io.quarkus.runtime.configuration.NameIterator Maven / Gradle / Ivy
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package io.quarkus.runtime.configuration;
import java.util.NoSuchElementException;
import org.wildfly.common.Assert;
/**
*/
public final class NameIterator {
/**
* Configuration key maximum allowed length.
*/
public static final int MAX_LENGTH = 2048;
private static final int POS_MASK = 0x0FFF;
private static final int POS_BITS = 12;
private static final int SE_SHIFT = 32 - POS_BITS;
private final String name;
private int pos;
public NameIterator(final String name) {
this(name, false);
}
public NameIterator(final String name, final boolean startAtEnd) {
this(name, startAtEnd ? name.length() : -1);
}
public NameIterator(final String name, final int pos) {
Assert.checkNotNullParam("name", name);
if (name.length() > MAX_LENGTH)
throw new IllegalArgumentException("Name is too long");
Assert.checkMinimumParameter("pos", -1, pos);
Assert.checkMaximumParameter("pos", name.length(), pos);
if (pos != -1 && pos != name.length() && name.charAt(pos) != '.')
throw new IllegalArgumentException("Position is not located at a delimiter");
this.name = name;
this.pos = pos;
}
public void goToEnd() {
this.pos = name.length();
}
public void goToStart() {
this.pos = -1;
}
/**
* Get the cursor position. It will be {@code -1} if the cursor is at the beginning of the string, or {@code name.length()}
* if it is at the end.
*
* @return the cursor position
*/
public int getPosition() {
return pos;
}
/*
* next-iteration DFA
* → ## on EOI
* I → ## on '.'
* I → Q ## on '"'
* Q → I ## on '"'
* Q → QBS ## on '\'
* QBS → Q ## on any
* I → BS ## on '\'
* BS → I ## on any
*/
private static final int FS_INITIAL = 0;
private static final int FS_QUOTE = 1;
private static final int FS_BACKSLASH = 2;
private static final int FS_QUOTE_BACKSLASH = 3;
/*
* Iteration cookie format
*
* Bit: 14...12 11 ... 0
* ┌───────┬────────────┐
* │ state │ position │
* │ │ (signed) │
* └───────┴────────────┘
*/
/**
* Create a new iteration cookie at the current position.
*
* @return the new cookie
*/
private int initIteration() {
return this.pos & POS_MASK;
}
private int cookieOf(int state, int pos) {
return state << POS_BITS | pos & POS_MASK;
}
private int getPosition(int cookie) {
return (cookie & POS_MASK) << SE_SHIFT >> SE_SHIFT;
}
private int getState(int cookie) {
return cookie >> POS_BITS;
}
/**
* Move to the next position.
*
* @param cookie the original cookie value
* @return the new cookie value
*/
private int nextPos(int cookie) {
int pos = getPosition(cookie);
if (isEndOfString(cookie)) {
throw new NoSuchElementException();
}
int state = getState(cookie);
int ch;
for (;;) {
pos++;
if (pos == name.length()) {
return cookieOf(state, pos);
}
ch = name.charAt(pos);
if (state == FS_INITIAL) {
if (ch == '.') {
return cookieOf(state, pos);
} else if (ch == '"') {
state = FS_QUOTE;
} else if (ch == '\\') {
state = FS_BACKSLASH;
} else {
return cookieOf(state, pos);
}
} else if (state == FS_QUOTE) {
if (ch == '"') {
state = FS_INITIAL;
} else if (ch == '\\') {
state = FS_QUOTE_BACKSLASH;
} else {
return cookieOf(state, pos);
}
} else if (state == FS_BACKSLASH) {
state = FS_INITIAL;
return cookieOf(state, pos);
} else {
assert state == FS_QUOTE_BACKSLASH;
state = FS_QUOTE;
return cookieOf(state, pos);
}
}
}
private int prevPos(int cookie) {
int pos = getPosition(cookie);
if (isStartOfString(cookie)) {
throw new NoSuchElementException();
}
int state = getState(cookie);
int ch;
for (;;) {
pos--;
if (pos == -1) {
return cookieOf(state, pos);
}
ch = name.charAt(pos);
if (state == FS_INITIAL) {
if (pos >= 1 && name.charAt(pos - 1) == '\\') {
// always accept as-is
return cookieOf(state, pos);
} else if (ch == '.') {
return cookieOf(state, pos);
} else if (ch == '"') {
state = FS_QUOTE;
} else if (ch == '\\') {
// skip
} else {
// regular char
return cookieOf(state, pos);
}
} else if (state == FS_QUOTE) {
if (pos >= 1 && name.charAt(pos - 1) == '\\') {
// always accept as-is
return cookieOf(state, pos);
} else if (ch == '"') {
state = FS_INITIAL;
} else if (ch == '\\') {
// skip
} else {
return cookieOf(state, pos);
}
} else {
throw Assert.unreachableCode();
}
}
}
private boolean isSegmentDelimiter(int cookie) {
return isStartOfString(cookie) || isEndOfString(cookie) || getState(cookie) == FS_INITIAL && charAt(cookie) == '.';
}
private boolean isEndOfString(int cookie) {
return getPosition(cookie) == name.length();
}
private boolean isStartOfString(int cookie) {
return getPosition(cookie) == -1;
}
private int charAt(int cookie) {
return name.charAt(getPosition(cookie));
}
public int getPreviousStart() {
int cookie = initIteration();
do {
cookie = prevPos(cookie);
} while (!isSegmentDelimiter(cookie));
return getPosition(cookie) + 1;
}
public int getNextEnd() {
int cookie = initIteration();
do {
cookie = nextPos(cookie);
} while (!isSegmentDelimiter(cookie));
return getPosition(cookie);
}
public boolean nextSegmentEquals(String other) {
return nextSegmentEquals(other, 0, other.length());
}
public boolean nextSegmentEquals(String other, int offs, int len) {
int cookie = initIteration();
int strPos = 0;
for (;;) {
cookie = nextPos(cookie);
if (isSegmentDelimiter(cookie)) {
return strPos == len;
}
if (strPos == len) {
return false;
}
if (other.charAt(offs + strPos) != charAt(cookie)) {
return false;
}
strPos++;
}
}
public String getNextSegment() {
final StringBuilder b = new StringBuilder();
int cookie = initIteration();
for (;;) {
cookie = nextPos(cookie);
if (isSegmentDelimiter(cookie)) {
return b.toString();
}
b.append((char) charAt(cookie));
}
}
public boolean previousSegmentEquals(String other) {
return previousSegmentEquals(other, 0, other.length());
}
public boolean previousSegmentEquals(final String other, final int offs, final int len) {
int cookie = initIteration();
int strPos = len;
for (;;) {
strPos--;
cookie = prevPos(cookie);
if (isSegmentDelimiter(cookie)) {
return strPos == -1;
}
if (strPos == -1) {
return false;
}
if (other.charAt(offs + strPos) != charAt(cookie)) {
return false;
}
}
}
public String getPreviousSegment() {
final StringBuilder b = new StringBuilder();
int cookie = initIteration();
for (;;) {
cookie = prevPos(cookie);
if (isSegmentDelimiter(cookie)) {
return b.reverse().toString();
}
b.append((char) charAt(cookie));
}
}
public String getAllPreviousSegments() {
final int pos = getPosition();
if (pos == -1) {
return "";
}
return name.substring(0, pos);
}
public String getAllPreviousSegmentsWith(String suffix) {
final int pos = getPosition();
if (pos == -1) {
return suffix;
}
return name.substring(0, pos) + "." + suffix;
}
public boolean hasNext() {
return pos < name.length();
}
public boolean hasPrevious() {
return pos > -1;
}
public void next() {
pos = getNextEnd();
}
public void previous() {
pos = getPreviousStart() - 1;
}
public String getName() {
return name;
}
public String toString() {
if (pos == -1) {
return "*" + name;
} else if (pos == name.length()) {
return name + "*";
} else {
return name.substring(0, pos) + '*' + name.substring(pos + 1);
}
}
}
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