blob: 8b544e31f29f8b709308c98038f267f82f0f7ae4 [file] [log] [blame]
#include "cache.h"
#include "config.h"
#include "dir.h"
#include "ewah/ewok.h"
#include "fsmonitor.h"
#include "fsmonitor-ipc.h"
#include "run-command.h"
#include "strbuf.h"
#define INDEX_EXTENSION_VERSION1 (1)
#define INDEX_EXTENSION_VERSION2 (2)
#define HOOK_INTERFACE_VERSION1 (1)
#define HOOK_INTERFACE_VERSION2 (2)
struct trace_key trace_fsmonitor = TRACE_KEY_INIT(FSMONITOR);
static void assert_index_minimum(struct index_state *istate, size_t pos)
{
if (pos > istate->cache_nr)
BUG("fsmonitor_dirty has more entries than the index (%"PRIuMAX" > %u)",
(uintmax_t)pos, istate->cache_nr);
}
static void fsmonitor_ewah_callback(size_t pos, void *is)
{
struct index_state *istate = (struct index_state *)is;
struct cache_entry *ce;
assert_index_minimum(istate, pos + 1);
ce = istate->cache[pos];
ce->ce_flags &= ~CE_FSMONITOR_VALID;
}
static int fsmonitor_hook_version(void)
{
int hook_version;
if (git_config_get_int("core.fsmonitorhookversion", &hook_version))
return -1;
if (hook_version == HOOK_INTERFACE_VERSION1 ||
hook_version == HOOK_INTERFACE_VERSION2)
return hook_version;
warning("Invalid hook version '%i' in core.fsmonitorhookversion. "
"Must be 1 or 2.", hook_version);
return -1;
}
int read_fsmonitor_extension(struct index_state *istate, const void *data,
unsigned long sz)
{
const char *index = data;
uint32_t hdr_version;
uint32_t ewah_size;
struct ewah_bitmap *fsmonitor_dirty;
int ret;
uint64_t timestamp;
struct strbuf last_update = STRBUF_INIT;
if (sz < sizeof(uint32_t) + 1 + sizeof(uint32_t))
return error("corrupt fsmonitor extension (too short)");
hdr_version = get_be32(index);
index += sizeof(uint32_t);
if (hdr_version == INDEX_EXTENSION_VERSION1) {
timestamp = get_be64(index);
strbuf_addf(&last_update, "%"PRIu64"", timestamp);
index += sizeof(uint64_t);
} else if (hdr_version == INDEX_EXTENSION_VERSION2) {
strbuf_addstr(&last_update, index);
index += last_update.len + 1;
} else {
return error("bad fsmonitor version %d", hdr_version);
}
istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
ewah_size = get_be32(index);
index += sizeof(uint32_t);
fsmonitor_dirty = ewah_new();
ret = ewah_read_mmap(fsmonitor_dirty, index, ewah_size);
if (ret != ewah_size) {
ewah_free(fsmonitor_dirty);
return error("failed to parse ewah bitmap reading fsmonitor index extension");
}
istate->fsmonitor_dirty = fsmonitor_dirty;
if (!istate->split_index)
assert_index_minimum(istate, istate->fsmonitor_dirty->bit_size);
trace2_data_string("index", NULL, "extension/fsmn/read/token",
istate->fsmonitor_last_update);
trace_printf_key(&trace_fsmonitor,
"read fsmonitor extension successful '%s'",
istate->fsmonitor_last_update);
return 0;
}
void fill_fsmonitor_bitmap(struct index_state *istate)
{
unsigned int i, skipped = 0;
istate->fsmonitor_dirty = ewah_new();
for (i = 0; i < istate->cache_nr; i++) {
if (istate->cache[i]->ce_flags & CE_REMOVE)
skipped++;
else if (!(istate->cache[i]->ce_flags & CE_FSMONITOR_VALID))
ewah_set(istate->fsmonitor_dirty, i - skipped);
}
}
void write_fsmonitor_extension(struct strbuf *sb, struct index_state *istate)
{
uint32_t hdr_version;
uint32_t ewah_start;
uint32_t ewah_size = 0;
int fixup = 0;
if (!istate->split_index)
assert_index_minimum(istate, istate->fsmonitor_dirty->bit_size);
put_be32(&hdr_version, INDEX_EXTENSION_VERSION2);
strbuf_add(sb, &hdr_version, sizeof(uint32_t));
strbuf_addstr(sb, istate->fsmonitor_last_update);
strbuf_addch(sb, 0); /* Want to keep a NUL */
fixup = sb->len;
strbuf_add(sb, &ewah_size, sizeof(uint32_t)); /* we'll fix this up later */
ewah_start = sb->len;
ewah_serialize_strbuf(istate->fsmonitor_dirty, sb);
ewah_free(istate->fsmonitor_dirty);
istate->fsmonitor_dirty = NULL;
/* fix up size field */
put_be32(&ewah_size, sb->len - ewah_start);
memcpy(sb->buf + fixup, &ewah_size, sizeof(uint32_t));
trace2_data_string("index", NULL, "extension/fsmn/write/token",
istate->fsmonitor_last_update);
trace_printf_key(&trace_fsmonitor,
"write fsmonitor extension successful '%s'",
istate->fsmonitor_last_update);
}
/*
* Call the query-fsmonitor hook passing the last update token of the saved results.
*/
static int query_fsmonitor(int version, struct index_state *istate, struct strbuf *query_result)
{
struct repository *r = istate->repo ? istate->repo : the_repository;
const char *last_update = istate->fsmonitor_last_update;
struct child_process cp = CHILD_PROCESS_INIT;
int result;
if (!core_fsmonitor)
return -1;
if (r->settings.use_builtin_fsmonitor > 0) {
#ifdef HAVE_FSMONITOR_DAEMON_BACKEND
return fsmonitor_ipc__send_query(last_update, query_result);
#else
/* Fake a trivial response. */
warning(_("fsmonitor--daemon unavailable; falling back"));
strbuf_add(query_result, "/", 2);
return 0;
#endif
}
strvec_push(&cp.args, core_fsmonitor);
strvec_pushf(&cp.args, "%d", version);
strvec_pushf(&cp.args, "%s", last_update);
cp.use_shell = 1;
cp.dir = get_git_work_tree();
trace2_region_enter("fsm_hook", "query", NULL);
result = capture_command(&cp, query_result, 1024);
if (result)
trace2_data_intmax("fsm_hook", NULL, "query/failed", result);
else {
trace2_data_intmax("fsm_hook", NULL, "query/response-length",
query_result->len);
if (fsmonitor_is_trivial_response(query_result))
trace2_data_intmax("fsm_hook", NULL,
"query/trivial-response", 1);
}
trace2_region_leave("fsm_hook", "query", NULL);
return result;
}
int fsmonitor_is_trivial_response(const struct strbuf *query_result)
{
static char trivial_response[3] = { '\0', '/', '\0' };
return query_result->len >= 3 &&
!memcmp(trivial_response,
&query_result->buf[query_result->len - 3], 3);
}
static void fsmonitor_refresh_callback(struct index_state *istate, char *name)
{
int i, len = strlen(name);
if (name[len - 1] == '/') {
/*
* TODO We should binary search to find the first path with
* TODO this directory prefix. Then linearly update entries
* TODO while the prefix matches. Taking care to search without
* TODO the trailing slash -- because '/' sorts after a few
* TODO interesting special chars, like '.' and ' '.
*/
/* Mark all entries for the folder invalid */
for (i = 0; i < istate->cache_nr; i++) {
if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID &&
starts_with(istate->cache[i]->name, name))
istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
}
/* Need to remove the / from the path for the untracked cache */
name[len - 1] = '\0';
} else {
int pos = index_name_pos(istate, name, strlen(name));
if (pos >= 0) {
struct cache_entry *ce = istate->cache[pos];
ce->ce_flags &= ~CE_FSMONITOR_VALID;
}
}
/*
* Mark the untracked cache dirty even if it wasn't found in the index
* as it could be a new untracked file.
*/
trace_printf_key(&trace_fsmonitor, "fsmonitor_refresh_callback '%s'", name);
untracked_cache_invalidate_path(istate, name, 0);
}
void refresh_fsmonitor(struct index_state *istate)
{
struct strbuf query_result = STRBUF_INIT;
int query_success = 0, hook_version = -1;
size_t bol = 0; /* beginning of line */
uint64_t last_update;
struct strbuf last_update_token = STRBUF_INIT;
char *buf;
unsigned int i;
if (!core_fsmonitor || istate->fsmonitor_has_run_once)
return;
hook_version = fsmonitor_hook_version();
istate->fsmonitor_has_run_once = 1;
trace_printf_key(&trace_fsmonitor, "refresh fsmonitor");
/*
* This could be racy so save the date/time now and query_fsmonitor
* should be inclusive to ensure we don't miss potential changes.
*/
last_update = getnanotime();
if (hook_version == HOOK_INTERFACE_VERSION1)
strbuf_addf(&last_update_token, "%"PRIu64"", last_update);
/*
* If we have a last update token, call query_fsmonitor for the set of
* changes since that token, else assume everything is possibly dirty
* and check it all.
*/
if (istate->fsmonitor_last_update) {
if (hook_version == -1 || hook_version == HOOK_INTERFACE_VERSION2) {
query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION2,
istate, &query_result);
if (query_success) {
if (hook_version < 0)
hook_version = HOOK_INTERFACE_VERSION2;
/*
* First entry will be the last update token
* Need to use a char * variable because static
* analysis was suggesting to use strbuf_addbuf
* but we don't want to copy the entire strbuf
* only the chars up to the first NUL
*/
buf = query_result.buf;
strbuf_addstr(&last_update_token, buf);
if (!last_update_token.len) {
warning("Empty last update token.");
query_success = 0;
} else {
bol = last_update_token.len + 1;
}
} else if (hook_version < 0) {
hook_version = HOOK_INTERFACE_VERSION1;
if (!last_update_token.len)
strbuf_addf(&last_update_token, "%"PRIu64"", last_update);
}
}
if (hook_version == HOOK_INTERFACE_VERSION1) {
query_success = !query_fsmonitor(HOOK_INTERFACE_VERSION1,
istate, &query_result);
}
trace_performance_since(last_update, "fsmonitor process '%s'", core_fsmonitor);
trace_printf_key(&trace_fsmonitor, "fsmonitor process '%s' returned %s",
core_fsmonitor, query_success ? "success" : "failure");
}
/* a fsmonitor process can return '/' to indicate all entries are invalid */
if (query_success && query_result.buf[bol] != '/') {
/* Mark all entries returned by the monitor as dirty */
buf = query_result.buf;
for (i = bol; i < query_result.len; i++) {
if (buf[i] != '\0')
continue;
fsmonitor_refresh_callback(istate, buf + bol);
bol = i + 1;
}
if (bol < query_result.len)
fsmonitor_refresh_callback(istate, buf + bol);
/* Now mark the untracked cache for fsmonitor usage */
if (istate->untracked)
istate->untracked->use_fsmonitor = 1;
} else {
/* We only want to run the post index changed hook if we've actually changed entries, so keep track
* if we actually changed entries or not */
int is_cache_changed = 0;
/* Mark all entries invalid */
for (i = 0; i < istate->cache_nr; i++) {
if (istate->cache[i]->ce_flags & CE_FSMONITOR_VALID) {
is_cache_changed = 1;
istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
}
}
/* If we're going to check every file, ensure we save the results */
if (is_cache_changed)
istate->cache_changed |= FSMONITOR_CHANGED;
if (istate->untracked)
istate->untracked->use_fsmonitor = 0;
}
strbuf_release(&query_result);
/*
* If the fsmonitor response and the subsequent scan of the disk
* did not cause the in-memory index to be marked dirty, then force
* it so that we advance the fsmonitor token in our extension, so
* that future requests don't keep re-requesting the same range.
*/
if (istate->fsmonitor_last_update &&
strcmp(istate->fsmonitor_last_update, last_update_token.buf))
istate->cache_changed |= FSMONITOR_CHANGED;
/* Now that we've updated istate, save the last_update_token */
FREE_AND_NULL(istate->fsmonitor_last_update);
istate->fsmonitor_last_update = strbuf_detach(&last_update_token, NULL);
}
/*
* The caller wants to turn on FSMonitor. And when the caller writes
* the index to disk, a FSMonitor extension should be included. This
* requires that `istate->fsmonitor_last_update` not be NULL. But we
* have not actually talked to a FSMonitor process yet, so we don't
* have an initial value for this field.
*
* For a protocol V1 FSMonitor process, this field is a formatted
* "nanoseconds since epoch" field. However, for a protocol V2
* FSMonitor process, this field is an opaque token.
*
* Historically, `add_fsmonitor()` has initialized this field to the
* current time for protocol V1 processes. There are lots of race
* conditions here, but that code has shipped...
*
* The only true solution is to use a V2 FSMonitor and get a current
* or default token value (that it understands), but we cannot do that
* until we have actually talked to an instance of the FSMonitor process
* (but the protocol requires that we send a token first...).
*
* For simplicity, just initialize like we have a V1 process and require
* that V2 processes adapt.
*/
static void initialize_fsmonitor_last_update(struct index_state *istate)
{
struct strbuf last_update = STRBUF_INIT;
strbuf_addf(&last_update, "%"PRIu64"", getnanotime());
istate->fsmonitor_last_update = strbuf_detach(&last_update, NULL);
}
void add_fsmonitor(struct index_state *istate)
{
unsigned int i;
if (!istate->fsmonitor_last_update) {
trace_printf_key(&trace_fsmonitor, "add fsmonitor");
istate->cache_changed |= FSMONITOR_CHANGED;
initialize_fsmonitor_last_update(istate);
/* reset the fsmonitor state */
for (i = 0; i < istate->cache_nr; i++)
istate->cache[i]->ce_flags &= ~CE_FSMONITOR_VALID;
/* reset the untracked cache */
if (istate->untracked) {
add_untracked_cache(istate);
istate->untracked->use_fsmonitor = 1;
}
/* Update the fsmonitor state */
refresh_fsmonitor(istate);
}
}
void remove_fsmonitor(struct index_state *istate)
{
if (istate->fsmonitor_last_update) {
trace_printf_key(&trace_fsmonitor, "remove fsmonitor");
istate->cache_changed |= FSMONITOR_CHANGED;
FREE_AND_NULL(istate->fsmonitor_last_update);
}
}
void tweak_fsmonitor(struct index_state *istate)
{
unsigned int i;
int fsmonitor_enabled = repo_config_get_fsmonitor(istate->repo ? istate->repo : the_repository);
if (istate->fsmonitor_dirty) {
if (fsmonitor_enabled) {
/* Mark all entries valid */
for (i = 0; i < istate->cache_nr; i++) {
istate->cache[i]->ce_flags |= CE_FSMONITOR_VALID;
}
/* Mark all previously saved entries as dirty */
assert_index_minimum(istate, istate->fsmonitor_dirty->bit_size);
ewah_each_bit(istate->fsmonitor_dirty, fsmonitor_ewah_callback, istate);
refresh_fsmonitor(istate);
}
ewah_free(istate->fsmonitor_dirty);
istate->fsmonitor_dirty = NULL;
}
switch (fsmonitor_enabled) {
case -1: /* keep: do nothing */
break;
case 0: /* false */
remove_fsmonitor(istate);
break;
case 1: /* true */
add_fsmonitor(istate);
break;
default: /* unknown value: do nothing */
break;
}
}