[PATCH 2/3] Add read-cache--daemon
---
.gitignore | 1 +
Makefile | 6 ++
config.mak.uname | 1 +
git-compat-util.h | 8 +++
read-cache--daemon.c (new) | 167 +++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 183 insertions(+)
create mode 100644 read-cache--daemon.c
diff --git a/.gitignore b/.gitignore
index 70992a4..07e0cb6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -110,6 +110,7 @@
/git-pull
/git-push
/git-quiltimport
+/git-read-cache--daemon
/git-read-tree
/git-rebase
/git-rebase--am
diff --git a/Makefile b/Makefile
index 028749b..98d22de 100644
--- a/Makefile
+++ b/Makefile
@@ -1502,6 +1502,12 @@ ifdef HAVE_DEV_TTY
BASIC_CFLAGS += -DHAVE_DEV_TTY
endif
+ifdef HAVE_SHM
+ BASIC_CFLAGS += -DHAVE_SHM
+ EXTLIBS += -lrt
+ PROGRAM_OBJS += read-cache--daemon.o
+endif
+
ifdef DIR_HAS_BSD_GROUP_SEMANTICS
COMPAT_CFLAGS += -DDIR_HAS_BSD_GROUP_SEMANTICS
endif
diff --git a/config.mak.uname b/config.mak.uname
index 23a8803..b6a37e5 100644
--- a/config.mak.uname
+++ b/config.mak.uname
@@ -33,6 +33,7 @@ ifeq ($(uname_S),Linux)
HAVE_PATHS_H = YesPlease
LIBC_CONTAINS_LIBINTL = YesPlease
HAVE_DEV_TTY = YesPlease
+ HAVE_SHM = YesPlease
endif
ifeq ($(uname_S),GNU/kFreeBSD)
NO_STRLCPY = YesPlease
diff --git a/git-compat-util.h b/git-compat-util.h
index f6d3a46..b2116ab 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -723,4 +723,12 @@ struct tm *git_gmtime_r(const time_t *, struct tm *);
#define gmtime_r git_gmtime_r
#endif
+#ifndef HAVE_SHM
+static inline int shm_open(const char *path, int flags, int mode)
+{
+ errno = ENOSYS;
+ return -1;
+}
+#endif
+
#endif
diff --git a/read-cache--daemon.c b/read-cache--daemon.c
new file mode 100644
index 0000000..52b4067
--- /dev/null
+++ b/read-cache--daemon.c
@@ -0,0 +1,167 @@
+#include "cache.h"
+#include "sigchain.h"
+#include "unix-socket.h"
+#include "split-index.h"
+#include "pkt-line.h"
+
+static char *socket_path;
+static struct strbuf shm_index = STRBUF_INIT;
+static struct strbuf shm_sharedindex = STRBUF_INIT;
+
+static void cleanup_socket(void)
+{
+ if (socket_path)
+ unlink(socket_path);
+ if (shm_index.len)
+ shm_unlink(shm_index.buf);
+ if (shm_sharedindex.len)
+ shm_unlink(shm_sharedindex.buf);
+}
+
+static void cleanup_socket_on_signal(int sig)
+{
+ cleanup_socket();
+ sigchain_pop(sig);
+ raise(sig);
+}
+
+static void share_index(struct index_state *istate, struct strbuf *shm_path)
+{
+ struct strbuf sb = STRBUF_INIT;
+ void *map;
+ int fd;
+
+ strbuf_addf(&sb, "/git-index-%s", sha1_to_hex(istate->sha1));
+ if (shm_path->len && strcmp(sb.buf, shm_path->buf)) {
+ shm_unlink(shm_path->buf);
+ strbuf_reset(shm_path);
+ }
+ fd = shm_open(sb.buf, O_RDWR | O_CREAT | O_TRUNC, 0700);
+ if (fd < 0)
+ return;
+ /*
+ * We "lock" the shm in preparation by set its size larger
+ * than expected. The reader is supposed to check the size and
+ * ignore if shm size is different than the actual file size
+ */
+ if (ftruncate(fd, istate->mmap_size + 1)) {
+ close(fd);
+ shm_unlink(shm_path->buf);
+ return;
+ }
+ strbuf_addbuf(shm_path, &sb);
+ map = xmmap(NULL, istate->mmap_size, PROT_READ | PROT_WRITE,
+ MAP_SHARED, fd, 0);
+ if (map == MAP_FAILED) {
+ close(fd);
+ shm_unlink(shm_path->buf);
+ return;
+ }
+ memcpy(map, istate->mmap, istate->mmap_size);
+ munmap(map, istate->mmap_size);
+ /* Now "unlock" it */
+ if (ftruncate(fd, istate->mmap_size)) {
+ close(fd);
+ shm_unlink(shm_path->buf);
+ return;
+ }
+ close(fd);
+}
+
+static void refresh()
+{
+ the_index.keep_mmap = 1;
+ if (read_cache() < 0)
+ die("could not read index");
+ share_index(&the_index, &shm_index);
+ if (the_index.split_index &&
+ the_index.split_index->base)
+ share_index(the_index.split_index->base, &shm_sharedindex);
+ discard_index(&the_index);
+}
+
+static unsigned long next;
+static int serve_cache_loop(int fd)
+{
+ struct pollfd pfd;
+ unsigned long now = time(NULL);
+
+ if (now > next)
+ return 0;
+
+ pfd.fd = fd;
+ pfd.events = POLLIN;
+ if (poll(&pfd, 1, 1000 * (next - now)) < 0) {
+ if (errno != EINTR)
+ die_errno("poll failed");
+ return 1;
+ }
+
+ if (pfd.revents & POLLIN) {
+ int client = accept(fd, NULL, NULL);
+ if (client < 0) {
+ warning("accept failed: %s", strerror(errno));
+ return 1;
+ }
+ refresh();
+ close(client);
+ next = now + 600;
+ }
+ return 1;
+}
+
+static void serve_cache(const char *socket_path)
+{
+ int fd;
+
+ fd = unix_stream_listen(socket_path);
+ if (fd < 0)
+ die_errno("unable to bind to '%s'", socket_path);
+
+ refresh();
+
+ printf("ok\n");
+ fclose(stdout);
+
+ next = time(NULL) + 600;
+ while (serve_cache_loop(fd))
+ ; /* nothing */
+
+ close(fd);
+ unlink(socket_path);
+}
+
+static void check_socket_directory(const char *path)
+{
+ struct stat st;
+ char *path_copy = xstrdup(path);
+ char *dir = dirname(path_copy);
+
+ if (!stat(dir, &st)) {
+ free(path_copy);
+ return;
+ }
+
+ /*
+ * We must be sure to create the directory with the correct mode,
+ * not just chmod it after the fact; otherwise, there is a race
+ * condition in which somebody can chdir to it, sleep, then try to open
+ * our protected socket.
+ */
+ if (safe_create_leading_directories_const(dir) < 0)
+ die_errno("unable to create directories for '%s'", dir);
+ if (mkdir(dir, 0700) < 0)
+ die_errno("unable to mkdir '%s'", dir);
+ free(path_copy);
+}
+
+int main(int argc, const char **argv)
+{
+ setup_git_directory();
+ socket_path = git_pathdup("daemon/index");
+ check_socket_directory(socket_path);
+ atexit(cleanup_socket);
+ sigchain_push_common(cleanup_socket_on_signal);
+ serve_cache(socket_path);
+ return 0;
+}
--
1.9.1.346.ga2b5940
Nguyễn Thái Ngọc Duy <pclouds@gmail.com>