From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Achleitner Subject: [RFC 01/16] Implement a remote helper for svn in C. Date: Thu, 26 Jul 2012 09:32:22 +0200 Message-ID: <1343287957-22040-2-git-send-email-florian.achleitner.2.6.31@gmail.com> References: <1343287957-22040-1-git-send-email-florian.achleitner.2.6.31@gmail.com> Cc: florian.achleitner.2.6.31@gmail.com To: Jonathan Nieder , David Michael Barr , git@vger.kernel.org X-From: git-owner@vger.kernel.org Thu Jul 26 09:34:31 2012 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1SuIaZ-0004iX-Kh for gcvg-git-2@plane.gmane.org; Thu, 26 Jul 2012 09:34:28 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751360Ab2GZHeW (ORCPT ); Thu, 26 Jul 2012 03:34:22 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:58737 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751125Ab2GZHeV (ORCPT ); Thu, 26 Jul 2012 03:34:21 -0400 Received: by mail-bk0-f46.google.com with SMTP id j10so1067267bkw.19 for ; Thu, 26 Jul 2012 00:34:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; bh=seRxYBQd2Z72AH0epRycRVy1lQe47cPhvXLEvqcG/Yc=; b=a00s6EW2JyLHNXxPuzEjTnL4m2gWsOQM4nJIDySpDem38hEs1wyOxX0+NgnvnYcvLD NlaGS4K1ARXZIZJYl0DqBJJX3ko/QSu7STabjnfxT+3Q/Idqp6GSxtYBI1dsxRCO17if ghhZo+/hKNawK/a29MnU5rmudicI9LHE/MMRqWPDaJCseuFAxAsm43jrtOEcG7TH20es FygcTXT6EaZQ9VJ5R/83TAH3pScb/soGP1K/lTX2wjiNX/2Gvs7hvRjMuMy9GGheK2/0 +Ywi7ORa5cJdgU5gFohXTGt48WxJRzjNmXyTad4WwQkqdsXU+ea+hfAfhMUzD4lWrT7/ uZPA== Received: by 10.204.13.82 with SMTP id b18mr13584749bka.118.1343288060803; Thu, 26 Jul 2012 00:34:20 -0700 (PDT) Received: from localhost.localdomain (cm56-227-93.liwest.at. [86.56.227.93]) by mx.google.com with ESMTPS id n5sm13880348bkv.14.2012.07.26.00.34.18 (version=SSLv3 cipher=OTHER); Thu, 26 Jul 2012 00:34:19 -0700 (PDT) X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1343287957-22040-1-git-send-email-florian.achleitner.2.6.31@gmail.com> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Enables basic fetching from subversion repositories. When processing Remote URLs starting with svn::, git invokes this remote-helper. It starts svnrdump to extract revisions from the subversion repository in the 'dump file format', and converts them to a git-fast-import stream using the functions of vcs-svn/. Imported refs are created in a private namespace at refs/svn/ --- contrib/svn-fe/remote-svn.c | 219 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 219 insertions(+) create mode 100644 contrib/svn-fe/remote-svn.c diff --git a/contrib/svn-fe/remote-svn.c b/contrib/svn-fe/remote-svn.c new file mode 100644 index 0000000..29fc371 --- /dev/null +++ b/contrib/svn-fe/remote-svn.c @@ -0,0 +1,219 @@ + +#include "cache.h" +#include "remote.h" +#include "strbuf.h" +#include "url.h" +#include "exec_cmd.h" +#include "run-command.h" +#include "svndump.h" +#include "argv-array.h" + +static int debug; + +static inline void printd(const char *fmt, ...) +{ + if (debug) { + va_list vargs; + va_start(vargs, fmt); + fprintf(stderr, "rhsvn debug: "); + vfprintf(stderr, fmt, vargs); + fprintf(stderr, "\n"); + va_end(vargs); + } +} + +static const char *url; +static const char *private_ref; +static const char *remote_ref = "refs/heads/master"; + +/* + * remote-helpers receive commands on their stdin. Command handler functions + * can return cmd_result, on fatal errors they die(). + * NOT_HANDLED: the command was not handled by this function, name doesn't match. + * TERMINATE: Requests normal termination of the remote-helper. + */ +enum cmd_result { SUCCESS, NOT_HANDLED, TERMINATE }; +enum cmd_result cmd_capabilities(struct strbuf *line); +enum cmd_result cmd_import(struct strbuf *line); +enum cmd_result cmd_list(struct strbuf *line); +enum cmd_result cmd_terminate(struct strbuf *line); + +typedef enum cmd_result (*input_command_handler)(struct strbuf *); + +const input_command_handler input_command_list[] = { + cmd_capabilities, cmd_import, cmd_list, cmd_terminate, NULL +}; + +enum cmd_result cmd_capabilities(struct strbuf *line) +{ + if (strcmp(line->buf, "capabilities")) + return NOT_HANDLED; + + printf("import\n"); + printf("refspec %s:%s\n\n", remote_ref, private_ref); + fflush(stdout); + return SUCCESS; +} + +enum cmd_result cmd_import(struct strbuf *line) +{ + static int batch_active; + int code, report_fd; + char *back_pipe_env; + int dumpin_fd; + unsigned int startrev = 0; + struct argv_array svndump_argv = ARGV_ARRAY_INIT; + struct child_process svndump_proc; + + /* terminate a current batch's fast-import stream */ + if (line->len == 0 && batch_active) { + printf("done\n"); + fflush(stdout); + batch_active = 0; + printd("import-batch finished."); + /* + * should the remote helper terminate after a batch? + * It seems that it should. + */ + return TERMINATE; + } + if (prefixcmp(line->buf, "import")) + return NOT_HANDLED; + + /* import commands can be grouped together in a batch. Batches are ended by \n */ + batch_active = 1; + + /* + * When the remote-helper is invoked by transport-helper.c it passes the + * filename of this pipe in the env-var. + */ + back_pipe_env = getenv("GIT_REPORT_FIFO"); + if (!back_pipe_env) { + die("Cannot get cat-blob-pipe from environment! GIT_REPORT_FIFO has to" + "be set by the caller."); + } + + /* + * Opening a fifo for reading usually blocks until a writer has opened it too. + * Opening a fifo for writing usually blocks until a reader has opened it too. + * Therefore, we open with RDWR on both sides to avoid deadlocks. + * Especially if there's nothing to do and one pipe end is closed immediately. + */ + report_fd = open(back_pipe_env, O_RDWR); + if (report_fd < 0) { + die("Unable to open fast-import back-pipe! %s", strerror(errno)); + } + printd("Opened fast-import back-pipe %s for reading.", back_pipe_env); + + memset(&svndump_proc, 0, sizeof (struct child_process)); + svndump_proc.out = -1; + argv_array_push(&svndump_argv, "svnrdump"); + argv_array_push(&svndump_argv, "dump"); + argv_array_push(&svndump_argv, url); + argv_array_pushf(&svndump_argv, "-r%u:HEAD", startrev); + svndump_proc.argv = svndump_argv.argv; + + code = start_command(&svndump_proc); + if (code) + die("Unable to start %s, code %d", svndump_proc.argv[0], code); + dumpin_fd = svndump_proc.out; + + svndump_init_fd(dumpin_fd, report_fd); + svndump_read(url, private_ref); + svndump_deinit(); + svndump_reset(); + + close(dumpin_fd); + close(report_fd); + code = finish_command(&svndump_proc); + if (code) + warning("%s, returned %d", svndump_proc.argv[0], code); + argv_array_clear(&svndump_argv); + + return SUCCESS; +} + +enum cmd_result cmd_list(struct strbuf *line) +{ + if (strcmp(line->buf, "list")) + return NOT_HANDLED; + + printf("? HEAD\n"); + printf("? %s\n\n", remote_ref); + fflush(stdout); + return SUCCESS; +} + +enum cmd_result cmd_terminate(struct strbuf *line) +{ + /* an empty line terminates the program, if not in a batch sequence */ + if (line->len == 0) + return TERMINATE; + else + return NOT_HANDLED; +} +enum cmd_result do_command(struct strbuf *line) +{ + const input_command_handler *p = input_command_list; + enum cmd_result ret; + printd("command line '%s'", line->buf); + while(*p) { + ret = (*p)(line); + if (ret != NOT_HANDLED) + return ret; + p++; + } + warning("Unknown command '%s'\n", line->buf); + return ret; +} + +int main(int argc, const char **argv) +{ + struct strbuf buf = STRBUF_INIT; + int nongit; + static struct remote *remote; + + if (getenv("GIT_TRANSPORT_HELPER_DEBUG")) + debug = 1; + + git_extract_argv0_path(argv[0]); + setup_git_directory_gently(&nongit); + if (argc < 2) { + usage("git-remote-svn []"); + return 1; + } + + remote = remote_get(argv[1]); + if (argc == 3) + url = argv[2]; + else if (argc == 2) + url = remote->url[0]; + else + warning("Excess arguments!"); + + end_url_with_slash(&buf, url); + url = strbuf_detach(&buf, NULL); + + printd("remote-svn starting with url %s", url); + + strbuf_init(&buf, 0); + strbuf_addf(&buf, "refs/svn/%s/master", remote->name); + private_ref = strbuf_detach(&buf, NULL); + + while(1) { + if (strbuf_getline(&buf, stdin, '\n') == EOF) { + if (ferror(stdin)) + die_errno("Error reading command stream"); + else + die_errno("Unexpected end of command stream"); + } + if (do_command(&buf) == TERMINATE) + break; + strbuf_reset(&buf); + } + + strbuf_release(&buf); + free((void*)url); + free((void*)private_ref); + return 0; +} -- 1.7.9.5