Signed-off-by: Lei Li <li...@linux.vnet.ibm.com>
---
qemu-char.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 72 insertions(+), 0 deletions(-)
diff --git a/qemu-char.c b/qemu-char.c
index b082bae..b174da1 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2588,6 +2588,78 @@ size_t qemu_chr_mem_osize(const CharDriverState *chr)
return d->outbuf_size;
}
+/*********************************************************/
+/*CircularMemoryr chardev*/
+
+typedef struct {
+ size_t size;
+ size_t producer;
+ size_t consumer;
+ uint8_t *cbuf;
+} CirMemCharDriver;
+
+static bool cirmem_chr_is_empty(const CharDriverState *chr)
+{
+ const CirMemCharDriver *d = chr->opaque;
+
+ return d->producer == d->consumer;
+}
+
+static bool cirmem_chr_is_full(const CharDriverState *chr)
+{
+ const CirMemCharDriver *d = chr->opaque;
+
+ return (d->producer - d->consumer) >= d->size;
+}
+
+static int cirmem_chr_write(CharDriverState *chr, const uint8_t *buf, int len)
+{
+ CirMemCharDriver *d = chr->opaque;
+ int i;
+
+ if (len < 0) {
+ return -1;
+ }
+
+ /* The size should be a power of 2. */
+ for (i = 0; i < len; i++ ) {
+ d->cbuf[d->producer % d->size] = buf[i];
+ d->producer++;
+ }
+
+ return 0;
+}
+
+static int cirmem_chr_read(CharDriverState *chr, uint8_t *buf, int len)
+{
+ CirMemCharDriver *d = chr->opaque;
+ int i;
+
+ if (cirmem_chr_is_empty(chr) || len < 0) {
+ return -1;
+ }
+
+ if (len > d->size) {
+ len = d->size;
+ }
+
+ for (i = 0; i < len; i++) {
+ buf[i] = d->cbuf[d->consumer % d->size];
+ d->consumer++;
+ }
+
+ return 0;
+}
+
+static void cirmem_chr_close(struct CharDriverState *chr)
+{
+ CirMemCharDriver *d = chr->opaque;
+
+ g_free(d);
+ g_free(chr->opaque);
+ chr->opaque = NULL;
+}
+
QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
{
char host[65], port[33], width[8], height[8];
--
1.7.7.6
