Add bzip2 stream compression support

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

2 files changed, 92 insertions, 0 deletions

diff --git a/lib/fstream/compress/bzip2.c b/lib/fstream/compress/bzip2.c
new file mode 100644
index 0000000..3ca425a
--- /dev/null
+++ b/lib/fstream/compress/bzip2.c
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * bzip2.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "../internal.h"
+
+#include <bzlib.h>
+
+typedef struct {
+	ostream_comp_t base;
+
+	bz_stream strm;
+} ostream_bzip2_t;
+
+static int flush_inbuf(ostream_comp_t *base, bool finish)
+{
+	ostream_bzip2_t *bzip2 = (ostream_bzip2_t *)base;
+	size_t have;
+	int ret;
+
+	bzip2->strm.next_in = (char *)base->inbuf;
+	bzip2->strm.avail_in = base->inbuf_used;
+
+	for (;;) {
+		bzip2->strm.next_out = (char *)base->outbuf;
+		bzip2->strm.avail_out = sizeof(base->outbuf);
+
+		ret = BZ2_bzCompress(&bzip2->strm, finish ? BZ_FINISH : BZ_RUN);
+
+		if (ret < 0 && ret != BZ_OUTBUFF_FULL) {
+			fprintf(stderr, "%s: internal error in bzip2 "
+				"compressor.\n",
+				base->wrapped->get_filename(base->wrapped));
+			return -1;
+		}
+
+		have = sizeof(base->outbuf) - bzip2->strm.avail_out;
+
+		if (base->wrapped->append(base->wrapped, base->outbuf, have))
+			return -1;
+
+		if (ret == BZ_STREAM_END || ret == BZ_OUTBUFF_FULL ||
+		    bzip2->strm.avail_in == 0) {
+			break;
+		}
+	}
+
+	if (bzip2->strm.avail_in > 0) {
+		memmove(base->inbuf, bzip2->strm.next_in,
+			bzip2->strm.avail_in);
+	}
+
+	base->inbuf_used = bzip2->strm.avail_in;
+	return 0;
+}
+
+static void cleanup(ostream_comp_t *base)
+{
+	ostream_bzip2_t *bzip2 = (ostream_bzip2_t *)base;
+
+	BZ2_bzCompressEnd(&bzip2->strm);
+}
+
+ostream_comp_t *ostream_bzip2_create(const char *filename)
+{
+	ostream_bzip2_t *bzip2 = calloc(1, sizeof(*bzip2));
+	ostream_comp_t *base = (ostream_comp_t *)bzip2;
+
+	if (bzip2 == NULL) {
+		fprintf(stderr, "%s: creating bzip2 compressor: %s.\n",
+			filename, strerror(errno));
+		return NULL;
+	}
+
+	if (BZ2_bzCompressInit(&bzip2->strm, 9, 0, 30) != BZ_OK) {
+		fprintf(stderr, "%s: error initializing bzip2 compressor.\n",
+			filename);
+		free(bzip2);
+		return NULL;
+	}
+
+	base->flush_inbuf = flush_inbuf;
+	base->cleanup = cleanup;
+	return base;
+}
diff --git a/lib/fstream/compress/ostream_compressor.c b/lib/fstream/compress/ostream_compressor.c
index d1d55e1..7ea7919 100644
--- a/lib/fstream/compress/ostream_compressor.c
+++ b/lib/fstream/compress/ostream_compressor.c
@@ -82,6 +82,11 @@ ostream_t *ostream_compressor_create(ostream_t *strm, int comp_id)
 		comp = ostream_zstd_create(strm->get_filename(strm));
 #endif
 		break;
+	case FSTREAM_COMPRESSOR_BZIP2:
+#ifdef WITH_BZIP2
+		comp = ostream_bzip2_create(strm->get_filename(strm));
+#endif
+		break;
 	default:
 		break;
 	}