lzham_z_compress2 often returrns error

[andr1972]

I write test how big enough must be buffer for good compression

void testSize(char *path, int size)
{	
	uLong IN_LEN;
	uLong in_len;
	uLong out_len;
	uLong new_len;
	IN_LEN = size;
	uint8 *in = (uint8 *)malloc(IN_LEN);
	out_len = compressBound(IN_LEN);
	uint8 *out = (uint8 *)malloc(out_len);
	FILE *fp = fopen(path, "rb");
	long sumin = 0;
	long sumout = 0;
	while (!feof(fp))
	{
		in_len = fread(in, 1, IN_LEN, fp);
		sumin += in_len;		
		int cmp_status = compress(out, &out_len, in, in_len);
		if (cmp_status != Z_OK)
		{
			printf("compress() failed dla size=%d %d %d\n", size, in_len, out_len);
		}
		sumout += out_len;
	}
	fclose(fp);
	free(in);
	free(out);
	printf("size=%d to %d compr=%f\n", size, sumout, (double)sumout / sumin);
}

void test()
{
	double dsize = 1000;
	while (dsize < 350000)
	{
		testSize("path_to_file_size_380kB", (int)dsize);
		dsize *= 1.1;
	}
}

Often cmp_status != Z_OK and is very slow for small buffers.

[andr1972]

Was out_len too small:

		out_len = compressBound(IN_LEN);
		int cmp_status = compress(out, &out_len, in, in_len);

slow for small buffers because for small buffer it must init big dictionaries, I think.