From patchwork Mon Mar 30 13:46:59 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Steinhardt X-Patchwork-Id: 11465549 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F3603913 for ; Mon, 30 Mar 2020 13:46:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C878220771 for ; Mon, 30 Mar 2020 13:46:59 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=pks.im header.i=@pks.im header.b="c9acE2Ed"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="UeDpk2UF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728548AbgC3Nq7 (ORCPT ); Mon, 30 Mar 2020 09:46:59 -0400 Received: from wout4-smtp.messagingengine.com ([64.147.123.20]:52871 "EHLO wout4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727954AbgC3Nq6 (ORCPT ); Mon, 30 Mar 2020 09:46:58 -0400 Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id D30FE574; Mon, 30 Mar 2020 09:46:57 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Mon, 30 Mar 2020 09:46:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pks.im; h=date :from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=0pFPLNib2Yy1XpwBHY2APRcUkux UcyhbtXEO6q10LaA=; b=c9acE2Ed2fqJGW476QENhObKbciKT6I+iuabUqtx87/ /eyRzkGnpoGEa5mB3cTHoMTWY165lQjvP5aDx3z8BaJiMN9MKcB2y1jAgpiC/irh 5Q0ghaIvifO8rfE3fQVc8BAf9IMc/SvnM0FBMZPSoRDvCkO2x0Zr38i48q7c7GWl 3t9/3I2sX7x/VpGOHyN8HSOj2CW4MFXy3CUq2cSYQwCzj4i9ezdPxtmsmdW+wYnE FndEOq/pMCA8j6qUvsNmZuDLqlMmXP8yETBBOoZh18jIgWYHo9Pabuf02grrq/42 zBvNx4eHcSa+W9/oJ/E1INI/gAaX1Tknfg2K2M9xkAQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=0pFPLN ib2Yy1XpwBHY2APRcUkuxUcyhbtXEO6q10LaA=; b=UeDpk2UFP7U8PWO2IAzsQ5 zFXi1czfVwlOsW6iSG+DaM1rvbCO4N+KSMS0g+J3sCutBvDjMfbVDjMpV12womD9 1stLZi9c3C+/IBpPLdSlzlHB8wVeX7o+UshYN9ta6ciz12evq+NbnZ7OHWL3wehR FHABXaPhvBHk0O+R2mk0rsKT3/HG5N255tVSsJC98Yq5YGz14aWDnJxdC8ioB2yM 53pv+eeUVZqP02FgOU13suHTKC2lG0KPvjr3+0I+Hk10+tcc9TQlG/1P0Q6g83mw 2yF8oSWKvgWlag7azHApxdzaSRGp+Pza6KGZykC/KgRrwRuEOEm1Ow30wrP+gC5A == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedugedrudeihedgieekucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehgtderredttddvnecuhfhrohhmpefrrghtrhhi tghkucfuthgvihhnhhgrrhguthcuoehpshesphhkshdrihhmqeenucfkphepjeekrdehge drvddvtddruddtvdenucevlhhushhtvghrufhiiigvpeeknecurfgrrhgrmhepmhgrihhl fhhrohhmpehpshesphhkshdrihhm X-ME-Proxy: Received: from vm-mail.pks.im (x4e36dc66.dyn.telefonica.de [78.54.220.102]) by mail.messagingengine.com (Postfix) with ESMTPA id C361C328005A; Mon, 30 Mar 2020 09:46:56 -0400 (EDT) Received: from localhost (ncase [10.192.0.11]) by vm-mail.pks.im (OpenSMTPD) with ESMTPSA id 0dc33be9 (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Mon, 30 Mar 2020 13:46:55 +0000 (UTC) Date: Mon, 30 Mar 2020 15:46:59 +0200 From: Patrick Steinhardt To: git Cc: Christian Couder , Junio C Hamano Subject: [PATCH v2 8/9] update-ref: read commands in a line-wise fashion Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org The git-update-ref(1) supports a `--stdin` mode that allows it to read all reference updates from standard input. This is mainly used to allow for atomic reference updates that are all or nothing, so that either all references will get updated or none. Currently, git-update-ref(1) reads all commands as a single block of up to 1000 characters and only starts processing after stdin gets closed. This is less flexible than one might wish for, as it doesn't really allow for longer-lived transactions and doesn't allow any verification without committing everything. E.g. one may imagine the following exchange: > start < start: ok > update refs/heads/master $NEWOID1 $OLDOID1 > update refs/heads/branch $NEWOID2 $OLDOID2 > prepare < prepare: ok > commit < commit: ok When reading all input as a whole block, the above interactive protocol is obviously impossible to achieve. But by converting the command to read commands linewise, we can make it more interactive than before. Obviously, the linewise interface is only a first step in making git-update-ref(1) work in a more transaction-oriented way. Missing is most importantly support for transactional commands that manage the current transaction. Signed-off-by: Patrick Steinhardt --- builtin/update-ref.c | 80 +++++++++++++++++++++++--------------------- 1 file changed, 41 insertions(+), 39 deletions(-) diff --git a/builtin/update-ref.c b/builtin/update-ref.c index 1a7906545d..77cd235dfc 100644 --- a/builtin/update-ref.c +++ b/builtin/update-ref.c @@ -178,8 +178,8 @@ static int parse_next_oid(const char **next, const char *end, * line_termination is set. */ -static const char *parse_cmd_update(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_update(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -212,12 +212,10 @@ static const char *parse_cmd_update(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_create(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_create(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -247,12 +245,10 @@ static const char *parse_cmd_create(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_delete(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_delete(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -286,12 +282,10 @@ static const char *parse_cmd_delete(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_verify(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_verify(struct ref_transaction *transaction, + const char *next, const char *end) { struct strbuf err = STRBUF_INIT; char *refname; @@ -318,12 +312,10 @@ static const char *parse_cmd_verify(struct ref_transaction *transaction, update_flags = default_flags; free(refname); strbuf_release(&err); - - return next; } -static const char *parse_cmd_option(struct ref_transaction *transaction, - const char *next, const char *end) +static void parse_cmd_option(struct ref_transaction *transaction, + const char *next, const char *end) { const char *rest; if (!skip_prefix(next, " ", &next)) @@ -332,48 +324,49 @@ static const char *parse_cmd_option(struct ref_transaction *transaction, update_flags |= REF_NO_DEREF; else die("option unknown: %s", next); - return rest; } static const struct parse_cmd { const char *prefix; - const char *(*fn)(struct ref_transaction *, const char *, const char *); + void (*fn)(struct ref_transaction *, const char *, const char *); + /* + * If using NUL-terminated format, only the first argument will be + * available in the first line. In case a command expects more than one + * argument, we thus have to fetch an additional `extra_lines` number + * of lines. + */ + unsigned extra_lines; } command[] = { - { "update", parse_cmd_update }, - { "create", parse_cmd_create }, - { "delete", parse_cmd_delete }, - { "verify", parse_cmd_verify }, - { "option", parse_cmd_option }, + { "update", parse_cmd_update, 2 }, + { "create", parse_cmd_create, 1 }, + { "delete", parse_cmd_delete, 1 }, + { "verify", parse_cmd_verify, 1 }, + { "option", parse_cmd_option, 0 }, }; static void update_refs_stdin(void) { struct strbuf input = STRBUF_INIT, err = STRBUF_INIT; struct ref_transaction *transaction; - const char *next; - int i; - - if (strbuf_read(&input, 0, 1000) < 0) - die_errno("could not read from stdin"); - next = input.buf; + int i, j; transaction = ref_transaction_begin(&err); if (!transaction) die("%s", err.buf); /* Read each line dispatch its command */ - while (next < input.buf + input.len) { + while (!strbuf_getwholeline(&input, stdin, line_termination)) { const struct parse_cmd *cmd = NULL; - if (*next == line_termination) + if (*input.buf == line_termination) die("empty command in input"); - else if (isspace(*next)) - die("whitespace before command: %s", next); + else if (isspace(*input.buf)) + die("whitespace before command: %s", input.buf); for (i = 0; i < ARRAY_SIZE(command); i++) { const char *prefix = command[i].prefix; - if (!skip_prefix(next, prefix, &next)) + if (!starts_with(input.buf, prefix)) continue; /* @@ -389,10 +382,19 @@ static void update_refs_stdin(void) break; } if (!cmd) - die("unknown command: %s", next); + die("unknown command: %s", input.buf); - next = cmd->fn(transaction, next, input.buf + input.len); - next++; + /* + * Read extra lines if NUL-terminated. Do not raise an error in + * case there is an early EOF to let the command handle missing + * arguments with a proper error message. + */ + for (j = 0; line_termination == '\0' && j < cmd->extra_lines; j++) + if (strbuf_appendwholeline(&input, stdin, line_termination)) + break; + + cmd->fn(transaction, input.buf + strlen(cmd->prefix), + input.buf + input.len); } if (ref_transaction_commit(transaction, &err))