On Wed, 12 Sep 2012 19:57:22 +0800 Lei Li <li...@linux.vnet.ibm.com> wrote:
> 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; > +} Both argument's from the functions above can be const. > + > +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; > +} I remember I made a few comments about using pointers instead of indexes, did you consider doing that? Btw, does this patch even build by its own? You're adding static functions but no users. > + > +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];