db_decompress(): New function, from boukengine

1 files changed, 77 insertions, 0 deletions

diff --git a/src/compression.c b/src/compression.c
new file mode 100644
index 0000000..5e7b07a
--- /dev/null
+++ b/src/compression.c
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2013  P. J. McDermott
+ *
+ * This file is part of Dodge Balls
+ *
+ * Dodge Balls is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Dodge Balls is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Dodge Balls.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stddef.h>
+#include <zlib.h>
+#include "compression.h"
+#include "output.h"
+
+static void
+_db_zlib_err(int status)
+{
+	switch (status) {
+		case Z_OK:
+		case Z_STREAM_END:
+			break;
+		case Z_MEM_ERROR:
+			db_err("zlib error: out of memory");
+			break;
+		case Z_VERSION_ERROR:
+			db_err("zlib error: incompatible library version");
+			break;
+		case Z_STREAM_ERROR:
+			db_err("zlib error: invalid stream");
+			break;
+		case Z_NEED_DICT:
+			db_err("zlib error: need dictionary");
+			break;
+		case Z_DATA_ERROR:
+			db_err("zlib error: corrupted data");
+			break;
+		case Z_BUF_ERROR:
+			db_err("zlib error: buffer error");
+			break;
+		default:
+			db_err("zlib error: unknown");
+			break;
+	}
+}
+
+void
+db_decompress(char *src, size_t src_len, char *dest, size_t dest_len)
+{
+	z_stream d_stream;
+
+	d_stream.zalloc    =           Z_NULL;
+	d_stream.zfree     =           Z_NULL;
+	d_stream.opaque    =           Z_NULL;
+	d_stream.next_in   = (Bytef *) src;
+	d_stream.avail_in  =           src_len;
+	d_stream.next_out  = (Bytef *) dest;
+	d_stream.avail_out =           dest_len;
+
+	db_dbg("Initializing inflation stream...");
+	_db_zlib_err(inflateInit2(&d_stream, 15 + 32));
+
+	db_dbg("Inflating %zu bytes into up to %zu bytes...", src_len, dest_len);
+	_db_zlib_err(inflate(&d_stream, Z_NO_FLUSH));
+
+	db_dbg("Ending inflation stream...");
+	_db_zlib_err(inflateEnd(&d_stream));
+}