git/server-info.c
Jonathan Tan 0abe14f6a5 pack: move {,re}prepare_packed_git and approximate_object_count
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23 15:12:07 -07:00

289 lines
5.7 KiB
C

#include "cache.h"
#include "refs.h"
#include "object.h"
#include "commit.h"
#include "tag.h"
#include "packfile.h"
/*
* Create the file "path" by writing to a temporary file and renaming
* it into place. The contents of the file come from "generate", which
* should return non-zero if it encounters an error.
*/
static int update_info_file(char *path, int (*generate)(FILE *))
{
char *tmp = mkpathdup("%s_XXXXXX", path);
int ret = -1;
int fd = -1;
FILE *fp = NULL, *to_close;
safe_create_leading_directories(path);
fd = git_mkstemp_mode(tmp, 0666);
if (fd < 0)
goto out;
to_close = fp = fdopen(fd, "w");
if (!fp)
goto out;
fd = -1;
ret = generate(fp);
if (ret)
goto out;
fp = NULL;
if (fclose(to_close))
goto out;
if (adjust_shared_perm(tmp) < 0)
goto out;
if (rename(tmp, path) < 0)
goto out;
ret = 0;
out:
if (ret) {
error_errno("unable to update %s", path);
if (fp)
fclose(fp);
else if (fd >= 0)
close(fd);
unlink(tmp);
}
free(tmp);
return ret;
}
static int add_info_ref(const char *path, const struct object_id *oid,
int flag, void *cb_data)
{
FILE *fp = cb_data;
struct object *o = parse_object(oid);
if (!o)
return -1;
if (fprintf(fp, "%s %s\n", oid_to_hex(oid), path) < 0)
return -1;
if (o->type == OBJ_TAG) {
o = deref_tag(o, path, 0);
if (o)
if (fprintf(fp, "%s %s^{}\n",
oid_to_hex(&o->oid), path) < 0)
return -1;
}
return 0;
}
static int generate_info_refs(FILE *fp)
{
return for_each_ref(add_info_ref, fp);
}
static int update_info_refs(int force)
{
char *path = git_pathdup("info/refs");
int ret = update_info_file(path, generate_info_refs);
free(path);
return ret;
}
/* packs */
static struct pack_info {
struct packed_git *p;
int old_num;
int new_num;
int nr_alloc;
int nr_heads;
unsigned char (*head)[20];
} **info;
static int num_pack;
static const char *objdir;
static int objdirlen;
static struct pack_info *find_pack_by_name(const char *name)
{
int i;
for (i = 0; i < num_pack; i++) {
struct packed_git *p = info[i]->p;
/* skip "/pack/" after ".git/objects" */
if (!strcmp(p->pack_name + objdirlen + 6, name))
return info[i];
}
return NULL;
}
/* Returns non-zero when we detect that the info in the
* old file is useless.
*/
static int parse_pack_def(const char *line, int old_cnt)
{
struct pack_info *i = find_pack_by_name(line + 2);
if (i) {
i->old_num = old_cnt;
return 0;
}
else {
/* The file describes a pack that is no longer here */
return 1;
}
}
/* Returns non-zero when we detect that the info in the
* old file is useless.
*/
static int read_pack_info_file(const char *infofile)
{
FILE *fp;
char line[1000];
int old_cnt = 0;
fp = fopen_or_warn(infofile, "r");
if (!fp)
return 1; /* nonexistent is not an error. */
while (fgets(line, sizeof(line), fp)) {
int len = strlen(line);
if (len && line[len-1] == '\n')
line[--len] = 0;
if (!len)
continue;
switch (line[0]) {
case 'P': /* P name */
if (parse_pack_def(line, old_cnt++))
goto out_stale;
break;
case 'D': /* we used to emit D but that was misguided. */
case 'T': /* we used to emit T but nobody uses it. */
goto out_stale;
default:
error("unrecognized: %s", line);
break;
}
}
fclose(fp);
return 0;
out_stale:
fclose(fp);
return 1;
}
static int compare_info(const void *a_, const void *b_)
{
struct pack_info *const *a = a_;
struct pack_info *const *b = b_;
if (0 <= (*a)->old_num && 0 <= (*b)->old_num)
/* Keep the order in the original */
return (*a)->old_num - (*b)->old_num;
else if (0 <= (*a)->old_num)
/* Only A existed in the original so B is obviously newer */
return -1;
else if (0 <= (*b)->old_num)
/* The other way around. */
return 1;
/* then it does not matter but at least keep the comparison stable */
if ((*a)->p == (*b)->p)
return 0;
else if ((*a)->p < (*b)->p)
return -1;
else
return 1;
}
static void init_pack_info(const char *infofile, int force)
{
struct packed_git *p;
int stale;
int i = 0;
objdir = get_object_directory();
objdirlen = strlen(objdir);
prepare_packed_git();
for (p = packed_git; p; p = p->next) {
/* we ignore things on alternate path since they are
* not available to the pullers in general.
*/
if (!p->pack_local)
continue;
i++;
}
num_pack = i;
info = xcalloc(num_pack, sizeof(struct pack_info *));
for (i = 0, p = packed_git; p; p = p->next) {
if (!p->pack_local)
continue;
info[i] = xcalloc(1, sizeof(struct pack_info));
info[i]->p = p;
info[i]->old_num = -1;
i++;
}
if (infofile && !force)
stale = read_pack_info_file(infofile);
else
stale = 1;
for (i = 0; i < num_pack; i++) {
if (stale) {
info[i]->old_num = -1;
info[i]->nr_heads = 0;
}
}
/* renumber them */
QSORT(info, num_pack, compare_info);
for (i = 0; i < num_pack; i++)
info[i]->new_num = i;
}
static void free_pack_info(void)
{
int i;
for (i = 0; i < num_pack; i++)
free(info[i]);
free(info);
}
static int write_pack_info_file(FILE *fp)
{
int i;
for (i = 0; i < num_pack; i++) {
if (fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6) < 0)
return -1;
}
if (fputc('\n', fp) == EOF)
return -1;
return 0;
}
static int update_info_packs(int force)
{
char *infofile = mkpathdup("%s/info/packs", get_object_directory());
int ret;
init_pack_info(infofile, force);
ret = update_info_file(infofile, write_pack_info_file);
free_pack_info();
free(infofile);
return ret;
}
/* public */
int update_server_info(int force)
{
/* We would add more dumb-server support files later,
* including index of available pack files and their
* intended audiences.
*/
int errs = 0;
errs = errs | update_info_refs(force);
errs = errs | update_info_packs(force);
/* remove leftover rev-cache file if there is any */
unlink_or_warn(git_path("info/rev-cache"));
return errs;
}