From patchwork Wed Jan 21 13:21:25 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yousong Zhou X-Patchwork-Id: 431470 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from arrakis.dune.hu (arrakis.dune.hu [78.24.191.176]) (using TLSv1.1 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 43106140151 for ; Thu, 22 Jan 2015 00:23:03 +1100 (AEDT) Received: from arrakis.dune.hu (localhost [127.0.0.1]) by arrakis.dune.hu (Postfix) with ESMTP id 06CFA28BDAD; Wed, 21 Jan 2015 14:19:56 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on arrakis.dune.hu X-Spam-Level: X-Spam-Status: No, score=-1.5 required=5.0 tests=BAYES_00,FREEMAIL_FROM, T_DKIM_INVALID autolearn=unavailable version=3.3.2 Received: from arrakis.dune.hu (localhost [127.0.0.1]) by arrakis.dune.hu (Postfix) with ESMTP id DEDEA28BD40 for ; Wed, 21 Jan 2015 14:19:42 +0100 (CET) X-policyd-weight: using cached result; rate: -8.5 Received: from mail-pa0-f51.google.com (mail-pa0-f51.google.com [209.85.220.51]) by arrakis.dune.hu (Postfix) with ESMTPS for ; Wed, 21 Jan 2015 14:19:42 +0100 (CET) Received: by mail-pa0-f51.google.com with SMTP id fb1so18378094pad.10 for ; Wed, 21 Jan 2015 05:22:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=ZT+awz7/J25aJ2NCIPWyXeFQz7na46gu5MmZQgreKH4=; b=Or4ml09uTNhuCtIEhzf6apLuHgihHXkgRZluWwwQ91nxSZTdx3BV6GGW4LMCa9eN2q bo28JD7qZSoUbITDAbyAA85np0o9hfc1GXEOUY4pwIswlSpBduW4s5qNFTVv3PeQXWtN VqXTOzZwFaQZOOk5RepRhR4PfIM8bl82EIUrwdb1Vmp1/igfU7+us0yxxj6ssFChDWSV 9pCYhqexNavQ+Pn/e75S2oDSr2Dh+BcFogwBbtQ5RWoSEmn6RlEfDsnaPtX6GMkeEkaK 09CR6qbJt7Cjy6/cYP81dMkR5DWLCUyDDbSdyxHYME1bE+hqo6lcKQt2Xpgp0rd/jNQU 28ug== X-Received: by 10.70.48.201 with SMTP id o9mr23758932pdn.4.1421846521079; Wed, 21 Jan 2015 05:22:01 -0800 (PST) Received: from yousongs-MacBook-Air.local.info ([103.29.140.56]) by mx.google.com with ESMTPSA id kv4sm6314878pab.22.2015.01.21.05.21.57 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 21 Jan 2015 05:21:59 -0800 (PST) From: Yousong Zhou To: nbd@openwrt.org Date: Wed, 21 Jan 2015 21:21:25 +0800 Message-Id: <1421846488-323-2-git-send-email-yszhou4tech@gmail.com> X-Mailer: git-send-email 2.2.1 In-Reply-To: <1421846488-323-1-git-send-email-yszhou4tech@gmail.com> References: <1421846488-323-1-git-send-email-yszhou4tech@gmail.com> Cc: openwrt-devel@lists.openwrt.org Subject: [OpenWrt-Devel] [PATCH 2/5] ustream: add function ustream_read(). X-BeenThere: openwrt-devel@lists.openwrt.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: OpenWrt Development List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: openwrt-devel-bounces@lists.openwrt.org Sender: "openwrt-devel" It can be used to fill caller-specified buffer with data already in ustream read buffer. Useful in the following use pattern. int available = ustream_pending_data(s, false); if (available >= sizeof(struct msghdr)) { struct msghdr h; ustream_read(s, &h, sizeof(h)); } Signed-off-by: Yousong Zhou --- ustream.c | 20 ++++++++++++++++++++ ustream.h | 5 +++++ 2 files changed, 25 insertions(+) diff --git a/ustream.c b/ustream.c index 828a025..fc93bc2 100644 --- a/ustream.c +++ b/ustream.c @@ -333,6 +333,26 @@ char *ustream_get_read_buf(struct ustream *s, int *buflen) return data; } +int ustream_read(struct ustream *s, char *buf, int buflen) +{ + char *chunk; + int chunk_len; + int len = 0; + + do { + chunk = ustream_get_read_buf(s, &chunk_len); + if (!chunk) + break; + if (chunk_len > buflen - len) + chunk_len = buflen - len; + memcpy(buf + len, chunk, chunk_len); + ustream_consume(s, chunk_len); + len += chunk_len; + } while (len < buflen); + + return len; +} + static void ustream_write_error(struct ustream *s) { if (!s->write_error) diff --git a/ustream.h b/ustream.h index 6431744..53e0828 100644 --- a/ustream.h +++ b/ustream.h @@ -143,6 +143,11 @@ void ustream_free(struct ustream *s); /* ustream_consume: remove data from the head of the read buffer */ void ustream_consume(struct ustream *s, int len); +/* + * ustream_read: read and consume data in read buffer into caller-specified + * area. Return length of data read. + */ +int ustream_read(struct ustream *s, char *buf, int buflen); /* ustream_write: add data to the write buffer */ int ustream_write(struct ustream *s, const char *buf, int len, bool more); int ustream_printf(struct ustream *s, const char *format, ...);