Checkpoint. Just access JSON directly in FUSE handlers.

extension/background.js

@@ -2,9 +2,13 @@ const ws = new WebSocket("ws://localhost:8888");
 
 const ops = {
   NONE: 0,
+
   GETATTR: 1,
-  READDIR: 2
+  OPEN: 2,
+  READDIR: 3,
+  READ: 4
 };
+
 const unix = {
   EPERM: 1,
   ENOENT: 2,
@@ -24,6 +28,12 @@ const unix = {
   S_IFSOCK: 0140000, // socket
 }
 
+function UnixError(error) {
+  this.name = "UnixError";
+  this.error = error;
+}
+UnixError.prototype = Error.prototype;
+
 function queryTabs() {
   return new Promise((resolve, reject) => chrome.tabs.query({}, resolve));
 }
@@ -54,22 +64,14 @@ function findRoute(path) {
   for (let segment of path.split("/")) {
     if (segment === "") continue;
     route = route[segment] || route["*"];
+
+    if (!route) throw new UnixError(unix.ENOENT);
   }
   return route;
 }
 
-async function readdir(path) {
-  let route = findRoute(path);
-
-  if (route.readdir) {
-    return route.readdir();
-  }
-  return Object.keys(route);
-}
-
 async function getattr(path) {
   let route = findRoute(path);
-
   if (route.getattr) {
     return route.getattr();
   } else {
@@ -78,39 +80,51 @@ async function getattr(path) {
       st_nlink: 3
     };
   }
-  /* 
+}
-   * const response = {};
-   * if (path === "/" || path === "/tabs" || path === "/tabs/by-title" || path === "/tabs/by-id") {
-   *   response.st_mode = unix.S_IFDIR | 0755;
-   *   response.st_nlink = 3;
 
-   * } else if (path === "/tabs/hello.txt") {
+async function readdir(path) {
-   *  
+  let route = findRoute(path);
-   * } else {
+  if (route.readdir) {
-   *   response.error = unix.ENOENT;
+    return route.readdir();
-   * }
+  }
-   * return response;*/
+  return Object.keys(route);
 }
 
 ws.onmessage = async function(event) {
   const req = JSON.parse(event.data);
   console.log('req', Object.entries(ops).find(([op, opcode]) => opcode === req.op)[0], req);
 
-  let response;
+  let response = { op: req.op, error: unix.EIO };
-  if (req.op === ops.READDIR) {
+  try {
-    response = {
+    if (req.op === ops.GETATTR) {
-      op: ops.READDIR,
+      response = {
-      entries: [".", "..", ...(await readdir(req.path))]
+        op: ops.GETATTR,
-    };
+        st_mode: 0,
+        st_nlink: 0,
+        st_size: 0,
+        ...(await getattr(req.path))
+      };
+    } else if (req.op === ops.OPEN) {
+      throw new UnixError(unix.EIO);
 
-  } else if (req.op === ops.GETATTR) {
+    } else if (req.op === ops.READDIR) {
+      response = {
+        op: ops.READDIR,
+        entries: [".", "..", ...(await readdir(req.path))]
+      };
+
+    } else if (req.op === ops.READ) {
+      response = {
+        op: ops.READ,
+        buf: await read(req.path)
+      };
+    }
+
+  } catch (e) {
     response = {
-      op: ops.GETATTR,
+      op: req.op,
-      st_mode: 0,
+      error: e instanceof UnixError ? e.error : unix.EIO
-      st_nlink: 0,
+    }
-      st_size: 0,
-      ...(await getattr(req.path))
-    };
   }
 
   console.log('response', Object.entries(ops).find(([op, opcode]) => opcode === response.op)[0], response);

fs/Makefile

@@ -28,3 +28,12 @@ hello: hello.c
 clean:
 	rm -f $(TARGETS) *.o
 	rm -rf *.dSYM
+
+remount: unmount mount
+
+unmount:
+	killall -9 hello || true
+	diskutil unmount force mnt || true
+
+mount: hello
+	./hello -s -f mnt

fs/hello.c

@@ -24,28 +24,14 @@ enum opcode {
     NONE = 0,
 
     GETATTR,
-    READDIR
+    OPEN,
-};
+    READDIR,
-
+    READ
-struct readdir {
-    char **entries;
-    size_t num_entries;
-};
-
-struct response {
-    enum opcode op;
-
-    int error;
-
-    union {
-        struct stat getattr;
-        struct readdir readdir;
-    } body;
 };
 
 pthread_cond_t response_cv = PTHREAD_COND_INITIALIZER;
 pthread_mutex_t response_mutex = PTHREAD_MUTEX_INITIALIZER;
-struct response response = (struct response) { .op = NONE };
+cJSON *response = NULL;
 
 static const char  *file_path      = "/hello.txt";
 static const char   file_content[] = "Hello World!\n";
@@ -76,34 +62,59 @@ void send_req_if_any() {
   pthread_mutex_unlock(&request_data_mutex);
 }
 
-#define MAKE_REQ(op, body) \
+static cJSON *await_response() {
-  do { \
-    pthread_mutex_lock(&request_data_mutex); \
-    int disconnected = (con == NULL); \
-    pthread_mutex_unlock(&request_data_mutex); \
-    if (disconnected) return -EIO; \
-    \
-    cJSON *req = cJSON_CreateObject(); \
-    cJSON_AddNumberToObject(req, "op", (int) op);        \
-    body \
-    dispatch_send_req(req); \
-    cJSON_Delete(req); \
-} while (0)
-
-static struct response await_response(enum opcode op) {
   pthread_mutex_lock(&response_mutex);
 
-  memset(&response, 0, sizeof response);
+  response = NULL;
-  while (response.op == NONE) {
+  while (response == NULL) {
     pthread_cond_wait(&response_cv, &response_mutex);
   }
 
-  struct response ret = response;
+  cJSON *resp = response;
   pthread_mutex_unlock(&response_mutex);
 
-  return ret;
+  return resp;
 }
 
+#define MAKE_REQ(op, req_body, resp_handler) \
+  do { \
+    int ret = -1;                                     \
+    cJSON *req = NULL;                              \
+    cJSON *resp = NULL;                           \
+                                                  \
+    pthread_mutex_lock(&request_data_mutex); \
+    int disconnected = (con == NULL); \
+    pthread_mutex_unlock(&request_data_mutex); \
+    if (disconnected) { ret = -EIO; goto done; }        \
+    \
+    req = cJSON_CreateObject(); \
+    cJSON_AddNumberToObject(req, "op", (int) op);        \
+    req_body \
+    \
+    dispatch_send_req(req); \
+    \
+    resp = await_response();\
+    \
+    cJSON *error_item = cJSON_GetObjectItemCaseSensitive(resp, "error"); \
+    if (error_item) { \
+      ret = -error_item->valueint; \
+      if (ret != 0) goto done; \
+    } \
+    \
+    resp_handler \
+    \
+    ret = 0; \
+done: \
+    if (req != NULL) cJSON_Delete(req); \
+    if (resp != NULL) cJSON_Delete(resp); \
+    return ret;                               \
+  } while (0)
+
+#define JSON_GET_PROP_INT(lvalue, key) \
+  do { \
+    lvalue = cJSON_GetObjectItemCaseSensitive(resp, key)->valueint;     \
+  } while (0)
+
 static int
 hello_getattr(const char *path, struct stat *stbuf)
 {
@@ -112,42 +123,24 @@ hello_getattr(const char *path, struct stat *stbuf)
 
     MAKE_REQ(GETATTR, {
         cJSON_AddStringToObject(req, "path", path);
-      });
+    }, {
-
+        JSON_GET_PROP_INT(stbuf->st_mode, "st_mode");
-    struct response resp = await_response(GETATTR);
+        JSON_GET_PROP_INT(stbuf->st_nlink, "st_nlink");
-    if (resp.error != 0) {
+        JSON_GET_PROP_INT(stbuf->st_size, "st_size");
-      printf("error re getattr(%s): %d\n", path, resp.error);
+        printf("returning re getattr(%s)\n", path);
-      return -resp.error;
+    });
-    }
-
-    stbuf->st_mode = resp.body.getattr.st_mode;
-    stbuf->st_nlink = resp.body.getattr.st_nlink;
-    stbuf->st_size = resp.body.getattr.st_size;
-    printf("returning re getattr(%s)\n", path);
-    /* if (strcmp(path, "/") == 0) { /\* The root directory of our file system. *\/ */
-    /*     stbuf->st_mode = S_IFDIR | 0755; */
-    /*     stbuf->st_nlink = 3; */
-    /* } else if (strcmp(path, file_path) == 0) { /\* The only file we have. *\/ */
-    /*     stbuf->st_mode = S_IFREG | 0444; */
-    /*     stbuf->st_nlink = 1; */
-    /*     stbuf->st_size = file_size; */
-    /* } else /\* We reject everything else. *\/ */
-    /*     return -ENOENT; */
-
-
-    return 0;
 }
 
 static int
 hello_open(const char *path, struct fuse_file_info *fi)
 {
-    if (strcmp(path, file_path) != 0) /* We only recognize one file. */
+    MAKE_REQ(OPEN, {
-        return -ENOENT;
+        cJSON_AddStringToObject(req, "path", path);
-
+        cJSON_AddNumberToObject(req, "flags", fi->flags);
-    if ((fi->flags & O_ACCMODE) != O_RDONLY) /* Only reading allowed. */
+    }, {
-        return -EACCES;
+        cJSON *fh_item = cJSON_GetObjectItemCaseSensitive(resp, "fh");
-
+        if (fh_item) fi->fh = fh_item->valueint;
-    return 0;
+    });
 }
 
 static int
@@ -155,30 +148,35 @@ hello_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
               off_t offset, struct fuse_file_info *fi)
 {
     printf("\n\nreaddir(%s)\n", path);
-
+    
-    // send {op: "readdir", path} to the websocket handler
+    // send {op: READDIR, path} to the websocket handler
     MAKE_REQ(READDIR, {
         cJSON_AddStringToObject(req, "path", path);
-      });
+    }, {
-
+        cJSON *entries = cJSON_GetObjectItemCaseSensitive(resp, "entries");
-    printf("awaiting response to readdir(%s)\n", path);
+        cJSON *entry;
-    struct response resp = await_response(READDIR);
+        cJSON_ArrayForEach(entry, entries) {
-
+            filler(buf, cJSON_GetStringValue(entry), NULL, 0);
-    struct readdir *readdir = &resp.body.readdir;
+            printf("entry: [%s]\n", cJSON_GetStringValue(entry));
-    printf("response: %d files\n", (int) readdir->num_entries);
+        }
-
+    });
-    for (size_t i = 0; i < readdir->num_entries; ++i) {
-        filler(buf, readdir->entries[i], NULL, 0);
-        printf("entry: [%s]\n", readdir->entries[i]);
-    }
-
-    return 0;
 }
 
 static int
 hello_read(const char *path, char *buf, size_t size, off_t offset,
            struct fuse_file_info *fi)
 {
+    MAKE_REQ(OPEN, {
+        cJSON_AddStringToObject(req, "path", path);
+        cJSON_AddNumberToObject(req, "size", size);
+        cJSON_AddNumberToObject(req, "offset", offset);
+
+        cJSON_AddNumberToObject(req, "fh", fi->fh);
+        cJSON_AddNumberToObject(req, "flags", fi->flags);
+    }, {
+        
+    });
+
     if (strcmp(path, file_path) != 0)
         return -ENOENT;
 
@@ -226,7 +224,7 @@ websocket_connected(struct wby_con *connection, void *userdata)
 static int
 websocket_frame(struct wby_con *connection, const struct wby_frame *frame, void *userdata)
 {
-    unsigned char data[1024] = {0};
+    unsigned char data[131072] = {0};
 
     int i = 0;
     printf("WebSocket frame incoming\n");
@@ -237,6 +235,7 @@ websocket_frame(struct wby_con *connection, const struct wby_frame *frame, void
 
     if ((unsigned long) frame->payload_length > sizeof(data)) {
         printf("Data too long!\n");
+        exit(1);
     }
     
     while (i < frame->payload_length) {
@@ -266,44 +265,10 @@ websocket_frame(struct wby_con *connection, const struct wby_frame *frame, void
     }
 
     pthread_mutex_lock(&response_mutex);
-
+    response = cJSON_Parse((const char *) data);
-    cJSON *ret = cJSON_Parse((const char *) data);
-
-    cJSON *op_item = cJSON_GetObjectItemCaseSensitive(ret, "op");
-    response.op = (enum opcode) op_item->valueint;
-
-    cJSON *error_item = cJSON_GetObjectItemCaseSensitive(ret, "error");
-    if (error_item) {
-      response.error = error_item->valueint;
-      if (response.error != 0) goto done;
-    }
-
-    if (response.op == READDIR) {
-      struct readdir *readdir = &response.body.readdir;
-
-      cJSON *entries = cJSON_GetObjectItemCaseSensitive(ret, "entries");
-
-      readdir->num_entries = cJSON_GetArraySize(entries);
-      readdir->entries = malloc(sizeof(char *) * readdir->num_entries);
-
-      int i = 0;
-      cJSON *entry;
-      cJSON_ArrayForEach(entry, entries) {
-        readdir->entries[i++] = strdup(cJSON_GetStringValue(entry));
-      }
-
-    } else if (response.op == GETATTR) {
-      struct stat *getattr = &response.body.getattr;
-      getattr->st_mode = cJSON_GetObjectItemCaseSensitive(ret, "st_mode")->valueint;
-      getattr->st_nlink = cJSON_GetObjectItemCaseSensitive(ret, "st_nlink")->valueint;
-      getattr->st_size = cJSON_GetObjectItemCaseSensitive(ret, "st_size")->valueint;
-    }
-
- done:
-    if (ret) cJSON_Delete(ret);
-
     pthread_cond_signal(&response_cv);
     pthread_mutex_unlock(&response_mutex);
+
     return 0;
 }