/**
* ensure that have number char available and not allready read
*
* @param number ?
* @throws IOException
*/
private void fill(int number) throws IOException {
int needed = nextChar + number - buffer.size();
if (needed > 0) {
char[] cbuf = new char[needed + READ_AHEAD];
int read = in.read(cbuf);
for (int i = 0; i < read; i++) {
buffer.add(cbuf[i]);
}
}
}
/**
* remove number of char in buffer
*
* @param number
* @return the real number of char removed from the head of buffer
* @throws IOException
*/
private int free(int number) throws IOException {
// fill(number);
int result = Math.min(buffer.size(), number);
buffer.subList(0, result).clear();
nextChar -= result;
markChar -= result;
return result;
}
/**
* read one char in buffer
*
* @return the next car
* @throws IOException pour tout pb de lecture
*/
public int read() throws IOException {
fill(1);
int result = -1;
if (nextChar < buffer.size()) {
result = buffer.get(nextChar++);
charNumber++;
if (result == '\n') {
lineNumber++;
}
}
return result;
}
/**
* go left in reading char buffer
*
* @param number
* @return realy unread char number
*/
public int unread(int number) {
int result = Math.min(number, nextChar);
nextChar -= result;
charNumber -= result;
for (int i = nextChar; i < nextChar + result; i++) {
if (buffer.get(i) == '\n') {
lineNumber--;
}
}
return result;
}
