bzip2: port bzip2 1.0.4 to busybox. note: bzip2 code resides

in separate directory (archival/bz/*)
and is covered by BSD-style license.
code size: 13k

archival/bzip2.c

@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
+ *
+ * This file uses bzip2 library code which is written
+ * by Julian Seward <jseward@bzip.org>.
+ * See README and LICENSE files in bz/ directory for more information
+ * about bzip2 library code.
+ */
+
+#include "libbb.h"
+
+/* This buys 6% speed for nearly 4k code */
+/*#define FAST_GROUP6 1*/
+
+#include "bz/bzlib.h"
+
+#include "bz/bzlib_private.h"
+
+#include "bz/blocksort.c"
+#include "bz/bzlib.c"
+#include "bz/compress.c"
+#include "bz/crctable.c"
+#include "bz/huffman.c"
+#include "bz/randtable.c"
+
+/* No point in being shy and having very small buffer here.
+ * bzip2 internal buffers are much bigger anyway, hundreds of kbytes.
+ * If iobuf is several pages long, malloc() may use mmap,
+ * making iobuf is page aligned and thus (maybe) have one memcpy less
+ * if kernel is clever enough.
+ */
+enum {
+	IOBUF_SIZE = 8 * 1024
+};
+
+/* Returns:
+ * <0 on write errors (examine errno),
+ * >0 on short writes (errno == 0)
+ * 0  no error (entire input consume, gimme more)
+ * on "impossible" errors (internal bzip2 compressor bug) dies
+ */
+static
+ssize_t bz_write(bz_stream *strm, void* rbuf, ssize_t rlen, void *wbuf)
+{
+	int n, n2, ret;
+
+	/* if (len == 0) return 0; */
+
+	strm->avail_in = rlen;
+	strm->next_in  = rbuf;
+	while (1) {
+		strm->avail_out = IOBUF_SIZE;
+		strm->next_out = wbuf;
+
+		ret = BZ2_bzCompress(strm, BZ_RUN);
+		if (ret != BZ_RUN_OK)
+			bb_error_msg_and_die("internal error %d", ret);
+
+		n = IOBUF_SIZE - strm->avail_out;
+		if (n) {
+			/* short reads must have errno == 0 */
+			errno = 0;
+			n2 = full_write(STDOUT_FILENO, wbuf, n);
+			if (n2 != n)
+				return n2 ? n2 : 1;
+		}
+
+		if (strm->avail_in == 0)
+			return 0;
+	}
+}
+
+
+/*---------------------------------------------------*/
+static
+USE_DESKTOP(long long) int bz_write_tail(bz_stream *strm, void *wbuf)
+{
+	int n, n2, ret;
+	USE_DESKTOP(long long) int total;
+
+	total = -1;
+	while (1) {
+		strm->avail_out = IOBUF_SIZE;
+		strm->next_out = wbuf;
+
+		ret = BZ2_bzCompress(strm, BZ_FINISH);
+		if (ret != BZ_FINISH_OK && ret != BZ_STREAM_END)
+			bb_error_msg_and_die("internal error %d", ret);
+
+		n = IOBUF_SIZE - strm->avail_out;
+		if (n) {
+			n2 = full_write(STDOUT_FILENO, wbuf, n);
+			if (n2 != n)
+				goto err;
+		}
+
+		if (ret == BZ_STREAM_END)
+			break;
+	}
+
+	total = 0 USE_DESKTOP( + strm->total_out );
+ err:
+	BZ2_bzCompressEnd(strm);
+	return total;
+}
+
+
+static
+USE_DESKTOP(long long) int compressStream(void)
+{
+	USE_DESKTOP(long long) int total;
+	ssize_t count;
+	bz_stream bzs; /* it's small */
+#define strm (&bzs)
+	char *iobuf;
+#define rbuf iobuf
+#define wbuf (iobuf + IOBUF_SIZE)
+
+	iobuf = xmalloc(2 * IOBUF_SIZE);
+
+	BZ2_bzCompressInit(strm, 9 /*blockSize100k*/);
+
+	while (1) {
+		count = full_read(STDIN_FILENO, rbuf, IOBUF_SIZE);
+		if (count < 0)
+			bb_perror_msg("read error");
+		if (count <= 0)
+			break;
+		count = bz_write(strm, rbuf, count, wbuf);
+		if (count) {
+			bb_perror_msg(count < 0 ? "write error" : "short write");
+			break;
+		}
+	}
+
+	total = bz_write_tail(strm, wbuf);
+	free(iobuf);
+	/* we had no error _only_ if count == 0 */
+	return count == 0 ? total : -1;
+}
+
+static
+char* make_new_name_bzip2(char *filename)
+{
+	return xasprintf("%s.bz2", filename);
+}
+
+int bzip2_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int bzip2_main(int argc, char **argv)
+{
+	unsigned opt;
+
+	/* Must match bbunzip's constants OPT_STDOUT, OPT_FORCE! */
+	opt = getopt32(argv, "cfv" USE_BUNZIP2("d") "q123456789" );
+#if ENABLE_BUNZIP2 /* bunzip2_main may not be visible... */
+	if (opt & 0x8) // -d
+		return bunzip2_main(argc, argv);
+#endif
+	option_mask32 &= 0x7; /* ignore -q, -0..9 */
+	//if (opt & 0x1) // -c
+	//if (opt & 0x2) // -f
+	//if (opt & 0x4) // -v
+	argv += optind;
+
+	return bbunpack(argv, make_new_name_bzip2, compressStream);
+}