rgb-cln/devtools/mkencoded.c

66 lines
1.8 KiB
C

/* Simple wrapper to create zlib or raw encodings of hex. */
#include "config.h"
#include <bitcoin/short_channel_id.h>
#include <ccan/err/err.h>
#include <ccan/str/hex/hex.h>
#include <common/decode_array.h>
#include <stdio.h>
#include <zlib.h>
static NORETURN void usage(void)
{
errx(1, "Usage: mkencoded <encoding> <hexstr>, OR\n"
"mkencoded --scids <encoding> <scid>...");
}
int main(int argc, char *argv[])
{
u8 encoding, *data;
setup_locale();
if (argv[1] && streq(argv[1], "--scids")) {
argv++;
argc--;
if (argc < 2)
usage();
data = tal_arr(NULL, u8, 0);
for (size_t i = 2; i < argc; i++) {
struct short_channel_id scid;
if (!short_channel_id_from_str(argv[i], strlen(argv[i]),
&scid))
errx(1, "Invalid short_channel_id %s", argv[i]);
towire_short_channel_id(&data, &scid);
}
} else {
data = tal_hexdata(NULL, argv[2], strlen(argv[2]));
if (!data)
errx(1, "Invalid hex string %s", argv[2]);
}
if (!hex_decode(argv[1], strlen(argv[1]), &encoding, sizeof(encoding)))
errx(1, "Expected single hex byte not %s", argv[1]);
if (encoding == ARR_UNCOMPRESSED)
printf("%02x%s\n", encoding, tal_hex(NULL, data));
else if (encoding == ARR_ZLIB_DEPRECATED) {
/* https://www.zlib.net/zlib_tech.html:
* the only expansion is an overhead of five bytes per 16 KB
* block (about 0.03%), plus a one-time overhead of six bytes
* for the entire stream.
*/
unsigned long compressed_len = tal_bytelen(data)
+ 6 + 5*(tal_bytelen(data) + 16384)/16384;
u8 *z = tal_arr(NULL, u8, compressed_len);
if (compress2(z, &compressed_len, data, tal_bytelen(data),
Z_DEFAULT_COMPRESSION) != Z_OK)
errx(1, "Error compressing stream?");
printf("%02x%s\n", encoding,
tal_hexstr(NULL, z, compressed_len));
} else {
errx(1, "Unknown encoding %u", encoding);
}
return 0;
}