tinyosc.h

/**
 * Copyright (c) 2015, Martin Roth (mhroth@gmail.com)
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _TINY_OSC_
#define _TINY_OSC_

#include <stdbool.h>
#include <stdint.h>
#pragma GCC system_header

#define TINYOSC_TIMETAG_IMMEDIATELY 1L

#ifdef __cplusplus
extern "C" {
#endif

typedef struct tosc_message {
	char *format; // a pointer to the format field
	char *marker; // the current read head
	char *buffer; // the original message data (also points to the address)
	uint32_t len; // length of the buffer data
} tosc_message;

typedef struct tosc_bundle {
	char *marker;       // the current write head (where the next message will be
			    // written)
	char *buffer;       // the original buffer
	uint32_t bufLen;    // the byte length of the original buffer
	uint32_t bundleLen; // the byte length of the total bundle
} tosc_bundle;

/**
 * Returns true if the buffer refers to a bundle of OSC messages. False
 * otherwise.
 */
bool tosc_isBundle(const char *buffer);

/**
 * Reads a buffer containing a bundle of OSC messages.
 */
void tosc_parseBundle(tosc_bundle *b, char *buffer, const int len);

/**
 * Returns the timetag of an OSC bundle.
 */
uint64_t tosc_getTimetag(tosc_bundle *b);

/**
 * Parses the next message in a bundle. Returns true if successful.
 * False otherwise.
 */
bool tosc_getNextMessage(tosc_bundle *b, tosc_message *o);

/**
 * Returns a point to the address block of the OSC buffer.
 * This is also the start of the buffer.
 */
char *tosc_getAddress(tosc_message *o);

/**
 * Returns a pointer to the format block of the OSC buffer.
 */
char *tosc_getFormat(tosc_message *o);

/**
 * Returns the length in bytes of this message.
 */
uint32_t tosc_getLength(tosc_message *o);

/**
 * Returns the next 32-bit int. Does not check buffer bounds.
 */
int32_t tosc_getNextInt32(tosc_message *o);

/**
 * Returns the next 64-bit int. Does not check buffer bounds.
 */
int64_t tosc_getNextInt64(tosc_message *o);

/**
 * Returns the next 64-bit timetag. Does not check buffer bounds.
 */
uint64_t tosc_getNextTimetag(tosc_message *o);

/**
 * Returns the next 32-bit float. Does not check buffer bounds.
 */
float tosc_getNextFloat(tosc_message *o);

/**
 * Returns the next 64-bit float. Does not check buffer bounds.
 */
double tosc_getNextDouble(tosc_message *o);

/**
 * Returns the next string, or NULL if the buffer length is exceeded.
 */
const char *tosc_getNextString(tosc_message *o);

/**
 * Points the given buffer pointer to the next blob.
 * The len pointer is set to the length of the blob.
 * Returns NULL and 0 if the OSC buffer bounds are exceeded.
 */
void tosc_getNextBlob(tosc_message *o, const char **buffer, int *len);

/**
 * Returns the next set of midi bytes. Does not check bounds.
 * Bytes from MSB to LSB are: port id, status byte, data1, data2.
 */
unsigned char *tosc_getNextMidi(tosc_message *o);

/**
 * Parse a buffer containing an OSC message.
 * The contents of the buffer are NOT copied.
 * The tosc_message struct only points at relevant parts of the original buffer.
 * Returns 0 if there is no error. An error code (a negative number) otherwise.
 */
int tosc_parseMessage(tosc_message *o, char *buffer, const int len);

/**
 * Starts writing a bundle to the given buffer with length.
 */
void tosc_writeBundle(tosc_bundle *b, uint64_t timetag, char *buffer, const int len);

/**
 * Write a message to a bundle buffer. Returns the number of bytes written.
 */
uint32_t tosc_writeNextMessage(tosc_bundle *b, const char *address, const char *format, ...);

/**
 * Returns the length in bytes of the bundle.
 */
uint32_t tosc_getBundleLength(tosc_bundle *b);

/**
 * Writes an OSC packet to a buffer. Returns the total number of bytes written.
 * The entire buffer is cleared before writing.
 */
uint32_t tosc_writeMessage(char *buffer, const int len, const char *address, const char *fmt, ...);

/**
 * A convenience function to (non-destructively) print a buffer containing
 * an OSC message to stdout.
 */
void tosc_printOscBuffer(char *buffer, const int len);

/**
 * A convenience function to (non-destructively) print a pre-parsed OSC message
 * to stdout.
 */
void tosc_printMessage(tosc_message *o);

// TODO : write that the dst should already have a buffer attached
int tosc_copy_message(tosc_message *dst, tosc_message *src);

// TODO : write that the dst should already have a buffer attached
int tosc_copy_bundle(tosc_bundle *dst, tosc_bundle *src);

#ifdef __cplusplus
}
#endif

// ---- beginning of .c

/**
 * Copyright (c) 2015, Martin Roth (mhroth@gmail.com)
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */
#include "tinyosc.h"
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <string.h>

/* OSC is big-endian, and this must be enforced. These protable endianness functions are
   inspired by Rob Pike's article 'The data order fallacy'
   (https://commandcenter.blogspot.fr/2012/04/byte-order-fallacy.html) */
void encode_32(uint32_t val, char *data)
{
	uint8_t *v = (uint8_t *)&val;
	data[3] = *(v);
	data[2] = *(v + 1);
	data[1] = *(v + 2);
	data[0] = *(v + 3);
}

uint32_t decode_32(char *data)
{
	return (data[3] << 0) | (data[2] << 8) | (data[1] << 16) | (data[0] << 24);
}

void encode_64(uint64_t val, char *data)
{
	uint8_t *v = (uint8_t *)&val;
	data[7] = *v;
	data[6] = *(v + 1);
	data[5] = *(v + 2);
	data[4] = *(v + 3);
	data[3] = *(v + 4);
	data[2] = *(v + 5);
	data[1] = *(v + 6);
	data[0] = *(v + 7);
}

uint64_t decode_64(char *data)
{
	return (data[7] << 0) | (data[6] << 8) | (data[5] << 16) | (data[4] << 24) |
	       (data[3] << 32) | (data[2] << 40) | (data[1] << 48) | (data[0] << 56);
}

const char bundle_id[] = {'#', 'b', 'u', 'n', 'd', 'l', 'e', 0};

// http://opensoundcontrol.org/spec-1_0
int tosc_parseMessage(tosc_message *o, char *buffer, const int len)
{
	// NOTE(mhroth): if there's a comma in the address, that's weird
	int i = 0;
	while (buffer[i] != '\0')
		++i; // find the null-terimated address
	while (buffer[i] != ',')
		++i; // find the comma which starts the format string
	if (i >= len)
		return -1; // error while looking for format string
	// format string is null terminated
	o->format = buffer + i + 1; // format starts after comma

	while (i < len && buffer[i] != '\0')
		++i;
	if (i == len)
		return -2; // format string not null terminated

	i = (i + 4) & ~0x3; // advance to the next multiple of 4 after trailing '\0'
	o->marker = buffer + i;

	o->buffer = buffer;
	o->len = len;

	return 0;
}

// check if first eight bytes are '#bundle '
bool tosc_isBundle(const char *buffer) { return memcmp(bundle_id, buffer, 8) == 0; }

void tosc_parseBundle(tosc_bundle *b, char *buffer, const int len)
{
	b->buffer = (char *)buffer;
	b->marker = buffer + 16; // move past '#bundle ' and timetag fields
	b->bufLen = len;
	b->bundleLen = len;
}

uint64_t tosc_getTimetag(tosc_bundle *b) { return decode_64(b->buffer + 8); }

uint32_t tosc_getBundleLength(tosc_bundle *b) { return b->bundleLen; }

bool tosc_getNextMessage(tosc_bundle *b, tosc_message *o)
{
	if ((b->marker - b->buffer) >= b->bundleLen)
		return false;
	uint32_t len = decode_32(b->marker);
	tosc_parseMessage(o, b->marker + 4, len);
	b->marker += (4 + len); // move marker to next bundle element
	return true;
}

char *tosc_getAddress(tosc_message *o) { return o->buffer; }

char *tosc_getFormat(tosc_message *o) { return o->format; }

uint32_t tosc_getLength(tosc_message *o) { return o->len; }

int32_t tosc_getNextInt32(tosc_message *o)
{
	// convert from big-endian (network btye order)
	const int32_t i = decode_32(o->marker);
	o->marker += 4;
	return i;
}

int64_t tosc_getNextInt64(tosc_message *o)
{
	const int64_t i = (int64_t)decode_64(o->marker);
	o->marker += 8;
	return i;
}

uint64_t tosc_getNextTimetag(tosc_message *o) { return (uint64_t)tosc_getNextInt64(o); }

float tosc_getNextFloat(tosc_message *o)
{
	// convert from big-endian (network btye order)
	const uint32_t i = decode_32(o->marker);
	o->marker += 4;
	return *((float *)(&i));
}

double tosc_getNextDouble(tosc_message *o)
{
	const uint64_t i = decode_64(o->marker);
	o->marker += 8;
	return *((double *)(&i));
}

const char *tosc_getNextString(tosc_message *o)
{
	int i = (int)strlen(o->marker);
	if (o->marker + i >= o->buffer + o->len)
		return NULL;
	const char *s = o->marker;
	i = (i + 4) & ~0x3; // advance to next multiple of 4 after trailing '\0'
	o->marker += i;
	return s;
}

void tosc_getNextBlob(tosc_message *o, const char **buffer, int *len)
{
	int i = decode_32(o->marker); // get the blob length
	if (o->marker + 4 + i <= o->buffer + o->len) {
		*len = i; // length of blob
		*buffer = o->marker + 4;
		i = (i + 7) & ~0x3;
		o->marker += i;
	} else {
		*len = 0;
		*buffer = NULL;
	}
}

unsigned char *tosc_getNextMidi(tosc_message *o)
{
	unsigned char *m = (unsigned char *)o->marker;
	o->marker += 4;
	return m;
}

void tosc_writeBundle(tosc_bundle *b, uint64_t timetag, char *buffer, const int len)
{
	memcpy(buffer, bundle_id, 8);
	encode_64(timetag, buffer + 8);

	b->buffer = buffer;
	b->marker = buffer + 16;
	b->bufLen = len;
	b->bundleLen = 16;
}

// always writes a multiple of 4 bytes
static uint32_t tosc_vwrite(char *buffer, const int len, const char *address, const char *format,
			    va_list ap)
{
	memset(buffer, 0, len); // clear the buffer
	uint32_t i = (uint32_t)strlen(address);
	if (address == NULL || i >= len)
		return -1;
	strcpy(buffer, address);
	i = (i + 4) & ~0x3;
	buffer[i++] = ',';
	int s_len = (int)strlen(format);
	if (format == NULL || (i + s_len) >= len)
		return -2;
	strcpy(buffer + i, format);
	i = (i + 4 + s_len) & ~0x3;

	int j = 0;
	for (j = 0; format[j] != '\0'; ++j) {
		switch (format[j]) {
		case 'b': {
			const uint32_t n = (uint32_t)va_arg(ap, int); // length of blob
			if (i + 4 + n > len)
				return -3;
			char *b = (char *)va_arg(ap, void *); // pointer to binary data
			encode_32(n, (buffer + i));
			i += 4;
			memcpy(buffer + i, b, n);
			i = (i + 3 + n) & ~0x3;
			break;
		}
		case 'f': {
			if (i + 4 > len)
				return -3;
			const float f = (float)va_arg(ap, double);
			encode_32(f, (buffer + i));
			i += 4;
			break;
		}
		case 'd': {
			if (i + 8 > len)
				return -3;
			const double f = (double)va_arg(ap, double);
			encode_64(f, buffer + i);
			i += 8;
			break;
		}
		case 'i': {
			if (i + 4 > len)
				return -3;
			const uint32_t k = (uint32_t)va_arg(ap, int);
			encode_32(k, (buffer + i));
			i += 4;
			break;
		}
		case 'm': {
			if (i + 4 > len)
				return -3;
			const unsigned char *const k = (unsigned char *)va_arg(ap, void *);
			memcpy(buffer + i, k, 4);
			i += 4;
			break;
		}
		case 't':
		case 'h': {
			if (i + 8 > len)
				return -3;
			const uint64_t k = (uint64_t)va_arg(ap, long long);
			encode_64(k, buffer + 1);
			i += 8;
			break;
		}
		case 's': {
			const char *str = (const char *)va_arg(ap, void *);
			s_len = (int)strlen(str);
			if (i + s_len >= len)
				return -3;
			strcpy(buffer + i, str);
			i = (i + 4 + s_len) & ~0x3;
			break;
		}
		case 'T': // true
		case 'F': // false
		case 'N': // nil
		case 'I': // infinitum
			break;
		default:
			return -4; // unknown type
		}
	}

	return i; // return the total number of bytes written
}

uint32_t tosc_writeNextMessage(tosc_bundle *b, const char *address, const char *format, ...)
{
	va_list ap;
	va_start(ap, format);
	if (b->bundleLen >= b->bufLen)
		return 0;
	const uint32_t i =
	    tosc_vwrite(b->marker + 4, b->bufLen - b->bundleLen - 4, address, format, ap);
	va_end(ap);
	encode_32(i, b->marker); // write the length of the message
	b->marker += (4 + i);
	b->bundleLen += (4 + i);
	return i;
}

uint32_t tosc_writeMessage(char *buffer, const int len, const char *address, const char *format,
			   ...)
{
	va_list ap;
	va_start(ap, format);
	const uint32_t i = tosc_vwrite(buffer, len, address, format, ap);
	va_end(ap);
	return i; // return the total number of bytes written
}

void tosc_printOscBuffer(char *buffer, const int len)
{
	// parse the buffer contents (the raw OSC bytes)
	// a return value of 0 indicates no error
	tosc_message m;
	const int err = tosc_parseMessage(&m, buffer, len);
	if (err == 0)
		tosc_printMessage(&m);
	else
		printf("Error while reading OSC buffer: %i\n", err);
}

void tosc_printMessage(tosc_message *osc)
{
	fprintf(stderr, "[%i bytes] %s %s",
		osc->len,	     // the number of bytes in the OSC message
		tosc_getAddress(osc), // the OSC address string, e.g. "/button1"
		tosc_getFormat(osc)); // the OSC format string, e.g. "f"

	for (int i = 0; osc->format[i] != '\0'; i++) {
		switch (osc->format[i]) {
		case 'b': {
			const char *b = NULL; // will point to binary data
			int n = 0;	    // takes the length of the blob
			tosc_getNextBlob(osc, &b, &n);
			fprintf(stderr, " [%i]", n); // print length of blob
			for (int j = 0; j < n; ++j)
				fprintf(stderr, "%02X", b[j] & 0xFF); // print blob bytes
			break;
		}
		case 'm': {
			unsigned char *m = tosc_getNextMidi(osc);
			fprintf(stderr, " 0x%02X%02X%02X%02X", m[0], m[1], m[2], m[3]);
			break;
		}
		case 'f':
			fprintf(stderr, " %g", tosc_getNextFloat(osc));
			break;
		case 'd':
			fprintf(stderr, " %g", tosc_getNextDouble(osc));
			break;
		case 'i':
			fprintf(stderr, " %d", tosc_getNextInt32(osc));
			break;
		case 'h':
			fprintf(stderr, " %lld", tosc_getNextInt64(osc));
			break;
		case 't':
			fprintf(stderr, " %lld", tosc_getNextTimetag(osc));
			break;
		case 's':
			fprintf(stderr, " %s", tosc_getNextString(osc));
			break;
		case 'F':
			fprintf(stderr, " false");
			break;
		case 'I':
			fprintf(stderr, " inf");
			break;
		case 'N':
			fprintf(stderr, " nil");
			break;
		case 'T':
			fprintf(stderr, " true");
			break;
		default:
			fprintf(stderr, " Unknown format: '%c'", osc->format[i]);
			break;
		}
	}
	fprintf(stderr, "\n");
}

// TODO : write that the dst should already have a buffer attached
int tosc_copy_message(tosc_message *dst, tosc_message *src)
{
	if (dst->len < src->len) {
		return 0;
	} // checking space is enough
	memcpy(dst->buffer, src->buffer, src->len);
	dst->len = src->len;
	dst->marker = dst->buffer + (src->marker - src->buffer);
	dst->format = dst->buffer + (src->format - src->buffer);
	return 1;
}

// TODO : write that the dst should already have a buffer attached
int tosc_copy_bundle(tosc_bundle *dst, tosc_bundle *src)
{
	if (dst->bufLen < src->bundleLen) {
		return 0;
	} // checking space is enough
	memcpy(dst->buffer, src->buffer, src->bundleLen);
	dst->bundleLen = src->bundleLen;
	dst->marker = dst->buffer + (src->marker - src->buffer);
	return 1;
}
////////// end of .c

#endif // _TINY_OSC_