gecko-dev/xpcom/io/nsStringStream.h

/* -*- Mode: C++; 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/. */

#ifndef nsStringStream_h__
#define nsStringStream_h__

#include "nsIStringStream.h"
#include "nsStringGlue.h"
#include "nsMemory.h"

/**
 * Implements:
 *   nsIStringInputStream
 *   nsIInputStream
 *   nsISeekableStream
 *   nsISupportsCString
 */
#define NS_STRINGINPUTSTREAM_CLASSNAME  "nsStringInputStream"
#define NS_STRINGINPUTSTREAM_CONTRACTID "@mozilla.org/io/string-input-stream;1"
#define NS_STRINGINPUTSTREAM_CID                     \
{ /* 0abb0835-5000-4790-af28-61b3ba17c295 */         \
    0x0abb0835,                                      \
    0x5000,                                          \
    0x4790,                                          \
    {0xaf, 0x28, 0x61, 0xb3, 0xba, 0x17, 0xc2, 0x95} \
}

/**
 * Factory method to get an nsInputStream from a byte buffer.  Result will
 * implement nsIStringInputStream and nsISeekableStream.
 *
 * If aAssignment is NS_ASSIGNMENT_COPY, then the resulting stream holds a copy
 * of the given buffer (aStringToRead), and the caller is free to discard
 * aStringToRead after this function returns.
 *
 * If aAssignment is NS_ASSIGNMENT_DEPEND, then the resulting stream refers
 * directly to the given buffer (aStringToRead), so the caller must ensure that
 * the buffer remains valid for the lifetime of the stream object.  Use with
 * care!!
 *
 * If aAssignment is NS_ASSIGNMENT_ADOPT, then the resulting stream refers
 * directly to the given buffer (aStringToRead) and will free aStringToRead
 * once the stream is closed.
 *
 * If aLength is less than zero, then the length of aStringToRead will be
 * determined by scanning the buffer for the first null byte.
 */
extern nsresult
NS_NewByteInputStream(nsIInputStream** aStreamResult,
                      const char* aStringToRead, int32_t aLength = -1,
                      nsAssignmentType aAssignment = NS_ASSIGNMENT_DEPEND);

/**
 * Factory method to get an nsInputStream from an nsAString.  Result will
 * implement nsIStringInputStream and nsISeekableStream.
 *
 * The given string data will be converted to a single-byte data buffer via
 * truncation (i.e., the high-order byte of each character will be discarded).
 * This could result in data-loss, so be careful when using this function.
 */
extern nsresult
NS_NewStringInputStream(nsIInputStream** aStreamResult,
                        const nsAString& aStringToRead);

/**
 * Factory method to get an nsInputStream from an nsACString.  Result will
 * implement nsIStringInputStream and nsISeekableStream.
 */
extern nsresult
NS_NewCStringInputStream(nsIInputStream** aStreamResult,
                         const nsACString& aStringToRead);

#endif // nsStringStream_h__