Mercurial > hg > nginx-quic
view src/stream/ngx_stream_write_filter_module.c @ 8824:81a3429db8b0 quic
HTTP/3: delayed Insert Count Increment instruction.
Sending the instruction is delayed until the end of the current event cycle.
Delaying the instruction is allowed by quic-qpack-21, section 2.2.2.3.
The goal is to reduce the amount of data sent back to client by accumulating
several inserts in one instruction and sometimes not sending the instruction at
all, if Section Acknowledgement was sent just before it.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Thu, 27 Jan 2022 12:20:47 +0300 |
parents | d127837c714f |
children | 32b0ba4855a6 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_chain_t *from_upstream; ngx_chain_t *from_downstream; } ngx_stream_write_filter_ctx_t; static ngx_int_t ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in, ngx_uint_t from_upstream); static ngx_int_t ngx_stream_write_filter_init(ngx_conf_t *cf); static ngx_stream_module_t ngx_stream_write_filter_module_ctx = { NULL, /* preconfiguration */ ngx_stream_write_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_write_filter_module = { NGX_MODULE_V1, &ngx_stream_write_filter_module_ctx, /* module context */ NULL, /* module directives */ NGX_STREAM_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in, ngx_uint_t from_upstream) { off_t size; ngx_uint_t last, flush, sync; ngx_chain_t *cl, *ln, **ll, **out, *chain; ngx_connection_t *c; ngx_stream_write_filter_ctx_t *ctx; ctx = ngx_stream_get_module_ctx(s, ngx_stream_write_filter_module); if (ctx == NULL) { ctx = ngx_pcalloc(s->connection->pool, sizeof(ngx_stream_write_filter_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_stream_set_ctx(s, ctx, ngx_stream_write_filter_module); } if (from_upstream) { c = s->connection; out = &ctx->from_upstream; } else { c = s->upstream->peer.connection; out = &ctx->from_downstream; } if (c->error) { return NGX_ERROR; } size = 0; flush = 0; sync = 0; last = 0; ll = out; /* find the size, the flush point and the last link of the saved chain */ for (cl = *out; cl; cl = cl->next) { ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write old buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } if (ngx_buf_size(cl->buf) < 0) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "negative size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } /* add the new chain to the existent one */ for (ln = in; ln; ln = ln->next) { cl = ngx_alloc_chain_link(c->pool); if (cl == NULL) { return NGX_ERROR; } cl->buf = ln->buf; *ll = cl; ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write new buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } if (ngx_buf_size(cl->buf) < 0) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "negative size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } *ll = NULL; ngx_log_debug3(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream write filter: l:%ui f:%ui s:%O", last, flush, size); if (size == 0 && !(c->buffered & NGX_LOWLEVEL_BUFFERED) && !(last && c->need_last_buf) && !(c->type == SOCK_DGRAM && flush)) { if (last || flush || sync) { for (cl = *out; cl; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(c->pool, ln); } *out = NULL; c->buffered &= ~NGX_STREAM_WRITE_BUFFERED; return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, c->log, 0, "the stream output chain is empty"); ngx_debug_point(); return NGX_ERROR; } chain = c->send_chain(c, *out, 0); ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream write filter %p", chain); if (chain == NGX_CHAIN_ERROR) { c->error = 1; return NGX_ERROR; } for (cl = *out; cl && cl != chain; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(c->pool, ln); } *out = chain; if (chain) { if (c->shared) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "shared connection is busy"); return NGX_ERROR; } c->buffered |= NGX_STREAM_WRITE_BUFFERED; return NGX_AGAIN; } c->buffered &= ~NGX_STREAM_WRITE_BUFFERED; if (c->buffered & NGX_LOWLEVEL_BUFFERED) { return NGX_AGAIN; } return NGX_OK; } static ngx_int_t ngx_stream_write_filter_init(ngx_conf_t *cf) { ngx_stream_top_filter = ngx_stream_write_filter; return NGX_OK; }