Signed-off-by: Orit Wasserman <owass...@redhat.com>
---
arch_init.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 58 insertions(+), 0 deletions(-)
diff --git a/arch_init.c b/arch_init.c
index fdda277..426b34d 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -139,6 +139,9 @@ typedef struct XBRLEHeader {
uint32_t xh_cksum;
} XBRLEHeader;
+static int rle_encode(uint8_t *src, int slen, uint8_t *dst, int dlen);
+static int rle_decode(uint8_t *src, int slen, uint8_t *dst, int dlen);
+
/***********************************************************/
/* XBRLE page cache implementation */
static CacheItem *cache_item_get(unsigned long pos, int item)
@@ -277,6 +280,61 @@ static void cache_insert(unsigned long addr, uint8_t
*pdata)
it->it_addr = addr;
}
+/* XBRLE (Xor Based Run-Length Encoding) */
+static int rle_encode(uint8_t *src, int slen, uint8_t *dst, int dlen)
+{
+ int d = 0, ch_run = 0, i;
+ uint8_t prev = 0, ch = 0;
+
+ for (i = 0; i <= slen; i++) {
+ if (i != slen) {
+ ch = src[i];
+ }
+
+ if (!i || (i != slen && ch == prev && ch_run < 255)) {
+ ch_run++;
+ } else {
+ if (d+2 > dlen) {
+ return -1;
+ }
+ *dst++ = ch_run;
+ *dst++ = prev;
+ d += 2;
+ ch_run = 1;
+ }
+
+ prev = ch;
+ }
+ return d;
+}
+
+static int rle_decode(uint8_t *src, int slen, uint8_t *dst, int dlen)
+{
+ int d = 0, s;
+
+ for (s = 0; s < slen-1; s += 2) {
+ uint8_t ch_run = src[s];
+ uint8_t ch = src[s+1];
+ while (ch_run--) {
+ if (d == dlen) {
+ return -1;
+ }
+ dst[d] = ch;
+ d++;
+ }
+ }
+ return d;
+}
+
+static void xor_encode(uint8_t *dst, uint8_t *src1, uint8_t *src2)
+{
+ int i;
+
+ for (i = 0; i < TARGET_PAGE_SIZE; i++) {
+ dst[i] = src1[i] ^ src2[i];
+ }
+}
+
static int is_dup_page(uint8_t *page, uint8_t ch)
{
uint32_t val = ch << 24 | ch << 16 | ch << 8 | ch;
--
1.7.6.5
