From a0002acc9ca88481c4f8c9a44b76c28b1220c1bf Mon Sep 17 00:00:00 2001
From: xiaoming <2014500726@smail.xtu.edu.cn>
Date: Tue, 1 Aug 2023 23:14:18 +0800
Subject: [PATCH] Add JFFS2_COMPR_RTIME support

Signed-off-by: xiaoming <2014500726@smail.xtu.edu.cn>
---
 jffs2extract.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/jffs2extract.c b/jffs2extract.c
index 8fadca5..1f9ea3f 100644
--- a/jffs2extract.c
+++ b/jffs2extract.c
@@ -92,6 +92,38 @@ void visit(char *o, size_t size, const char *path, int verbose, visitor visitor)
 /* writes file node into buffer, to the proper position. */
 /* reading all valid nodes in version order reconstructs the file. */
 
+static int jffs2_rtime_decompress(unsigned char *data_in,
+				  unsigned char *cpage_out,
+				  uint32_t srclen, uint32_t destlen)
+{
+	short positions[256];
+	int outpos = 0;
+	int pos=0;
+	memset(positions,0,sizeof(positions));
+	while (outpos<destlen) {
+		unsigned char value;
+		int backoffs;
+		int repeat;
+		value = data_in[pos++];
+		cpage_out[outpos++] = value; /* first the verbatim copied byte */
+		repeat = data_in[pos++];
+		backoffs = positions[value];
+		positions[value]=outpos;
+		if (repeat) {
+			if (backoffs + repeat >= outpos) {
+				while(repeat) {
+					cpage_out[outpos++] = cpage_out[backoffs++];
+					repeat--;
+				}
+			} else {
+				memcpy(&cpage_out[outpos],&cpage_out[backoffs],repeat);
+				outpos+=repeat;
+			}
+		}
+	}
+	return 0;
+}
+
 /*
    b       - buffer
    bsize   - buffer size
@@ -126,6 +158,12 @@ void putblock(char *b, size_t bsize, size_t * rsize,
 			bzero(b + je32_to_cpu(n->offset), dlen);
 			break;
 
+		case JFFS2_COMPR_RTIME:
+			jffs2_rtime_decompress((unsigned char *) ((char *) n) + sizeof(struct jffs2_raw_inode),
+					(unsigned char *) (b + je32_to_cpu(n->offset)),
+                    je32_to_cpu(n->csize), je32_to_cpu(n->dsize));
+			break;
+
 			/* [DYN]RUBIN support required! */
 
 		default: