start writing code for decompressing chunk data.

I still haven't much of an idea where I'll take this, but it's a start.

I know it is needed for block filtering and such, I still need to find a
way how I'll actually implement it.

src/dat/mcx.c

@@ -2,6 +2,7 @@
  * Licensed under the MIT Licence. See LICENSE for details */
 #include "mcx.h"
 
+#include <archive.h>
 #include <assert.h>
 #include <endian.h>
 #include <stdint.h>
@@ -9,12 +10,46 @@
 #include <string.h>
 #include <time.h>
 
+#include "../error.h"
 #include "../util/intdef.h"
 
 #define SECTOR 0x1000 // sector size
 #define TABLE  0x800  // table (total) element count
 #define CHUNKS 0x400  // amount of chunks in a file
 
+enum mcx_compression {
+	MCX_COMPRESSION_GZIP = 0x01,
+	MCX_COMPRESSION_ZLIB = 0x02,
+	MCX_COMPRESSION_NONE = 0x03,
+	MCX_COMPRESSION_LZ4 = 0x04,
+	MCX_COMPRESSION_CUSTOM = 0x7F,
+};
+
+/* first 4 bytes is an i32 indicating remaining bytes, the following byte defines the compression scheme */
+static void mcx_loadchunk(const u8 *restrict buf, const i32 *restrict table, int idx) {
+	const u8 *chunk = buf + (be32toh(table[idx]) >> 8) * SECTOR;
+
+	i32 len;
+	memcpy(&len, chunk, 4);
+	len = be32toh(len);
+	chunk += 4;
+
+	if (*chunk != MCX_COMPRESSION_CUSTOM) {
+		struct archive *archive = archive_read_new();
+		archive_read_support_format_raw(archive);
+		switch (*chunk) {
+		case MCX_COMPRESSION_GZIP:   archive_read_support_filter_gzip(archive); break;
+		case MCX_COMPRESSION_ZLIB:   archive_read_support_filter_zlib(archive); break; // BUG: this does not exist, but will have to do for now
+		case MCX_COMPRESSION_LZ4:    archive_read_support_filter_lz4(archive); break;
+		case MCX_COMPRESSION_CUSTOM: // TODO: implement using filtering any format
+		default:                     fatal("compression type of '%ihh' is unsupported!", *chunk);
+		}
+
+		// TODO: implement decompression, somehow.
+		// https://github.com/libarchive/libarchive/wiki/Examples#user-content-A_Universal_Decompressor
+	}
+}
+
 /* Moves chunks `src_s` to `src_e` (inclusive) from `src`, back onto `dst`. */
 static void mvchunks(u8 *dst, u8 *src, u32 *restrict table, int src_s, int src_e) {
 	assert(src > dst);

src/error.c

@@ -0,0 +1,51 @@
+#include "error.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+
+#include "util/intdef.h"
+
+static void error_log(FILE *restrict stream, const char *restrict pfx, uint ln, const char *restrict file, const char *restrict fmt, va_list ap) {
+	fprintf(stream, "(%s:%lu) [%s] '", file, ln, pfx);
+
+	vfprintf(stream, fmt, ap);
+
+	fprintf(stream, "'\n");
+}
+
+void error_dbg(uint ln, const char *restrict file, const char *restrict fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	error_log(stdout, "\033[95mDBG\033[0m", ln, file, fmt, ap);
+	va_end(ap);
+}
+
+void error_inf(uint ln, const char *restrict file, const char *restrict fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	error_log(stdout, "\033[93mINF\033[0m", ln, file, fmt, ap);
+	va_end(ap);
+}
+
+void error_war(uint ln, const char *restrict file, const char *restrict fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	error_log(stdout, "\033[91mWAR\033[0m", ln, file, fmt, ap);
+	va_end(ap);
+}
+
+void error_err(uint ln, const char *restrict file, const char *restrict fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	error_log(stdout, "\033[mFAT\033[0m", ln, file, fmt, ap);
+	va_end(ap);
+}
+
+void error_fat(uint ln, const char *restrict file, const char *restrict fmt, ...) {
+	va_list ap;
+	va_start(ap, fmt);
+	error_log(stdout, "\033[mFAT\033[0m", ln, file, fmt, ap);
+	va_end(ap);
+
+	exit(EXIT_FAILURE);
+}

src/error.h

@@ -2,20 +2,21 @@
  * Licensed under the MIT Licence. See LICENSE for details */
 #pragma once
 
-#if __INCLUDE_LEVEL__ > 0
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "util/atrb.h"
+#include "util/intdef.h"
 #include "util/macro.h"
-#endif
 
-#define debug(s, ...) printf("\033[95m" __FILE__ ":" MACRO_STR2(__LINE__) ": [DBG]: " s "\033[0m\n", ##__VA_ARGS__)
+void error_dbg(uint ln, const char *restrict file, const char *restrict fmt, ...);
-#define info(s, ...)  printf(__FILE__ ":" MACRO_STR2(__LINE__) ": [INF]: " s "\n", ##__VA_ARGS__)
+void error_inf(uint ln, const char *restrict file, const char *restrict fmt, ...);
-#define warn(s, ...)  fprintf(stderr, "\033[93m" __FILE__ ":" MACRO_STR2(__LINE__) ": [WAR]: " s "\033[0m\n", ##__VA_ARGS__)
+void error_war(uint ln, const char *restrict file, const char *restrict fmt, ...);
-#define error(s, ...) fprintf(stderr, "\033[91m" __FILE__ ":" MACRO_STR2(__LINE__) ": [ERR]: " s "\033[0m\n", ##__VA_ARGS__)
+void error_err(uint ln, const char *restrict file, const char *restrict fmt, ...);
+void error_fat(uint ln, const char *restrict file, const char *restrict fmt, ...) NORET;
 
-#define fatal(s, ...)                                                                                                    \
+#define debug(s, ...) error_dbg(__LINE__, __FILE__, s, ##__VA_ARGS__)
-	do {                                                                                                             \
+#define info(s, ...)  error_inf(__LINE__, __FILE__, s, ##__VA_ARGS__)
-		fprintf(stderr, "\033[101m" __FILE__ ":" MACRO_STR2(__LINE__) ": [FAT]: " s "\033[0m\n", ##__VA_ARGS__); \
+#define warn(s, ...)  error_war(__LINE__, __FILE__, s, ##__VA_ARGS__)
-		exit(EXIT_FAILURE);                                                                                      \
+#define error(s, ...) error_err(__LINE__, __FILE__, s, ##__VA_ARGS__)
-	} while (0)
+#define fatal(s, ...) error_fat(__LINE__, __FILE__, s, ##__VA_ARGS__)