Initial commit

src/os/unix/ngx_readv_chain.c

@@ -0,0 +1,214 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) Nginx, Inc.
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_event.h>
+
+
+ssize_t
+ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *chain, off_t limit)
+{
+    u_char        *prev;
+    ssize_t        n, size;
+    ngx_err_t      err;
+    ngx_array_t    vec;
+    ngx_event_t   *rev;
+    struct iovec  *iov, iovs[NGX_IOVS_PREALLOCATE];
+
+    rev = c->read;
+
+#if (NGX_HAVE_KQUEUE)
+
+    if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
+        ngx_log_debug3(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                       "readv: eof:%d, avail:%d, err:%d",
+                       rev->pending_eof, rev->available, rev->kq_errno);
+
+        if (rev->available == 0) {
+            if (rev->pending_eof) {
+                rev->ready = 0;
+                rev->eof = 1;
+
+                ngx_log_error(NGX_LOG_INFO, c->log, rev->kq_errno,
+                              "kevent() reported about an closed connection");
+
+                if (rev->kq_errno) {
+                    rev->error = 1;
+                    ngx_set_socket_errno(rev->kq_errno);
+                    return NGX_ERROR;
+                }
+
+                return 0;
+
+            } else {
+                return NGX_AGAIN;
+            }
+        }
+    }
+
+#endif
+
+#if (NGX_HAVE_EPOLLRDHUP)
+
+    if (ngx_event_flags & NGX_USE_EPOLL_EVENT) {
+        ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                       "readv: eof:%d, avail:%d",
+                       rev->pending_eof, rev->available);
+
+        if (!rev->available && !rev->pending_eof) {
+            return NGX_AGAIN;
+        }
+    }
+
+#endif
+
+    prev = NULL;
+    iov = NULL;
+    size = 0;
+
+    vec.elts = iovs;
+    vec.nelts = 0;
+    vec.size = sizeof(struct iovec);
+    vec.nalloc = NGX_IOVS_PREALLOCATE;
+    vec.pool = c->pool;
+
+    /* coalesce the neighbouring bufs */
+
+    while (chain) {
+        n = chain->buf->end - chain->buf->last;
+
+        if (limit) {
+            if (size >= limit) {
+                break;
+            }
+
+            if (size + n > limit) {
+                n = (ssize_t) (limit - size);
+            }
+        }
+
+        if (prev == chain->buf->last) {
+            iov->iov_len += n;
+
+        } else {
+            if (vec.nelts >= IOV_MAX) {
+                break;
+            }
+
+            iov = ngx_array_push(&vec);
+            if (iov == NULL) {
+                return NGX_ERROR;
+            }
+
+            iov->iov_base = (void *) chain->buf->last;
+            iov->iov_len = n;
+        }
+
+        size += n;
+        prev = chain->buf->end;
+        chain = chain->next;
+    }
+
+    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0,
+                   "readv: %ui, last:%uz", vec.nelts, iov->iov_len);
+
+    do {
+        n = readv(c->fd, (struct iovec *) vec.elts, vec.nelts);
+
+        if (n == 0) {
+            rev->ready = 0;
+            rev->eof = 1;
+
+#if (NGX_HAVE_KQUEUE)
+
+            /*
+             * on FreeBSD readv() may return 0 on closed socket
+             * even if kqueue reported about available data
+             */
+
+            if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
+                rev->available = 0;
+            }
+
+#endif
+
+            return 0;
+        }
+
+        if (n > 0) {
+
+#if (NGX_HAVE_KQUEUE)
+
+            if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
+                rev->available -= n;
+
+                /*
+                 * rev->available may be negative here because some additional
+                 * bytes may be received between kevent() and readv()
+                 */
+
+                if (rev->available <= 0) {
+                    if (!rev->pending_eof) {
+                        rev->ready = 0;
+                    }
+
+                    rev->available = 0;
+                }
+
+                return n;
+            }
+
+#endif
+
+#if (NGX_HAVE_EPOLLRDHUP)
+
+            if ((ngx_event_flags & NGX_USE_EPOLL_EVENT)
+                && ngx_use_epoll_rdhup)
+            {
+                if (n < size) {
+                    if (!rev->pending_eof) {
+                        rev->ready = 0;
+                    }
+
+                    rev->available = 0;
+                }
+
+                return n;
+            }
+
+#endif
+
+            if (n < size && !(ngx_event_flags & NGX_USE_GREEDY_EVENT)) {
+                rev->ready = 0;
+            }
+
+            return n;
+        }
+
+        err = ngx_socket_errno;
+
+        if (err == NGX_EAGAIN || err == NGX_EINTR) {
+            ngx_log_debug0(NGX_LOG_DEBUG_EVENT, c->log, err,
+                           "readv() not ready");
+            n = NGX_AGAIN;
+
+        } else {
+            n = ngx_connection_error(c, err, "readv() failed");
+            break;
+        }
+
+    } while (err == NGX_EINTR);
+
+    rev->ready = 0;
+
+    if (n == NGX_ERROR) {
+        c->read->error = 1;
+    }
+
+    return n;
+}