1 files changed, 80 insertions, 0 deletions
diff --git a/libstore/do-gunzip.c b/libstore/do-gunzip.c
new file mode 100644
index 00000000..a9d019e7
--- /dev/null
+++ b/libstore/do-gunzip.c
@@ -0,0 +1,80 @@
+/* gzip decompression
+
+   Copyright (C) 2014 Free Software Foundation, Inc.
+   Written by Ignazio Sgalmuzzo <ignaker@gmail.com>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd 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 2, or (at
+   your option) any later version.
+
+   The GNU Hurd 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 this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. */
+
+#include <zlib.h>
+
+/* I/O interface */
+extern int (*unzip_read) (char *buf, size_t maxread);
+extern void (*unzip_write) (const char *buf, size_t nwrite);
+extern void (*unzip_read_error) (void);
+extern void (*unzip_error) (const char *msg);
+
+#define INBUFSIZ	0x1000
+#define OUTBUFSIZ	0x1000
+
+static unsigned char inbuf[INBUFSIZ];
+static unsigned char outbuf[OUTBUFSIZ];
+
+void
+do_gunzip (void)
+{
+  int result;
+  z_stream strm;
+
+  strm.zalloc = NULL;
+  strm.zfree = NULL;
+  strm.opaque = NULL;
+
+  strm.avail_in  = 0;
+  strm.next_out = outbuf;
+  strm.avail_out = OUTBUFSIZ;
+
+  result = inflateInit2 (&strm, 32 + MAX_WBITS);
+
+  while (result == Z_OK)
+  {
+    if (strm.avail_in == 0)
+    {
+      strm.next_in = inbuf;
+      strm.avail_in  = (*unzip_read)((char*) strm.next_in, INBUFSIZ);
+
+      if (strm.avail_in == 0)
+        break;
+    }
+
+    result = inflate (&strm, Z_NO_FLUSH);
+
+    if ((result != Z_OK) && (result != Z_STREAM_END))
+      break;
+
+    if ((strm.avail_out == 0) || (result == Z_STREAM_END))
+    {
+      (*unzip_write) ((char*) outbuf, OUTBUFSIZ - strm.avail_out);
+      strm.next_out = outbuf;
+      strm.avail_out = OUTBUFSIZ;
+    }
+  }
+
+  inflateEnd (&strm);
+
+  if (result != Z_STREAM_END)
+    (*unzip_error) (NULL);
+}