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Re: [Qemu-devel] [PATCH 1/5] qemu-char: Add new char device CirMemCharDr
From: |
Luiz Capitulino |
Subject: |
Re: [Qemu-devel] [PATCH 1/5] qemu-char: Add new char device CirMemCharDriver |
Date: |
Wed, 19 Sep 2012 14:43:22 -0300 |
On Wed, 12 Sep 2012 19:57:22 +0800
Lei Li <address@hidden> wrote:
> Signed-off-by: Lei Li <address@hidden>
> ---
> 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];