSize -= 3;
}
}
}
buf = new byte[correctSize];
} else {
buf = new byte[slength];
}
int bufpos = 0;
int thebyte;
byte nextbyte;
byte secondbyte;
for (int i = 0; i < slength; i++) {
nextbyte = s[i];
if (nextbyte == (byte) '\\') {
secondbyte = s[++i];
if (secondbyte == (byte) '\\') {
// escaped \
buf[bufpos++] = (byte) '\\';
} else {
thebyte = (secondbyte - 48) * 64 + (s[++i] - 48) * 8 + (s[++i] - 48);
if (thebyte > 127) {
thebyte -= 256;
}
buf[bufpos++] = (byte) thebyte;
}
} else {
buf[bufpos++] = nextbyte;
}
}
if (bufpos == correctSize) {
return buf;
}
byte[] result = new byte[bufpos];
System.arraycopy(buf, 0, result, 0, bufpos);
return result;
}
/*
* Converts a java byte[] into a PG bytea string (i.e. the text representation of the bytea data
* type)
*/
public static @PolyNull String toPGString(byte @PolyNull[] buf) {
if (buf == null) {
return null;
}
StringBuilder stringBuilder = new StringBuilder(2 * buf.length);
for (byte element : buf) {
int elementAsInt = (int) element;
if (elementAsInt < 0) {
elementAsInt = 256 + elementAsInt;
}
// we escape the same non-printable characters as the backend
// we must escape all 8bit characters otherwise when converting
// from java unicode to the db character set we may end up with
// question marks if the character set is SQL_ASCII
if (elementAsInt < 32 || elementAsInt > 126) {
// escape character with the form \000, but need two \\ because of
// the Java parser
stringBuilder.append("\\");
stringBuilder.append((char) (((elementAsInt >> 6) & 0x3) + 48));
stringBuilder.append((char) (((elementAsInt >> 3) & 0x7) + 48));
stringBuilder.append((char) ((elementAsInt & 0x07) + 48));
} else if (element == (byte) '\\') {
// escape the backslash character as \\, but need four \\\\ because
// of the Java parser
stringBuilder.append("\\\\");
} else {
// other characters are left alone
stringBuilder.append((char) element);
}
}
return stringBuilder.toString();
}
}
© 2015 - 2024 Weber Informatics LLC | Privacy Policy