heatshrink_decoder_poll return HSDR_POLL_MORE if out buffer is exactly sized as the decoded result

[IvanoBono]

in this example output buffer is sized exactly as the input buffer: program remain il loop.
if i resize the output buffer as sizeof(data)+1 it work, and leftover 1 byte

`
const char data[] = "Cappuccetto Rosso, chiamata anche Cappuccetto, e' una bambina che vive con la sua mamma in una casetta vicino al bosco. Un giorno la mamma le consegna un cestino pieno di cose buone da portare alla nonna malata, che vive al di la' della foresta. La mamma "; //256byte data

char compress[1500];
char out[sizeof(data)];

int Encode() {
heatshrink_encoder hse; //512byte in stack
heatshrink_encoder_reset(&hse);
size_t copied;
size_t tot_copied = 0;
const char* in=data;
size_t remaining = sizeof(data);
size_t srclen = remaining;
size_t readed;
do
{
heatshrink_encoder_sink(&hse, (uint8_t*)in, remaining, &readed);
in += readed;
remaining -= readed;
//printf("readed:%lu\n",readed);
heatshrink_encoder_poll(&hse, (uint8_t*)compress + tot_copied, sizeof(compress)- tot_copied,&copied);
tot_copied += copied;
//printf("copied:%lu tot:%lu\n",copied,tot_copied);
} while (remaining);
heatshrink_encoder_finish(&hse);
HSE_poll_res pres;
do
{
pres = heatshrink_encoder_poll(&hse, (uint8_t*)compress + tot_copied, sizeof(compress)- tot_copied,&copied);
tot_copied += copied;
} while (pres != HSER_POLL_EMPTY);
Uart_Printf(">>>>>>>>>>>>src:%lu dst:%lu\n", srclen, tot_copied);
return tot_copied;
}

int Decode(size_t remaining) {
HSD_sink_res sres;
HSD_poll_res pres;
HSD_finish_res fres;
heatshrink_decoder hsd;
heatshrink_decoder_reset(&hsd);
size_t tot_copied = 0;
size_t readed;
size_t copied;
const uint8_t* in = (const uint8_t*)compress;
do
{
sres =
heatshrink_decoder_sink(&hsd, in, remaining, &readed);
in += readed;
remaining -= readed;
//printf("readed:%lu\n",readed);
pres =heatshrink_decoder_poll(&hsd, (uint8_t*)out + tot_copied,sizeof(out)- tot_copied, &copied);
tot_copied += copied;
//printf("copied:%lu tot:%lu\n",copied,tot_copied);
} while (remaining);
fres = heatshrink_decoder_finish(&hsd);
do //REMAIN ON THIS LOOP FOREVER !!!
{
pres =heatshrink_decoder_poll(&hsd, (uint8_t*)out + tot_copied, sizeof(out) - tot_copied, &copied);
tot_copied += copied;
//printf("src:%lu dst:%lu\n",srclen,tot_copied);
} while (pres != HSER_POLL_EMPTY);
Uart_Printf(">>>>>>>>>>>>decompress:%lu\n", tot_copied);
return tot_copied;
}

void main() {
SysTimer_Init();
Uart_Init(Uart_STDOUT, 0); //console
int n=Encode();
Decode(n);
Uart_Println(out);
Uart_Println("end");
while (1);
}
`

[unixdj]

Bug introduced in commit 8669992

Sorry about that.

[unixdj]

To reproduce:

cc -g -Iinclude -Isrc -DHEATSHRINK_DYNAMIC_ALLOC=0 foo.c src/heatshrink_decoder.c src/heatshrink_encoder.c -o foo && ./foo

with foo.c containing:

#include <stdio.h>
#include "heatshrink_encoder.h"
#include "heatshrink_decoder.h"

const char data[] = "Cappuccetto Rosso, chiamata anche Cappuccetto, e' una bambina che vive con la sua mamma in una casetta vicino al bosco. Un giorno la mamma le consegna un cestino pieno di cose buone da portare alla nonna malata, che vive al di la' della foresta. La mamma "; //256byte data

char compress[1500];
char out[sizeof(data)];

int Encode() {
	heatshrink_encoder hse; //512byte in stack
	heatshrink_encoder_reset(&hse);
	size_t copied;
	size_t tot_copied = 0;
	const char* in=data;
	size_t remaining = sizeof(data);
	size_t srclen = remaining;
	size_t readed;
	do
	{
		heatshrink_encoder_sink(&hse, (uint8_t*)in, remaining, &readed);
		in += readed;
		remaining -= readed;
		//printf("readed:%lu\n",readed);
		heatshrink_encoder_poll(&hse, (uint8_t*)compress + tot_copied, sizeof(compress)- tot_copied,&copied);
		tot_copied += copied;
		//printf("copied:%lu tot:%lu\n",copied,tot_copied);
	} while (remaining);
	heatshrink_encoder_finish(&hse);
	HSE_poll_res pres;
	do
	{
		pres = heatshrink_encoder_poll(&hse, (uint8_t*)compress + tot_copied, sizeof(compress)- tot_copied,&copied);
		tot_copied += copied;
	} while (pres != HSER_POLL_EMPTY);
	printf(">>>>>>>>>>>>src:%lu dst:%lu\n", srclen, tot_copied);
	return tot_copied;
}

int Decode(size_t remaining) {
	HSD_sink_res sres;
	HSD_poll_res pres;
	HSD_finish_res fres;
	heatshrink_decoder hsd;
	heatshrink_decoder_reset(&hsd);
	size_t tot_copied = 0;
	size_t readed;
	size_t copied;
	const uint8_t* in = (const uint8_t*)compress;
	do
	{
		sres =
		    heatshrink_decoder_sink(&hsd, in, remaining, &readed);
		in += readed;
		remaining -= readed;
		//printf("readed:%lu\n",readed);
		pres =heatshrink_decoder_poll(&hsd, (uint8_t*)out + tot_copied,sizeof(out)- tot_copied, &copied);
		tot_copied += copied;
		//printf("copied:%lu tot:%lu\n",copied,tot_copied);
	} while (remaining);
	fres = heatshrink_decoder_finish(&hsd);
	do //REMAIN ON THIS LOOP FOREVER !!!
	{
		pres =heatshrink_decoder_poll(&hsd, (uint8_t*)out + tot_copied, sizeof(out) - tot_copied, &copied);
		tot_copied += copied;
		//printf("src:%lu dst:%lu\n",srclen,tot_copied);
	} while (pres != HSER_POLL_EMPTY);
	printf(">>>>>>>>>>>>decompress:%lu\n", tot_copied);
	return tot_copied;
}

void main() {
	// SysTimer_Init();
	// Uart_Init(Uart_STDOUT, 0); //console
	int n=Encode();
	Decode(n);
	// Uart_Println(out);
	// Uart_Println("end");
	// while (1);
}

[unixdj]

@silentbicycle Please check that my answer is correct.

You should check the return value of heatshrink_decoder_finish() in the last loop, like so:

        while (heatshrink_decoder_finish(&hsd) != HSDR_FINISH_DONE) {
                pres =heatshrink_decoder_poll(&hsd, (uint8_t*)out + tot_copied, sizeof(out) - tot_copied, &copied);
                tot_copied += copied;
                //printf("src:%lu dst:%lu\n",srclen,tot_copied);
        }

[IvanoBono]

in this example your suggestion would solve the problem. but in my application i'm developing i receive small packets of 8 bytes and as they arrive i decode them and reply to the sender that he can send the next packet.
the problem is that when i get to fill the heatshrink_decoder_poll buffer i get HSER_POLL_MORE and i can't confirm to the sender to send the next packet (normally the next packet would be the one that indicates the end and would trigger the heatshrink_decoder_finish but i can't be sure and since i know that there are more bytes to decode and the buffer is full i should signal error...)