1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/xpconnect/src/XPCString.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,108 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* vim: set ts=8 sts=4 et sw=4 tw=99: */
1.6 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +/*
1.11 + * Infrastructure for sharing DOMString data with JSStrings.
1.12 + *
1.13 + * Importing an nsAString into JS:
1.14 + * If possible (GetSharedBufferHandle works) use the external string support in
1.15 + * JS to create a JSString that points to the readable's buffer. We keep a
1.16 + * reference to the buffer handle until the JSString is finalized.
1.17 + *
1.18 + * Exporting a JSString as an nsAReadable:
1.19 + * Wrap the JSString with a root-holding XPCJSReadableStringWrapper, which roots
1.20 + * the string and exposes its buffer via the nsAString interface, as
1.21 + * well as providing refcounting support.
1.22 + */
1.23 +
1.24 +#include "nscore.h"
1.25 +#include "nsString.h"
1.26 +#include "nsStringBuffer.h"
1.27 +#include "jsapi.h"
1.28 +#include "xpcpublic.h"
1.29 +
1.30 +using namespace JS;
1.31 +
1.32 +// static
1.33 +void
1.34 +XPCStringConvert::FreeZoneCache(JS::Zone *zone)
1.35 +{
1.36 + // Put the zone user data into an AutoPtr (which will do the cleanup for us),
1.37 + // and null out the user data (which may already be null).
1.38 + nsAutoPtr<ZoneStringCache> cache(static_cast<ZoneStringCache*>(JS_GetZoneUserData(zone)));
1.39 + JS_SetZoneUserData(zone, nullptr);
1.40 +}
1.41 +
1.42 +// static
1.43 +void
1.44 +XPCStringConvert::ClearZoneCache(JS::Zone *zone)
1.45 +{
1.46 + ZoneStringCache *cache = static_cast<ZoneStringCache*>(JS_GetZoneUserData(zone));
1.47 + if (cache) {
1.48 + cache->mBuffer = nullptr;
1.49 + cache->mString = nullptr;
1.50 + }
1.51 +}
1.52 +
1.53 +// static
1.54 +void
1.55 +XPCStringConvert::FinalizeLiteral(const JSStringFinalizer *fin, jschar *chars)
1.56 +{
1.57 +}
1.58 +
1.59 +const JSStringFinalizer XPCStringConvert::sLiteralFinalizer =
1.60 + { XPCStringConvert::FinalizeLiteral };
1.61 +
1.62 +// static
1.63 +void
1.64 +XPCStringConvert::FinalizeDOMString(const JSStringFinalizer *fin, jschar *chars)
1.65 +{
1.66 + nsStringBuffer* buf = nsStringBuffer::FromData(chars);
1.67 + buf->Release();
1.68 +}
1.69 +
1.70 +const JSStringFinalizer XPCStringConvert::sDOMStringFinalizer =
1.71 + { XPCStringConvert::FinalizeDOMString };
1.72 +
1.73 +// convert a readable to a JSString, copying string data
1.74 +// static
1.75 +bool
1.76 +XPCStringConvert::ReadableToJSVal(JSContext *cx,
1.77 + const nsAString &readable,
1.78 + nsStringBuffer** sharedBuffer,
1.79 + MutableHandleValue vp)
1.80 +{
1.81 + *sharedBuffer = nullptr;
1.82 +
1.83 + uint32_t length = readable.Length();
1.84 +
1.85 + if (readable.IsLiteral()) {
1.86 + JSString *str = JS_NewExternalString(cx,
1.87 + static_cast<const jschar*>(readable.BeginReading()),
1.88 + length, &sLiteralFinalizer);
1.89 + if (!str)
1.90 + return false;
1.91 + vp.setString(str);
1.92 + return true;
1.93 + }
1.94 +
1.95 + nsStringBuffer *buf = nsStringBuffer::FromString(readable);
1.96 + if (buf) {
1.97 + bool shared;
1.98 + if (!StringBufferToJSVal(cx, buf, length, vp, &shared))
1.99 + return false;
1.100 + if (shared)
1.101 + *sharedBuffer = buf;
1.102 + return true;
1.103 + }
1.104 +
1.105 + // blech, have to copy.
1.106 + JSString *str = JS_NewUCStringCopyN(cx, readable.BeginReading(), length);
1.107 + if (!str)
1.108 + return false;
1.109 + vp.setString(str);
1.110 + return true;
1.111 +}
