tor-browser

IOUtils.webidl (25996B)

---

/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/.
*/

interface nsIFile;

/**
* IOUtils is a simple, efficient interface for performing file I/O from a
* privileged chrome-only context. All asynchronous I/O tasks are run on
* a background thread.
*
* Pending I/O tasks will block shutdown at the |profileBeforeChange| phase.
* During this shutdown phase, no additional I/O tasks will be accepted --
* method calls to this interface will reject once shutdown has entered this
* phase.
*
* IOUtils methods may reject for any number of reasons. Reasonable attempts
* have been made to map each common operating system error to a |DOMException|.
* Most often, a caller only needs to check if a given file wasn't found by
* catching the rejected error and checking if |ex.name === 'NotFoundError'|.
* In other cases, it is likely sufficient to allow the error to be caught and
* reported elsewhere.
*/
[ChromeOnly, Exposed=(Window, Worker)]
namespace IOUtils {
/**
  * Reads up to |opts.maxBytes| of the file at |path| according to |opts|.
  *
  * NB: The maximum file size that can be read is UINT32_MAX.
  *
  * @param path An absolute file path.
  *
  * @return Resolves with an array of unsigned byte values read from disk,
  *         otherwise rejects with a DOMException.
  */
 [NewObject]
 Promise<Uint8Array> read(DOMString path, optional ReadOptions opts = {});
 /**
  * Reads the UTF-8 text file located at |path| and returns the decoded
  * contents as a |DOMString|. If a UTF-8 byte order marker (BOM) is
  * present, it will be stripped from the returned string.
  *
  * NB: The maximum file size that can be read is UINT32_MAX.
  *
  * @param path An absolute file path.
  *
  * @return Resolves with the file contents encoded as a string, otherwise
  *         rejects with a DOMException.
  */
 [NewObject]
 Promise<UTF8String> readUTF8(DOMString path, optional ReadUTF8Options opts = {});
 /**
  * Read the UTF-8 text file located at |path| and return the contents
  * parsed as JSON into a JS value.
  *
  * NB: The maximum file size that can be read is UINT32_MAX.
  *
  * @param path An absolute path.
  *
  * @return Resolves with the contents of the file parsed as JSON.
  */
 [NewObject]
 Promise<any> readJSON(DOMString path, optional ReadUTF8Options opts = {});
 /**
  * Attempts to safely write |data| to a file at |path|.
  *
  * This operation can be made atomic by specifying the |tmpPath| option. If
  * specified, then this method ensures that the destination file is not
  * modified until the data is entirely written to the temporary file, after
  * which point the |tmpPath| is moved to the specified |path|.
  *
  * The target file can also be backed up to a |backupFile| before any writes
  * are performed to prevent data loss in case of corruption.
  *
  * @param path    An absolute file path.
  * @param data    Data to write to the file at path.
  *
  * @return Resolves with the number of bytes successfully written to the file,
  *         otherwise rejects with a DOMException.
  */
 [NewObject]
 Promise<unsigned long long> write(DOMString path, Uint8Array data, optional WriteOptions options = {});
 /**
  * Attempts to encode |string| to UTF-8, then safely write the result to a
  * file at |path|. Works exactly like |write|.
  *
  * @param path      An absolute file path.
  * @param string    A string to write to the file at path.
  * @param options   Options for writing the file.
  *
  * @return Resolves with the number of bytes successfully written to the file,
  *         otherwise rejects with a DOMException.
  */
 [NewObject]
 Promise<unsigned long long> writeUTF8(DOMString path, UTF8String string, optional WriteOptions options = {});
 /**
  * Attempts to serialize |value| into a JSON string and encode it as into a
  * UTF-8 string, then safely write the result to a file at |path|. Works
  * exactly like |write|.
  *
  * @param path      An absolute file path
  * @param value     The value to be serialized.
  * @param options   Options for writing the file. The "append" mode is not supported.
  *
  * @return Resolves with the number of bytes successfully written to the file,
  *         otherwise rejects with a DOMException.
  */
 [NewObject]
 Promise<unsigned long long> writeJSON(DOMString path, any value, optional WriteOptions options = {});
 /**
  * Moves the file from |sourcePath| to |destPath|, creating necessary parents.
  * If |destPath| is a directory, then the source file will be moved into the
  * destination directory.
  *
  * @param sourcePath An absolute file path identifying the file or directory
  *                   to move.
  * @param destPath   An absolute file path identifying the destination
  *                   directory and/or file name.
  *
  * @return Resolves if the file is moved successfully, otherwise rejects with
  *         a DOMException.
  */
 [NewObject]
 Promise<undefined> move(DOMString sourcePath, DOMString destPath, optional MoveOptions options = {});
 /**
  * Removes a file or directory at |path| according to |options|.
  *
  * @param path An absolute file path identifying the file or directory to
  *             remove.
  *
  * @return Resolves if the file is removed successfully, otherwise rejects
  *         with a DOMException.
  */
 [NewObject]
 Promise<undefined> remove(DOMString path, optional RemoveOptions options = {});
 /**
  * Creates a new directory at |path| according to |options|.
  *
  * @param path An absolute file path identifying the directory to create.
  *
  * @return Resolves if the directory is created successfully, otherwise
  *         rejects with a DOMException.
  */
 [NewObject]
 Promise<undefined> makeDirectory(DOMString path, optional MakeDirectoryOptions options = {});
 /**
  * Obtains information about a file, such as size, modification dates, etc.
  *
  * @param path An absolute file path identifying the file or directory to
  *             inspect.
  *
  * @return Resolves with a |FileInfo| object for the file at path, otherwise
  *         rejects with a DOMException.
  *
  * @see FileInfo
  */
 [NewObject]
 Promise<FileInfo> stat(DOMString path);
 /**
  * Copies a file or directory from |sourcePath| to |destPath| according to
  * |options|.
  *
  * @param sourcePath An absolute file path identifying the source file to be
  *                   copied.
  * @param destPath   An absolute file path identifying the location for the
  *                   copy.
  *
  * @return Resolves if the file was copied successfully, otherwise rejects
  *         with a DOMException.
  */
 [NewObject]
 Promise<undefined> copy(DOMString sourcePath, DOMString destPath, optional CopyOptions options = {});
 /**
  * Updates the access time for the file at |path|.
  *
  * @param path         An absolute file path identifying the file whose
  *                     modification time is to be set. This file must exist
  *                     and will not be created.
  * @param modification An optional access time for the file expressed in
  *                     milliseconds since the Unix epoch
  *                     (1970-01-01T00:00:00Z). The current system time is used
  *                     if this parameter is not provided.
  *
  * @return Resolves with the updated access time time expressed in
  *         milliseconds since the Unix epoch, otherwise rejects with a
  *         DOMException.
  */
 [NewObject]
 Promise<long long> setAccessTime(DOMString path, optional long long access);
 /**
  * Updates the modification time for the file at |path|.
  *
  * @param path         An absolute file path identifying the file whose
  *                     modification time is to be set. This file must exist
  *                     and will not be created.
  * @param modification An optional modification time for the file expressed in
  *                     milliseconds since the Unix epoch
  *                     (1970-01-01T00:00:00Z). The current system time is used
  *                     if this parameter is not provided.
  *
  * @return Resolves with the updated modification time expressed in
  *         milliseconds since the Unix epoch, otherwise rejects with a
  *         DOMException.
  */
 [NewObject]
 Promise<long long> setModificationTime(DOMString path, optional long long modification);
 /**
  * Checks whether the directory at |path| has any immediate children.
  *
  * @param path An absolute file path.
  *
  * @return Resolves with a boolean indicating whether the directory at |path|
  *         has any immediate children, otherwise rejects with a DOMException.
  */
 [NewObject]
 Promise<boolean> hasChildren(DOMString path, optional HasChildrenOptions options = {});
 /**
  * Retrieves a (possibly empty) list of immediate children of the directory at
  * |path|.
  *
  * @param path An absolute file path.
  *
  * @return Resolves with a sequence of absolute file paths representing the
  *         children of the directory at |path|, otherwise rejects with a
  *         DOMException.
  */
 [NewObject]
 Promise<sequence<DOMString>> getChildren(DOMString path, optional GetChildrenOptions options = {});
 /**
  * Set the permissions of the file at |path|.
  *
  * Windows does not make a distinction between user, group, and other
  * permissions like UNICES do. If a permission flag is set for any of user,
  * group, or other has a permission, then all users will have that
  * permission. Additionally, Windows does not support setting the
  * "executable" permission.
  *
  * @param path        An absolute file path
  * @param permissions The UNIX file mode representing the permissions.
  * @param honorUmask  If omitted or true, any UNIX file mode value is
  *                    modified by the process umask. If false, the exact value
  *                    of UNIX file mode will be applied. This value has no effect
  *                    on Windows.
  *
  * @return Resolves if the permissions were set successfully, otherwise
  *         rejects with a DOMException.
  */
 [NewObject]
 Promise<undefined> setPermissions(DOMString path, unsigned long permissions, optional boolean honorUmask = true);
 /**
  * Return whether or not the file exists at the given path.
  *
  * @param path An absolute file path.
  *
  * @return A promise that resolves to whether or not the given file exists.
  */
 [NewObject]
 Promise<boolean> exists(DOMString path);

 /**
  * Create a file with a unique name and return its path.
  *
  * @param parent An absolute path to the directory where the file is to be
  *               created.
  * @param prefix A prefix for the filename.
  *
  * @return A promise that resolves to a unique filename.
  */
 [NewObject]
 Promise<DOMString> createUniqueFile(DOMString parent, DOMString prefix, optional unsigned long permissions = 0644);

 /**
  * Create a directory with a unique name and return its path.
  *
  * @param parent An absolute path to the directory where the file is to be
  *               created.
  * @param prefix A prefix for the directory name.
  *
  * @return A promise that resolves to a unique directory name.
  */
 [NewObject]
 Promise<DOMString> createUniqueDirectory(DOMString parent, DOMString prefix, optional unsigned long permissions = 0755);

 /**
  * Compute the hash of a file as a hex digest.
  *
  * @param path   The absolute path of the file to hash.
  * @param method The hashing method to use.
  *
  * @return A promise that resolves to the hex digest of the file's hash in lowercase.
  */
 [NewObject]
 Promise<UTF8String> computeHexDigest(DOMString path, HashAlgorithm method);

#if defined(XP_WIN)
 /**
  * Return the Windows-specific file attributes of the file at the given path.
  *
  * @param path An absolute file path.
  *
  * @return A promise that resolves to the Windows-specific file attributes.
  */
 [NewObject]
 Promise<WindowsFileAttributes> getWindowsAttributes(DOMString path);

 /**
  * Set the Windows-specific file attributes of the file at the given path.
  *
  * @param path An absolute file path.
  * @param attrs The attributes to set. Attributes will only be set if they are
  *              |true| or |false| (i.e., |undefined| attributes are not
  *              changed).
  * @param recursive  Whether or not to apply the changes to folder contents
  *                   recursively.
  *
  * @return A promise that resolves is the attributes were set successfully.
  */
 [NewObject]
 Promise<undefined> setWindowsAttributes(DOMString path,
     optional WindowsFileAttributes attrs = {},
     optional boolean recursive = false);
#elif defined(XP_MACOSX)
 /**
  * Return whether or not the file has a specific extended attribute.
  *
  * @param path An absolute path.
  * @param attr The attribute to check for.
  *
  * @return A promise that resolves to whether or not the file has an extended
  *         attribute, or rejects with an error.
  */
 [NewObject]
 Promise<boolean> hasMacXAttr(DOMString path, UTF8String attr);
 /**
  * Return the value of an extended attribute for a file.
  *
  * @param path An absolute path.
  * @param attr The attribute to get the value of.
  *
  * @return A promise that resolves to the value of the extended attribute, or
  *         rejects with an error.
  */
 [NewObject]
 Promise<Uint8Array> getMacXAttr(DOMString path, UTF8String attr);
 /**
  * Set the extended attribute on a file.
  *
  * @param path  An absolute path.
  * @param attr  The attribute to set.
  * @param value The value of the attribute to set.
  *
  * @return A promise that resolves to whether or not the file has an extended
  *         attribute, or rejects with an error.
  */
 [NewObject]
 Promise<undefined> setMacXAttr(DOMString path, UTF8String attr, Uint8Array value);
 /**
  * Delete the extended attribute on a file.
  *
  * @param path An absolute path.
  * @param attr The attribute to delete.
  *
  * @return A promise that resolves if the attribute was deleted, or rejects
  *         with an error.
  */
 [NewObject]
 Promise<undefined> delMacXAttr(DOMString path, UTF8String attr);
#endif

 /**
  * Return a nsIFile whose parent directory exists. The parent directory of the
  * file will be created off main thread if it does not already exist.
  *
  * @param components The path components. The first component must be an
  *                   absolute path.
  *
  * @return A promise that resolves to an nsIFile for the requested file.
  */
 [NewObject]
 Promise<nsIFile> getFile(DOMString... components);

 /**
  * Return an nsIFile corresponding to a directory. It will be created
  * off-main-thread if it does not already exist.
  *
  * @param components The path components. The first component must be an
  *                   absolute path.
  *
  * @return A promise that resolves to an nsIFile for the requested directory.
  */
 [NewObject]
 Promise<nsIFile> getDirectory(DOMString... components);
};

[Exposed=Window]
partial namespace IOUtils {
 /**
  * The async shutdown client for the profile-before-change shutdown phase.
  */
 [Throws]
 readonly attribute any profileBeforeChange;

 /**
  * The async shutdown client for the profile-before-change-telemetry shutdown
  * phase.
  *
  * ONLY telemetry should register blockers on this client.
  */
 [Throws]
 readonly attribute any sendTelemetry;
};

[Exposed=Worker]
partial namespace IOUtils {
 /**
  * Synchronously opens the file at |path|. This API is only available in workers.
  *
  * @param path An absolute file path.
  *
  * @return A |SyncReadFile| object for the file.
  */
 [Throws]
 SyncReadFile openFileForSyncReading(DOMString path);

#ifdef XP_UNIX
 /**
  * Launch a child process; uses `base::LaunchApp` from IPC.  (This WebIDL
  * binding is currently Unix-only; it could also be supported on Windows
  * but it would use u16-based strings, so it would basically be a separate
  * copy of the bindings.)
  *
  * This interface was added for use by `Subprocess.sys.mjs`; other would-be
  * callers may want to just use Subprocess instead of calling this directly.
  *
  * @param argv The command to run and its arguments.
  * @param options Various parameters about how the child process is launched
  *                and its initial environment.
  *
  * @return The process ID.  Note that various errors (e.g., the
  *         executable to be launched doesn't exist) may not be
  *         encountered until after the process is created, so a
  *         successful return doesn't necessarily imply a successful
  *         launch.
  */
 [Throws]
 unsigned long launchProcess(sequence<UnixString> argv, LaunchOptions options);
#endif
};

/**
* An object representing an open file, allowing parts of the file contents to be
* read synchronously. Only available in workers.
*/
[ChromeOnly, Exposed=Worker]
interface SyncReadFile {
 /**
  * The file size, in bytes.
  */
 readonly attribute long long size;

 /**
  * Synchronously read |dest.length| bytes at offset |offset| into |dest|.
  * Throws if the file has been closed already or if the read would be out-of-bounds.
  *
  * @param dest   A Uint8Array whose entire contents will be overwritten with
  *               bytes read from the file.
  * @param offset The file offset at which the read range begins. (The length of the
  *               range is given by |dest.length|.)
  */
 [Throws]
 undefined readBytesInto(Uint8Array dest, long long offset);

 /**
  * Close the file. Subsequent calls to readBytesInto will throw.
  * If the file is not closed manually, it will be closed once this object is GC'ed.
  */
 undefined close();
};

/**
* Options to be passed to the |IOUtils.readUTF8| method.
*/
dictionary ReadUTF8Options {
 /**
  * If true, this option indicates that the file to be read is compressed with
  * LZ4-encoding, and should be decompressed before the data is returned to
  * the caller.
  */
 boolean decompress = false;
};

/**
* Options to be passed to the |IOUtils.read| method.
*/
dictionary ReadOptions : ReadUTF8Options {
 /**
  * The offset into the file to read from. If unspecified, the file will be read
  * from the start.
  */
 unsigned long long offset = 0;

 /**
  * The max bytes to read from the file at path. If unspecified, the entire
  * file will be read. This option is incompatible with |decompress|.
  */
 unsigned long? maxBytes = null;
};

/**
* Modes for writing to a file.
*/
enum WriteMode {
 /**
  * Overwrite the contents of the file.
  *
  * The file will be created if it does not exist.
  */
 "overwrite",
 /**
  * Append to the end of the file.
  *
  * This mode will refuse to create the file if it does not exist.
  */
 "append",
 /**
  * Append to the end of the file, or create it if it does not exist.
  */
 "appendOrCreate",
 /**
  * Create a new file.
  *
  * This mode will refuse to overwrite an existing file.
  */
 "create",
};

/**
* Options to be passed to the |IOUtils.write| and |writeUTF8|
* methods.
*/
dictionary WriteOptions {
 /**
  * If specified, backup the destination file to this path before writing.
  */
 DOMString backupFile;
 /**
  * If specified, write the data to a file at |tmpPath| instead of directly to
  * the destination. Once the write is complete, the destination will be
  * overwritten by a move. Specifying this option will make the write a little
  * slower, but also safer.
  */
 DOMString tmpPath;
 /**
  * The mode used to write to the file.
  */
 WriteMode mode = "overwrite";
 /**
  * If true, force the OS to write its internal buffers to the disk.
  * This is considerably slower for the whole system, but safer in case of
  * an improper system shutdown (e.g. due to a kernel panic) or device
  * disconnection before the buffers are flushed.
  */
 boolean flush = false;
 /**
  * If true, compress the data with LZ4-encoding before writing to the file.
  */
 boolean compress = false;
};

/**
* Options to be passed to the |IOUtils.move| method.
*/
dictionary MoveOptions {
 /**
  * If true, fail if the destination already exists.
  */
 boolean noOverwrite = false;
};

/**
* Options to be passed to the |IOUtils.remove| method.
*/
dictionary RemoveOptions {
 /**
  * If true, no error will be reported if the target file is missing.
  */
 boolean ignoreAbsent = true;
 /**
  * If true, and the target is a directory, recursively remove files.
  */
 boolean recursive = false;

 /**
  * If true, a failed delete on a readonly file will be retried by first
  * removing the readonly attribute.
  *
  * Only has an effect on Windows.
  */
 boolean retryReadonly = false;
};

/**
* Options to be passed to the |IOUtils.makeDirectory| method.
*/
dictionary MakeDirectoryOptions {
 /**
  * If true, create the directory and all necessary ancestors if they do not
  * already exist. If false and any ancestor directories do not exist,
  * |makeDirectory| will reject with an error.
  */
 boolean createAncestors = true;
 /**
  * If true, succeed even if the directory already exists (default behavior).
  * Otherwise, fail if the directory already exists.
  */
 boolean ignoreExisting = true;
 /**
  * The file mode to create the directory with.
  *
  * This is ignored on Windows.
  */
 unsigned long permissions = 0755;

};

/**
* Options to be passed to the |IOUtils.copy| method.
*/
dictionary CopyOptions {
 /**
  * If true, fail if the destination already exists.
  */
 boolean noOverwrite = false;
 /**
  * If true, copy the source recursively.
  */
 boolean recursive = false;
};

/**
* Options to be passed to the |IOUtils.hasChildren| method.
*/
dictionary HasChildrenOptions {
 /**
  * If true, no error will be reported if the target file is missing.
  */
 boolean ignoreAbsent = false;
};

/**
* Options to be passed to the |IOUtils.getChildren| method.
*/
dictionary GetChildrenOptions {
 /**
  * If true, no error will be reported if the target file is missing.
  */
 boolean ignoreAbsent = false;
};

/**
* Types of files that are recognized by the |IOUtils.stat| method.
*/
enum FileType { "regular", "directory", "other" };

/**
* Basic metadata about a file.
*/
dictionary FileInfo {
 /**
  * The absolute path to the file on disk, as known when this file info was
  * obtained.
  */
 DOMString path;

 /**
  * Identifies if the file at |path| is a regular file, directory, or something
  * something else.
  */
 FileType type;

 /**
  * If this represents a regular file, the size of the file in bytes.
  * Otherwise, -1.
  */
 long long size;

 /**
  * The timestamp of file creation, represented in milliseconds since Epoch
  * (1970-01-01T00:00:00.000Z).
  *
  * This is only available on MacOS and Windows.
  */
 long long creationTime;

 /**
  * The timestmp of last file accesss, represented in milliseconds since Epoch
  * (1970-01-01T00:00:00.000Z).
  */
 long long lastAccessed;

 /**
  * The timestamp of the last file modification, represented in milliseconds
  * since Epoch (1970-01-01T00:00:00.000Z).
  */
 long long lastModified;

 /**
  * The permissions of the file, expressed as a UNIX file mode.
  *
  * NB: Windows does not make a distinction between user, group, and other
  * permissions like UNICES do. The user, group, and other parts will always
  * be identical on Windows.
  */
 unsigned long permissions;
};

/**
* The supported hash algorithms for |IOUtils.hashFile|.
*/
enum HashAlgorithm { "sha256", "sha384", "sha512" };

#ifdef XP_WIN
/**
* Windows-specific file attributes.
*/
dictionary WindowsFileAttributes {
 /**
  * Whether or not the file is read-only.
  */
 boolean readOnly;
 /**
  * Whether or not the file is hidden.
  */
 boolean hidden;
 /**
  * Whether or not the file is classified as a system file.
  */
 boolean system;
};
#endif

#ifdef XP_UNIX
/**
* Used where the POSIX API allows an arbitrary byte string but in
* practice it's usually UTF-8, so JS strings are accepted for
* convenience.
*/
typedef (UTF8String or Uint8Array) UnixString;

/**
* Options for the `launchApp` method.  See also `base::LaunchOptions`
* in C++.
*/
dictionary LaunchOptions {
 /**
  * The environment variables, as a sequence of `NAME=value` strings.
  * (The underlying C++ code can also inherit the current environment
  * with optional changes; that feature could be added here if needed.)
  */
 required sequence<UnixString> environment;

 /**
  * The initial current working directory.
  */
 UnixString workdir;

 /**
  * File descriptors to pass to the child process.  Any fds not
  * mentioned here, other than stdin/out/err, will not be inherited
  * even if they aren't marked close-on-exec.
  */
 sequence<FdMapping> fdMap;

 /**
  * On macOS 10.14+, disclaims responsibility for the child process
  * with respect to privacy/security permission prompts and
  * decisions.  Ignored if not supported by the OS.
  */
 boolean disclaim = false;
};

/**
* Describes a file descriptor to give to the child process.
*/
dictionary FdMapping {
 /**
  * The fd in the parent process to pass.  This must remain open during
  * the call to `launchApp` but can be closed after it returns (or throws).
  */
 required unsigned long src;

 /**
  * The fd number to map it to in the child process.
  */
 required unsigned long dst;
};
#endif