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mirror of https://github.com/janet-lang/janet synced 2024-11-23 17:07:17 +00:00

Work on the filewatch module.

Currently a wrapper around inotify, should be expanded to work with
kqueue, icop, and eventually a implementation with polling and stat.
This commit is contained in:
Calvin Rose 2024-08-11 17:50:58 -05:00
parent 6bd58dd4c0
commit a59b5765b6
7 changed files with 317 additions and 3 deletions

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@ -139,6 +139,7 @@ JANET_CORE_SOURCES=src/core/abstract.c \
src/core/ev.c \
src/core/ffi.c \
src/core/fiber.c \
src/core/filewatch.c \
src/core/gc.c \
src/core/inttypes.c \
src/core/io.c \

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@ -122,6 +122,7 @@ core_src = [
'src/core/ev.c',
'src/core/ffi.c',
'src/core/fiber.c',
'src/core/filewatch.c',
'src/core/gc.c',
'src/core/inttypes.c',
'src/core/io.c',

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@ -4706,6 +4706,7 @@
"src/core/ev.c"
"src/core/ffi.c"
"src/core/fiber.c"
"src/core/filewatch.c"
"src/core/gc.c"
"src/core/inttypes.c"
"src/core/io.c"

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@ -74,7 +74,7 @@ typedef struct {
} mode;
} JanetChannelPending;
typedef struct {
struct JanetChannel {
JanetQueue items;
JanetQueue read_pending;
JanetQueue write_pending;
@ -86,7 +86,7 @@ typedef struct {
#else
pthread_mutex_t lock;
#endif
} JanetChannel;
};
typedef struct {
JanetFiber *fiber;
@ -866,7 +866,7 @@ static int janet_channel_push_with_lock(JanetChannel *channel, Janet x, int mode
/* No root fiber, we are in completion on a root fiber. Don't block. */
if (mode == 2) {
janet_chan_unlock(channel);
return 0;
return 1;
}
/* Pushed successfully, but should block. */
JanetChannelPending pending;
@ -922,6 +922,7 @@ static int janet_channel_pop_with_lock(JanetChannel *channel, Janet *item, int i
int is_threaded = janet_chan_is_threaded(channel);
if (janet_q_pop(&channel->items, item, sizeof(Janet))) {
/* Queue empty */
if (is_choice == 2) return 0; // Skip pending read
JanetChannelPending pending;
pending.thread = &janet_vm;
pending.fiber = janet_vm.root_fiber,
@ -979,6 +980,14 @@ JanetChannel *janet_optchannel(const Janet *argv, int32_t argc, int32_t n, Janet
}
}
int janet_channel_give(JanetChannel *channel, Janet x) {
return janet_channel_push(channel, x, 2);
}
int janet_channel_take(JanetChannel *channel, Janet *out) {
return janet_channel_pop(channel, out, 2);
}
/* Channel Methods */
JANET_CORE_FN(cfun_channel_push,
@ -3278,6 +3287,8 @@ void janet_lib_ev(JanetTable *env) {
janet_register_abstract_type(&janet_channel_type);
janet_register_abstract_type(&janet_mutex_type);
janet_register_abstract_type(&janet_rwlock_type);
janet_lib_filewatch(env);
}
#endif

292
src/core/filewatch.c Normal file
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@ -0,0 +1,292 @@
/*
* Copyright (c) 2024 Calvin Rose
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal in the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#ifndef JANET_AMALG
#include "features.h"
#include <janet.h>
#include "util.h"
#endif
#ifdef JANET_EV
typedef struct {
JanetTable *watch_descriptors;
JanetStream *stream;
JanetChannel *channel;
uint32_t default_flags;
} JanetWatcher;
#ifdef JANET_LINUX
#include <sys/inotify.h>
#include <unistd.h>
#endif
typedef struct {
const char *name;
uint32_t flag;
} JanetWatchFlagName;
static const JanetWatchFlagName watcher_flags_linux[] = {
{"access", IN_ACCESS},
{"all", IN_ALL_EVENTS},
{"attrib", IN_ATTRIB},
{"close-nowrite", IN_CLOSE_NOWRITE},
{"close-write", IN_CLOSE_WRITE},
{"create", IN_CREATE},
{"delete", IN_DELETE},
{"delete-self", IN_DELETE_SELF},
{"ignored", IN_OPEN},
{"modify", IN_MODIFY},
{"move-self", IN_MOVE_SELF},
{"moved-from", IN_MOVED_FROM},
{"moved-to", IN_MOVED_TO},
{"open", IN_OPEN},
{"q-overflow", IN_Q_OVERFLOW},
{"unmount", IN_UNMOUNT},
};
static uint32_t decode_inotify_flags(const Janet *options, int32_t n) {
uint32_t flags = 0;
for (int32_t i = 0; i < n; i++) {
if (!(janet_checktype(options[i], JANET_KEYWORD))) {
janet_panicf("expected keyword, got %v", options[i]);
}
JanetKeyword keyw = janet_unwrap_keyword(options[i]);
const JanetWatchFlagName *result = janet_strbinsearch(watcher_flags_linux,
sizeof(watcher_flags_linux) / sizeof(JanetWatchFlagName),
sizeof(JanetWatchFlagName),
keyw);
if (!result) {
janet_panicf("unknown inotify flag %v", options[i]);
}
flags |= result->flag;
}
return flags;
}
static void janet_watcher_init(JanetWatcher *watcher, JanetChannel *channel, uint32_t default_flags) {
int fd;
do {
fd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
} while (fd == -1 && errno == EINTR);
watcher->watch_descriptors = janet_table(0);
watcher->channel = channel;
watcher->default_flags = default_flags;
watcher->stream = janet_stream(fd, JANET_STREAM_READABLE, NULL);
}
static void janet_watcher_add(JanetWatcher *watcher, const char *path, uint32_t flags) {
if (watcher->stream == NULL) janet_panic("watcher closed");
int result;
do {
result = inotify_add_watch(watcher->stream->handle, path, flags);
} while (result == -1 && errno == EINTR);
Janet name = janet_cstringv(path);
Janet wd = janet_wrap_integer(result);
janet_table_put(watcher->watch_descriptors, name, wd);
janet_table_put(watcher->watch_descriptors, wd, name);
}
static void janet_watcher_remove(JanetWatcher *watcher, const char *path) {
if (watcher->stream == NULL) janet_panic("watcher closed");
Janet check = janet_table_get(watcher->watch_descriptors, janet_cstringv(path));
janet_assert(janet_checktype(check, JANET_NUMBER), "bad watch descriptor");
int watch_handle = janet_unwrap_integer(check);
int result;
do {
result = inotify_rm_watch(watcher->stream->handle, watch_handle);
} while (result != -1 && errno == EINTR);
if (result == -1) {
janet_panicf("%s", janet_strerror(errno));
}
}
static void watcher_callback_read(JanetFiber *fiber, JanetAsyncEvent event) {
JanetStream *stream = fiber->ev_stream;
JanetWatcher *watcher = (JanetWatcher *) fiber->ev_state;
char buf[1024];
switch (event) {
default:
break;
case JANET_ASYNC_EVENT_MARK:
janet_mark(janet_wrap_abstract(watcher));
break;
case JANET_ASYNC_EVENT_CLOSE:
janet_schedule(fiber, janet_wrap_nil());
fiber->ev_state = NULL;
janet_async_end(fiber);
break;
case JANET_ASYNC_EVENT_ERR:
{
janet_schedule(fiber, janet_wrap_nil());
fiber->ev_state = NULL;
janet_async_end(fiber);
break;
}
read_more:
case JANET_ASYNC_EVENT_HUP:
case JANET_ASYNC_EVENT_INIT:
case JANET_ASYNC_EVENT_READ:
{
Janet name = janet_wrap_nil();
/* Assumption - read will never return partial events *
* From documentation:
*
* The behavior when the buffer given to read(2) is too small to
* return information about the next event depends on the kernel
* version: before Linux 2.6.21, read(2) returns 0; since Linux
* 2.6.21, read(2) fails with the error EINVAL. Specifying a buffer
* of size
*
* sizeof(struct inotify_event) + NAME_MAX + 1
*
* will be sufficient to read at least one event. */
ssize_t nread;
do {
nread = read(stream->handle, buf, sizeof(buf));
} while (nread == -1 && errno == EINTR);
/* Check for errors - special case errors that can just be waited on to fix */
if (nread == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
break;
}
janet_cancel(fiber, janet_ev_lasterr());
fiber->ev_state = NULL;
janet_async_end(fiber);
break;
}
if (nread < (ssize_t) sizeof(struct inotify_event)) break;
/* Iterate through all events read from the buffer */
char *cursor = buf;
while (cursor < buf + nread) {
struct inotify_event inevent;
memcpy(&inevent, cursor, sizeof(inevent));
cursor += sizeof(inevent);
/* Read path of inevent */
if (inevent.len) {
name = janet_cstringv(cursor);
cursor += inevent.len;
}
/* Got an event */
Janet path = janet_table_get(watcher->watch_descriptors, janet_wrap_integer(inevent.wd));
JanetKV *event = janet_struct_begin(6);
janet_struct_put(event, janet_ckeywordv("wd"), janet_wrap_integer(inevent.wd));
janet_struct_put(event, janet_ckeywordv("wd-path"), path);
janet_struct_put(event, janet_ckeywordv("mask"), janet_wrap_integer(inevent.mask));
janet_struct_put(event, janet_ckeywordv("path"), name);
janet_struct_put(event, janet_ckeywordv("cookie"), janet_wrap_integer(inevent.cookie));
Janet etype = janet_ckeywordv("type");
const JanetWatchFlagName *wfn_end = watcher_flags_linux + sizeof(watcher_flags_linux) / sizeof(watcher_flags_linux[0]);
for (const JanetWatchFlagName *wfn = watcher_flags_linux; wfn < wfn_end; wfn++) {
if ((inevent.mask & wfn->flag) == wfn->flag) janet_struct_put(event, etype, janet_ckeywordv(wfn->name));
}
Janet eventv = janet_wrap_struct(janet_struct_end(event));
janet_channel_give(watcher->channel, eventv);
}
/* Read some more if possible */
goto read_more;
}
break;
}
}
static void janet_watcher_listen(JanetWatcher *watcher) {
janet_async_start(watcher->stream, JANET_ASYNC_LISTEN_READ, watcher_callback_read, watcher);
}
/* C Functions */
static int janet_filewatch_mark(void *p, size_t s) {
JanetWatcher *watcher = (JanetWatcher *) p;
(void) s;
janet_mark(janet_wrap_abstract(watcher->stream));
janet_mark(janet_wrap_abstract(watcher->channel));
janet_mark(janet_wrap_table(watcher->watch_descriptors));
return 0;
}
static const JanetAbstractType janet_filewatch_at = {
"filewatch/watcher",
NULL,
janet_filewatch_mark,
JANET_ATEND_GCMARK
};
JANET_CORE_FN(cfun_filewatch_make,
"(filewatch/make channel &opt default-flags)",
"Create a new filewatcher.") {
janet_arity(argc, 1, -1);
JanetChannel *channel = janet_getchannel(argv, 0);
JanetWatcher *watcher = janet_abstract(&janet_filewatch_at, sizeof(JanetWatcher));
uint32_t default_flags = decode_inotify_flags(argv + 1, argc - 1);
janet_watcher_init(watcher, channel, default_flags);
return janet_wrap_abstract(watcher);
}
JANET_CORE_FN(cfun_filewatch_add,
"(filewatch/add watcher path &opt flags)",
"Add a path to the watcher.") {
janet_arity(argc, 2, -1);
JanetWatcher *watcher = janet_getabstract(argv, 0, &janet_filewatch_at);
const char *path = janet_getcstring(argv, 1);
uint32_t flags = watcher->default_flags | decode_inotify_flags(argv + 2, argc - 2);
janet_watcher_add(watcher, path, flags);
return argv[0];
}
JANET_CORE_FN(cfun_filewatch_remove,
"(filewatch/remove watcher path)",
"Remove a path from the watcher.") {
janet_fixarity(argc, 2);
JanetWatcher *watcher = janet_getabstract(argv, 0, &janet_filewatch_at);
const char *path = janet_getcstring(argv, 1);
janet_watcher_remove(watcher, path);
return argv[0];
}
JANET_CORE_FN(cfun_filewatch_listen,
"(filewatch/listen watcher)",
"Listen for changes in the watcher.") {
janet_fixarity(argc, 1);
JanetWatcher *watcher = janet_getabstract(argv, 0, &janet_filewatch_at);
janet_watcher_listen(watcher);
return janet_wrap_nil();
}
/* Module entry point */
void janet_lib_filewatch(JanetTable *env) {
JanetRegExt cfuns[] = {
JANET_CORE_REG("filewatch/make", cfun_filewatch_make),
JANET_CORE_REG("filewatch/add", cfun_filewatch_add),
JANET_CORE_REG("filewatch/remove", cfun_filewatch_remove),
JANET_CORE_REG("filewatch/listen", cfun_filewatch_listen),
JANET_REG_END
};
janet_core_cfuns_ext(env, NULL, cfuns);
}
#endif

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@ -204,6 +204,7 @@ extern const JanetAbstractType janet_address_type;
void janet_lib_ev(JanetTable *env);
void janet_ev_mark(void);
int janet_make_pipe(JanetHandle handles[2], int mode);
void janet_lib_filewatch(JanetTable *env);
#endif
#ifdef JANET_FFI
void janet_lib_ffi(JanetTable *env);

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@ -354,6 +354,7 @@ typedef struct {
#ifdef JANET_EV
typedef struct JanetOSMutex JanetOSMutex;
typedef struct JanetOSRWLock JanetOSRWLock;
typedef struct JanetChannel JanetChannel;
#endif
/***** END SECTION CONFIG *****/
@ -1443,6 +1444,12 @@ JANET_API void *janet_abstract_threaded(const JanetAbstractType *atype, size_t s
JANET_API int32_t janet_abstract_incref(void *abst);
JANET_API int32_t janet_abstract_decref(void *abst);
/* Expose channel utilities */
JanetChannel *janet_getchannel(const Janet *argv, int32_t n);
JanetChannel *janet_optchannel(const Janet *argv, int32_t argc, int32_t n, JanetChannel *dflt);
JANET_API int janet_channel_give(JanetChannel *channel, Janet x);
JANET_API int janet_channel_take(JanetChannel *channel, Janet *out);
/* Expose some OS sync primitives */
JANET_API size_t janet_os_mutex_size(void);
JANET_API size_t janet_os_rwlock_size(void);