From patchwork Mon Aug 30 21:34:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Schindelin X-Patchwork-Id: 12465981 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4538EC4320E for ; Mon, 30 Aug 2021 21:34:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2336D60F6B for ; Mon, 30 Aug 2021 21:34:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236996AbhH3Vfs (ORCPT ); Mon, 30 Aug 2021 17:35:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232049AbhH3Vfr (ORCPT ); Mon, 30 Aug 2021 17:35:47 -0400 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4ACEFC06175F for ; Mon, 30 Aug 2021 14:34:53 -0700 (PDT) Received: by mail-wr1-x42e.google.com with SMTP id d26so24485437wrc.0 for ; Mon, 30 Aug 2021 14:34:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=iXLjZUJ4SF7urD3/OFYAEJlIY8QKTaQKSGLrhuMOp/o=; b=QymHmIzbXDcWrefFxQh+N7puJ0MHaLvzRyyv5bs7HVcG3Gh6BqSBN+bFaarpM/Ca84 eJb6V1UXULGyihsgfq/IsGtlkboRvaMQdodAijYOnkwJKqpoWPJFiYyPBHSl59apCYdU VJThhGqhMNUTKDrBPUou+7tbBfJchumFKMKAwGiD5knXEes6BvlL41NVliXT0USrFpuW 0VQwG+PPV4+gqUpmLBFMJNcDMZ/FwbRBYieUc0AInlGL8uHO9f0btqsHXjgYf9Stto7I df4coOVz4il5sa9JCpITGnyvrRIBrvVRXX1xM/UVY4MDiHfjlkP2OI0NRI0xvj7s27Xl 7Kwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=iXLjZUJ4SF7urD3/OFYAEJlIY8QKTaQKSGLrhuMOp/o=; b=eiG86UCp85EuuKBsML8zJQIWUf4ZVQ8VY/o74er9pHMk0zYhrzfvqh1PTC10wvEkwA VwNX+7n4r3s8KhXpy7gATPsrgZcnwc3wDSCpNtMPOpaF8MG1CjlFMLGg4g1MHw19Fxxf gPPW+qNHtWKAXykvmKUqPGWYA3jDpPvLTM2BZ8YuAIzkZZlBWlphu5tQkTnWk708pVMn rH0xcc3JMpH9Tabt/orQY3Jn2d/m9kP4C28/H1895XJauzORqDpGQg5kevRd+tBk2cHi W41lWEEuy8mgChSrB105Culz8Z8ePtMxObEryqqt63T1Lclw+JztYR2G5kxvBXuEwv0B IRDg== X-Gm-Message-State: AOAM531EmmALQqcLiRIZ2LC2LA3pFBwYZZ64vdkeCZKxt2vBd6d7XrxQ xYV83TYhGOXyJhk3ogaDSdKXpBX/LxI= X-Google-Smtp-Source: ABdhPJwC89JT/QuvmUN66RHrcqm0PVvCamRx4JwLdIB0ffZn9bpKgssXqO7QT48zp2hItdlNlKmIsg== X-Received: by 2002:a5d:58e7:: with SMTP id f7mr28491677wrd.51.1630359291869; Mon, 30 Aug 2021 14:34:51 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id b24sm559278wmj.43.2021.08.30.14.34.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 30 Aug 2021 14:34:51 -0700 (PDT) Message-Id: In-Reply-To: References: Date: Mon, 30 Aug 2021 21:34:36 +0000 Subject: [PATCH 01/15] scalar: create a rudimentary executable Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Johannes Schindelin , Johannes Schindelin Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Johannes Schindelin From: Johannes Schindelin The idea of Scalar (https://github.com/microsoft/scalar), and before that, of VFS for Git, has always been to prove that Git _can_ scale, and to upstream whatever strategies have been demonstrated to help. With this patch, we start the journey from that C# project to move what is left to Git's own `contrib/` directory, reimplementing it in pure C, with the intention to facilitate integrating the functionality into core Git all while maintaining backwards-compatibility for existing Scalar users (which will be much easier when both live in the same worktree). It was always to plan to contribute all of the proven strategies back to core Git. For example, while the virtual filesystem provided by VFS for Git helped the team developing the Windows operating system to move onto Git, while trying to upstream it we realized that it cannot be done: getting the virtual filesystem to work (which we only managed to implement fully on Windows, but not on, say, macOS or Linux), and the required server-side support for the GVFS protocol, made this not quite feasible. The Scalar project learned from that and tackled the problem with different tactics: instead of pretending to Git that the working directory is fully populated, it _specifically_ teaches Git about partial clone (which is based on VFS for Git's cache server), about sparse checkout (which VFS for Git tried to do transparently, in the file system layer), and regularly runs maintenance tasks to keep the repository in a healthy state. With partial clone, sparse checkout and `git maintenance` having been upstreamed, there is little left that `scalar.exe` does that which `git.exe` cannot do. One such thing is that `scalar clone ` will automatically set up a partial, sparse clone, and configure known-helpful settings from the start. So let's bring this convenience into Git's tree. The idea here is that you can (optionally) build Scalar via make -C contrib/scalar/Makefile This will build the `scalar` executable and put it into the contrib/scalar/ subdirectory. The slightly awkward addition of the `contrib/scalar/*` bits to the top-level `Makefile` are actually really required: we want to link to `libgit.a`, which means that we will need to use the very same `CFLAGS` and `LDFLAGS` as the rest of Git. An early development version of this patch tried to replicate all the conditional code in `contrib/scalar/Makefile` (e.g. `NO_POLL`) just like `contrib/svn-fe/Makefile` used to do before it was retired. It turned out to be quite the whack-a-mole game: the SHA-1-related flags, the flags enabling/disabling `compat/poll/`, `compat/regex/`, `compat/win32mmap.c` & friends depending on the current platform... To put it mildly: it was a major mess. Instead, this patch makes minimal changes to the top-level `Makefile` so that the bits in `contrib/scalar/` can be compiled and linked, and adds a `contrib/scalar/Makefile` that uses the top-level `Makefile` in a most minimal way to do the actual compiling. Note: With this commit, we only establish the infrastructure, no Scalar functionality is implemented yet; We will do that incrementally over the next few commits. Signed-off-by: Johannes Schindelin --- Makefile | 8 ++++++++ contrib/scalar/.gitignore | 2 ++ contrib/scalar/Makefile | 34 ++++++++++++++++++++++++++++++++++ contrib/scalar/scalar.c | 36 ++++++++++++++++++++++++++++++++++++ 4 files changed, 80 insertions(+) create mode 100644 contrib/scalar/.gitignore create mode 100644 contrib/scalar/Makefile create mode 100644 contrib/scalar/scalar.c diff --git a/Makefile b/Makefile index c3565fc0f8f..2d5c822f7a8 100644 --- a/Makefile +++ b/Makefile @@ -2447,6 +2447,10 @@ endif .PHONY: objects objects: $(OBJECTS) +SCALAR_SOURCES := contrib/scalar/scalar.c +SCALAR_OBJECTS := $(SCALAR_SOURCES:c=o) +OBJECTS += $(SCALAR_OBJECTS) + dep_files := $(foreach f,$(OBJECTS),$(dir $f).depend/$(notdir $f).d) dep_dirs := $(addsuffix .depend,$(sort $(dir $(OBJECTS)))) @@ -2586,6 +2590,10 @@ $(REMOTE_CURL_PRIMARY): remote-curl.o http.o http-walker.o GIT-LDFLAGS $(GITLIBS $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) $(filter %.o,$^) \ $(CURL_LIBCURL) $(EXPAT_LIBEXPAT) $(LIBS) +contrib/scalar/scalar$X: $(SCALAR_OBJECTS) GIT-LDFLAGS $(GITLIBS) + $(QUIET_LINK)$(CC) $(ALL_CFLAGS) -o $@ $(ALL_LDFLAGS) \ + $(filter %.o,$^) $(LIBS) + $(LIB_FILE): $(LIB_OBJS) $(QUIET_AR)$(RM) $@ && $(AR) $(ARFLAGS) $@ $^ diff --git a/contrib/scalar/.gitignore b/contrib/scalar/.gitignore new file mode 100644 index 00000000000..ff3d47e84d0 --- /dev/null +++ b/contrib/scalar/.gitignore @@ -0,0 +1,2 @@ +/*.exe +/scalar diff --git a/contrib/scalar/Makefile b/contrib/scalar/Makefile new file mode 100644 index 00000000000..40c03ad10e1 --- /dev/null +++ b/contrib/scalar/Makefile @@ -0,0 +1,34 @@ +QUIET_SUBDIR0 = +$(MAKE) -C # space to separate -C and subdir +QUIET_SUBDIR1 = + +ifneq ($(findstring s,$(MAKEFLAGS)),s) +ifndef V + QUIET_SUBDIR0 = +@subdir= + QUIET_SUBDIR1 = ;$(NO_SUBDIR) echo ' ' SUBDIR $$subdir; \ + $(MAKE) $(PRINT_DIR) -C $$subdir +else + export V +endif +endif + +all: + +include ../../config.mak.uname +-include ../../config.mak.autogen +-include ../../config.mak + +TARGETS = scalar$(X) scalar.o +GITLIBS = ../../common-main.o ../../libgit.a ../../xdiff/lib.a + +all: scalar$X + +$(GITLIBS): + $(QUIET_SUBDIR0)../.. $(QUIET_SUBDIR1) $(subst ../../,,$@) + +$(TARGETS): $(GITLIBS) scalar.c + $(QUIET_SUBDIR0)../.. $(QUIET_SUBDIR1) $(patsubst %,contrib/scalar/%,$@) + +clean: + $(RM) $(TARGETS) + +.PHONY: all clean FORCE diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c new file mode 100644 index 00000000000..7cff29e0fcd --- /dev/null +++ b/contrib/scalar/scalar.c @@ -0,0 +1,36 @@ +/* + * The Scalar command-line interface. + */ + +#include "cache.h" +#include "gettext.h" +#include "parse-options.h" + +static struct { + const char *name; + int (*fn)(int, const char **); +} builtins[] = { + { NULL, NULL}, +}; + +int cmd_main(int argc, const char **argv) +{ + struct strbuf scalar_usage = STRBUF_INIT; + int i; + + if (argc > 1) { + argv++; + argc--; + + for (i = 0; builtins[i].name; i++) + if (!strcmp(builtins[i].name, argv[0])) + return !!builtins[i].fn(argc, argv); + } + + strbuf_addstr(&scalar_usage, + N_("scalar []\n\nCommands:\n")); + for (i = 0; builtins[i].name; i++) + strbuf_addf(&scalar_usage, "\t%s\n", builtins[i].name); + + usage(scalar_usage.buf); +}