On 11/16/2008 08:22 PM, [EMAIL PROTECTED] wrote:
> Author: minfrin
> Date: Sun Nov 16 11:22:41 2008
> New Revision: 718082
>
> URL: http://svn.apache.org/viewvc?rev=718082&view=rev
> Log:
> Refactor the input buffer filter to use a context as the output buffer
> filter does. Ensure that the filter properly handles the non blocking
> case, both when a downstream filter returns EAGAIN, or if a filter
> returns APR_SUCCESS and an empty brigade.
>
> Modified:
> httpd/httpd/trunk/modules/filters/mod_buffer.c
>
> Modified: httpd/httpd/trunk/modules/filters/mod_buffer.c
> URL:
> http://svn.apache.org/viewvc/httpd/httpd/trunk/modules/filters/mod_buffer.c?rev=718082&r1=718081&r2=718082&view=diff
> ==============================================================================
> --- httpd/httpd/trunk/modules/filters/mod_buffer.c (original)
> +++ httpd/httpd/trunk/modules/filters/mod_buffer.c Sun Nov 16 11:22:41 2008
> @@ -170,65 +171,84 @@
> return ap_get_brigade(f->next, bb, mode, block, readbytes);
> }
>
> + /* first time in? create a context */
> + if (!ctx) {
> + ctx = f->ctx = apr_pcalloc(f->r->pool, sizeof(*ctx));
> + ctx->bb = apr_brigade_create(f->r->pool, f->c->bucket_alloc);
> + ctx->tmp = apr_brigade_create(f->r->pool, f->c->bucket_alloc);
> + ctx->conf = ap_get_module_config(f->r->per_dir_config,
> &buffer_module);
> + }
> +
> /* just get out of the way of things we don't want. */
> if (mode != AP_MODE_READBYTES) {
> return ap_get_brigade(f->next, bb, mode, block, readbytes);
> }
>
> - c = ap_get_module_config(f->r->per_dir_config, &buffer_module);
> -
> - tmp = apr_brigade_create(f->r->pool, f->c->bucket_alloc);
> -
> - remaining = readbytes;
> - while (remaining > 0) {
> - const char *data;
> - apr_off_t len;
> - apr_size_t size;
> -
> - rv = ap_get_brigade(f->next, tmp, mode, block, remaining);
> -
> - /* if an error was received, bail out now */
> - if (rv != APR_SUCCESS) {
> - APR_BRIGADE_CONCAT(bb, tmp);
> - return rv;
> - }
> -
> - apr_brigade_length(tmp, 1, &len);
> - remaining -= len;
> -
> - for (e = APR_BRIGADE_FIRST(tmp); e != APR_BRIGADE_SENTINEL(tmp); e
> - = APR_BUCKET_NEXT(e)) {
> -
> - /* if we see an EOS, we are done */
> - if (APR_BUCKET_IS_EOS(e)) {
> - APR_BUCKET_REMOVE(e);
> - APR_BRIGADE_INSERT_TAIL(bb, e);
> - remaining = 0;
> - break;
> + /* if our buffer is empty, read off the network until the buffer is full
> */
> + if (APR_BRIGADE_EMPTY(ctx->bb)) {
> + ctx->remaining = ctx->conf->size;
> +
> + while (!ctx->seen_eos && ctx->remaining > 0) {
> + const char *data;
> + apr_size_t size = 0;
> +
> + rv = ap_get_brigade(f->next, ctx->tmp, mode, block,
> ctx->remaining);
> +
> + /* if an error was received, bail out now. If the error is
> + * EAGAIN and we have not yet seen an EOS, we will definitely
> + * be called again, at which point we will send our buffered
> + * data. Instead of sending EAGAIN, some filters return an
> + * empty brigade instead when data is not yet available. In
> + * this case, pass through the APR_SUCCESS and emulate the
> + * underlying filter.
> + */
> + if (rv != APR_SUCCESS || APR_BRIGADE_EMPTY(ctx->tmp)) {
> + return rv;
> }
>
> - /* pass flush buckets through */
> - if (APR_BUCKET_IS_FLUSH(e)) {
> - APR_BUCKET_REMOVE(e);
> - APR_BRIGADE_INSERT_TAIL(bb, e);
> - continue;
> - }
> + for (e = APR_BRIGADE_FIRST(ctx->tmp); e != APR_BRIGADE_SENTINEL(
> + ctx->tmp); e = APR_BUCKET_NEXT(e)) {
>
> - /* pass metadata buckets through */
> - if (APR_BUCKET_IS_METADATA(e)) {
> - APR_BUCKET_REMOVE(e);
> - APR_BRIGADE_INSERT_TAIL(bb, e);
> - continue;
> - }
> + /* if we see an EOS, we are done */
> + if (APR_BUCKET_IS_EOS(e)) {
> + APR_BUCKET_REMOVE(e);
> + APR_BRIGADE_INSERT_TAIL(ctx->bb, e);
> + ctx->seen_eos = 1;
> + break;
> + }
> +
> + /* pass flush and metadata buckets through */
> + if (APR_BUCKET_IS_FLUSH(e) || APR_BUCKET_IS_METADATA(e)) {
This is redundant as flush buckets are metadata buckets :-).
> + APR_BUCKET_REMOVE(e);
> + APR_BRIGADE_INSERT_TAIL(bb, e);
> + continue;
> + }
> +
> + /* read the bucket in, pack it into the buffer */
> + if (APR_SUCCESS == (rv = apr_bucket_read(e, &data, &size,
> + APR_BLOCK_READ))) {
> + apr_brigade_write(ctx->bb, NULL, NULL, data, size);
> + ctx->remaining -= size;
> + apr_bucket_delete(e);
> + } else {
> + return rv;
> + }
>
> - /* read */
> - if (APR_SUCCESS == (rv = apr_bucket_read(e, &data, &size,
> - APR_BLOCK_READ))) {
> - apr_brigade_write(bb, NULL, NULL, data, size);
> }
> + }
> + }
>
> + /* give the caller the data they asked for from the buffer */
> + apr_brigade_partition(ctx->bb, readbytes, &after);
> + e = APR_BRIGADE_FIRST(ctx->bb);
> + while (e != after) {
> + if (APR_BUCKET_IS_EOS(e)) {
> + /* last bucket read, step out of the way */
> + ap_remove_input_filter(f);
> }
> - apr_brigade_cleanup(tmp);
> + APR_BUCKET_REMOVE(e);
> + APR_BRIGADE_INSERT_TAIL(bb, e);
> + e = APR_BRIGADE_FIRST(ctx->bb);
> }
This should be possible without a loop over the brigade. See
brigade_move in core_filters for a similar function.
Regards
Rüdiger
