gecko-dev/xpcom/base/nsIGZFileWriter.idl
Gerald Squelart 782cf5d3ad Bug 1657033 - Use Span<const char> in JSONWriter - r=froydnj
In most situations, JSONWriter users already know string lengths (either directly, or through `nsCString` and friends), so we should keep this information through JSONWriter and not recompute it again.
This also allows using JSONWriter with sub-strings (e.g., from a bigger buffer), without having to create null-terminated strings.

Public JSONWriter functions have overloads that accept literal strings.

Differential Revision: https://phabricator.services.mozilla.com/D86192
2020-09-14 02:33:20 +00:00

83 lines
2.4 KiB
Plaintext

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
#include "nsISupports.idl"
%{C++
#include "nsDependentString.h"
#include <stdio.h>
%}
interface nsIFile;
[ptr] native FILE(FILE);
/**
* A simple interface for writing to a .gz file.
*
* Note that the file that this interface produces has a different format than
* what you'd get if you compressed your data as a gzip stream and dumped the
* result to a file.
*
* The standard gunzip tool cannot decompress a raw gzip stream, but can handle
* the files produced by this interface.
*/
[scriptable, uuid(6bd5642c-1b90-4499-ba4b-199f27efaba5)]
interface nsIGZFileWriter : nsISupports
{
/**
* Initialize this object. We'll write our gzip'ed data to the given file,
* overwriting its contents if the file exists.
*
* init() will return an error if called twice. It's an error to call any
* other method on this interface without first calling init().
*/
[must_use] void init(in nsIFile file);
/**
* Alternate version of init() for use when the file is already opened;
* e.g., with a FileDescriptor passed over IPC.
*/
[noscript, must_use] void initANSIFileDesc(in FILE file);
/**
* Write the given string to the file.
*/
[must_use] void write(in AUTF8String str);
/*
* The following two overloads of Write() are C++ because we can't overload
* methods in XPIDL. Anyway, they don't add much functionality for JS
* callers.
*/
%{C++
/**
* Write the given char* to the file (not including the null-terminator).
*/
[[nodiscard]] nsresult Write(const char* str)
{
return Write(str, strlen(str));
}
/**
* Write |length| bytes of |str| to the file.
*/
[[nodiscard]] nsresult Write(const char* str, uint32_t len)
{
return Write(nsDependentCSubstring(str, len));
}
%}
/**
* Close this nsIGZFileWriter. Classes implementing nsIGZFileWriter will run
* this method when the underlying object is destroyed, so it's not strictly
* necessary to explicitly call it from your code.
*
* It's an error to call this method twice, and it's an error to call write()
* after finish() has been called.
*/
void finish();
};