[PATCH v3 05/26] Add git-file-watcher and basic connection handling logic

From

Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

Date

Feb 3, 2014, 04:28 UTC

Message-ID

<1391401754-15347-6-git-send-email-pclouds@gmail.com>

In-Reply-To

<1391401754-15347-1-git-send-email-pclouds@gmail.com>

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 .gitignore                               |   1 +
 Documentation/git-file-watcher.txt (new) |  29 +++++++
 Makefile                                 |   1 +
 file-watcher.c (new)                     | 140 +++++++++++++++++++++++++++++++
 4 files changed, 171 insertions(+)
 create mode 100644 Documentation/git-file-watcher.txt
 create mode 100644 file-watcher.c

diff --git a/.gitignore b/.gitignore
index b5f9def..12c78f0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -56,6 +56,7 @@
 /git-fast-import
 /git-fetch
 /git-fetch-pack
+/git-file-watcher
 /git-filter-branch
 /git-fmt-merge-msg
 /git-for-each-ref
diff --git a/Documentation/git-file-watcher.txt b/Documentation/git-file-watcher.txt
new file mode 100644
index 0000000..625a389
--- /dev/null
+++ b/Documentation/git-file-watcher.txt
@@ -0,0 +1,29 @@
+git-file-watcher(1)
+===================
+
+NAME
+----
+git-file-watcher - File update notification daemon
+
+SYNOPSIS
+--------
+[verse]
+'git file-watcher' [options] <socket directory>
+
+DESCRIPTION
+-----------
+This program watches file changes in a git working directory and let
+Git now what files have been changed so that Git does not have to call
+lstat(2) to detect that itself.
+
+OPTIONS
+-------
+
+SEE ALSO
+--------
+linkgit:git-update-index[1],
+linkgit:git-config[1]
+
+GIT
+---
+Part of the linkgit:git[1] suite
diff --git a/Makefile b/Makefile
index dddaf4f..8eef0d6 100644
--- a/Makefile
+++ b/Makefile
@@ -536,6 +536,7 @@ PROGRAMS += $(EXTRA_PROGRAMS)
 PROGRAM_OBJS += credential-store.o
 PROGRAM_OBJS += daemon.o
 PROGRAM_OBJS += fast-import.o
+PROGRAM_OBJS += file-watcher.o
 PROGRAM_OBJS += http-backend.o
 PROGRAM_OBJS += imap-send.o
 PROGRAM_OBJS += sh-i18n--envsubst.o
diff --git a/file-watcher.c b/file-watcher.c
new file mode 100644
index 0000000..a6d7f17
--- /dev/null
+++ b/file-watcher.c
@@ -0,0 +1,140 @@
+#include "cache.h"
+#include "sigchain.h"
+#include "parse-options.h"
+#include "exec_cmd.h"
+#include "unix-socket.h"
+
+static const char *const file_watcher_usage[] = {
+	N_("git file-watcher [options] <socket directory>"),
+	NULL
+};
+
+struct connection {
+	int sock;
+};
+
+static struct connection **conns;
+static struct pollfd *pfd;
+static int conns_alloc, pfd_nr, pfd_alloc;
+
+static int shutdown_connection(int id)
+{
+	struct connection *conn = conns[id];
+	conns[id] = NULL;
+	pfd[id].fd = -1;
+	if (!conn)
+		return 0;
+	close(conn->sock);
+	free(conn);
+	return 0;
+}
+
+static int handle_command(int conn_id)
+{
+	return 0;
+}
+
+static void accept_connection(int fd)
+{
+	struct connection *conn;
+	int client = accept(fd, NULL, NULL);
+	if (client < 0) {
+		warning(_("accept failed: %s"), strerror(errno));
+		return;
+	}
+
+	ALLOC_GROW(pfd, pfd_nr + 1, pfd_alloc);
+	pfd[pfd_nr].fd = client;
+	pfd[pfd_nr].events = POLLIN;
+	pfd[pfd_nr].revents = 0;
+
+	ALLOC_GROW(conns, pfd_nr + 1, conns_alloc);
+	conn = xmalloc(sizeof(*conn));
+	memset(conn, 0, sizeof(*conn));
+	conn->sock = client;
+	conns[pfd_nr] = conn;
+	pfd_nr++;
+}
+
+int main(int argc, const char **argv)
+{
+	struct strbuf sb = STRBUF_INIT;
+	int i, new_nr, fd, quit = 0, nr_common;
+	const char *socket_path = NULL;
+	struct option options[] = {
+		OPT_END()
+	};
+
+	git_extract_argv0_path(argv[0]);
+	git_setup_gettext();
+	argc = parse_options(argc, argv, NULL, options,
+			     file_watcher_usage, 0);
+	if (argc < 1)
+		die(_("socket path missing"));
+	else if (argc > 1)
+		die(_("too many arguments"));
+
+	socket_path = argv[0];
+	strbuf_addf(&sb, "%s/socket", socket_path);
+	fd = unix_stream_listen(sb.buf, 0);
+	if (fd == -1)
+		die_errno(_("unable to listen at %s"), sb.buf);
+	strbuf_reset(&sb);
+
+	nr_common = 1;
+	pfd_alloc = pfd_nr = nr_common;
+	pfd = xmalloc(sizeof(*pfd) * pfd_alloc);
+	pfd[0].fd = fd;
+	pfd[0].events = POLLIN;
+
+	while (!quit) {
+		if (poll(pfd, pfd_nr, -1) < 0) {
+			if (errno != EINTR) {
+				error("Poll failed, resuming: %s",
+				      strerror(errno));
+				sleep(1);
+			}
+			continue;
+		}
+
+		for (new_nr = i = nr_common; i < pfd_nr; i++) {
+			if (pfd[i].revents & (POLLERR | POLLNVAL))
+				shutdown_connection(i);
+			else if ((pfd[i].revents & POLLIN) && conns[i]) {
+				unsigned int avail = 1;
+				/*
+				 * pkt-line is not gentle with eof, at
+				 * least not with
+				 * packet_read_line(). Avoid feeding
+				 * eof to it.
+				 */
+				if ((pfd[i].revents & POLLHUP) &&
+				    ioctl(pfd[i].fd, FIONREAD, &avail))
+					die_errno("unable to FIONREAD inotify handle");
+				/*
+				 * We better have a way to handle all
+				 * packets in one go...
+				 */
+				if (avail)
+					handle_command(i);
+				else
+					shutdown_connection(i);
+			} else if (pfd[i].revents & POLLHUP)
+				shutdown_connection(i);
+			if (!conns[i])
+				continue;
+			if (i != new_nr) { /* pfd[] is shrunk, move pfd[i] up */
+				conns[new_nr] = conns[i];
+				pfd[new_nr] = pfd[i];
+			}
+			new_nr++; /* keep the good socket */
+		}
+		pfd_nr = new_nr;
+
+		if (pfd[0].revents & POLLIN)
+			accept_connection(pfd[0].fd);
+		if (pfd[0].revents & (POLLHUP | POLLERR | POLLNVAL))
+			die(_("error on listening socket"));
+	}
+	return 0;
+}

-- 
1.8.5.2.240.g8478abd