mozJSLoaderUtils.cpp (2483B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #include "mozilla/scache/StartupCache.h" 8 9 #include "jsapi.h" 10 #include "jsfriendapi.h" 11 #include "js/CompileOptions.h" 12 #include "js/Transcoding.h" 13 #include "js/experimental/JSStencil.h" 14 15 #include "mozilla/BasePrincipal.h" 16 #include "mozilla/Span.h" 17 18 using namespace JS; 19 using namespace mozilla::scache; 20 using mozilla::UniquePtr; 21 22 static nsresult HandleTranscodeResult(JSContext* cx, 23 JS::TranscodeResult result) { 24 if (result == JS::TranscodeResult::Ok) { 25 return NS_OK; 26 } 27 28 if (result == JS::TranscodeResult::Throw) { 29 JS_ClearPendingException(cx); 30 return NS_ERROR_OUT_OF_MEMORY; 31 } 32 33 MOZ_ASSERT(IsTranscodeFailureResult(result)); 34 return NS_ERROR_FAILURE; 35 } 36 37 nsresult ReadCachedStencil(StartupCache* cache, nsACString& cachePath, 38 JSContext* cx, 39 const JS::ReadOnlyDecodeOptions& options, 40 JS::Stencil** stencilOut) { 41 MOZ_ASSERT(options.borrowBuffer); 42 MOZ_ASSERT(!options.usePinnedBytecode); 43 44 const char* buf; 45 uint32_t len; 46 nsresult rv = 47 cache->GetBuffer(PromiseFlatCString(cachePath).get(), &buf, &len); 48 if (NS_FAILED(rv)) { 49 return rv; // don't warn since NOT_AVAILABLE is an ok error 50 } 51 52 JS::TranscodeRange range(AsBytes(mozilla::Span(buf, len))); 53 JS::TranscodeResult code = JS::DecodeStencil(cx, options, range, stencilOut); 54 return HandleTranscodeResult(cx, code); 55 } 56 57 nsresult WriteCachedStencil(StartupCache* cache, nsACString& cachePath, 58 JSContext* cx, JS::Stencil* stencil) { 59 JS::TranscodeBuffer buffer; 60 JS::TranscodeResult code = JS::EncodeStencil(cx, stencil, buffer); 61 if (code != JS::TranscodeResult::Ok) { 62 return HandleTranscodeResult(cx, code); 63 } 64 65 size_t size = buffer.length(); 66 if (size > UINT32_MAX) { 67 return NS_ERROR_FAILURE; 68 } 69 70 // Move the vector buffer into a unique pointer buffer. 71 mozilla::UniqueFreePtr<char[]> buf( 72 reinterpret_cast<char*>(buffer.extractOrCopyRawBuffer())); 73 nsresult rv = cache->PutBuffer(PromiseFlatCString(cachePath).get(), 74 std::move(buf), size); 75 return rv; 76 }