/*
* Try locking path, retrying with quadratic backoff for at least
* timeout_ms milliseconds. If timeout_ms is 0, try locking the file
* exactly once. If timeout_ms is -1, try indefinitely.
*/
static int lock_file_timeout(struct lock_file *lk, const char *path,
int flags, long timeout_ms)
{
int n = 1;
int multiplier = 1;
long remaining_ms = 0;
static int random_initialized = 0;
if (timeout_ms == 0)
return lock_file(lk, path, flags);
if (!random_initialized) {
srand((unsigned int)getpid());
random_initialized = 1;
}
if (timeout_ms > 0)
remaining_ms = timeout_ms;
while (1) {
long backoff_ms, wait_ms;
int fd;
fd = lock_file(lk, path, flags);
if (fd >= 0)
return fd; /* success */
else if (errno != EEXIST)
return -1; /* failure other than lock held */
else if (timeout_ms > 0 && remaining_ms <= 0)
return -1; /* failure due to timeout */
backoff_ms = multiplier * INITIAL_BACKOFF_MS;
/* back off for between 0.75*backoff_ms and 1.25*backoff_ms */
wait_ms = (750 + rand() % 500) * backoff_ms / 1000;
sleep_millisec(wait_ms);
remaining_ms -= wait_ms;
/* Recursion: (n+1)^2 = n^2 + 2n + 1 */
multiplier += 2*n + 1;
if (multiplier > BACKOFF_MAX_MULTIPLIER)
multiplier = BACKOFF_MAX_MULTIPLIER;
else
n++;
}
}
const char *help_unknown_cmd(const char *cmd)
{
int i, n, best_similarity = 0;
struct cmdnames main_cmds, other_cmds;
struct cmdname_help *common_cmds;
memset(&main_cmds, 0, sizeof(main_cmds));
memset(&other_cmds, 0, sizeof(other_cmds));
memset(&aliases, 0, sizeof(aliases));
read_early_config(git_unknown_cmd_config, NULL);
load_command_list("git-", &main_cmds, &other_cmds);
add_cmd_list(&main_cmds, &aliases);
add_cmd_list(&main_cmds, &other_cmds);
QSORT(main_cmds.names, main_cmds.cnt, cmdname_compare);
uniq(&main_cmds);
extract_cmds(&common_cmds, common_mask);
/* This abuses cmdname->len for levenshtein distance */
for (i = 0, n = 0; i < main_cmds.cnt; i++) {
int cmp = 0; /* avoid compiler stupidity */
const char *candidate = main_cmds.names[i]->name;
/*
* An exact match means we have the command, but
* for some reason exec'ing it gave us ENOENT; probably
* it's a bad interpreter in the #! line.
*/
if (!strcmp(candidate, cmd))
die(_(bad_interpreter_advice), cmd, cmd);
/* Does the candidate appear in common_cmds list? */
while (common_cmds[n].name &&
(cmp = strcmp(common_cmds[n].name, candidate)) < 0)
n++;
if (common_cmds[n].name && !cmp) {
/* Yes, this is one of the common commands */
n++; /* use the entry from common_cmds[] */
if (starts_with(candidate, cmd)) {
/* Give prefix match a very good score */
main_cmds.names[i]->len = 0;
continue;
}
}
main_cmds.names[i]->len =
levenshtein(cmd, candidate, 0, 2, 1, 3) + 1;
}
FREE_AND_NULL(common_cmds);
QSORT(main_cmds.names, main_cmds.cnt, levenshtein_compare);
if (!main_cmds.cnt)
die(_("Uh oh. Your system reports no Git commands at all."));
/* skip and count prefix matches */
for (n = 0; n < main_cmds.cnt && !main_cmds.names[n]->len; n++)
; /* still counting */
if (main_cmds.cnt <= n) {
/* prefix matches with everything? that is too ambiguous */
best_similarity = SIMILARITY_FLOOR + 1;
} else {
/* count all the most similar ones */
for (best_similarity = main_cmds.names[n++]->len;
(n < main_cmds.cnt &&
best_similarity == main_cmds.names[n]->len);
n++)
; /* still counting */
}
if (autocorrect && n == 1 && SIMILAR_ENOUGH(best_similarity)) {
const char *assumed = main_cmds.names[0]->name;
main_cmds.names[0] = NULL;
clean_cmdnames(&main_cmds);
fprintf_ln(stderr,
_("WARNING: You called a Git command named '%s', "
"which does not exist."),
cmd);
if (autocorrect < 0)
fprintf_ln(stderr,
_("Continuing under the assumption that "
"you meant '%s'."),
assumed);
else {
fprintf_ln(stderr,
_("Continuing in %0.1f seconds, "
"assuming that you meant '%s'."),
(float)autocorrect/10.0, assumed);
sleep_millisec(autocorrect * 100);
}
return assumed;
}
fprintf_ln(stderr, _("git: '%s' is not a git command. See 'git --help'."), cmd);
if (SIMILAR_ENOUGH(best_similarity)) {
fprintf_ln(stderr,
Q_("\nThe most similar command is",
"\nThe most similar commands are",
n));
for (i = 0; i < n; i++)
fprintf(stderr, "\t%s\n", main_cmds.names[i]->name);
}
exit(1);
}
