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adapter/darwin: housekeeping
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Will committed Jul 12, 2024
1 parent 798af5c commit bfe12eb
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Showing 2 changed files with 28 additions and 118 deletions.
70 changes: 13 additions & 57 deletions devel/include/detail/wtr/watcher/adapter/darwin/watch.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -70,55 +70,13 @@ struct ContextData {
std::mutex* mtx{nullptr};
};

/* We make a path from a C string...
In an array, in a dictionary...
Without type safety...
Because most of darwin's apis are `void*`-typed.
We should be guarenteed that nothing in here is
or can be null, but I'm skeptical. We ask Darwin
for utf8 strings from a dictionary of utf8 strings
which it gave us. Nothing should be able to be null.
We'll check anyway, just in case Darwin lies.
The dictionary contains looks like this:
{ "path": String
, "fileID": Number
}
We can only call `CFStringGetCStringPtr()`
on the `path` field. Not sure what function
the `fileID` requires, or if it's different
from what we'd get from `stat()`. (Is it an
inode number?) Anyway, we seem to get this:
-[__NSCFNumber length]: unrecognized ...
Whenever we try to inspect it with Int or
CStringPtr functions for CFStringGet...().
The docs don't say much about these fields.
I don't think they mention fileID at all.
*/
inline auto path_from_event_at(void* event_recv_paths, unsigned long i)
-> std::filesystem::path
{
if (! event_recv_paths) return {};
auto paths = static_cast<char const**>(event_recv_paths);
return {paths[i]};
}

inline auto event_recv_one(
ContextData& ctx,
std::filesystem::path const& path,
unsigned flags)
inline auto event_recv_one(ContextData& ctx, char const* path, unsigned flags)
{
using ::wtr::watcher::event;
using path_type = enum ::wtr::watcher::event::path_type;
using effect_type = enum ::wtr::watcher::event::effect_type;

auto cb = ctx.callback;

auto path_str = path.string();

/* A single path won't have different "types". */

auto pt = flags & fsev_flag_path_file ? path_type::file
: flags & fsev_flag_path_dir ? path_type::dir
: flags & fsev_flag_path_sym_link ? path_type::sym_link
Expand All @@ -128,9 +86,8 @@ inline auto event_recv_one(
/* We want to report odd events (even with an empty path)
but we can bail early if we don't recognize the effect
because everything else we do depends on that. */

if (! (flags & fsev_flag_effect_any)) {
cb({path, effect_type::other, pt});
ctx.callback({path, effect_type::other, pt});
return;
}

Expand All @@ -139,24 +96,24 @@ inline auto event_recv_one(

if (flags & fsev_flag_effect_create) {
auto et = effect_type::create;
auto at = ctx.seen_created_paths->find(path_str);
auto at = ctx.seen_created_paths->find(path);
if (at == ctx.seen_created_paths->end()) {
ctx.seen_created_paths->emplace(path_str);
cb({path, et, pt});
ctx.seen_created_paths->emplace(path);
ctx.callback({path, et, pt});
}
}
if (flags & fsev_flag_effect_remove) {
auto et = effect_type::destroy;
auto at = ctx.seen_created_paths->find(path_str);
auto at = ctx.seen_created_paths->find(path);
if (at != ctx.seen_created_paths->end()) {
ctx.seen_created_paths->erase(at);
cb({path, et, pt});
ctx.callback({path, et, pt});
}
}
if (flags & fsev_flag_effect_modify) {
if (! (flags & kFSEventStreamEventFlagItemInodeMetaMod)) {
auto et = effect_type::modify;
cb({path, et, pt});
ctx.callback({path, et, pt});
}
}
if (flags & fsev_flag_effect_rename) {
Expand Down Expand Up @@ -191,7 +148,7 @@ inline auto event_recv_one(
auto differs = ! lr_path.empty() && lr_path != path;
auto missing = access(lr_path.c_str(), F_OK) == -1;
if (differs && missing) {
cb({
ctx.callback({
{lr_path, et, pt},
{ path, et, pt}
});
Expand Down Expand Up @@ -222,21 +179,20 @@ inline auto event_recv(
ConstFSEventStreamRef, /* `ConstFS..` is important */
void* maybe_ctx, /* Arguments passed to us */
unsigned long count, /* Event count */
void* paths, /* Paths with events */
void* maybe_paths, /* Paths with events */
unsigned const* flags, /* Event flags */
FSEventStreamEventId const* /* A unique stream id */
) -> void
{
/* These checks are unfortunate, but they are also necessary.
Once in a blue moon, some of them are missing. */
auto data_ok = paths && flags && maybe_ctx;
auto data_ok = maybe_paths && flags && maybe_ctx;
if (! data_ok) return;
auto paths = static_cast<char const**>(maybe_paths);
auto ctx = *static_cast<ContextData*>(maybe_ctx);
if (! ctx.mtx->try_lock()) return;
for (unsigned long i = 0; i < count; i++) {
auto path = path_from_event_at(paths, i);
auto flag = flags[i];
event_recv_one(ctx, path, flag);
event_recv_one(ctx, paths[i], flags[i]);
}
ctx.mtx->unlock();
}
Expand Down
76 changes: 15 additions & 61 deletions include/wtr/watcher.hpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -494,8 +494,7 @@ namespace {
be noticeable. I'm not sure what Darwin sets the "period
of inactivity" to, and I'm not sure it matters. */
inline constexpr unsigned fsev_listen_for
= kFSEventStreamCreateFlagFileEvents
;
= kFSEventStreamCreateFlagFileEvents;
inline constexpr auto fsev_listen_since
= kFSEventStreamEventIdSinceNow;
inline constexpr unsigned fsev_flag_path_file
Expand All @@ -516,8 +515,7 @@ inline constexpr unsigned fsev_flag_effect_modify
| kFSEventStreamEventFlagItemChangeOwner
| kFSEventStreamEventFlagItemXattrMod
| kFSEventStreamEventFlagItemFinderInfoMod
| kFSEventStreamEventFlagItemInodeMetaMod
;
| kFSEventStreamEventFlagItemInodeMetaMod;
inline constexpr unsigned fsev_flag_effect_rename
= kFSEventStreamEventFlagItemRenamed;
inline constexpr unsigned fsev_flag_effect_any
Expand All @@ -539,55 +537,13 @@ struct ContextData {
std::mutex* mtx{nullptr};
};

/* We make a path from a C string...
In an array, in a dictionary...
Without type safety...
Because most of darwin's apis are `void*`-typed.
We should be guarenteed that nothing in here is
or can be null, but I'm skeptical. We ask Darwin
for utf8 strings from a dictionary of utf8 strings
which it gave us. Nothing should be able to be null.
We'll check anyway, just in case Darwin lies.
The dictionary contains looks like this:
{ "path": String
, "fileID": Number
}
We can only call `CFStringGetCStringPtr()`
on the `path` field. Not sure what function
the `fileID` requires, or if it's different
from what we'd get from `stat()`. (Is it an
inode number?) Anyway, we seem to get this:
-[__NSCFNumber length]: unrecognized ...
Whenever we try to inspect it with Int or
CStringPtr functions for CFStringGet...().
The docs don't say much about these fields.
I don't think they mention fileID at all.
*/
inline auto path_from_event_at(void* event_recv_paths, unsigned long i)
-> std::filesystem::path
{
if (! event_recv_paths) return {};
auto paths = static_cast<char const**>(event_recv_paths);
return {paths[i]};
}

inline auto event_recv_one(
ContextData& ctx,
std::filesystem::path const& path,
unsigned flags)
inline auto event_recv_one(ContextData& ctx, char const* path, unsigned flags)
{
using ::wtr::watcher::event;
using path_type = enum ::wtr::watcher::event::path_type;
using effect_type = enum ::wtr::watcher::event::effect_type;

auto cb = ctx.callback;

auto path_str = path.string();

/* A single path won't have different "types". */

auto pt = flags & fsev_flag_path_file ? path_type::file
: flags & fsev_flag_path_dir ? path_type::dir
: flags & fsev_flag_path_sym_link ? path_type::sym_link
Expand All @@ -597,9 +553,8 @@ inline auto event_recv_one(
/* We want to report odd events (even with an empty path)
but we can bail early if we don't recognize the effect
because everything else we do depends on that. */

if (! (flags & fsev_flag_effect_any)) {
cb({path, effect_type::other, pt});
ctx.callback({path, effect_type::other, pt});
return;
}

Expand All @@ -608,24 +563,24 @@ inline auto event_recv_one(

if (flags & fsev_flag_effect_create) {
auto et = effect_type::create;
auto at = ctx.seen_created_paths->find(path_str);
auto at = ctx.seen_created_paths->find(path);
if (at == ctx.seen_created_paths->end()) {
ctx.seen_created_paths->emplace(path_str);
cb({path, et, pt});
ctx.seen_created_paths->emplace(path);
ctx.callback({path, et, pt});
}
}
if (flags & fsev_flag_effect_remove) {
auto et = effect_type::destroy;
auto at = ctx.seen_created_paths->find(path_str);
auto at = ctx.seen_created_paths->find(path);
if (at != ctx.seen_created_paths->end()) {
ctx.seen_created_paths->erase(at);
cb({path, et, pt});
ctx.callback({path, et, pt});
}
}
if (flags & fsev_flag_effect_modify) {
if (! (flags & kFSEventStreamEventFlagItemInodeMetaMod)) {
auto et = effect_type::modify;
cb({path, et, pt});
ctx.callback({path, et, pt});
}
}
if (flags & fsev_flag_effect_rename) {
Expand Down Expand Up @@ -660,7 +615,7 @@ inline auto event_recv_one(
auto differs = ! lr_path.empty() && lr_path != path;
auto missing = access(lr_path.c_str(), F_OK) == -1;
if (differs && missing) {
cb({
ctx.callback({
{lr_path, et, pt},
{ path, et, pt}
});
Expand Down Expand Up @@ -691,21 +646,20 @@ inline auto event_recv(
ConstFSEventStreamRef, /* `ConstFS..` is important */
void* maybe_ctx, /* Arguments passed to us */
unsigned long count, /* Event count */
void* paths, /* Paths with events */
void* maybe_paths, /* Paths with events */
unsigned const* flags, /* Event flags */
FSEventStreamEventId const* /* A unique stream id */
) -> void
{
/* These checks are unfortunate, but they are also necessary.
Once in a blue moon, some of them are missing. */
auto data_ok = paths && flags && maybe_ctx;
auto data_ok = maybe_paths && flags && maybe_ctx;
if (! data_ok) return;
auto paths = static_cast<char const**>(maybe_paths);
auto ctx = *static_cast<ContextData*>(maybe_ctx);
if (! ctx.mtx->try_lock()) return;
for (unsigned long i = 0; i < count; i++) {
auto path = path_from_event_at(paths, i);
auto flag = flags[i];
event_recv_one(ctx, path, flag);
event_recv_one(ctx, paths[i], flags[i]);
}
ctx.mtx->unlock();
}
Expand Down

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