1 files changed, 118 insertions, 0 deletions
diff --git a/lib/io/uncompress/bzip2.c b/lib/io/uncompress/bzip2.c
new file mode 100644
index 0000000..3b44383
--- /dev/null
+++ b/lib/io/uncompress/bzip2.c
@@ -0,0 +1,118 @@
+/* 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 {
+	istream_comp_t base;
+
+	bool initialized;
+	bz_stream strm;
+} istream_bzip2_t;
+
+static int precache(istream_t *base)
+{
+	istream_bzip2_t *bzip2 = (istream_bzip2_t *)base;
+	istream_t *wrapped = ((istream_comp_t *)base)->wrapped;
+	size_t avail;
+	int ret;
+
+	for (;;) {
+		if (!bzip2->initialized) {
+			if (BZ2_bzDecompressInit(&bzip2->strm, 0, 0) != BZ_OK) {
+				fprintf(stderr, "%s: error initializing "
+					"bzip2 decompressor.\n",
+					wrapped->get_filename(wrapped));
+				return -1;
+			}
+
+			bzip2->initialized = true;
+		}
+
+		ret = istream_precache(wrapped);
+		if (ret != 0)
+			return ret;
+
+		avail = wrapped->buffer_used;
+		if ((sizeof(size_t) > sizeof(unsigned int)) &&
+		    (avail > (size_t)UINT_MAX)) {
+			avail = UINT_MAX;
+		}
+
+		bzip2->strm.next_in = (char *)wrapped->buffer;
+		bzip2->strm.avail_in = (unsigned int)avail;
+
+		if (base->buffer_used > BUFSZ)
+			base->buffer_used = BUFSZ;
+
+		avail = BUFSZ - base->buffer_used;
+
+		if ((sizeof(size_t) > sizeof(unsigned int)) &&
+		    (avail > (size_t)UINT_MAX)) {
+			avail = UINT_MAX;
+		}
+
+		bzip2->strm.next_out = (char *)base->buffer + base->buffer_used;
+		bzip2->strm.avail_out = (unsigned int)avail;
+
+		if (bzip2->strm.avail_out < 1)
+			break;
+
+		ret = BZ2_bzDecompress(&bzip2->strm);
+
+		if (ret < 0) {
+			fprintf(stderr, "%s: internal error in bzip2 "
+				"decompressor.\n",
+				wrapped->get_filename(wrapped));
+			return -1;
+		}
+
+		base->buffer_used = BUFSZ - bzip2->strm.avail_out;
+		wrapped->buffer_offset = wrapped->buffer_used -
+					 bzip2->strm.avail_in;
+
+		if (ret == BZ_STREAM_END) {
+			if (istream_precache(wrapped))
+				return -1;
+
+			BZ2_bzDecompressEnd(&bzip2->strm);
+			bzip2->initialized = false;
+
+			if (wrapped->buffer_used == 0) {
+				base->eof = true;
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static void cleanup(istream_comp_t *base)
+{
+	istream_bzip2_t *bzip2 = (istream_bzip2_t *)base;
+
+	if (bzip2->initialized)
+		BZ2_bzDecompressEnd(&bzip2->strm);
+}
+
+istream_comp_t *istream_bzip2_create(const char *filename)
+{
+	istream_bzip2_t *bzip2 = calloc(1, sizeof(*bzip2));
+	istream_comp_t *base = (istream_comp_t *)bzip2;
+
+	if (bzip2 == NULL) {
+		fprintf(stderr, "%s: creating bzip2 compressor: %s.\n",
+			filename, strerror(errno));
+		return NULL;
+	}
+
+	((istream_t *)base)->precache = precache;
+	base->cleanup = cleanup;
+	return base;
+}