git/reftable/system.c

#include "../git-compat-util.h"

#include "system.h"
#include "basics.h"
#include "reftable-error.h"
#include "../lockfile.h"
#include "../trace.h"
#include "../tempfile.h"
#include "../write-or-die.h"

uint32_t reftable_rand(void)
{
	return git_rand(CSPRNG_BYTES_INSECURE);
}

int tmpfile_from_pattern(struct reftable_tmpfile *out, const char *pattern)
{
	struct tempfile *tempfile;

	tempfile = mks_tempfile(pattern);
	if (!tempfile)
		return REFTABLE_IO_ERROR;

	out->path = tempfile->filename.buf;
	out->fd = tempfile->fd;
	out->priv = tempfile;

	return 0;
}

int tmpfile_close(struct reftable_tmpfile *t)
{
	struct tempfile *tempfile = t->priv;
	int ret = close_tempfile_gently(tempfile);
	t->fd = -1;
	if (ret < 0)
		return REFTABLE_IO_ERROR;
	return 0;
}

int tmpfile_delete(struct reftable_tmpfile *t)
{
	struct tempfile *tempfile = t->priv;
	int ret = delete_tempfile(&tempfile);
	*t = REFTABLE_TMPFILE_INIT;
	if (ret < 0)
		return REFTABLE_IO_ERROR;
	return 0;
}

int tmpfile_rename(struct reftable_tmpfile *t, const char *path)
{
	struct tempfile *tempfile = t->priv;
	int ret = rename_tempfile(&tempfile, path);
	*t = REFTABLE_TMPFILE_INIT;
	if (ret < 0)
		return REFTABLE_IO_ERROR;
	return 0;
}

int flock_acquire(struct reftable_flock *l, const char *target_path,
		  long timeout_ms)
{
	struct lock_file *lockfile;
	int err;

	lockfile = reftable_malloc(sizeof(*lockfile));
	if (!lockfile)
		return REFTABLE_OUT_OF_MEMORY_ERROR;

	err = hold_lock_file_for_update_timeout(lockfile, target_path, LOCK_NO_DEREF,
						timeout_ms);
	if (err < 0) {
		reftable_free(lockfile);
		if (errno == EEXIST)
			return REFTABLE_LOCK_ERROR;
		return REFTABLE_IO_ERROR;
	}

	l->fd = get_lock_file_fd(lockfile);
	l->path = get_lock_file_path(lockfile);
	l->priv = lockfile;

	return 0;
}

int flock_close(struct reftable_flock *l)
{
	struct lock_file *lockfile = l->priv;
	int ret;

	if (!lockfile)
		return REFTABLE_API_ERROR;

	ret = close_lock_file_gently(lockfile);
	l->fd = -1;
	if (ret < 0)
		return REFTABLE_IO_ERROR;

	return 0;
}

int flock_release(struct reftable_flock *l)
{
	struct lock_file *lockfile = l->priv;
	int ret;

	if (!lockfile)
		return 0;

	ret = rollback_lock_file(lockfile);
	reftable_free(lockfile);
	*l = REFTABLE_FLOCK_INIT;
	if (ret < 0)
		return REFTABLE_IO_ERROR;

	return 0;
}

int flock_commit(struct reftable_flock *l)
{
	struct lock_file *lockfile = l->priv;
	int ret;

	if (!lockfile)
		return REFTABLE_API_ERROR;

	ret = commit_lock_file(lockfile);
	reftable_free(lockfile);
	*l = REFTABLE_FLOCK_INIT;
	if (ret < 0)
		return REFTABLE_IO_ERROR;

	return 0;
}

int reftable_fsync(int fd)
{
	return fsync_component(FSYNC_COMPONENT_REFERENCE, fd);
}

uint64_t reftable_time_ms(void)
{
	return getnanotime() / 1000000;
}

int reftable_mmap(struct reftable_mmap *out, int fd, size_t len)
{
	void *data = xmmap_gently(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
	if (data == MAP_FAILED)
		return REFTABLE_IO_ERROR;

	out->data = data;
	out->size = len;

	return 0;
}

int reftable_munmap(struct reftable_mmap *mmap)
{
	if (munmap(mmap->data, mmap->size) < 0)
		return REFTABLE_IO_ERROR;
	memset(mmap, 0, sizeof(*mmap));
	return 0;
}