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exports.debugLevel = 0; // Increase to get more verbose debug output
function debugMessage (msg) {
if (exports.debugLevel > 0) {
node.error(__filename + ": " + msg.toString());
}
}
function debugObject (obj) {
if (exports.debugLevel > 0) {
node.error(__filename + ": " + JSON.stringify(obj));
}
}
exports.read = node.fs.cat;
exports.write = function (filename, data, encoding) {
var promise = new node.Promise();
encoding = encoding || "utf8"; // default to utf8
node.fs.open(filename, node.O_WRONLY | node.O_TRUNC | node.O_CREAT, 0666)
.addCallback(function (fd) {
function doWrite (_data) {
node.fs.write(fd, _data, 0, encoding)
.addErrback(function () {
node.fs.close(fd);
})
.addCallback(function (written) {
if (written == _data.length) {
node.fs.close(fd);
} else {
doWrite(_data.slice(written));
}
});
}
doWrite(data);
})
.addErrback(function () {
promise.emitError()
});
return promise;
};
exports.File = function (filename, mode, options) {
var self = this;
options = options || {};
self.encoding = options.encoding || "utf8";
self.filename = filename;
self.actionQueue = [];
self.currentAction = null;
switch (mode) {
case "r":
self.flags = node.O_RDONLY;
break;
case "r+":
self.flags = node.O_RDWR;
break;
case "w":
self.flags = node.O_CREAT | node.O_TRUNC | node.O_WRONLY;
break;
case "w+":
self.flags = node.O_CREAT | node.O_TRUNC | node.O_RDWR;
break;
case "a":
self.flags = node.O_APPEND | node.O_CREAT | node.O_WRONLY;
break;
case "a+":
self.flags = node.O_APPEND | node.O_CREAT | node.O_RDWR;
break;
default:
throw new Error("Unknown mode");
}
self.open(self.filename, self.flags, 0666).addCallback(function (fd) {
debugMessage(self.filename + " opened. fd = " + fd);
self.fd = fd;
}).addErrback(function () {
self.emit("error", ["open"]);
});
};
var proto = exports.File.prototype;
proto._maybeDispatch = function () {
var self = this;
if (self.currentAction) return;
self.currentAction = self.actionQueue.shift();
if (!self.currentAction) return;
debugObject(self.currentAction);
var args = self.currentAction.args || [];
if (self.currentAction.method != "open") {
args.unshift(self.fd);
}
var method = self.currentAction.method;
if (!args[3] && (method == "read" || method == "write")) {
args[3] = self.encoding;
}
var promise = node.fs[method].apply(self, args);
var userPromise = self.currentAction.promise;
promise.addCallback(function () {
node.assert(self.currentAction.promise == userPromise);
userPromise.emitSuccess.apply(userPromise, arguments);
self.currentAction = null;
self._maybeDispatch();
}).addErrback(function () {
debugMessage("Error in method " + method);
node.assert(self.currentAction.promise == userPromise);
userPromise.emitError.apply(userPromise, arguments);
self.currentAction = null;
self._maybeDispatch();
});
};
proto._queueAction = function (method, args) {
var userPromise = new node.Promise;
this.actionQueue.push({ method: method, args: args, promise: userPromise });
this._maybeDispatch();
return userPromise;
};
// FIXME the following can probably be DRY'd up with some fancy getter
// stuff.
proto.open = function (filename, flags, mode) {
return this._queueAction("open", [filename, flags, mode]);
};
proto.write = function (data, pos, encoding) {
return this._queueAction("write", [data, pos, encoding]);
};
proto.read = function (length, pos, encoding) {
return this._queueAction("read", [length, pos, encoding]);
};
proto.close = function () {
return this._queueAction("close");
};
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