1 files changed, 123 insertions, 0 deletions
diff --git a/gs/src/srld.c b/gs/src/srld.c
new file mode 100644
index 000000000..814d152ee
--- /dev/null
+++ b/gs/src/srld.c
@@ -0,0 +1,123 @@
+/* Copyright (C) 1995, 1996, 1997 Aladdin Enterprises.  All rights reserved.
+  
+  This file is part of Aladdin Ghostscript.
+  
+  Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
+  or distributor accepts any responsibility for the consequences of using it,
+  or for whether it serves any particular purpose or works at all, unless he
+  or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
+  License (the "License") for full details.
+  
+  Every copy of Aladdin Ghostscript must include a copy of the License,
+  normally in a plain ASCII text file named PUBLIC.  The License grants you
+  the right to copy, modify and redistribute Aladdin Ghostscript, but only
+  under certain conditions described in the License.  Among other things, the
+  License requires that the copyright notice and this notice be preserved on
+  all copies.
+*/
+
+/* srld.c */
+/* RunLengthDecode filter */
+#include "stdio_.h"		/* includes std.h */
+#include "memory_.h"
+#include "strimpl.h"
+#include "srlx.h"
+
+/* ------ RunLengthDecode ------ */
+
+private_st_RLD_state();
+
+#define ss ((stream_RLD_state *)st)
+
+/* Set defaults */
+private void
+s_RLD_set_defaults(stream_state *st)
+{	s_RLD_set_defaults_inline(ss);
+}
+
+/* Initialize */
+private int
+s_RLD_init(stream_state *st)
+{	return s_RLD_init_inline(ss);
+}
+
+/* Refill the buffer */
+private int
+s_RLD_process(stream_state *st, stream_cursor_read *pr,
+  stream_cursor_write *pw, bool last)
+{	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;
+}
+
+#undef ss
+
+/* Stream template */
+const stream_template s_RLD_template =
+{	&st_RLD_state, s_RLD_init, s_RLD_process, 1, 1, NULL,
+	s_RLD_set_defaults
+};