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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/**
+ * Code shared by OS.File front-ends.
+ *
+ * This code is meant to be included by another library. It is also meant to
+ * be executed only on a worker thread.
+ */
+
+if (typeof Components != "undefined") {
+ throw new Error("osfile_shared_front.jsm cannot be used from the main thread");
+}
+(function(exports) {
+
+var SharedAll =
+ require("resource://gre/modules/osfile/osfile_shared_allthreads.jsm");
+var Path = require("resource://gre/modules/osfile/ospath.jsm");
+var Lz4 =
+ require("resource://gre/modules/lz4.js");
+var LOG = SharedAll.LOG.bind(SharedAll, "Shared front-end");
+var clone = SharedAll.clone;
+
+/**
+ * Code shared by implementations of File.
+ *
+ * @param {*} fd An OS-specific file handle.
+ * @param {string} path File path of the file handle, used for error-reporting.
+ * @constructor
+ */
+var AbstractFile = function AbstractFile(fd, path) {
+ this._fd = fd;
+ if (!path) {
+ throw new TypeError("path is expected");
+ }
+ this._path = path;
+};
+
+AbstractFile.prototype = {
+ /**
+ * Return the file handle.
+ *
+ * @throw OS.File.Error if the file has been closed.
+ */
+ get fd() {
+ if (this._fd) {
+ return this._fd;
+ }
+ throw OS.File.Error.closed("accessing file", this._path);
+ },
+ /**
+ * Read bytes from this file to a new buffer.
+ *
+ * @param {number=} maybeBytes (deprecated, please use options.bytes)
+ * @param {JSON} options
+ * @return {Uint8Array} An array containing the bytes read.
+ */
+ read: function read(maybeBytes, options = {}) {
+ if (typeof maybeBytes === "object") {
+ // Caller has skipped `maybeBytes` and provided an options object.
+ options = clone(maybeBytes);
+ maybeBytes = null;
+ } else {
+ options = options || {};
+ }
+ let bytes = options.bytes || undefined;
+ if (bytes === undefined) {
+ bytes = maybeBytes == null ? this.stat().size : maybeBytes;
+ }
+ let buffer = new Uint8Array(bytes);
+ let pos = 0;
+ while (pos < bytes) {
+ let length = bytes - pos;
+ let view = new DataView(buffer.buffer, pos, length);
+ let chunkSize = this._read(view, length, options);
+ if (chunkSize == 0) {
+ break;
+ }
+ pos += chunkSize;
+ }
+ if (pos == bytes) {
+ return buffer;
+ } else {
+ return buffer.subarray(0, pos);
+ }
+ },
+
+ /**
+ * Write bytes from a buffer to this file.
+ *
+ * Note that, by default, this function may perform several I/O
+ * operations to ensure that the buffer is fully written.
+ *
+ * @param {Typed array} buffer The buffer in which the the bytes are
+ * stored. The buffer must be large enough to accomodate |bytes| bytes.
+ * @param {*=} options Optionally, an object that may contain the
+ * following fields:
+ * - {number} bytes The number of |bytes| to write from the buffer. If
+ * unspecified, this is |buffer.byteLength|.
+ *
+ * @return {number} The number of bytes actually written.
+ */
+ write: function write(buffer, options = {}) {
+ let bytes =
+ SharedAll.normalizeBufferArgs(buffer, ("bytes" in options) ? options.bytes : undefined);
+ let pos = 0;
+ while (pos < bytes) {
+ let length = bytes - pos;
+ let view = new DataView(buffer.buffer, buffer.byteOffset + pos, length);
+ let chunkSize = this._write(view, length, options);
+ pos += chunkSize;
+ }
+ return pos;
+ }
+};
+
+/**
+ * Creates and opens a file with a unique name. By default, generate a random HEX number and use it to create a unique new file name.
+ *
+ * @param {string} path The path to the file.
+ * @param {*=} options Additional options for file opening. This
+ * implementation interprets the following fields:
+ *
+ * - {number} humanReadable If |true|, create a new filename appending a decimal number. ie: filename-1.ext, filename-2.ext.
+ * If |false| use HEX numbers ie: filename-A65BC0.ext
+ * - {number} maxReadableNumber Used to limit the amount of tries after a failed
+ * file creation. Default is 20.
+ *
+ * @return {Object} contains A file object{file} and the path{path}.
+ * @throws {OS.File.Error} If the file could not be opened.
+ */
+AbstractFile.openUnique = function openUnique(path, options = {}) {
+ let mode = {
+ create : true
+ };
+
+ let dirName = Path.dirname(path);
+ let leafName = Path.basename(path);
+ let lastDotCharacter = leafName.lastIndexOf('.');
+ let fileName = leafName.substring(0, lastDotCharacter != -1 ? lastDotCharacter : leafName.length);
+ let suffix = (lastDotCharacter != -1 ? leafName.substring(lastDotCharacter) : "");
+ let uniquePath = "";
+ let maxAttempts = options.maxAttempts || 99;
+ let humanReadable = !!options.humanReadable;
+ const HEX_RADIX = 16;
+ // We produce HEX numbers between 0 and 2^24 - 1.
+ const MAX_HEX_NUMBER = 16777215;
+
+ try {
+ return {
+ path: path,
+ file: OS.File.open(path, mode)
+ };
+ } catch (ex if ex instanceof OS.File.Error && ex.becauseExists) {
+ for (let i = 0; i < maxAttempts; ++i) {
+ try {
+ if (humanReadable) {
+ uniquePath = Path.join(dirName, fileName + "-" + (i + 1) + suffix);
+ } else {
+ let hexNumber = Math.floor(Math.random() * MAX_HEX_NUMBER).toString(HEX_RADIX);
+ uniquePath = Path.join(dirName, fileName + "-" + hexNumber + suffix);
+ }
+ return {
+ path: uniquePath,
+ file: OS.File.open(uniquePath, mode)
+ };
+ } catch (ex if ex instanceof OS.File.Error && ex.becauseExists) {
+ // keep trying ...
+ }
+ }
+ throw OS.File.Error.exists("could not find an unused file name.", path);
+ }
+};
+
+/**
+ * Code shared by iterators.
+ */
+AbstractFile.AbstractIterator = function AbstractIterator() {
+};
+AbstractFile.AbstractIterator.prototype = {
+ /**
+ * Allow iterating with |for|
+ */
+ __iterator__: function __iterator__() {
+ return this;
+ },
+ /**
+ * Apply a function to all elements of the directory sequentially.
+ *
+ * @param {Function} cb This function will be applied to all entries
+ * of the directory. It receives as arguments
+ * - the OS.File.Entry corresponding to the entry;
+ * - the index of the entry in the enumeration;
+ * - the iterator itself - calling |close| on the iterator stops
+ * the loop.
+ */
+ forEach: function forEach(cb) {
+ let index = 0;
+ for (let entry in this) {
+ cb(entry, index++, this);
+ }
+ },
+ /**
+ * Return several entries at once.
+ *
+ * Entries are returned in the same order as a walk with |forEach| or
+ * |for(...)|.
+ *
+ * @param {number=} length If specified, the number of entries
+ * to return. If unspecified, return all remaining entries.
+ * @return {Array} An array containing the next |length| entries, or
+ * less if the iteration contains less than |length| entries left.
+ */
+ nextBatch: function nextBatch(length) {
+ let array = [];
+ let i = 0;
+ for (let entry in this) {
+ array.push(entry);
+ if (++i >= length) {
+ return array;
+ }
+ }
+ return array;
+ }
+};
+
+/**
+ * Utility function shared by implementations of |OS.File.open|:
+ * extract read/write/trunc/create/existing flags from a |mode|
+ * object.
+ *
+ * @param {*=} mode An object that may contain fields |read|,
+ * |write|, |truncate|, |create|, |existing|. These fields
+ * are interpreted only if true-ish.
+ * @return {{read:bool, write:bool, trunc:bool, create:bool,
+ * existing:bool}} an object recapitulating the options set
+ * by |mode|.
+ * @throws {TypeError} If |mode| contains other fields, or
+ * if it contains both |create| and |truncate|, or |create|
+ * and |existing|.
+ */
+AbstractFile.normalizeOpenMode = function normalizeOpenMode(mode) {
+ let result = {
+ read: false,
+ write: false,
+ trunc: false,
+ create: false,
+ existing: false,
+ append: true
+ };
+ for (let key in mode) {
+ let val = !!mode[key]; // bool cast.
+ switch (key) {
+ case "read":
+ result.read = val;
+ break;
+ case "write":
+ result.write = val;
+ break;
+ case "truncate": // fallthrough
+ case "trunc":
+ result.trunc = val;
+ result.write |= val;
+ break;
+ case "create":
+ result.create = val;
+ result.write |= val;
+ break;
+ case "existing": // fallthrough
+ case "exist":
+ result.existing = val;
+ break;
+ case "append":
+ result.append = val;
+ break;
+ default:
+ throw new TypeError("Mode " + key + " not understood");
+ }
+ }
+ // Reject opposite modes
+ if (result.existing && result.create) {
+ throw new TypeError("Cannot specify both existing:true and create:true");
+ }
+ if (result.trunc && result.create) {
+ throw new TypeError("Cannot specify both trunc:true and create:true");
+ }
+ // Handle read/write
+ if (!result.write) {
+ result.read = true;
+ }
+ return result;
+};
+
+/**
+ * Return the contents of a file.
+ *
+ * @param {string} path The path to the file.
+ * @param {number=} bytes Optionally, an upper bound to the number of bytes
+ * to read. DEPRECATED - please use options.bytes instead.
+ * @param {object=} options Optionally, an object with some of the following
+ * fields:
+ * - {number} bytes An upper bound to the number of bytes to read.
+ * - {string} compression If "lz4" and if the file is compressed using the lz4
+ * compression algorithm, decompress the file contents on the fly.
+ *
+ * @return {Uint8Array} A buffer holding the bytes
+ * and the number of bytes read from the file.
+ */
+AbstractFile.read = function read(path, bytes, options = {}) {
+ if (bytes && typeof bytes == "object") {
+ options = bytes;
+ bytes = options.bytes || null;
+ }
+ if ("encoding" in options && typeof options.encoding != "string") {
+ throw new TypeError("Invalid type for option encoding");
+ }
+ if ("compression" in options && typeof options.compression != "string") {
+ throw new TypeError("Invalid type for option compression: " + options.compression);
+ }
+ if ("bytes" in options && typeof options.bytes != "number") {
+ throw new TypeError("Invalid type for option bytes");
+ }
+ let file = exports.OS.File.open(path);
+ try {
+ let buffer = file.read(bytes, options);
+ if ("compression" in options) {
+ if (options.compression == "lz4") {
+ options = Object.create(options);
+ options.path = path;
+ buffer = Lz4.decompressFileContent(buffer, options);
+ } else {
+ throw OS.File.Error.invalidArgument("Compression");
+ }
+ }
+ if (!("encoding" in options)) {
+ return buffer;
+ }
+ let decoder;
+ try {
+ decoder = new TextDecoder(options.encoding);
+ } catch (ex if ex instanceof RangeError) {
+ throw OS.File.Error.invalidArgument("Decode");
+ }
+ return decoder.decode(buffer);
+ } finally {
+ file.close();
+ }
+};
+
+/**
+ * Write a file, atomically.
+ *
+ * By opposition to a regular |write|, this operation ensures that,
+ * until the contents are fully written, the destination file is
+ * not modified.
+ *
+ * Limitation: In a few extreme cases (hardware failure during the
+ * write, user unplugging disk during the write, etc.), data may be
+ * corrupted. If your data is user-critical (e.g. preferences,
+ * application data, etc.), you may wish to consider adding options
+ * |tmpPath| and/or |flush| to reduce the likelihood of corruption, as
+ * detailed below. Note that no combination of options can be
+ * guaranteed to totally eliminate the risk of corruption.
+ *
+ * @param {string} path The path of the file to modify.
+ * @param {Typed Array | C pointer} buffer A buffer containing the bytes to write.
+ * @param {*=} options Optionally, an object determining the behavior
+ * of this function. This object may contain the following fields:
+ * - {number} bytes The number of bytes to write. If unspecified,
+ * |buffer.byteLength|. Required if |buffer| is a C pointer.
+ * - {string} tmpPath If |null| or unspecified, write all data directly
+ * to |path|. If specified, write all data to a temporary file called
+ * |tmpPath| and, once this write is complete, rename the file to
+ * replace |path|. Performing this additional operation is a little
+ * slower but also a little safer.
+ * - {bool} noOverwrite - If set, this function will fail if a file already
+ * exists at |path|.
+ * - {bool} flush - If |false| or unspecified, return immediately once the
+ * write is complete. If |true|, before writing, force the operating system
+ * to write its internal disk buffers to the disk. This is considerably slower
+ * (not just for the application but for the whole system) but also safer:
+ * if the system shuts down improperly (typically due to a kernel freeze
+ * or a power failure) or if the device is disconnected before the buffer
+ * is flushed, the file has more chances of not being corrupted.
+ * - {string} compression - If empty or unspecified, do not compress the file.
+ * If "lz4", compress the contents of the file atomically using lz4. For the
+ * time being, the container format is specific to Mozilla and cannot be read
+ * by means other than OS.File.read(..., { compression: "lz4"})
+ * - {string} backupTo - If specified, backup the destination file as |backupTo|.
+ * Note that this function renames the destination file before overwriting it.
+ * If the process or the operating system freezes or crashes
+ * during the short window between these operations,
+ * the destination file will have been moved to its backup.
+ *
+ * @return {number} The number of bytes actually written.
+ */
+AbstractFile.writeAtomic =
+ function writeAtomic(path, buffer, options = {}) {
+
+ // Verify that path is defined and of the correct type
+ if (typeof path != "string" || path == "") {
+ throw new TypeError("File path should be a (non-empty) string");
+ }
+ let noOverwrite = options.noOverwrite;
+ if (noOverwrite && OS.File.exists(path)) {
+ throw OS.File.Error.exists("writeAtomic", path);
+ }
+
+ if (typeof buffer == "string") {
+ // Normalize buffer to a C buffer by encoding it
+ let encoding = options.encoding || "utf-8";
+ buffer = new TextEncoder(encoding).encode(buffer);
+ }
+
+ if ("compression" in options && options.compression == "lz4") {
+ buffer = Lz4.compressFileContent(buffer, options);
+ options = Object.create(options);
+ options.bytes = buffer.byteLength;
+ }
+
+ let bytesWritten = 0;
+
+ if (!options.tmpPath) {
+ if (options.backupTo) {
+ try {
+ OS.File.move(path, options.backupTo, {noCopy: true});
+ } catch (ex if ex.becauseNoSuchFile) {
+ // The file doesn't exist, nothing to backup.
+ }
+ }
+ // Just write, without any renaming trick
+ let dest = OS.File.open(path, {write: true, truncate: true});
+ try {
+ bytesWritten = dest.write(buffer, options);
+ if (options.flush) {
+ dest.flush();
+ }
+ } finally {
+ dest.close();
+ }
+ return bytesWritten;
+ }
+
+ let tmpFile = OS.File.open(options.tmpPath, {write: true, truncate: true});
+ try {
+ bytesWritten = tmpFile.write(buffer, options);
+ if (options.flush) {
+ tmpFile.flush();
+ }
+ } catch (x) {
+ OS.File.remove(options.tmpPath);
+ throw x;
+ } finally {
+ tmpFile.close();
+ }
+
+ if (options.backupTo) {
+ try {
+ OS.File.move(path, options.backupTo, {noCopy: true});
+ } catch (ex if ex.becauseNoSuchFile) {
+ // The file doesn't exist, nothing to backup.
+ }
+ }
+
+ OS.File.move(options.tmpPath, path, {noCopy: true});
+ return bytesWritten;
+};
+
+/**
+ * This function is used by removeDir to avoid calling lstat for each
+ * files under the specified directory. External callers should not call
+ * this function directly.
+ */
+AbstractFile.removeRecursive = function(path, options = {}) {
+ let iterator = new OS.File.DirectoryIterator(path);
+ if (!iterator.exists()) {
+ if (!("ignoreAbsent" in options) || options.ignoreAbsent) {
+ return;
+ }
+ }
+
+ try {
+ for (let entry in iterator) {
+ if (entry.isDir) {
+ if (entry.isLink) {
+ // Unlike Unix symlinks, NTFS junctions or NTFS symlinks to
+ // directories are directories themselves. OS.File.remove()
+ // will not work for them.
+ OS.File.removeEmptyDir(entry.path, options);
+ } else {
+ // Normal directories.
+ AbstractFile.removeRecursive(entry.path, options);
+ }
+ } else {
+ // NTFS symlinks to files, Unix symlinks, or regular files.
+ OS.File.remove(entry.path, options);
+ }
+ }
+ } finally {
+ iterator.close();
+ }
+
+ OS.File.removeEmptyDir(path);
+};
+
+/**
+ * Create a directory and, optionally, its parent directories.
+ *
+ * @param {string} path The name of the directory.
+ * @param {*=} options Additional options.
+ *
+ * - {string} from If specified, the call to |makeDir| creates all the
+ * ancestors of |path| that are descendants of |from|. Note that |path|
+ * must be a descendant of |from|, and that |from| and its existing
+ * subdirectories present in |path| must be user-writeable.
+ * Example:
+ * makeDir(Path.join(profileDir, "foo", "bar"), { from: profileDir });
+ * creates directories profileDir/foo, profileDir/foo/bar
+ * - {bool} ignoreExisting If |false|, throw an error if the directory
+ * already exists. |true| by default. Ignored if |from| is specified.
+ * - {number} unixMode Under Unix, if specified, a file creation mode,
+ * as per libc function |mkdir|. If unspecified, dirs are
+ * created with a default mode of 0700 (dir is private to
+ * the user, the user can read, write and execute). Ignored under Windows
+ * or if the file system does not support file creation modes.
+ * - {C pointer} winSecurity Under Windows, if specified, security
+ * attributes as per winapi function |CreateDirectory|. If
+ * unspecified, use the default security descriptor, inherited from
+ * the parent directory. Ignored under Unix or if the file system
+ * does not support security descriptors.
+ */
+AbstractFile.makeDir = function(path, options = {}) {
+ let from = options.from;
+ if (!from) {
+ OS.File._makeDir(path, options);
+ return;
+ }
+ if (!path.startsWith(from)) {
+ // Apparently, `from` is not a parent of `path`. However, we may
+ // have false negatives due to non-normalized paths, e.g.
+ // "foo//bar" is a parent of "foo/bar/sna".
+ path = Path.normalize(path);
+ from = Path.normalize(from);
+ if (!path.startsWith(from)) {
+ throw new Error("Incorrect use of option |from|: " + path + " is not a descendant of " + from);
+ }
+ }
+ let innerOptions = Object.create(options, {
+ ignoreExisting: {
+ value: true
+ }
+ });
+ // Compute the elements that appear in |path| but not in |from|.
+ let items = Path.split(path).components.slice(Path.split(from).components.length);
+ let current = from;
+ for (let item of items) {
+ current = Path.join(current, item);
+ OS.File._makeDir(current, innerOptions);
+ }
+};
+
+if (!exports.OS.Shared) {
+ exports.OS.Shared = {};
+}
+exports.OS.Shared.AbstractFile = AbstractFile;
+})(this);
generated by cgit v1.2.3 (git 2.26.2) at 2024-11-10 12:38:17 +0000