/** Assigns {@code nextToken} based on the value of {@code nextValue}. */
private JsonToken decodeLiteral() throws IOException {
if (valuePos == -1) {
// it was too long to fit in the buffer so it can only be a string
return JsonToken.STRING;
} else if (valueLength == 4
&& ('n' == buffer[valuePos] || 'N' == buffer[valuePos])
&& ('u' == buffer[valuePos + 1] || 'U' == buffer[valuePos + 1])
&& ('l' == buffer[valuePos + 2] || 'L' == buffer[valuePos + 2])
&& ('l' == buffer[valuePos + 3] || 'L' == buffer[valuePos + 3])) {
value = "null";
return JsonToken.NULL;
} else if (valueLength == 4
&& ('t' == buffer[valuePos] || 'T' == buffer[valuePos])
&& ('r' == buffer[valuePos + 1] || 'R' == buffer[valuePos + 1])
&& ('u' == buffer[valuePos + 2] || 'U' == buffer[valuePos + 2])
&& ('e' == buffer[valuePos + 3] || 'E' == buffer[valuePos + 3])) {
value = TRUE;
return JsonToken.BOOLEAN;
} else if (valueLength == 5
&& ('f' == buffer[valuePos] || 'F' == buffer[valuePos])
&& ('a' == buffer[valuePos + 1] || 'A' == buffer[valuePos + 1])
&& ('l' == buffer[valuePos + 2] || 'L' == buffer[valuePos + 2])
&& ('s' == buffer[valuePos + 3] || 'S' == buffer[valuePos + 3])
&& ('e' == buffer[valuePos + 4] || 'E' == buffer[valuePos + 4])) {
value = FALSE;
return JsonToken.BOOLEAN;
} else {
value = stringPool.get(buffer, valuePos, valueLength);
return decodeNumber(buffer, valuePos, valueLength);
}
}
/**
* Unescapes the character identified by the character or characters that immediately follow a
* backslash. The backslash '\' should have already been read. This supports both unicode escapes
* "u000A" and two-character escapes "\n".
*
* @throws NumberFormatException if any unicode escape sequences are malformed.
*/
private char readEscapeCharacter() throws IOException {
if (pos == limit && !fillBuffer(1)) {
throw syntaxError("Unterminated escape sequence");
}
char escaped = buffer[pos++];
switch (escaped) {
case 'u':
if (pos + 4 > limit && !fillBuffer(4)) {
throw syntaxError("Unterminated escape sequence");
}
String hex = stringPool.get(buffer, pos, 4);
pos += 4;
return (char) Integer.parseInt(hex, 16);
case 't':
return '\t';
case 'b':
return '\b';
case 'n':
return '\n';
case 'r':
return '\r';
case 'f':
return '\f';
case '\'':
case '"':
case '\\':
default:
return escaped;
}
}
/**
* Returns the string up to but not including {@code quote}, unescaping any character escape
* sequences encountered along the way. The opening quote should have already been read. This
* consumes the closing quote, but does not include it in the returned string.
*
* @param quote either ' or ".
* @throws NumberFormatException if any unicode escape sequences are malformed.
*/
private String nextString(char quote) throws IOException {
StringBuilder builder = null;
do {
/* the index of the first character not yet appended to the builder. */
int start = pos;
while (pos < limit) {
int c = buffer[pos++];
if (c == quote) {
if (skipping) {
return "skipped!";
} else if (builder == null) {
return stringPool.get(buffer, start, pos - start - 1);
} else {
builder.append(buffer, start, pos - start - 1);
return builder.toString();
}
} else if (c == '\\') {
if (builder == null) {
builder = new StringBuilder();
}
builder.append(buffer, start, pos - start - 1);
builder.append(readEscapeCharacter());
start = pos;
}
}
if (builder == null) {
builder = new StringBuilder();
}
builder.append(buffer, start, pos - start);
} while (fillBuffer(1));
throw syntaxError("Unterminated string");
}
/**
* Reads the value up to but not including any delimiter characters. This does not consume the
* delimiter character.
*
* @param assignOffsetsOnly true for this method to only set the valuePos and valueLength fields
* and return a null result. This only works if the literal is short; a string is returned
* otherwise.
*/
private String nextLiteral(boolean assignOffsetsOnly) throws IOException {
StringBuilder builder = null;
valuePos = -1;
valueLength = 0;
int i = 0;
findNonLiteralCharacter:
while (true) {
for (; pos + i < limit; i++) {
switch (buffer[pos + i]) {
case '/':
case '\\':
case ';':
case '#':
case '=':
checkLenient(); // fall-through
case '{':
case '}':
case '[':
case ']':
case ':':
case ',':
case ' ':
case '\t':
case '\f':
case '\r':
case '\n':
break findNonLiteralCharacter;
}
}
/*
* Attempt to load the entire literal into the buffer at once. If
* we run out of input, add a non-literal character at the end so
* that decoding doesn't need to do bounds checks.
*/
if (i < buffer.length) {
if (fillBuffer(i + 1)) {
continue;
} else {
buffer[limit] = '\0';
break;
}
}
// use a StringBuilder when the value is too long. It must be an unquoted string.
if (builder == null) {
builder = new StringBuilder();
}
builder.append(buffer, pos, i);
valueLength += i;
pos += i;
i = 0;
if (!fillBuffer(1)) {
break;
}
}
String result;
if (assignOffsetsOnly && builder == null) {
valuePos = pos;
result = null;
} else if (skipping) {
result = "skipped!";
} else if (builder == null) {
result = stringPool.get(buffer, pos, i);
} else {
builder.append(buffer, pos, i);
result = builder.toString();
}
valueLength += i;
pos += i;
return result;
}
