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#include "cache.h"
#include "refs.h"
#include "object.h"
#include "commit.h"
#include "tag.h"
#include "rev-cache.h"
/* refs */
static FILE *info_ref_fp;
static unsigned long info_ref_time;
static int info_ref_is_stale = 0;
static int stat_ref(const char *path, const unsigned char *sha1)
{
struct stat st;
if (!stat(path, &st) && info_ref_time < st.st_mtime)
info_ref_is_stale = 1;
return 0;
}
static int add_info_ref(const char *path, const unsigned char *sha1)
{
fprintf(info_ref_fp, "%s %s\n", sha1_to_hex(sha1), path);
return 0;
}
static int update_info_refs(int force)
{
struct stat st;
char *path0 = strdup(git_path("info/refs"));
int len = strlen(path0);
char *path1 = xmalloc(len + 2);
strcpy(path1, path0);
strcpy(path1 + len, "+");
if (!force) {
if (stat(path0, &st)) {
if (errno == ENOENT)
info_ref_is_stale = 1;
else
return error("cannot stat %s", path0);
}
else {
info_ref_time = st.st_mtime;
for_each_ref(stat_ref);
}
if (!info_ref_is_stale)
return 0;
}
safe_create_leading_directories(path0);
info_ref_fp = fopen(path1, "w");
if (!info_ref_fp)
return error("unable to update %s", path0);
for_each_ref(add_info_ref);
fclose(info_ref_fp);
rename(path1, path0);
free(path0);
free(path1);
return 0;
}
/* packs */
static struct pack_info {
unsigned long latest;
struct packed_git *p;
int old_num;
int new_num;
int nr_alloc;
int nr_heads;
unsigned char (*head)[20];
char dep[0]; /* more */
} **info;
static int num_pack;
static const char *objdir;
static int objdirlen;
static struct object *parse_object_cheap(const unsigned char *sha1)
{
struct object *o;
if ((o = parse_object(sha1)) == NULL)
return NULL;
if (o->type == commit_type) {
struct commit *commit = (struct commit *)o;
free(commit->buffer);
commit->buffer = NULL;
}
return o;
}
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;
}
static struct pack_info *find_pack_by_old_num(int old_num)
{
int i;
for (i = 0; i < num_pack; i++)
if (info[i]->old_num == old_num)
return info[i];
return NULL;
}
static int add_head_def(struct pack_info *this, unsigned char *sha1)
{
if (this->nr_alloc <= this->nr_heads) {
this->nr_alloc = alloc_nr(this->nr_alloc);
this->head = xrealloc(this->head, this->nr_alloc * 20);
}
memcpy(this->head[this->nr_heads++], sha1, 20);
return 0;
}
/* 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;
* dependencies between packs needs to be recalculated.
*/
return 1;
}
}
/* Returns non-zero when we detect that the info in the
* old file is useless.
*/
static int parse_depend_def(char *line)
{
unsigned long num;
char *cp, *ep;
struct pack_info *this, *that;
cp = line + 2;
num = strtoul(cp, &ep, 10);
if (ep == cp)
return error("invalid input %s", line);
this = find_pack_by_old_num(num);
if (!this)
return 0;
while (ep && *(cp = ep)) {
num = strtoul(cp, &ep, 10);
if (ep == cp)
break;
that = find_pack_by_old_num(num);
if (!that)
/* The pack this one depends on does not
* exist; this should not happen because
* we write out the list of packs first and
* then dependency information, but it means
* the file is useless anyway.
*/
return 1;
this->dep[that->new_num] = 1;
}
return 0;
}
/* Returns non-zero when we detect that the info in the
* old file is useless.
*/
static int parse_head_def(char *line)
{
unsigned char sha1[20];
unsigned long num;
char *cp, *ep;
struct pack_info *this;
struct object *o;
cp = line + 2;
num = strtoul(cp, &ep, 10);
if (ep == cp || *ep++ != ' ')
return error("invalid input ix %s", line);
this = find_pack_by_old_num(num);
if (!this)
return 1; /* You know the drill. */
if (get_sha1_hex(ep, sha1) || ep[40] != ' ')
return error("invalid input sha1 %s (%s)", line, ep);
if ((o = parse_object_cheap(sha1)) == NULL)
return error("no such object: %s", line);
return add_head_def(this, sha1);
}
/* 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(infofile, "r");
if (!fp)
return 1; /* nonexisting is not an error. */
while (fgets(line, sizeof(line), fp)) {
int len = strlen(line);
if (line[len-1] == '\n')
line[len-1] = 0;
switch (line[0]) {
case 'P': /* P name */
if (parse_pack_def(line, old_cnt++))
goto out_stale;
break;
case 'D': /* D ix dep-ix1 dep-ix2... */
if (parse_depend_def(line))
goto out_stale;
break;
case 'T': /* T ix sha1 type */
if (parse_head_def(line))
goto out_stale;
break;
default:
error("unrecognized: %s", line);
break;
}
}
fclose(fp);
return 0;
out_stale:
fclose(fp);
return 1;
}
/* We sort the packs according to the date of the latest commit. That
* in turn indicates how young the pack is, and in general we would
* want to depend on younger packs.
*/
static unsigned long get_latest_commit_date(struct packed_git *p)
{
unsigned char sha1[20];
struct object *o;
int num = num_packed_objects(p);
int i;
unsigned long latest = 0;
for (i = 0; i < num; i++) {
if (nth_packed_object_sha1(p, i, sha1))
die("corrupt pack file %s?", p->pack_name);
if ((o = parse_object_cheap(sha1)) == NULL)
die("cannot parse %s", sha1_to_hex(sha1));
if (o->type == commit_type) {
struct commit *commit = (struct commit *)o;
if (latest < commit->date)
latest = commit->date;
}
}
return latest;
}
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;
if ((*a)->latest < (*b)->latest)
return -1;
else if ((*a)->latest == (*b)->latest)
return 0;
else
return 1;
}
static void init_pack_info(const char *infofile, int force)
{
struct packed_git *p;
int stale;
int i = 0;
char *dep_temp;
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 (strncmp(p->pack_name, objdir, objdirlen) ||
strncmp(p->pack_name + objdirlen, "/pack/", 6))
continue;
i++;
}
num_pack = i;
info = xcalloc(num_pack, sizeof(struct pack_info *));
for (i = 0, p = packed_git; p; p = p->next) {
if (strncmp(p->pack_name, objdir, objdirlen) ||
p->pack_name[objdirlen] != '/')
continue;
info[i] = xcalloc(1, sizeof(struct pack_info) + num_pack);
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;
memset(info[i]->dep, 0, num_pack);
info[i]->nr_heads = 0;
}
if (info[i]->old_num < 0)
info[i]->latest = get_latest_commit_date(info[i]->p);
}
qsort(info, num_pack, sizeof(info[0]), compare_info);
for (i = 0; i < num_pack; i++)
info[i]->new_num = i;
/* we need to fix up the dependency information
* for the old ones.
*/
dep_temp = NULL;
for (i = 0; i < num_pack; i++) {
int old;
if (info[i]->old_num < 0)
continue;
if (! dep_temp)
dep_temp = xmalloc(num_pack);
memset(dep_temp, 0, num_pack);
for (old = 0; old < num_pack; old++) {
struct pack_info *base;
if (!info[i]->dep[old])
continue;
base = find_pack_by_old_num(old);
if (!base)
die("internal error renumbering");
dep_temp[base->new_num] = 1;
}
memcpy(info[i]->dep, dep_temp, num_pack);
}
free(dep_temp);
}
static void write_pack_info_file(FILE *fp)
{
int i, j;
for (i = 0; i < num_pack; i++)
fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6);
for (i = 0; i < num_pack; i++) {
fprintf(fp, "D %1d", i);
for (j = 0; j < num_pack; j++) {
if ((i == j) || !(info[i]->dep[j]))
continue;
fprintf(fp, " %1d", j);
}
fputc('\n', fp);
}
for (i = 0; i < num_pack; i++) {
struct pack_info *this = info[i];
for (j = 0; j < this->nr_heads; j++) {
struct object *o = lookup_object(this->head[j]);
fprintf(fp, "T %1d %s %s\n",
i, sha1_to_hex(this->head[j]), o->type);
}
}
}
#define REFERENCED 01
#define INTERNAL 02
#define EMITTED 04
static void show(struct object *o, int pack_ix)
{
/*
* We are interested in objects that are not referenced,
* and objects that are referenced but not internal.
*/
if (o->flags & EMITTED)
return;
if (!(o->flags & REFERENCED))
add_head_def(info[pack_ix], o->sha1);
else if ((o->flags & REFERENCED) && !(o->flags & INTERNAL)) {
int i;
/* Which pack contains this object? That is what
* pack_ix can depend on. We earlier sorted info
* array from youngest to oldest, so try newer packs
* first to favor them here.
*/
for (i = num_pack - 1; 0 <= i; i--) {
struct packed_git *p = info[i]->p;
struct pack_entry ent;
if (find_pack_entry_one(o->sha1, &ent, p)) {
info[pack_ix]->dep[i] = 1;
break;
}
}
}
o->flags |= EMITTED;
}
static void find_pack_info_one(int pack_ix)
{
unsigned char sha1[20];
struct object *o;
struct object_list *ref;
int i;
struct packed_git *p = info[pack_ix]->p;
int num = num_packed_objects(p);
/* Scan objects, clear flags from all the edge ones and
* internal ones, possibly marked in the previous round.
*/
for (i = 0; i < num; i++) {
if (nth_packed_object_sha1(p, i, sha1))
die("corrupt pack file %s?", p->pack_name);
if ((o = lookup_object(sha1)) == NULL)
die("cannot parse %s", sha1_to_hex(sha1));
for (ref = o->refs; ref; ref = ref->next)
ref->item->flags = 0;
o->flags = 0;
}
/* Mark all the internal ones */
for (i = 0; i < num; i++) {
if (nth_packed_object_sha1(p, i, sha1))
die("corrupt pack file %s?", p->pack_name);
if ((o = lookup_object(sha1)) == NULL)
die("cannot find %s", sha1_to_hex(sha1));
for (ref = o->refs; ref; ref = ref->next)
ref->item->flags |= REFERENCED;
o->flags |= INTERNAL;
}
for (i = 0; i < num; i++) {
if (nth_packed_object_sha1(p, i, sha1))
die("corrupt pack file %s?", p->pack_name);
if ((o = lookup_object(sha1)) == NULL)
die("cannot find %s", sha1_to_hex(sha1));
show(o, pack_ix);
for (ref = o->refs; ref; ref = ref->next)
show(ref->item, pack_ix);
}
}
static void find_pack_info(void)
{
int i;
for (i = 0; i < num_pack; i++) {
/* The packed objects are cast in stone, and a head
* in a pack will stay as head, so is the set of missing
* objects. If the repo has been reorganized and we
* are missing some packs available back then, we have
* already discarded the info read from the file, so
* we will find (old_num < 0) in that case.
*/
if (0 <= info[i]->old_num)
continue;
find_pack_info_one(i);
}
}
static int update_info_packs(int force)
{
char infofile[PATH_MAX];
char name[PATH_MAX];
int namelen;
FILE *fp;
namelen = sprintf(infofile, "%s/info/packs", get_object_directory());
strcpy(name, infofile);
strcpy(name + namelen, "+");
init_pack_info(infofile, force);
find_pack_info();
safe_create_leading_directories(name);
fp = fopen(name, "w");
if (!fp)
return error("cannot open %s", name);
write_pack_info_file(fp);
fclose(fp);
rename(name, infofile);
return 0;
}
/* rev-cache */
static int record_rev_cache_ref(const char *path, const unsigned char *sha1)
{
struct object *obj = parse_object(sha1);
if (!obj)
return error("ref %s has bad sha %s", path, sha1_to_hex(sha1));
while (obj && obj->type == tag_type)
obj = parse_object(((struct tag *)obj)->tagged->sha1);
if (!obj || obj->type != commit_type)
/* tag pointing at a non-commit */
return 0;
return record_rev_cache(obj->sha1, NULL);
}
static int update_info_revs(int force)
{
char *path0 = strdup(git_path("info/rev-cache"));
int len = strlen(path0);
char *path1 = xmalloc(len + 2);
strcpy(path1, path0);
strcpy(path1 + len, "+");
/* read existing rev-cache */
if (!force)
read_rev_cache(path0, NULL, 0);
safe_create_leading_directories(path0);
for_each_ref(record_rev_cache_ref);
/* update the rev-cache database */
write_rev_cache(path1, force ? "/dev/null" : path0);
rename(path1, path0);
free(path1);
free(path0);
return 0;
}
/* 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);
errs = errs | update_info_revs(force);
return errs;
}
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