Signed-off-by: Lei Li <li...@linux.vnet.ibm.com>
---
qemu-char.c | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 84 insertions(+), 0 deletions(-)
diff --git a/qemu-char.c b/qemu-char.c
index 767da93..0470085 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2591,6 +2591,90 @@ size_t qemu_chr_mem_osize(const CharDriverState *chr)
return d->outbuf_size;
}
+/*********************************************************/
+/*CircularMemory chardev*/
+
+typedef struct {
+ size_t cbuf_capacity;
+ size_t cbuf_in;
+ size_t cbuf_out;
+ size_t cbuf_count;
+ uint8_t *cbuf;
+} CircMemCharDriver;
+
+static int cirmem_chr_is_empty(CharDriverState *chr)
+{
+ CircMemCharDriver *d = chr->opaque;
+
+ return d->cbuf_count == 0;
+}
+
+static int cirmem_chr_is_full(CharDriverState *chr)
+{
+ CircMemCharDriver *d = chr->opaque;
+
+ return d->cbuf_count == d->cbuf_capacity;
+}
+
+static int cirmem_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
+{
+ CircMemCharDriver *d = chr->opaque;
+ int left;
+
+ if (d->cbuf_capacity < len) {
+ return -1;
+ }
+
+ left = d->cbuf_capacity - d->cbuf_count % d->cbuf_capacity;
+
+ /* Some of cbuf need to be overwrited */
+ if (left < len) {
+ memcpy(d->cbuf + d->cbuf_in, buf, left);
+ memcpy(d->cbuf + d->cbuf_out, buf + left, len - left);
+ d->cbuf_out = (d->cbuf_out + len - left) % d->cbuf_capacity;
+ d->cbuf_count = d->cbuf_count + left;
+ } else {
+ /* Completely overwrite */
+ if (cirmem_chr_is_full(chr)) {
+ d->cbuf_out = (d->cbuf_out + len) % d->cbuf_capacity;
+ } else {
+ /* Enough cbuf to write */
+ d->cbuf_count += len;
+ }
+ memcpy(d->cbuf + d->cbuf_in, buf, len);
+ }
+
+ d->cbuf_in = (d->cbuf_in + len) % d->cbuf_capacity;
+
+ return len;
+}
+
+static void cirmem_chr_read(CharDriverState *chr, uint8_t *buf, int len)
+{
+ CircMemCharDriver *d = chr->opaque;
+ int left;
+
+ if (cirmem_chr_is_empty(chr)) {
+ return;
+ }
+
+ left = d->cbuf_capacity - d->cbuf_count % d->cbuf_capacity;
+
+ if (d->cbuf_capacity < len) {
+ len = d->cbuf_capacity;
+ }
+
+ if (left < len) {
+ memcpy(buf, d->cbuf + d->cbuf_out, left);
+ memcpy(buf + left, d->cbuf + d->cbuf_out + left, len - left);
+ } else {
+ memcpy(buf, d->cbuf + d->cbuf_out, len);
+ }
+
+ d->cbuf_out = (d->cbuf_out + len) % d->cbuf_capacity;
+ d->cbuf_count -= len;
+}
+
QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
{
char host[65], port[33], width[8], height[8];
--
1.7.7.6
