1 files changed, 122 insertions, 0 deletions
diff --git a/gs/base/srld.c b/gs/base/srld.c
new file mode 100644
index 000000000..afbd4c809
--- /dev/null
+++ b/gs/base/srld.c
@@ -0,0 +1,122 @@
+/* Copyright (C) 2001-2006 Artifex Software, Inc.
+   All Rights Reserved.
+  
+   This software is provided AS-IS with no warranty, either express or
+   implied.
+
+   This software is distributed under license and may not be copied, modified
+   or distributed except as expressly authorized under the terms of that
+   license.  Refer to licensing information at http://www.artifex.com/
+   or contact Artifex Software, Inc.,  7 Mt. Lassen Drive - Suite A-134,
+   San Rafael, CA  94903, U.S.A., +1(415)492-9861, for further information.
+*/
+
+/* $Id$ */
+/* RunLengthDecode filter */
+#include "stdio_.h"		/* includes std.h */
+#include "memory_.h"
+#include "strimpl.h"
+#include "srlx.h"
+
+/* ------ RunLengthDecode ------ */
+
+private_st_RLD_state();
+
+/* Set defaults */
+static void
+s_RLD_set_defaults(stream_state * st)
+{
+    stream_RLD_state *const ss = (stream_RLD_state *) st;
+
+    s_RLD_set_defaults_inline(ss);
+}
+
+/* Initialize */
+static int
+s_RLD_init(stream_state * st)
+{
+    stream_RLD_state *const ss = (stream_RLD_state *) st;
+
+    return s_RLD_init_inline(ss);
+}
+
+/* Refill the buffer */
+static int
+s_RLD_process(stream_state * st, stream_cursor_read * pr,
+	      stream_cursor_write * pw, bool last)
+{
+    stream_RLD_state *const ss = (stream_RLD_state *) st;
+    register const byte *p = pr->ptr;
+    register byte *q = pw->ptr;
+    const byte *rlimit = pr->limit;
+    byte *wlimit = pw->limit;
+    int left;
+    int status = 0;
+
+top:
+    if ((left = ss->copy_left) > 0) {
+	/*
+	 * We suspended because the output buffer was full:;
+	 * try again now.
+	 */
+	uint avail = wlimit - q;
+	int copy_status = 1;
+
+	if (left > avail)
+	    left = avail;
+	if (ss->copy_data >= 0)
+	    memset(q + 1, ss->copy_data, left);
+	else {
+	    avail = rlimit - p;
+	    if (left >= avail) {
+		copy_status = 0;
+		left = avail;
+	    }
+	    memcpy(q + 1, p + 1, left);
+	    p += left;
+	}
+	q += left;
+	if ((ss->copy_left -= left) > 0) {
+	    status = copy_status;
+	    goto x;
+	}
+    }
+    while (p < rlimit) {
+	int b = *++p;
+
+	if (b < 128) {
+	    if (++b > rlimit - p || b > wlimit - q) {
+		ss->copy_left = b;
+		ss->copy_data = -1;
+		goto top;
+	    }
+	    memcpy(q + 1, p + 1, b);
+	    p += b;
+	    q += b;
+	} else if (b == 128) {	/* end of data */
+	    if (ss->EndOfData) {
+		status = EOFC;
+		break;
+	    }
+	} else if (p == rlimit) {
+	    p--;
+	    break;
+	} else if ((b = 257 - b) > wlimit - q) {
+	    ss->copy_left = b;
+	    ss->copy_data = *++p;
+	    goto top;
+	} else {
+	    memset(q + 1, *++p, b);
+	    q += b;
+	}
+    }
+x:  pr->ptr = p;
+    pw->ptr = q;
+    return status;
+}
+
+/* Stream template */
+const stream_template s_RLD_template = {
+    &st_RLD_state, s_RLD_init, s_RLD_process, 1, 1, NULL,
+    s_RLD_set_defaults
+};