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fsmonitor--daemon.c
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1611 lines (1341 loc) · 43.1 KB
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#include "builtin.h"
#include "config.h"
#include "parse-options.h"
#include "fsmonitor.h"
#include "fsmonitor-ipc.h"
#include "compat/fsmonitor/fsmonitor-fs-listen.h"
#include "fsmonitor--daemon.h"
#include "simple-ipc.h"
#include "khash.h"
#include "pkt-line.h"
static const char * const builtin_fsmonitor__daemon_usage[] = {
N_("git fsmonitor--daemon --start [<options>]"),
N_("git fsmonitor--daemon --run [<options>]"),
N_("git fsmonitor--daemon --stop"),
N_("git fsmonitor--daemon --is-running"),
N_("git fsmonitor--daemon --query <token>"),
N_("git fsmonitor--daemon --query-index"),
N_("git fsmonitor--daemon --flush"),
NULL
};
#ifdef HAVE_FSMONITOR_DAEMON_BACKEND
/*
* Global state loaded from config.
*/
#define FSMONITOR__IPC_THREADS "fsmonitor.ipcthreads"
static int fsmonitor__ipc_threads = 8;
#define FSMONITOR__START_TIMEOUT "fsmonitor.starttimeout"
static int fsmonitor__start_timeout_sec = 60;
static int fsmonitor_config(const char *var, const char *value, void *cb)
{
if (!strcmp(var, FSMONITOR__IPC_THREADS)) {
int i = git_config_int(var, value);
if (i < 1)
return error(_("value of '%s' out of range: %d"),
FSMONITOR__IPC_THREADS, i);
fsmonitor__ipc_threads = i;
return 0;
}
if (!strcmp(var, FSMONITOR__START_TIMEOUT)) {
int i = git_config_int(var, value);
if (i < 0)
return error(_("value of '%s' out of range: %d"),
FSMONITOR__START_TIMEOUT, i);
fsmonitor__start_timeout_sec = i;
return 0;
}
return git_default_config(var, value, cb);
}
/*
* Acting as a CLIENT.
*
* Send an IPC query to a `git-fsmonitor--daemon` SERVER process and
* ask for the changes since the given token. This will implicitly
* start a daemon process if necessary. The daemon process will
* persist after we exit.
*
* This feature is primarily used by the test suite.
*/
static int do_as_client__query_token(const char *token)
{
struct strbuf answer = STRBUF_INIT;
int ret;
ret = fsmonitor_ipc__send_query(token, &answer);
if (ret < 0)
die(_("could not query fsmonitor--daemon"));
write_in_full(1, answer.buf, answer.len);
strbuf_release(&answer);
return 0;
}
/*
* Acting as a CLIENT.
*
* Read the `.git/index` to get the last token written to the FSMonitor index
* extension and use that to make a query.
*
* This feature is primarily used by the test suite.
*/
static int do_as_client__query_from_index(void)
{
struct index_state *istate = the_repository->index;
setup_git_directory();
if (do_read_index(istate, the_repository->index_file, 0) < 0)
die("unable to read index file");
if (!istate->fsmonitor_last_update)
die("index file does not have fsmonitor extension");
return do_as_client__query_token(istate->fsmonitor_last_update);
}
/*
* Acting as a CLIENT.
*
* Send a "quit" command to the `git-fsmonitor--daemon` (if running)
* and wait for it to shutdown.
*/
static int do_as_client__send_stop(void)
{
struct strbuf answer = STRBUF_INIT;
int ret;
ret = fsmonitor_ipc__send_command("quit", &answer);
/* The quit command does not return any response data. */
strbuf_release(&answer);
if (ret)
return ret;
trace2_region_enter("fsm_client", "polling-for-daemon-exit", NULL);
while (fsmonitor_ipc__get_state() == IPC_STATE__LISTENING)
sleep_millisec(50);
trace2_region_leave("fsm_client", "polling-for-daemon-exit", NULL);
return 0;
}
/*
* Acting as a CLIENT.
*
* Send a "flush" command to the `git-fsmonitor--daemon` (if running)
* and tell it to flush its cache.
*
* This feature is primarily used by the test suite to simulate a loss of
* sync with the filesystem where we miss kernel events.
*/
static int do_as_client__send_flush(void)
{
struct strbuf answer = STRBUF_INIT;
int ret;
ret = fsmonitor_ipc__send_command("flush", &answer);
if (ret)
return ret;
write_in_full(1, answer.buf, answer.len);
strbuf_release(&answer);
return 0;
}
enum fsmonitor_cookie_item_result {
FCIR_ERROR = -1, /* could not create cookie file ? */
FCIR_INIT = 0,
FCIR_SEEN,
FCIR_ABORT,
};
struct fsmonitor_cookie_item {
struct hashmap_entry entry;
const char *name;
enum fsmonitor_cookie_item_result result;
};
static int cookies_cmp(const void *data, const struct hashmap_entry *he1,
const struct hashmap_entry *he2, const void *keydata)
{
const struct fsmonitor_cookie_item *a =
container_of(he1, const struct fsmonitor_cookie_item, entry);
const struct fsmonitor_cookie_item *b =
container_of(he2, const struct fsmonitor_cookie_item, entry);
return strcmp(a->name, keydata ? keydata : b->name);
}
static enum fsmonitor_cookie_item_result fsmonitor_wait_for_cookie(
struct fsmonitor_daemon_state *state)
{
int fd;
struct fsmonitor_cookie_item cookie;
struct strbuf cookie_pathname = STRBUF_INIT;
struct strbuf cookie_filename = STRBUF_INIT;
const char *slash;
int my_cookie_seq;
pthread_mutex_lock(&state->main_lock);
my_cookie_seq = state->cookie_seq++;
strbuf_addbuf(&cookie_pathname, &state->path_cookie_prefix);
strbuf_addf(&cookie_pathname, "%i-%i", getpid(), my_cookie_seq);
slash = find_last_dir_sep(cookie_pathname.buf);
if (slash)
strbuf_addstr(&cookie_filename, slash + 1);
else
strbuf_addbuf(&cookie_filename, &cookie_pathname);
cookie.name = strbuf_detach(&cookie_filename, NULL);
cookie.result = FCIR_INIT;
// TODO should we have case-insenstive hash (and in cookie_cmp()) ??
hashmap_entry_init(&cookie.entry, strhash(cookie.name));
/*
* Warning: we are putting the address of a stack variable into a
* global hashmap. This feels dodgy. We must ensure that we remove
* it before this thread and stack frame returns.
*/
hashmap_add(&state->cookies, &cookie.entry);
trace_printf_key(&trace_fsmonitor, "cookie-wait: '%s' '%s'",
cookie.name, cookie_pathname.buf);
/*
* Create the cookie file on disk and then wait for a notification
* that the listener thread has seen it.
*/
fd = open(cookie_pathname.buf, O_WRONLY | O_CREAT | O_EXCL, 0600);
if (fd >= 0) {
close(fd);
unlink_or_warn(cookie_pathname.buf);
while (cookie.result == FCIR_INIT)
pthread_cond_wait(&state->cookies_cond,
&state->main_lock);
hashmap_remove(&state->cookies, &cookie.entry, NULL);
} else {
error_errno(_("could not create fsmonitor cookie '%s'"),
cookie.name);
cookie.result = FCIR_ERROR;
hashmap_remove(&state->cookies, &cookie.entry, NULL);
}
pthread_mutex_unlock(&state->main_lock);
free((char*)cookie.name);
strbuf_release(&cookie_pathname);
return cookie.result;
}
/*
* Mark these cookies as _SEEN and wake up the corresponding client threads.
*/
static void fsmonitor_cookie_mark_seen(struct fsmonitor_daemon_state *state,
const struct string_list *cookie_names)
{
/* assert state->main_lock */
int k;
int nr_seen = 0;
for (k = 0; k < cookie_names->nr; k++) {
struct fsmonitor_cookie_item key;
struct fsmonitor_cookie_item *cookie;
key.name = cookie_names->items[k].string;
hashmap_entry_init(&key.entry, strhash(key.name));
cookie = hashmap_get_entry(&state->cookies, &key, entry, NULL);
if (cookie) {
trace_printf_key(&trace_fsmonitor, "cookie-seen: '%s'",
cookie->name);
cookie->result = FCIR_SEEN;
nr_seen++;
}
}
if (nr_seen)
pthread_cond_broadcast(&state->cookies_cond);
}
/*
* Set _ABORT on all pending cookies and wake up all client threads.
*/
static void fsmonitor_cookie_abort_all(struct fsmonitor_daemon_state *state)
{
/* assert state->main_lock */
struct hashmap_iter iter;
struct fsmonitor_cookie_item *cookie;
int nr_aborted = 0;
hashmap_for_each_entry(&state->cookies, &iter, cookie, entry) {
trace_printf_key(&trace_fsmonitor, "cookie-abort: '%s'",
cookie->name);
cookie->result = FCIR_ABORT;
nr_aborted++;
}
if (nr_aborted)
pthread_cond_broadcast(&state->cookies_cond);
}
static int lookup_client_test_delay(void)
{
static int delay_ms = -1;
const char *s;
int ms;
if (delay_ms >= 0)
return delay_ms;
delay_ms = 0;
s = getenv("GIT_TEST_FSMONITOR_CLIENT_DELAY");
if (!s)
return delay_ms;
ms = atoi(s);
if (ms < 0)
return delay_ms;
delay_ms = ms;
return delay_ms;
}
/*
* Requests to and from a FSMonitor Protocol V2 provider use an opaque
* "token" as a virtual timestamp. Clients can request a summary of all
* created/deleted/modified files relative to a token. In the response,
* clients receive a new token for the next (relative) request.
*
*
* Token Format
* ============
*
* The contents of the token are private and provider-specific.
*
* For the built-in fsmonitor--daemon, we define a token as follows:
*
* "builtin" ":" <token_id> ":" <sequence_nr>
*
* The <token_id> is an arbitrary OPAQUE string, such as a GUID,
* UUID, or {timestamp,pid}. It is used to group all filesystem
* events that happened while the daemon was monitoring (and in-sync
* with the filesystem).
*
* Unlike FSMonitor Protocol V1, it is not defined as a timestamp
* and does not define less-than/greater-than relationships.
* (There are too many race conditions to rely on file system
* event timestamps.)
*
* The <sequence_nr> is a simple integer incremented for each event
* received. When a new <token_id> is created, the <sequence_nr> is
* reset to zero.
*
*
* About Token Ids
* ===============
*
* A new token_id is created:
*
* [1] each time the daemon is started.
*
* [2] any time that the daemon must re-sync with the filesystem
* (such as when the kernel drops or we miss events on a very
* active volume).
*
* [3] in response to a client "flush" command (for dropped event
* testing).
*
* [4] MAYBE We might want to change the token_id after very complex
* filesystem operations are performed, such as a directory move
* sequence that affects many files within. It might be simpler
* to just give up and fake a re-sync (and let the client do a
* full scan) than try to enumerate the effects of such a change.
*
* When a new token_id is created, the daemon is free to discard all
* cached filesystem events associated with any previous token_ids.
* Events associated with a non-current token_id will never be sent
* to a client. A token_id change implicitly means that the daemon
* has gap in its event history.
*
* Therefore, clients that present a token with a stale (non-current)
* token_id will always be given a trivial response.
*/
struct fsmonitor_token_data {
struct strbuf token_id;
struct fsmonitor_batch *batch_head;
struct fsmonitor_batch *batch_tail;
uint64_t client_ref_count;
};
static struct fsmonitor_token_data *fsmonitor_new_token_data(void)
{
static int test_env_value = -1;
static uint64_t flush_count = 0;
struct fsmonitor_token_data *token;
token = (struct fsmonitor_token_data *)xcalloc(1, sizeof(*token));
strbuf_init(&token->token_id, 0);
token->batch_head = NULL;
token->batch_tail = NULL;
token->client_ref_count = 0;
if (test_env_value < 0)
test_env_value = git_env_bool("GIT_TEST_FSMONITOR_TOKEN", 0);
if (!test_env_value) {
struct timeval tv;
struct tm tm;
time_t secs;
gettimeofday(&tv, NULL);
secs = tv.tv_sec;
gmtime_r(&secs, &tm);
strbuf_addf(&token->token_id,
"%"PRIu64".%d.%4d%02d%02dT%02d%02d%02d.%06ldZ",
flush_count++,
getpid(),
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec,
(long)tv.tv_usec);
} else {
strbuf_addf(&token->token_id, "test_%08x", test_env_value++);
}
return token;
}
struct fsmonitor_batch {
struct fsmonitor_batch *next;
uint64_t batch_seq_nr;
const char **interned_paths;
size_t nr, alloc;
time_t pinned_time;
};
struct fsmonitor_batch *fsmonitor_batch__new(void)
{
struct fsmonitor_batch *batch = xcalloc(1, sizeof(*batch));
return batch;
}
struct fsmonitor_batch *fsmonitor_batch__free(struct fsmonitor_batch *batch)
{
struct fsmonitor_batch *next;
if (!batch)
return NULL;
next = batch->next;
/*
* The actual strings within the array are interned, so we don't
* own them.
*/
free(batch->interned_paths);
return next;
}
void fsmonitor_batch__add_path(struct fsmonitor_batch *batch,
const char *path)
{
const char *interned_path = strintern(path);
trace_printf_key(&trace_fsmonitor, "event: %s", interned_path);
ALLOC_GROW(batch->interned_paths, batch->nr + 1, batch->alloc);
batch->interned_paths[batch->nr++] = interned_path;
}
static void fsmonitor_batch__combine(struct fsmonitor_batch *batch_dest,
const struct fsmonitor_batch *batch_src)
{
/* assert state->main_lock */
size_t k;
ALLOC_GROW(batch_dest->interned_paths,
batch_dest->nr + batch_src->nr + 1,
batch_dest->alloc);
for (k = 0; k < batch_src->nr; k++)
batch_dest->interned_paths[batch_dest->nr++] =
batch_src->interned_paths[k];
}
/*
* To keep the batch list from growing unbounded in response to filesystem
* activity, we try to truncate old batches from the end of the list as
* they become irrelevant.
*
* We assume that the .git/index will be updated with the most recent token
* any time the index is updated. And future commands will only ask for
* recent changes *since* that new token. So as tokens advance into the
* future, older batch items will never be requested/needed. So we can
* truncate them without loss of functionality.
*
* However, multiple commands may be talking to the daemon concurrently
* or perform a slow command, so a little "token skew" is possible.
* Therefore, we want this to be a little bit lazy and have a generous
* delay.
*
* The current reader thread walked backwards in time from `token->batch_head`
* back to `batch_marker` somewhere in the middle of the batch list.
*
* Let's walk backwards in time from that marker an arbitrary delay
* and truncate the list there. Note that these timestamps are completely
* artificial (based on when we pinned the batch item) and not on any
* filesystem activity.
*/
#define MY_TIME_DELAY (5 * 60) /* seconds */
static void fsmonitor_batch__truncate(struct fsmonitor_daemon_state *state,
const struct fsmonitor_batch *batch_marker)
{
/* assert state->main_lock */
const struct fsmonitor_batch *batch;
struct fsmonitor_batch *rest;
struct fsmonitor_batch *p;
time_t t;
if (!batch_marker)
return;
trace_printf_key(&trace_fsmonitor, "TRNC mark (%"PRIu64",%"PRIu64")",
batch_marker->batch_seq_nr,
(uint64_t)batch_marker->pinned_time);
for (batch = batch_marker; batch; batch = batch->next) {
if (!batch->pinned_time) /* an overflow batch */
continue;
t = batch->pinned_time + MY_TIME_DELAY;
if (t > batch_marker->pinned_time) /* too close to marker */
continue;
goto truncate_past_here;
}
return;
truncate_past_here:
state->current_token_data->batch_tail = (struct fsmonitor_batch *)batch;
rest = ((struct fsmonitor_batch *)batch)->next;
((struct fsmonitor_batch *)batch)->next = NULL;
for (p = rest; p; p = fsmonitor_batch__free(p)) {
trace_printf_key(&trace_fsmonitor,
"TRNC kill (%"PRIu64",%"PRIu64")",
p->batch_seq_nr, (uint64_t)p->pinned_time);
}
}
static void fsmonitor_free_token_data(struct fsmonitor_token_data *token)
{
struct fsmonitor_batch *p;
if (!token)
return;
assert(token->client_ref_count == 0);
strbuf_release(&token->token_id);
for (p = token->batch_head; p; p = fsmonitor_batch__free(p))
;
free(token);
}
/*
* Flush all of our cached data about the filesystem. Call this if we
* lose sync with the filesystem and miss some notification events.
*
* [1] If we are missing events, then we no longer have a complete
* history of the directory (relative to our current start token).
* We should create a new token and start fresh (as if we just
* booted up).
*
* [2] Some of those lost events may have been for cookie files. We
* should assume the worst and abort them rather letting them starve.
*
* If there are no readers of the the current token data series, we
* can free it now. Otherwise, let the last reader free it. Either
* way, the old token data series is no longer associated with our
* state data.
*/
void fsmonitor_force_resync(struct fsmonitor_daemon_state *state)
{
struct fsmonitor_token_data *free_me = NULL;
struct fsmonitor_token_data *new_one = NULL;
new_one = fsmonitor_new_token_data();
pthread_mutex_lock(&state->main_lock);
trace_printf_key(&trace_fsmonitor,
"force resync [old '%s'][new '%s']",
state->current_token_data->token_id.buf,
new_one->token_id.buf);
fsmonitor_cookie_abort_all(state);
if (state->current_token_data->client_ref_count == 0)
free_me = state->current_token_data;
state->current_token_data = new_one;
pthread_mutex_unlock(&state->main_lock);
fsmonitor_free_token_data(free_me);
}
/*
* Format an opaque token string to send to the client.
*/
static void fsmonitor_format_response_token(
struct strbuf *response_token,
const struct strbuf *response_token_id,
const struct fsmonitor_batch *batch)
{
uint64_t seq_nr = (batch) ? batch->batch_seq_nr + 1 : 0;
strbuf_reset(response_token);
strbuf_addf(response_token, "builtin:%s:%"PRIu64,
response_token_id->buf, seq_nr);
}
/*
* Parse an opaque token from the client.
*/
static int fsmonitor_parse_client_token(const char *buf_token,
struct strbuf *requested_token_id,
uint64_t *seq_nr)
{
const char *p;
char *p_end;
strbuf_reset(requested_token_id);
*seq_nr = 0;
if (!skip_prefix(buf_token, "builtin:", &p))
return 1;
while (*p && *p != ':')
strbuf_addch(requested_token_id, *p++);
if (!*p++)
return 1;
*seq_nr = (uint64_t)strtoumax(p, &p_end, 10);
if (*p_end)
return 1;
return 0;
}
KHASH_INIT(str, const char *, int, 0, kh_str_hash_func, kh_str_hash_equal);
static int do_handle_client(struct fsmonitor_daemon_state *state,
const char *command,
ipc_server_reply_cb *reply,
struct ipc_server_reply_data *reply_data)
{
struct fsmonitor_token_data *token_data = NULL;
struct strbuf response_token = STRBUF_INIT;
struct strbuf requested_token_id = STRBUF_INIT;
struct strbuf payload = STRBUF_INIT;
uint64_t requested_oldest_seq_nr = 0;
uint64_t total_response_len = 0;
const char *p;
const struct fsmonitor_batch *batch_head;
const struct fsmonitor_batch *batch;
intmax_t count = 0, duplicates = 0;
kh_str_t *shown;
int hash_ret;
int result;
enum fsmonitor_cookie_item_result cookie_result;
/*
* We expect `command` to be of the form:
*
* <command> := quit NUL
* | flush NUL
* | <V1-time-since-epoch-ns> NUL
* | <V2-opaque-fsmonitor-token> NUL
*/
if (!strcmp(command, "quit")) {
/*
* A client has requested over the socket/pipe that the
* daemon shutdown.
*
* Tell the IPC thread pool to shutdown (which completes
* the await in the main thread (which can stop the
* fsmonitor listener thread)).
*
* There is no reply to the client.
*/
return SIMPLE_IPC_QUIT;
}
/*
* For testing purposes, introduce an artificial delay in this
* worker to allow the filesystem listener thread to receive
* any fs events that may have been generated by the client
* process on the other end of the pipe/socket. This helps
* make the CI/PR test suite runs a little more predictable
* and hopefully eliminates the need to introduce `sleep`
* commands in the test scripts.
*/
if (state->test_client_delay_ms)
sleep_millisec(state->test_client_delay_ms);
if (!strcmp(command, "flush")) {
/*
* Flush all of our cached data and generate a new token
* just like if we lost sync with the filesystem.
*
* Then send a trivial response using the new token.
*/
fsmonitor_force_resync(state);
result = 0;
goto send_trivial_response;
}
if (!skip_prefix(command, "builtin:", &p)) {
/* assume V1 timestamp or garbage */
char *p_end;
strtoumax(command, &p_end, 10);
trace_printf_key(&trace_fsmonitor,
((*p_end) ?
"fsmonitor: invalid command line '%s'" :
"fsmonitor: unsupported V1 protocol '%s'"),
command);
result = -1;
goto send_trivial_response;
}
/* try V2 token */
if (fsmonitor_parse_client_token(command, &requested_token_id,
&requested_oldest_seq_nr)) {
trace_printf_key(&trace_fsmonitor,
"fsmonitor: invalid V2 protocol token '%s'",
command);
result = -1;
goto send_trivial_response;
}
pthread_mutex_lock(&state->main_lock);
if (!state->current_token_data) {
/*
* We don't have a current token. This may mean that
* the listener thread has not yet started.
*/
pthread_mutex_unlock(&state->main_lock);
result = 0;
goto send_trivial_response;
}
if (strcmp(requested_token_id.buf,
state->current_token_data->token_id.buf)) {
/*
* The client last spoke to a different daemon
* instance -OR- the daemon had to resync with
* the filesystem (and lost events), so reject.
*/
pthread_mutex_unlock(&state->main_lock);
result = 0;
trace2_data_string("fsmonitor", the_repository,
"response/token", "different");
goto send_trivial_response;
}
if (!state->current_token_data->batch_tail) {
/*
* The listener has not received any filesystem
* events yet since we created the current token.
* We can respond with an empty list, since the
* client has already seen the current token and
* we have nothing new to report. (This is
* instead of sending a trivial response.)
*/
pthread_mutex_unlock(&state->main_lock);
result = 0;
goto send_empty_response;
}
if (requested_oldest_seq_nr <
state->current_token_data->batch_tail->batch_seq_nr) {
/*
* The client wants older events than we have for
* this token_id. This means that the end of our
* batch list was truncated and we cannot give the
* client a complete snapshot relative to their
* request.
*/
pthread_mutex_unlock(&state->main_lock);
trace_printf_key(&trace_fsmonitor,
"client requested truncated data");
result = 0;
goto send_trivial_response;
}
pthread_mutex_unlock(&state->main_lock);
/*
* Write a cookie file inside the directory being watched in an
* effort to flush out existing filesystem events that we actually
* care about. Suspend this client thread until we see the filesystem
* events for this cookie file.
*/
cookie_result = fsmonitor_wait_for_cookie(state);
if (cookie_result != FCIR_SEEN) {
error(_("fsmonitor: cookie_result '%d' != SEEN"),
cookie_result);
result = 0;
goto send_trivial_response;
}
pthread_mutex_lock(&state->main_lock);
if (strcmp(requested_token_id.buf,
state->current_token_data->token_id.buf)) {
/*
* Ack! The listener thread lost sync with the filesystem
* and created a new token while we were waiting for the
* cookie file to be created! Just give up.
*/
pthread_mutex_unlock(&state->main_lock);
trace_printf_key(&trace_fsmonitor,
"lost filesystem sync");
result = 0;
goto send_trivial_response;
}
/*
* We're going to hold onto a pointer to the current
* token-data while we walk the list of batches of files.
* During this time, we will NOT be under the lock.
* So we ref-count it.
*
* This allows the listener thread to continue prepending
* new batches of items to the token-data (which we'll ignore).
*
* AND it allows the listener thread to do a token-reset
* (and install a new `current_token_data`).
*
* We mark the current head of the batch list as "pinned" so
* that the listener thread will treat this item as read-only
* (and prevent any more paths from being added to it) from
* now on.
*/
token_data = state->current_token_data;
token_data->client_ref_count++;
batch_head = token_data->batch_head;
((struct fsmonitor_batch *)batch_head)->pinned_time = time(NULL);
pthread_mutex_unlock(&state->main_lock);
/*
* FSMonitor Protocol V2 requires that we send a response header
* with a "new current token" and then all of the paths that changed
* since the "requested token".
*/
fsmonitor_format_response_token(&response_token,
&token_data->token_id,
batch_head);
reply(reply_data, response_token.buf, response_token.len + 1);
total_response_len += response_token.len + 1;
trace2_data_string("fsmonitor", the_repository, "response/token",
response_token.buf);
trace_printf_key(&trace_fsmonitor, "response token: %s", response_token.buf);
shown = kh_init_str();
for (batch = batch_head;
batch && batch->batch_seq_nr >= requested_oldest_seq_nr;
batch = batch->next) {
size_t k;
for (k = 0; k < batch->nr; k++) {
const char *s = batch->interned_paths[k];
size_t s_len;
if (kh_get_str(shown, s) != kh_end(shown))
duplicates++;
else {
kh_put_str(shown, s, &hash_ret);
trace_printf_key(&trace_fsmonitor,
"send[%"PRIuMAX"]: %s",
count, s);
/* Each path gets written with a trailing NUL */
s_len = strlen(s) + 1;
if (payload.len + s_len >=
LARGE_PACKET_DATA_MAX) {
reply(reply_data, payload.buf,
payload.len);
total_response_len += payload.len;
strbuf_reset(&payload);
}
strbuf_add(&payload, s, s_len);
count++;
}
}
}
if (payload.len) {
reply(reply_data, payload.buf, payload.len);
total_response_len += payload.len;
}
kh_release_str(shown);
pthread_mutex_lock(&state->main_lock);
if (token_data->client_ref_count > 0)
token_data->client_ref_count--;
if (token_data->client_ref_count == 0) {
if (token_data != state->current_token_data) {
/*
* The listener thread did a token-reset while we were
* walking the batch list. Therefore, this token is
* stale and can be discarded completely. If we are
* the last reader thread using this token, we own
* that work.
*/
fsmonitor_free_token_data(token_data);
} else if (batch) {
/*
* This batch is the first item in the list
* that is older than the requested sequence
* number and might be considered to be
* obsolete. See if we can truncate the list
* and save some memory.
*/
fsmonitor_batch__truncate(state, batch);
}
}
pthread_mutex_unlock(&state->main_lock);
trace2_data_intmax("fsmonitor", the_repository, "response/length", total_response_len);
trace2_data_intmax("fsmonitor", the_repository, "response/count/files", count);
trace2_data_intmax("fsmonitor", the_repository, "response/count/duplicates", duplicates);
strbuf_release(&response_token);
strbuf_release(&requested_token_id);
strbuf_release(&payload);
return 0;
send_trivial_response:
pthread_mutex_lock(&state->main_lock);
fsmonitor_format_response_token(&response_token,
&state->current_token_data->token_id,
state->current_token_data->batch_head);
pthread_mutex_unlock(&state->main_lock);
reply(reply_data, response_token.buf, response_token.len + 1);
trace2_data_string("fsmonitor", the_repository, "response/token",
response_token.buf);
reply(reply_data, "/", 2);
trace2_data_intmax("fsmonitor", the_repository, "response/trivial", 1);
strbuf_release(&response_token);
strbuf_release(&requested_token_id);
return result;
send_empty_response:
pthread_mutex_lock(&state->main_lock);
fsmonitor_format_response_token(&response_token,
&state->current_token_data->token_id,
NULL);
pthread_mutex_unlock(&state->main_lock);
reply(reply_data, response_token.buf, response_token.len + 1);
trace2_data_string("fsmonitor", the_repository, "response/token",
response_token.buf);
trace2_data_intmax("fsmonitor", the_repository, "response/empty", 1);
strbuf_release(&response_token);
strbuf_release(&requested_token_id);
return 0;
}
static ipc_server_application_cb handle_client;
static int handle_client(void *data, const char *command,
ipc_server_reply_cb *reply,