1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/base/src/nsDOMFileReader.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,557 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#include "nsDOMFileReader.h"
1.10 +
1.11 +#include "nsContentCID.h"
1.12 +#include "nsContentUtils.h"
1.13 +#include "nsDOMClassInfoID.h"
1.14 +#include "nsDOMFile.h"
1.15 +#include "nsError.h"
1.16 +#include "nsIConverterInputStream.h"
1.17 +#include "nsIDocument.h"
1.18 +#include "nsIFile.h"
1.19 +#include "nsIFileStreams.h"
1.20 +#include "nsIInputStream.h"
1.21 +#include "nsIMIMEService.h"
1.22 +#include "nsIUnicodeDecoder.h"
1.23 +#include "nsNetCID.h"
1.24 +#include "nsNetUtil.h"
1.25 +
1.26 +#include "nsLayoutCID.h"
1.27 +#include "nsXPIDLString.h"
1.28 +#include "nsReadableUtils.h"
1.29 +#include "nsIURI.h"
1.30 +#include "nsStreamUtils.h"
1.31 +#include "nsXPCOM.h"
1.32 +#include "nsIDOMEventListener.h"
1.33 +#include "nsJSEnvironment.h"
1.34 +#include "nsIScriptGlobalObject.h"
1.35 +#include "nsCExternalHandlerService.h"
1.36 +#include "nsIStreamConverterService.h"
1.37 +#include "nsCycleCollectionParticipant.h"
1.38 +#include "nsIScriptObjectPrincipal.h"
1.39 +#include "nsHostObjectProtocolHandler.h"
1.40 +#include "mozilla/Base64.h"
1.41 +#include "mozilla/DOMEventTargetHelper.h"
1.42 +#include "mozilla/Preferences.h"
1.43 +#include "mozilla/dom/EncodingUtils.h"
1.44 +#include "mozilla/dom/FileReaderBinding.h"
1.45 +#include "xpcpublic.h"
1.46 +#include "nsIScriptSecurityManager.h"
1.47 +#include "nsDOMJSUtils.h"
1.48 +
1.49 +#include "jsfriendapi.h"
1.50 +
1.51 +using namespace mozilla;
1.52 +using namespace mozilla::dom;
1.53 +
1.54 +#define LOAD_STR "load"
1.55 +#define LOADSTART_STR "loadstart"
1.56 +#define LOADEND_STR "loadend"
1.57 +
1.58 +NS_IMPL_CYCLE_COLLECTION_CLASS(nsDOMFileReader)
1.59 +
1.60 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsDOMFileReader,
1.61 + FileIOObject)
1.62 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mFile)
1.63 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPrincipal)
1.64 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
1.65 +
1.66 +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(nsDOMFileReader,
1.67 + FileIOObject)
1.68 + tmp->mResultArrayBuffer = nullptr;
1.69 + NS_IMPL_CYCLE_COLLECTION_UNLINK(mFile)
1.70 + NS_IMPL_CYCLE_COLLECTION_UNLINK(mPrincipal)
1.71 +NS_IMPL_CYCLE_COLLECTION_UNLINK_END
1.72 +
1.73 +
1.74 +NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(nsDOMFileReader,
1.75 + DOMEventTargetHelper)
1.76 + NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mResultArrayBuffer)
1.77 +NS_IMPL_CYCLE_COLLECTION_TRACE_END
1.78 +
1.79 +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION_INHERITED(nsDOMFileReader)
1.80 + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
1.81 + NS_INTERFACE_MAP_ENTRY(nsIDOMFileReader)
1.82 + NS_INTERFACE_MAP_ENTRY(nsIInterfaceRequestor)
1.83 + NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
1.84 +NS_INTERFACE_MAP_END_INHERITING(FileIOObject)
1.85 +
1.86 +NS_IMPL_ADDREF_INHERITED(nsDOMFileReader, FileIOObject)
1.87 +NS_IMPL_RELEASE_INHERITED(nsDOMFileReader, FileIOObject)
1.88 +
1.89 +NS_IMPL_EVENT_HANDLER(nsDOMFileReader, load)
1.90 +NS_IMPL_EVENT_HANDLER(nsDOMFileReader, loadend)
1.91 +NS_IMPL_EVENT_HANDLER(nsDOMFileReader, loadstart)
1.92 +NS_IMPL_FORWARD_EVENT_HANDLER(nsDOMFileReader, abort, FileIOObject)
1.93 +NS_IMPL_FORWARD_EVENT_HANDLER(nsDOMFileReader, progress, FileIOObject)
1.94 +NS_IMPL_FORWARD_EVENT_HANDLER(nsDOMFileReader, error, FileIOObject)
1.95 +
1.96 +void
1.97 +nsDOMFileReader::RootResultArrayBuffer()
1.98 +{
1.99 + mozilla::HoldJSObjects(this);
1.100 +}
1.101 +
1.102 +//nsDOMFileReader constructors/initializers
1.103 +
1.104 +nsDOMFileReader::nsDOMFileReader()
1.105 + : mFileData(nullptr),
1.106 + mDataLen(0), mDataFormat(FILE_AS_BINARY),
1.107 + mResultArrayBuffer(nullptr)
1.108 +{
1.109 + SetDOMStringToNull(mResult);
1.110 + SetIsDOMBinding();
1.111 +}
1.112 +
1.113 +nsDOMFileReader::~nsDOMFileReader()
1.114 +{
1.115 + FreeFileData();
1.116 + mResultArrayBuffer = nullptr;
1.117 + mozilla::DropJSObjects(this);
1.118 +}
1.119 +
1.120 +
1.121 +/**
1.122 + * This Init method is called from the factory constructor.
1.123 + */
1.124 +nsresult
1.125 +nsDOMFileReader::Init()
1.126 +{
1.127 + nsIScriptSecurityManager* secMan = nsContentUtils::GetSecurityManager();
1.128 + nsCOMPtr<nsIPrincipal> principal;
1.129 + if (secMan) {
1.130 + secMan->GetSystemPrincipal(getter_AddRefs(principal));
1.131 + }
1.132 + NS_ENSURE_STATE(principal);
1.133 + mPrincipal.swap(principal);
1.134 +
1.135 + // Instead of grabbing some random global from the context stack,
1.136 + // let's use the default one (junk scope) for now.
1.137 + // We should move away from this Init...
1.138 + nsCOMPtr<nsIGlobalObject> global = xpc::GetJunkScopeGlobal();
1.139 + NS_ENSURE_TRUE(global, NS_ERROR_FAILURE);
1.140 + BindToOwner(global);
1.141 + return NS_OK;
1.142 +}
1.143 +
1.144 +/* static */ already_AddRefed<nsDOMFileReader>
1.145 +nsDOMFileReader::Constructor(const GlobalObject& aGlobal, ErrorResult& aRv)
1.146 +{
1.147 + nsRefPtr<nsDOMFileReader> fileReader = new nsDOMFileReader();
1.148 +
1.149 + nsCOMPtr<nsPIDOMWindow> owner = do_QueryInterface(aGlobal.GetAsSupports());
1.150 + if (!owner) {
1.151 + NS_WARNING("Unexpected nsIJSNativeInitializer owner");
1.152 + aRv.Throw(NS_ERROR_FAILURE);
1.153 + return nullptr;
1.154 + }
1.155 +
1.156 + fileReader->BindToOwner(owner);
1.157 +
1.158 + // This object is bound to a |window|,
1.159 + // so reset the principal.
1.160 + nsCOMPtr<nsIScriptObjectPrincipal> scriptPrincipal = do_QueryInterface(owner);
1.161 + if (!scriptPrincipal) {
1.162 + aRv.Throw(NS_ERROR_FAILURE);
1.163 + return nullptr;
1.164 + }
1.165 + fileReader->mPrincipal = scriptPrincipal->GetPrincipal();
1.166 + return fileReader.forget();
1.167 +}
1.168 +
1.169 +// nsIInterfaceRequestor
1.170 +
1.171 +NS_IMETHODIMP
1.172 +nsDOMFileReader::GetInterface(const nsIID & aIID, void **aResult)
1.173 +{
1.174 + return QueryInterface(aIID, aResult);
1.175 +}
1.176 +
1.177 +// nsIDOMFileReader
1.178 +
1.179 +NS_IMETHODIMP
1.180 +nsDOMFileReader::GetReadyState(uint16_t *aReadyState)
1.181 +{
1.182 + *aReadyState = ReadyState();
1.183 + return NS_OK;
1.184 +}
1.185 +
1.186 +void
1.187 +nsDOMFileReader::GetResult(JSContext* aCx, JS::MutableHandle<JS::Value> aResult,
1.188 + ErrorResult& aRv)
1.189 +{
1.190 + aRv = GetResult(aCx, aResult);
1.191 +}
1.192 +
1.193 +NS_IMETHODIMP
1.194 +nsDOMFileReader::GetResult(JSContext* aCx, JS::MutableHandle<JS::Value> aResult)
1.195 +{
1.196 + JS::Rooted<JS::Value> result(aCx);
1.197 + if (mDataFormat == FILE_AS_ARRAYBUFFER) {
1.198 + if (mReadyState == nsIDOMFileReader::DONE && mResultArrayBuffer) {
1.199 + result.setObject(*mResultArrayBuffer);
1.200 + } else {
1.201 + result.setNull();
1.202 + }
1.203 + if (!JS_WrapValue(aCx, &result)) {
1.204 + return NS_ERROR_FAILURE;
1.205 + }
1.206 + aResult.set(result);
1.207 + return NS_OK;
1.208 + }
1.209 +
1.210 + nsString tmpResult = mResult;
1.211 + if (!xpc::StringToJsval(aCx, tmpResult, aResult)) {
1.212 + return NS_ERROR_FAILURE;
1.213 + }
1.214 + return NS_OK;
1.215 +}
1.216 +
1.217 +NS_IMETHODIMP
1.218 +nsDOMFileReader::GetError(nsISupports** aError)
1.219 +{
1.220 + NS_IF_ADDREF(*aError = GetError());
1.221 + return NS_OK;
1.222 +}
1.223 +
1.224 +NS_IMETHODIMP
1.225 +nsDOMFileReader::ReadAsArrayBuffer(nsIDOMBlob* aFile, JSContext* aCx)
1.226 +{
1.227 + NS_ENSURE_TRUE(aFile, NS_ERROR_NULL_POINTER);
1.228 + ErrorResult rv;
1.229 + ReadAsArrayBuffer(aCx, aFile, rv);
1.230 + return rv.ErrorCode();
1.231 +}
1.232 +
1.233 +NS_IMETHODIMP
1.234 +nsDOMFileReader::ReadAsBinaryString(nsIDOMBlob* aFile)
1.235 +{
1.236 + NS_ENSURE_TRUE(aFile, NS_ERROR_NULL_POINTER);
1.237 + ErrorResult rv;
1.238 + ReadAsBinaryString(aFile, rv);
1.239 + return rv.ErrorCode();
1.240 +}
1.241 +
1.242 +NS_IMETHODIMP
1.243 +nsDOMFileReader::ReadAsText(nsIDOMBlob* aFile,
1.244 + const nsAString &aCharset)
1.245 +{
1.246 + NS_ENSURE_TRUE(aFile, NS_ERROR_NULL_POINTER);
1.247 + ErrorResult rv;
1.248 + ReadAsText(aFile, aCharset, rv);
1.249 + return rv.ErrorCode();
1.250 +}
1.251 +
1.252 +NS_IMETHODIMP
1.253 +nsDOMFileReader::ReadAsDataURL(nsIDOMBlob* aFile)
1.254 +{
1.255 + NS_ENSURE_TRUE(aFile, NS_ERROR_NULL_POINTER);
1.256 + ErrorResult rv;
1.257 + ReadAsDataURL(aFile, rv);
1.258 + return rv.ErrorCode();
1.259 +}
1.260 +
1.261 +NS_IMETHODIMP
1.262 +nsDOMFileReader::Abort()
1.263 +{
1.264 + ErrorResult rv;
1.265 + FileIOObject::Abort(rv);
1.266 + return rv.ErrorCode();
1.267 +}
1.268 +
1.269 +/* virtual */ void
1.270 +nsDOMFileReader::DoAbort(nsAString& aEvent)
1.271 +{
1.272 + // Revert status and result attributes
1.273 + SetDOMStringToNull(mResult);
1.274 + mResultArrayBuffer = nullptr;
1.275 +
1.276 + // Non-null channel indicates a read is currently active
1.277 + if (mChannel) {
1.278 + // Cancel request requires an error status
1.279 + mChannel->Cancel(NS_ERROR_FAILURE);
1.280 + mChannel = nullptr;
1.281 + }
1.282 + mFile = nullptr;
1.283 +
1.284 + //Clean up memory buffer
1.285 + FreeFileData();
1.286 +
1.287 + // Tell the base class which event to dispatch
1.288 + aEvent = NS_LITERAL_STRING(LOADEND_STR);
1.289 +}
1.290 +
1.291 +static
1.292 +NS_METHOD
1.293 +ReadFuncBinaryString(nsIInputStream* in,
1.294 + void* closure,
1.295 + const char* fromRawSegment,
1.296 + uint32_t toOffset,
1.297 + uint32_t count,
1.298 + uint32_t *writeCount)
1.299 +{
1.300 + char16_t* dest = static_cast<char16_t*>(closure) + toOffset;
1.301 + char16_t* end = dest + count;
1.302 + const unsigned char* source = (const unsigned char*)fromRawSegment;
1.303 + while (dest != end) {
1.304 + *dest = *source;
1.305 + ++dest;
1.306 + ++source;
1.307 + }
1.308 + *writeCount = count;
1.309 +
1.310 + return NS_OK;
1.311 +}
1.312 +
1.313 +nsresult
1.314 +nsDOMFileReader::DoOnDataAvailable(nsIRequest *aRequest,
1.315 + nsISupports *aContext,
1.316 + nsIInputStream *aInputStream,
1.317 + uint64_t aOffset,
1.318 + uint32_t aCount)
1.319 +{
1.320 + if (mDataFormat == FILE_AS_BINARY) {
1.321 + //Continuously update our binary string as data comes in
1.322 + NS_ASSERTION(mResult.Length() == aOffset,
1.323 + "unexpected mResult length");
1.324 + uint32_t oldLen = mResult.Length();
1.325 + if (uint64_t(oldLen) + aCount > UINT32_MAX)
1.326 + return NS_ERROR_OUT_OF_MEMORY;
1.327 +
1.328 + char16_t *buf = nullptr;
1.329 + mResult.GetMutableData(&buf, oldLen + aCount, fallible_t());
1.330 + NS_ENSURE_TRUE(buf, NS_ERROR_OUT_OF_MEMORY);
1.331 +
1.332 + uint32_t bytesRead = 0;
1.333 + aInputStream->ReadSegments(ReadFuncBinaryString, buf + oldLen, aCount,
1.334 + &bytesRead);
1.335 + NS_ASSERTION(bytesRead == aCount, "failed to read data");
1.336 + }
1.337 + else if (mDataFormat == FILE_AS_ARRAYBUFFER) {
1.338 + uint32_t bytesRead = 0;
1.339 + aInputStream->Read((char*)JS_GetArrayBufferData(mResultArrayBuffer) + aOffset,
1.340 + aCount, &bytesRead);
1.341 + NS_ASSERTION(bytesRead == aCount, "failed to read data");
1.342 + }
1.343 + else {
1.344 + //Update memory buffer to reflect the contents of the file
1.345 + if (aOffset + aCount > UINT32_MAX) {
1.346 + // PR_Realloc doesn't support over 4GB memory size even if 64-bit OS
1.347 + return NS_ERROR_OUT_OF_MEMORY;
1.348 + }
1.349 + mFileData = (char *)moz_realloc(mFileData, aOffset + aCount);
1.350 + NS_ENSURE_TRUE(mFileData, NS_ERROR_OUT_OF_MEMORY);
1.351 +
1.352 + uint32_t bytesRead = 0;
1.353 + aInputStream->Read(mFileData + aOffset, aCount, &bytesRead);
1.354 + NS_ASSERTION(bytesRead == aCount, "failed to read data");
1.355 +
1.356 + mDataLen += aCount;
1.357 + }
1.358 +
1.359 + return NS_OK;
1.360 +}
1.361 +
1.362 +nsresult
1.363 +nsDOMFileReader::DoOnStopRequest(nsIRequest *aRequest,
1.364 + nsISupports *aContext,
1.365 + nsresult aStatus,
1.366 + nsAString& aSuccessEvent,
1.367 + nsAString& aTerminationEvent)
1.368 +{
1.369 + // Make sure we drop all the objects that could hold files open now.
1.370 + nsCOMPtr<nsIChannel> channel;
1.371 + mChannel.swap(channel);
1.372 +
1.373 + nsCOMPtr<nsIDOMBlob> file;
1.374 + mFile.swap(file);
1.375 +
1.376 + aSuccessEvent = NS_LITERAL_STRING(LOAD_STR);
1.377 + aTerminationEvent = NS_LITERAL_STRING(LOADEND_STR);
1.378 +
1.379 + // Clear out the data if necessary
1.380 + if (NS_FAILED(aStatus)) {
1.381 + FreeFileData();
1.382 + return NS_OK;
1.383 + }
1.384 +
1.385 + nsresult rv = NS_OK;
1.386 + switch (mDataFormat) {
1.387 + case FILE_AS_ARRAYBUFFER:
1.388 + break; //Already accumulated mResultArrayBuffer
1.389 + case FILE_AS_BINARY:
1.390 + break; //Already accumulated mResult
1.391 + case FILE_AS_TEXT:
1.392 + if (!mFileData) {
1.393 + if (mDataLen) {
1.394 + rv = NS_ERROR_OUT_OF_MEMORY;
1.395 + break;
1.396 + }
1.397 + rv = GetAsText(file, mCharset, "", mDataLen, mResult);
1.398 + break;
1.399 + }
1.400 + rv = GetAsText(file, mCharset, mFileData, mDataLen, mResult);
1.401 + break;
1.402 + case FILE_AS_DATAURL:
1.403 + rv = GetAsDataURL(file, mFileData, mDataLen, mResult);
1.404 + break;
1.405 + }
1.406 +
1.407 + mResult.SetIsVoid(false);
1.408 +
1.409 + FreeFileData();
1.410 +
1.411 + return rv;
1.412 +}
1.413 +
1.414 +// Helper methods
1.415 +
1.416 +void
1.417 +nsDOMFileReader::ReadFileContent(JSContext* aCx,
1.418 + nsIDOMBlob* aFile,
1.419 + const nsAString &aCharset,
1.420 + eDataFormat aDataFormat,
1.421 + ErrorResult& aRv)
1.422 +{
1.423 + MOZ_ASSERT(aFile);
1.424 +
1.425 + //Implicit abort to clear any other activity going on
1.426 + Abort();
1.427 + mError = nullptr;
1.428 + SetDOMStringToNull(mResult);
1.429 + mTransferred = 0;
1.430 + mTotal = 0;
1.431 + mReadyState = nsIDOMFileReader::EMPTY;
1.432 + FreeFileData();
1.433 +
1.434 + mFile = aFile;
1.435 + mDataFormat = aDataFormat;
1.436 + CopyUTF16toUTF8(aCharset, mCharset);
1.437 +
1.438 + //Establish a channel with our file
1.439 + {
1.440 + // Hold the internal URL alive only as long as necessary
1.441 + // After the channel is created it will own whatever is backing
1.442 + // the DOMFile.
1.443 + nsDOMFileInternalUrlHolder urlHolder(mFile, mPrincipal);
1.444 +
1.445 + nsCOMPtr<nsIURI> uri;
1.446 + aRv = NS_NewURI(getter_AddRefs(uri), urlHolder.mUrl);
1.447 + NS_ENSURE_SUCCESS_VOID(aRv.ErrorCode());
1.448 +
1.449 + nsCOMPtr<nsILoadGroup> loadGroup;
1.450 + if (HasOrHasHadOwner()) {
1.451 + if (!GetOwner()) {
1.452 + aRv.Throw(NS_ERROR_FAILURE);
1.453 + return;
1.454 + }
1.455 + nsIDocument* doc = GetOwner()->GetExtantDoc();
1.456 + if (doc) {
1.457 + loadGroup = doc->GetDocumentLoadGroup();
1.458 + }
1.459 + }
1.460 +
1.461 + aRv = NS_NewChannel(getter_AddRefs(mChannel), uri, nullptr, loadGroup,
1.462 + nullptr, nsIRequest::LOAD_BACKGROUND);
1.463 + NS_ENSURE_SUCCESS_VOID(aRv.ErrorCode());
1.464 + }
1.465 +
1.466 + //Obtain the total size of the file before reading
1.467 + mTotal = mozilla::dom::kUnknownSize;
1.468 + mFile->GetSize(&mTotal);
1.469 +
1.470 + aRv = mChannel->AsyncOpen(this, nullptr);
1.471 + NS_ENSURE_SUCCESS_VOID(aRv.ErrorCode());
1.472 +
1.473 + //FileReader should be in loading state here
1.474 + mReadyState = nsIDOMFileReader::LOADING;
1.475 + DispatchProgressEvent(NS_LITERAL_STRING(LOADSTART_STR));
1.476 +
1.477 + if (mDataFormat == FILE_AS_ARRAYBUFFER) {
1.478 + RootResultArrayBuffer();
1.479 + mResultArrayBuffer = JS_NewArrayBuffer(aCx, mTotal);
1.480 + if (!mResultArrayBuffer) {
1.481 + NS_WARNING("Failed to create JS array buffer");
1.482 + aRv.Throw(NS_ERROR_FAILURE);
1.483 + }
1.484 + }
1.485 +}
1.486 +
1.487 +nsresult
1.488 +nsDOMFileReader::GetAsText(nsIDOMBlob *aFile,
1.489 + const nsACString &aCharset,
1.490 + const char *aFileData,
1.491 + uint32_t aDataLen,
1.492 + nsAString& aResult)
1.493 +{
1.494 + // The BOM sniffing is baked into the "decode" part of the Encoding
1.495 + // Standard, which the File API references.
1.496 + nsAutoCString encoding;
1.497 + if (!nsContentUtils::CheckForBOM(
1.498 + reinterpret_cast<const unsigned char *>(aFileData),
1.499 + aDataLen,
1.500 + encoding)) {
1.501 + // BOM sniffing failed. Try the API argument.
1.502 + if (!EncodingUtils::FindEncodingForLabel(aCharset,
1.503 + encoding)) {
1.504 + // API argument failed. Try the type property of the blob.
1.505 + nsAutoString type16;
1.506 + aFile->GetType(type16);
1.507 + NS_ConvertUTF16toUTF8 type(type16);
1.508 + nsAutoCString specifiedCharset;
1.509 + bool haveCharset;
1.510 + int32_t charsetStart, charsetEnd;
1.511 + NS_ExtractCharsetFromContentType(type,
1.512 + specifiedCharset,
1.513 + &haveCharset,
1.514 + &charsetStart,
1.515 + &charsetEnd);
1.516 + if (!EncodingUtils::FindEncodingForLabel(specifiedCharset, encoding)) {
1.517 + // Type property failed. Use UTF-8.
1.518 + encoding.AssignLiteral("UTF-8");
1.519 + }
1.520 + }
1.521 + }
1.522 +
1.523 + nsDependentCSubstring data(aFileData, aDataLen);
1.524 + return nsContentUtils::ConvertStringFromEncoding(encoding, data, aResult);
1.525 +}
1.526 +
1.527 +nsresult
1.528 +nsDOMFileReader::GetAsDataURL(nsIDOMBlob *aFile,
1.529 + const char *aFileData,
1.530 + uint32_t aDataLen,
1.531 + nsAString& aResult)
1.532 +{
1.533 + aResult.AssignLiteral("data:");
1.534 +
1.535 + nsresult rv;
1.536 + nsString contentType;
1.537 + rv = aFile->GetType(contentType);
1.538 + if (NS_SUCCEEDED(rv) && !contentType.IsEmpty()) {
1.539 + aResult.Append(contentType);
1.540 + } else {
1.541 + aResult.AppendLiteral("application/octet-stream");
1.542 + }
1.543 + aResult.AppendLiteral(";base64,");
1.544 +
1.545 + nsCString encodedData;
1.546 + rv = Base64Encode(Substring(aFileData, aDataLen), encodedData);
1.547 + NS_ENSURE_SUCCESS(rv, rv);
1.548 +
1.549 + if (!AppendASCIItoUTF16(encodedData, aResult, fallible_t())) {
1.550 + return NS_ERROR_OUT_OF_MEMORY;
1.551 + }
1.552 +
1.553 + return NS_OK;
1.554 +}
1.555 +
1.556 +/* virtual */ JSObject*
1.557 +nsDOMFileReader::WrapObject(JSContext* aCx)
1.558 +{
1.559 + return FileReaderBinding::Wrap(aCx, this);
1.560 +}
