From patchwork Wed Sep 8 19:24:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Schindelin X-Patchwork-Id: 12481753 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 A8BFCC433FE for ; Wed, 8 Sep 2021 19:24:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 894AB610FF for ; Wed, 8 Sep 2021 19:24:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350549AbhIHTZ6 (ORCPT ); Wed, 8 Sep 2021 15:25:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43180 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350001AbhIHTZ5 (ORCPT ); Wed, 8 Sep 2021 15:25:57 -0400 Received: from mail-wm1-x329.google.com (mail-wm1-x329.google.com [IPv6:2a00:1450:4864:20::329]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26C04C061757 for ; Wed, 8 Sep 2021 12:24:49 -0700 (PDT) Received: by mail-wm1-x329.google.com with SMTP id m2so2581567wmm.0 for ; Wed, 08 Sep 2021 12:24:49 -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=iXLjZUJ4SF7urD3/OFYAEJlIY8QKTaQKSGLrhuMOp/o=; b=CV58o3IfH9jhkCTb+M9elnxUbGWtgYK+pZ8B9iaSMjEef1cIFvW4i1WBB5AwdksVOu NqvVe7HQaUaWyR1FaAZwYKbEK5b6mbRz7lwXilfuTJMi9lYSW8MfkOnt7FWXvYY6v7WZ WXkNFTxY/L3WO0MAVmXJuTvCYSI1odMUNmt+Rbh531vwmmKxcTbrt3AeivVxV6uLpll3 GbYc7h4xpXqziaVbTxBSB8EweaHcOKcjCmjeU1hJl8YfSFZQRdSuC+FepU+sefl67FEe ib7cKd7ezYrgGqmm/j+vaZYMot9OXtP3BS/dkSlxXBYTVw+ENEjURsdtGKmPd9DUfNed c9jQ== 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=iXLjZUJ4SF7urD3/OFYAEJlIY8QKTaQKSGLrhuMOp/o=; b=Cb79RGIquCZRLWirUxaIYTxVkqg/V5UwJ2CLlSOfft+UZZRDYXXOcqnXF1ChxbV1+m IchrEE3V5gXA8ykjvVJPnCNGVnke9J8w7e7GDZkydIpaCOASXzh9mQDJXsP8zJn1eaCY F4lqko8yQo/qjObIXe4C05lGJViUNYTgUroaZalibSEfQJPUJBqscFxhsqqrIKrJQJ+r UcblYN/AkQ/7fSf+FZRMmrinH4sqe5ebzY4I7ZRc7qT6CK86XZiBd5xA+8h6ySd00Rjj Ov0LuVW2wFRW30NDjPVwnHNiDvaGZuXWV+y2RRBSKjSX4nbrK8HNbhT2eCz2pa2geI1J hiLw== X-Gm-Message-State: AOAM533olpp8qACOL7IDouSlHvCKjfRhNaTnlMGfK7yJ4aefENRwUqRd MHVpBX7Q1anADCOPcZ6wTLqNujZ+U9Y= X-Google-Smtp-Source: ABdhPJyqeuw5RSsM345xqbDg1B4NZ7dqG0YHsN/mkPcoh1PSlytsMhNZvB15IDzH1aQwDyjHdvJfmQ== X-Received: by 2002:a7b:c4d2:: with SMTP id g18mr5212126wmk.135.1631129087716; Wed, 08 Sep 2021 12:24:47 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id j14sm25926wrp.21.2021.09.08.12.24.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Sep 2021 12:24:47 -0700 (PDT) Message-Id: In-Reply-To: References: Date: Wed, 08 Sep 2021 19:24:31 +0000 Subject: [PATCH v3 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 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); +}