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Re: [Qemu-devel] [PATCH v5 07/11] curl: make use of CURLDataCache.
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH v5 07/11] curl: make use of CURLDataCache. |
Date: |
Thu, 23 May 2013 16:23:27 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, May 23, 2013 at 11:38:05AM +0800, Fam Zheng wrote:
> @@ -221,31 +215,35 @@ static void curl_complete_io(BDRVCURLState *bs,
> CURLAIOCB *acb,
>
> static size_t curl_read_cb(void *ptr, size_t size, size_t nmemb, void
> *opaque)
> {
> - CURLState *s = ((CURLState*)opaque);
> + CURLState *s = (CURLState *)opaque;
You can drop the cast completely because opaque is void*.
> + CURLDataCache *c = s->cache;
> size_t realsize = size * nmemb;
> - int i;
> -
> - DPRINTF("CURL: Just reading %zd bytes\n", realsize);
> + CURLAIOCB *acb;
>
> - if (!s || !s->orig_buf)
> + if (!c || !c->data) {
> goto read_end;
> + }
> + if (c->write_pos >= c->data_len) {
> + goto read_end;
> + }
> + memcpy(c->data + c->write_pos, ptr,
> + MIN(realsize, c->data_len - c->write_pos));
> + c->write_pos += realsize;
> + if (c->write_pos >= c->data_len) {
> + c->write_pos = c->data_len;
> + }
>
> - memcpy(s->orig_buf + s->buf_off, ptr, realsize);
> - s->buf_off += realsize;
Why did you add MIN(realsize, c->data_len - c->write_pos)? The original
code trusts realsize to be within s->orig_buf.
> -
> - for(i=0; i<CURL_NUM_ACB; i++) {
> - CURLAIOCB *acb = s->acb[i];
> -
> - if (!acb)
> - continue;
> -
> - if ((s->buf_off >= acb->end)) {
> - qemu_iovec_from_buf(acb->qiov, 0, s->orig_buf + acb->start,
> - acb->end - acb->start);
> - acb->common.cb(acb->common.opaque, 0);
> - qemu_aio_release(acb);
> - s->acb[i] = NULL;
> + acb = QLIST_FIRST(&s->s->acbs);
> + while (acb) {
> + size_t aio_base = acb->sector_num * SECTOR_SIZE;
int64_t
> @@ -600,29 +596,41 @@ static void curl_readv_bh_cb(void *p)
> // No cache found, so let's start a new request
> state = curl_init_state(s);
> if (!state) {
> - acb->common.cb(acb->common.opaque, -EIO);
> - qemu_aio_release(acb);
> - return;
> + goto err_release;
> }
>
> - acb->start = 0;
> - acb->end = (acb->nb_sectors * SECTOR_SIZE);
> -
> - state->buf_off = 0;
> - if (state->orig_buf)
> - g_free(state->orig_buf);
> - state->buf_start = start;
> - state->buf_len = acb->end + s->readahead_size;
> - end = MIN(start + state->buf_len, s->len) - 1;
> - state->orig_buf = g_malloc(state->buf_len);
> - state->acb[0] = acb;
> -
> - snprintf(state->range, sizeof(state->range) - 1, "%zd-%zd", start, end);
> - DPRINTF("CURL (AIO): Reading %d at %zd (%s)\n",
> - (acb->nb_sectors * SECTOR_SIZE), start, state->range);
> - curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
> + cache = g_malloc0(sizeof(CURLDataCache));
> + cache->base_pos = acb->sector_num * SECTOR_SIZE;
> + cache->data_len = aio_bytes + s->readahead_size;
> + cache->write_pos = 0;
> + cache->data = g_malloc(cache->data_len);
>
> + QLIST_INSERT_HEAD(&s->acbs, acb, next);
> + snprintf(state->range, sizeof(state->range) - 1, "%zd-%zd",
> cache->base_pos,
> + cache->base_pos + cache->data_len);
> + DPRINTF("Reading range: %s\n", state->range);
> + curl_easy_setopt(state->curl, CURLOPT_RANGE, state->range);
> + QLIST_INSERT_HEAD(&s->cache, cache, next);
> + state->cache = cache;
> + cache->use_count++;
I don't see where you bump the use_count when a cache lookup is
successful. Maybe I just missed it in the other patches.
- [Qemu-devel] [PATCH v5 02/11] curl: change magic number to sizeof, (continued)
- [Qemu-devel] [PATCH v5 02/11] curl: change magic number to sizeof, Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 03/11] curl: change curl_multi_do to curl_fd_handler, Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 04/11] curl: fix curl_open, Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 05/11] curl: add timer to BDRVCURLState, Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 06/11] curl: introduce CURLDataCache, Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 07/11] curl: make use of CURLDataCache., Fam Zheng, 2013/05/22
- Re: [Qemu-devel] [PATCH v5 07/11] curl: make use of CURLDataCache.,
Stefan Hajnoczi <=
- [Qemu-devel] [PATCH v5 08/11] curl: use list to store CURLState, Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 09/11] curl: add cache quota., Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 10/11] curl: introduce ssl_no_cert runtime option., Fam Zheng, 2013/05/22
- [Qemu-devel] [PATCH v5 11/11] block/curl.c: Refuse to open the handle for writes., Fam Zheng, 2013/05/22
- Re: [Qemu-devel] [PATCH v5 00/11] curl: fix curl read, Richard W.M. Jones, 2013/05/23