From patchwork Tue Sep 14 14:39:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Schindelin X-Patchwork-Id: 12493763 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 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 4602EC433F5 for ; Tue, 14 Sep 2021 14:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 31F5C603E8 for ; Tue, 14 Sep 2021 14:43:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234813AbhINOoo (ORCPT ); Tue, 14 Sep 2021 10:44:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233858AbhINOns (ORCPT ); Tue, 14 Sep 2021 10:43:48 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2FB9DC06124A for ; Tue, 14 Sep 2021 07:39:20 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id c8-20020a7bc008000000b002e6e462e95fso2311138wmb.2 for ; Tue, 14 Sep 2021 07:39:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=A6Xh/Yi4qVOtMT91B3vencuWQjCKOIzIU3gsZOoyzC8=; b=DAgw25bOpKXWBlydYuhHtowXksBhwouG8PfJlVsM28BoB14U2FuU19rF2fnNNWj/4t iSMZCZNe5oZyoGVktkdy/0lUnchjsF73dIdstl65/6w2CkrsOTzweoJREE7G1Q8d1L0H 9Tggy4/nm4EZSwsMli7ygKM23f2e0CjRui87J9hqTVw+kQnvdZ1sx1uZW3nz+NyUOu/8 2XXzMP2zyGoH2jFp8NesBHgcm2RB9E+Z69Li1XS9/jHGMb98KcEsTkR7Ivtk61GUC1Bw 7mrKcXiHQ16T+3mlsvXR65tLKdsdRvekSL/w2SiCBW2b9KWp9K3cC72enI9SurEfYfTA Z1+A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=A6Xh/Yi4qVOtMT91B3vencuWQjCKOIzIU3gsZOoyzC8=; b=NDCz/o2exVJR66VSTEg6VOvAsCMTP0S48JLcNxqjEnkFReKxi6NWpKYFKG9St2u24e QM09wFoQy7PLEYCYb1tUb9epYrZz5bIh6IsGDfi85O/sHE3lQF2nrUGwSg7usXXBXOru VmF/PI5enuF+7L3TSHk3YWq8Kb7Z/9CrthfC/PZdzYxha4V0O0NPKslwmitxDEEpYejn DNRBF2sFI/6wRW+QmJjcyVBqpDg2hYOydoZFkT9hrkc2itcASk/ZrbP3mYU2o7y2FpTj 5Yeus4pEqJPsxyNfB70KnoZLs4VUYJPeJ5xi90CXgJpVnHBrjmim4CR0lnFAAHv/Hg8y 0+3w== X-Gm-Message-State: AOAM530sGGBB/syGNzJjaepwPoFNlaUgcnS0l6AcEXixF5Oql/rPCT6a 1Tr6enqJy2WtbDprfxQvZzFpOVOMnzI= X-Google-Smtp-Source: ABdhPJyichTMn5os3CEEzfz3arOI/tKrdtdNqbXBwNLIJLlgUCwbi0NN74zql1cG4sMn9JXL0j0dXw== X-Received: by 2002:a7b:c405:: with SMTP id k5mr2628714wmi.24.1631630358785; Tue, 14 Sep 2021 07:39:18 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id 129sm1331328wmz.26.2021.09.14.07.39.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Sep 2021 07:39:18 -0700 (PDT) Message-Id: <852ec003109b8244e2f9360ec64749779989c4a2.1631630356.git.gitgitgadget@gmail.com> In-Reply-To: References: Date: Tue, 14 Sep 2021 14:39:02 +0000 Subject: [PATCH v4 01/15] scalar: create a rudimentary executable Fcc: Sent MIME-Version: 1.0 To: git@vger.kernel.org Cc: Derrick Stolee , Eric Sunshine , =?utf-8?b?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason , Elijah Newren , Bagas Sanjaya , 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 has always been the 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 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); +}