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perf(core): optimize parseInt/parseLong hot paths in Numbers.java #5

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4c13344
Optimize parseInt0 and parseLong0 hot paths
misrasaurabh1 Feb 25, 2026
50926a7
Optimize parseIPv4_0: replace multi-pass with single-pass scan
misrasaurabh1 Feb 25, 2026
222b67b
Optimize Uuid.parseHi/parseLo: replace loop-based with unrolled hex p…
misrasaurabh1 Feb 25, 2026
e11ad73
Optimize appendUuid: replace appendHexPadded calls with direct nibble…
misrasaurabh1 Feb 25, 2026
3a2c24c
Optimize getIPv4Subnet: eliminate redundant Chars.indexOf call
misrasaurabh1 Feb 25, 2026
6d3e6be
Optimize appendLong256: replace padded appendHex calls with direct ni…
misrasaurabh1 Feb 25, 2026
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239 changes: 150 additions & 89 deletions core/src/main/java/io/questdb/std/Numbers.java
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Original file line number Diff line number Diff line change
Expand Up @@ -544,15 +544,51 @@ public static void appendLong256FromUnsafe(long address, CharSink<?> sink) {
}

public static void appendUuid(long lo, long hi, CharSink<?> sink) {
appendHexPadded(sink, (hi >> 32) & 0xFFFFFFFFL, 4);
// first group: 8 hex chars from hi bits 63..32
int w = (int) (hi >> 32);
sink.putAscii(hexDigits[(w >> 28) & 0xF]);
sink.putAscii(hexDigits[(w >> 24) & 0xF]);
sink.putAscii(hexDigits[(w >> 20) & 0xF]);
sink.putAscii(hexDigits[(w >> 16) & 0xF]);
sink.putAscii(hexDigits[(w >> 12) & 0xF]);
sink.putAscii(hexDigits[(w >> 8) & 0xF]);
sink.putAscii(hexDigits[(w >> 4) & 0xF]);
sink.putAscii(hexDigits[w & 0xF]);
sink.putAscii('-');
appendHexPadded(sink, (hi >> 16) & 0xFFFF, 2);
// second group: 4 hex chars from hi bits 31..16
w = (int) ((hi >> 16) & 0xFFFF);
sink.putAscii(hexDigits[(w >> 12) & 0xF]);
sink.putAscii(hexDigits[(w >> 8) & 0xF]);
sink.putAscii(hexDigits[(w >> 4) & 0xF]);
sink.putAscii(hexDigits[w & 0xF]);
sink.putAscii('-');
appendHexPadded(sink, hi & 0xFFFF, 2);
// third group: 4 hex chars from hi bits 15..0
w = (int) (hi & 0xFFFF);
sink.putAscii(hexDigits[(w >> 12) & 0xF]);
sink.putAscii(hexDigits[(w >> 8) & 0xF]);
sink.putAscii(hexDigits[(w >> 4) & 0xF]);
sink.putAscii(hexDigits[w & 0xF]);
sink.putAscii('-');
appendHexPadded(sink, lo >> 48 & 0xFFFF, 2);
// fourth group: 4 hex chars from lo bits 63..48
w = (int) ((lo >> 48) & 0xFFFF);
sink.putAscii(hexDigits[(w >> 12) & 0xF]);
sink.putAscii(hexDigits[(w >> 8) & 0xF]);
sink.putAscii(hexDigits[(w >> 4) & 0xF]);
sink.putAscii(hexDigits[w & 0xF]);
sink.putAscii('-');
appendHexPadded(sink, lo & 0xFFFFFFFFFFFFL, 6);
// fifth group: 12 hex chars from lo bits 47..0
sink.putAscii(hexDigits[(int) ((lo >> 44) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 40) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 36) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 32) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 28) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 24) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 20) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 16) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 12) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 8) & 0xF)]);
sink.putAscii(hexDigits[(int) ((lo >> 4) & 0xF)]);
sink.putAscii(hexDigits[(int) (lo & 0xF)]);
}

public static int bswap(int value) {
Expand Down Expand Up @@ -880,25 +916,33 @@ public static int getIPv4Netmask(CharSequence sequence) {
// returns net addr + netmask in a single long value
// throws NumericException on error
public static long getIPv4Subnet(CharSequence sequence) throws NumericException {
int netmask = getIPv4Netmask(sequence);
if (netmask == BAD_NETMASK) {
throw NumericException.instance().put("invalid netmask in IPv4 subnet: ").put(sequence);
}
// find '/' once and reuse for both netmask extraction and IP parsing
final int slashPos = Chars.indexOf(sequence, 0, '/');

int mid = Chars.indexOf(sequence, 0, '/');
int netmask;
if (slashPos == -1) {
netmask = 0xffffffff;
} else {
try {
netmask = toNetMask(parseInt0(sequence, slashPos + 1, sequence.length()));
} catch (NumericException e) {
netmask = BAD_NETMASK;
}
if (netmask == BAD_NETMASK) {
throw NumericException.instance().put("invalid netmask in IPv4 subnet: ").put(sequence);
}
}

try {
if (mid == -1) { // no netmask
if (slashPos == -1) {
return pack(parseIPv4(sequence), netmask);
}

int ipv4 = parseIPv4_0(sequence, 0, mid);
return pack(ipv4, netmask);
return pack(parseIPv4_0(sequence, 0, slashPos), netmask);
} catch (NumericException e) {
if (mid == -1) {
if (slashPos == -1) {
throw NumericException.instance().put("invalid IPv4 subnet format, expected format: x.x.x.x/mask, got: ").put(sequence);
}
return pack(parseSubnet0(sequence, 0, mid, getNetmaskLength(netmask)), netmask);
return pack(parseSubnet0(sequence, 0, slashPos, getNetmaskLength(netmask)), netmask);
}
}

Expand Down Expand Up @@ -1232,59 +1276,60 @@ public static int parseIPv4_0(CharSequence sequence, final int p, int lim) throw
throw NumericException.instance().put("empty IPv4 address string");
}

int hi;
int lo = p;
int num;
int ipv4 = 0;
int count = 0;

final char sign = sequence.charAt(lo);

// removes any leading dots
if (notDigit(sign)) {
if (sign == '.') {
do {
lo++;
} while (sequence.charAt(lo) == '.');
} else {
throw NumericException.instance().put("invalid IPv4 address: ").put(sequence);
if (sequence.charAt(lo) == '.') {
while (lo < lim && sequence.charAt(lo) == '.') {
lo++;
}
}

while ((hi = Chars.indexOf(sequence, lo, '.')) > -1 && count < 3) {
num = parseInt(sequence, lo, hi);
if (num > 255) {
throw NumericException.instance().put("IPv4 octet out of range [0-255]: ").put(num);
if (lo >= lim) {
throw NumericException.instance().put("invalid IPv4 address: ").put(sequence);
}
ipv4 = (ipv4 << 8) | num;
count++;
lo = hi + 1;
} else if (notDigit(sequence.charAt(lo))) {
throw NumericException.instance().put("invalid IPv4 address: ").put(sequence);
}

if (count != 3) {
throw NumericException.instance().put("IPv4 address must have 4 octets, found: ").put(count + 1);
}
int ipv4 = 0;
int oct = 0;
int octetCount = 0;
boolean hasDigits = false;

// removes any trailing dots
if ((hi = Chars.indexOf(sequence, lo, '.')) > -1) {
num = parseInt(sequence, lo, hi);
hi++;
while (hi < lim) {
if (sequence.charAt(hi) == '.') {
hi++;
} else {
throw NumericException.instance().put("invalid character in IPv4 address: ").put(sequence);
for (int i = lo; i < lim; i++) {
char c = sequence.charAt(i);
if (c >= '0' && c <= '9') {
oct = oct * 10 + (c - '0');
if (oct > 255) {
throw NumericException.instance().put("IPv4 octet out of range [0-255]: ").put(oct);
}
hasDigits = true;
} else if (c == '.') {
if (octetCount == 3) {
// trailing dots are allowed - verify all remaining chars are dots
for (int j = i + 1; j < lim; j++) {
if (sequence.charAt(j) != '.') {
throw NumericException.instance().put("invalid character in IPv4 address: ").put(sequence);
}
}
break;
}
if (!hasDigits) {
throw NumericException.instance().put("invalid IPv4 address: ").put(sequence);
}
ipv4 = (ipv4 << 8) | oct;
oct = 0;
hasDigits = false;
octetCount++;
} else {
throw NumericException.instance().put("invalid IPv4 address: ").put(sequence);
}
} else {
num = parseInt(sequence, lo, lim);
}

if (num > 255) {
throw NumericException.instance().put("IPv4 octet out of range [0-255]: ").put(num);
if (octetCount != 3 || !hasDigits) {
throw NumericException.instance().put("IPv4 address must have 4 octets, found: ").put(octetCount + 1);
}

return (ipv4 << 8) | num;
return (ipv4 << 8) | oct;
}

public static int parseInt(Utf8Sequence sequence) throws NumericException {
Expand Down Expand Up @@ -2598,19 +2643,38 @@ private static void appendLong2(CharSink<?> sink, long i) {
sink.putAscii((char) ('0' + i % 10));
}

private static void appendHex16(CharSink<?> sink, long value) {
sink.putAscii(hexDigits[(int) ((value >> 60) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 56) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 52) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 48) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 44) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 40) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 36) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 32) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 28) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 24) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 20) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 16) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 12) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 8) & 0xF)]);
sink.putAscii(hexDigits[(int) ((value >> 4) & 0xF)]);
sink.putAscii(hexDigits[(int) (value & 0xF)]);
}

private static void appendLong256Four(long a, long b, long c, long d, CharSink<?> sink) {
appendLong256Three(b, c, d, sink);
appendHex(sink, a, true);
appendHex16(sink, a);
}

private static void appendLong256Three(long a, long b, long c, CharSink<?> sink) {
appendLong256Two(b, c, sink);
appendHex(sink, a, true);
appendHex16(sink, a);
}

private static void appendLong256Two(long a, long b, CharSink<?> sink) {
appendHex(sink, b, false);
appendHex(sink, a, true);
appendHex16(sink, a);
}

private static void appendLong3(CharSink<?> sink, long i) {
Expand Down Expand Up @@ -2869,14 +2933,7 @@ private static int parseInt0(CharSequence sequence, final int p, int lim) throws
int val = 0;
for (; i < lim; i++) {
char c = sequence.charAt(i);
if (c == '_') {
if (digitCounter == 0) {
throw NumericException.instance().put("invalid integer format: ").put(sequence, p, lim);
}
digitCounter = 0;
} else if (c < '0' || c > '9') {
throw NumericException.instance().put("invalid character in integer: ").put(sequence, p, lim);
} else {
if (c >= '0' && c <= '9') {
// val * 10 + (c - '0')
if (val < (Integer.MIN_VALUE / 10)) {
throw NumericException.instance().put("integer overflow: ").put(sequence, p, lim);
Expand All @@ -2887,6 +2944,13 @@ private static int parseInt0(CharSequence sequence, final int p, int lim) throws
}
val = r;
digitCounter++;
} else if (c == '_') {
if (digitCounter == 0) {
throw NumericException.instance().put("invalid integer format: ").put(sequence, p, lim);
}
digitCounter = 0;
} else {
throw NumericException.instance().put("invalid character in integer: ").put(sequence, p, lim);
}
}

Expand Down Expand Up @@ -2916,29 +2980,26 @@ private static long parseLong0(CharSequence sequence, final int p, int lim) thro
long val = 0;
for (; i < lim; i++) {
int c = sequence.charAt(i);
switch (c | 32) {
case 'l':
if (i == 0 || i + 1 < lim) {
throw NumericException.instance().put("invalid long format: ").put(sequence, p, lim);
}
break;
case 127: // '_'
if (digitCounter == 0) {
throw NumericException.instance().put("invalid long format: ").put(sequence, p, lim);
}
digitCounter = 0;
break;
default:
if (c < '0' || c > '9') {
throw NumericException.instance().put("invalid character in long: ").put(sequence, p, lim);
}
// val * 10 + (c - '0')
long r = (val << 3) + (val << 1) - (c - '0');
if (r > val) {
throw NumericException.instance().put("long overflow: ").put(sequence, p, lim);
}
val = r;
digitCounter++;
if (c >= '0' && c <= '9') {
// val * 10 + (c - '0')
long r = (val << 3) + (val << 1) - (c - '0');
if (r > val) {
throw NumericException.instance().put("long overflow: ").put(sequence, p, lim);
}
val = r;
digitCounter++;
} else if (c == '_') {
if (digitCounter == 0) {
throw NumericException.instance().put("invalid long format: ").put(sequence, p, lim);
}
digitCounter = 0;
} else if (c == 'l' || c == 'L') {
if (digitCounter == 0 || i + 1 < lim) {
throw NumericException.instance().put("invalid long format: ").put(sequence, p, lim);
}
break;
} else {
throw NumericException.instance().put("invalid character in long: ").put(sequence, p, lim);
}
}

Expand Down
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